Add TransactionDB and OptimisticTransactionDB to the Java API

Summary:
Closes https://github.com/facebook/rocksdb/issues/697
Closes https://github.com/facebook/rocksdb/issues/1151
Closes https://github.com/facebook/rocksdb/pull/1298

Differential Revision: D7131402

Pulled By: sagar0

fbshipit-source-id: bcd34ce95ed88cc641786089ff4232df7b2f089f

java/Makefile

@@ -1,6 +1,7 @@
 NATIVE_JAVA_CLASSES = org.rocksdb.AbstractCompactionFilter\
 	org.rocksdb.AbstractCompactionFilterFactory\
 	org.rocksdb.AbstractSlice\
+	org.rocksdb.AbstractTransactionNotifier\
 	org.rocksdb.BackupEngine\
 	org.rocksdb.BackupableDBOptions\
 	org.rocksdb.BlockBasedTableConfig\
@@ -29,6 +30,8 @@ NATIVE_JAVA_CLASSES = org.rocksdb.AbstractCompactionFilter\
 	org.rocksdb.Logger\
 	org.rocksdb.LRUCache\
 	org.rocksdb.MergeOperator\
+	org.rocksdb.OptimisticTransactionDB\
+	org.rocksdb.OptimisticTransactionOptions\
 	org.rocksdb.Options\
 	org.rocksdb.OptionsUtil\
 	org.rocksdb.PlainTableConfig\
@@ -45,6 +48,10 @@ NATIVE_JAVA_CLASSES = org.rocksdb.AbstractCompactionFilter\
 	org.rocksdb.Slice\
 	org.rocksdb.SstFileWriter\
 	org.rocksdb.Statistics\
+	org.rocksdb.Transaction\
+	org.rocksdb.TransactionDB\
+	org.rocksdb.TransactionDBOptions\
+	org.rocksdb.TransactionOptions\
 	org.rocksdb.TransactionLogIterator\
 	org.rocksdb.TtlDB\
 	org.rocksdb.VectorMemTableConfig\
@@ -105,6 +112,9 @@ JAVA_TESTS = org.rocksdb.BackupableDBOptionsTest\
 	org.rocksdb.MixedOptionsTest\
 	org.rocksdb.MutableColumnFamilyOptionsTest\
 	org.rocksdb.NativeLibraryLoaderTest\
+	org.rocksdb.OptimisticTransactionTest\
+	org.rocksdb.OptimisticTransactionDBTest\
+	org.rocksdb.OptimisticTransactionOptionsTest\
 	org.rocksdb.OptionsUtilTest\
 	org.rocksdb.OptionsTest\
 	org.rocksdb.PlainTableConfigTest\
@@ -120,6 +130,10 @@ JAVA_TESTS = org.rocksdb.BackupableDBOptionsTest\
 	org.rocksdb.SliceTest\
 	org.rocksdb.SnapshotTest\
 	org.rocksdb.SstFileWriterTest\
+	org.rocksdb.TransactionTest\
+	org.rocksdb.TransactionDBTest\
+	org.rocksdb.TransactionOptionsTest\
+	org.rocksdb.TransactionDBOptionsTest\
 	org.rocksdb.TransactionLogIteratorTest\
 	org.rocksdb.TtlDBTest\
 	org.rocksdb.StatisticsTest\
@@ -209,6 +223,20 @@ column_family_sample: java
 	java $(JAVA_ARGS) -Djava.library.path=target -cp $(MAIN_CLASSES):$(SAMPLES_MAIN_CLASSES) RocksDBColumnFamilySample /tmp/rocksdbjni
 	$(AM_V_at)@rm -rf /tmp/rocksdbjni
 
+transaction_sample: java
+	$(AM_V_GEN)mkdir -p $(SAMPLES_MAIN_CLASSES)
+	$(AM_V_at)javac -cp $(MAIN_CLASSES) -d $(SAMPLES_MAIN_CLASSES) $(SAMPLES_MAIN_SRC)/TransactionSample.java
+	$(AM_V_at)@rm -rf /tmp/rocksdbjni
+	java -ea -Xcheck:jni -Djava.library.path=target -cp $(MAIN_CLASSES):$(SAMPLES_MAIN_CLASSES) TransactionSample /tmp/rocksdbjni
+	$(AM_V_at)@rm -rf /tmp/rocksdbjni
+
+optimistic_transaction_sample: java
+	$(AM_V_GEN)mkdir -p $(SAMPLES_MAIN_CLASSES)
+	$(AM_V_at)javac -cp $(MAIN_CLASSES) -d $(SAMPLES_MAIN_CLASSES) $(SAMPLES_MAIN_SRC)/OptimisticTransactionSample.java
+	$(AM_V_at)@rm -rf /tmp/rocksdbjni
+	java -ea -Xcheck:jni -Djava.library.path=target -cp $(MAIN_CLASSES):$(SAMPLES_MAIN_CLASSES) OptimisticTransactionSample /tmp/rocksdbjni
+	$(AM_V_at)@rm -rf /tmp/rocksdbjni
+
 resolve_test_deps:
 	test -d "$(JAVA_TEST_LIBDIR)" || mkdir -p "$(JAVA_TEST_LIBDIR)"
 	test -s "$(JAVA_JUNIT_JAR)" || cp $(MVN_LOCAL)/junit/junit/4.12/junit-4.12.jar $(JAVA_TEST_LIBDIR) || curl -k -L -o $(JAVA_JUNIT_JAR) $(SEARCH_REPO_URL)junit/junit/4.12/junit-4.12.jar

java/rocksjni/columnfamilyhandle.cc

@@ -3,8 +3,8 @@
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
 //
-// This file implements the "bridge" between Java and C++ and enables
-// calling c++ rocksdb::Iterator methods from Java side.
+// This file implements the "bridge" between Java and C++ for
+// rocksdb::ColumnFamilyHandle.
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -13,14 +13,56 @@
 #include "include/org_rocksdb_ColumnFamilyHandle.h"
 #include "rocksjni/portal.h"
 
+/*
+ * Class:     org_rocksdb_ColumnFamilyHandle
+ * Method:    getName
+ * Signature: (J)[B
+ */
+jbyteArray Java_org_rocksdb_ColumnFamilyHandle_getName(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* cfh = reinterpret_cast<rocksdb::ColumnFamilyHandle*>(jhandle);
+  std::string cf_name = cfh->GetName();
+  return rocksdb::JniUtil::copyBytes(env, cf_name);
+}
+
+/*
+* Class:     org_rocksdb_ColumnFamilyHandle
+* Method:    getID
+* Signature: (J)I
+*/
+jint Java_org_rocksdb_ColumnFamilyHandle_getID(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* cfh = reinterpret_cast<rocksdb::ColumnFamilyHandle*>(jhandle);
+  const int32_t id = cfh->GetID();
+  return static_cast<jint>(id);
+}
+
+/*
+ * Class:     org_rocksdb_ColumnFamilyHandle
+ * Method:    getDescriptor
+ * Signature: (J)Lorg/rocksdb/ColumnFamilyDescriptor;
+ */
+jobject Java_org_rocksdb_ColumnFamilyHandle_getDescriptor(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* cfh = reinterpret_cast<rocksdb::ColumnFamilyHandle*>(jhandle);
+  rocksdb::ColumnFamilyDescriptor desc;
+  rocksdb::Status s = cfh->GetDescriptor(&desc);
+  if (s.ok()) {
+    return rocksdb::ColumnFamilyDescriptorJni::construct(env, &desc);
+  } else {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+    return nullptr;
+  }
+}
+
 /*
  * Class:     org_rocksdb_ColumnFamilyHandle
  * Method:    disposeInternal
  * Signature: (J)V
  */
 void Java_org_rocksdb_ColumnFamilyHandle_disposeInternal(
-    JNIEnv* env, jobject jobj, jlong handle) {
-  auto* cfh = reinterpret_cast<rocksdb::ColumnFamilyHandle*>(handle);
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* cfh = reinterpret_cast<rocksdb::ColumnFamilyHandle*>(jhandle);
   assert(cfh != nullptr);
   delete cfh;
 }

java/rocksjni/optimistic_transaction_db.cc

@@ -0,0 +1,267 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the "bridge" between Java and C++
+// for rocksdb::TransactionDB.
+
+#include <jni.h>
+
+#include "include/org_rocksdb_OptimisticTransactionDB.h"
+
+#include "rocksdb/options.h"
+#include "rocksdb/utilities/optimistic_transaction_db.h"
+#include "rocksdb/utilities/transaction.h"
+
+#include "rocksjni/portal.h"
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    open
+ * Signature: (JLjava/lang/String;)J
+ */
+jlong Java_org_rocksdb_OptimisticTransactionDB_open__JLjava_lang_String_2(
+    JNIEnv* env, jclass jcls, jlong joptions_handle, jstring jdb_path) {
+  const char* db_path = env->GetStringUTFChars(jdb_path, nullptr);
+  if (db_path == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return 0;
+  }
+
+  auto* options = reinterpret_cast<rocksdb::Options*>(joptions_handle);
+  rocksdb::OptimisticTransactionDB* otdb = nullptr;
+  rocksdb::Status s =
+      rocksdb::OptimisticTransactionDB::Open(*options, db_path, &otdb);
+  env->ReleaseStringUTFChars(jdb_path, db_path);
+
+  if (s.ok()) {
+    return reinterpret_cast<jlong>(otdb);
+  } else {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+    return 0;
+  }
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    open
+ * Signature: (JLjava/lang/String;[[B[J)[J
+ */
+jlongArray Java_org_rocksdb_OptimisticTransactionDB_open__JLjava_lang_String_2_3_3B_3J(
+    JNIEnv* env, jclass jcls, jlong jdb_options_handle, jstring jdb_path,
+    jobjectArray jcolumn_names, jlongArray jcolumn_options_handles) {
+  const char* db_path = env->GetStringUTFChars(jdb_path, nullptr);
+  if (db_path == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return nullptr;
+  }
+
+  std::vector<rocksdb::ColumnFamilyDescriptor> column_families;
+  const jsize len_cols = env->GetArrayLength(jcolumn_names);
+  if (len_cols > 0) {
+    if (env->EnsureLocalCapacity(len_cols) != 0) {
+      // out of memory
+      env->ReleaseStringUTFChars(jdb_path, db_path);
+      return nullptr;
+    }
+
+    jlong* jco =
+        env->GetLongArrayElements(jcolumn_options_handles, nullptr);
+    if(jco == nullptr) {
+        // exception thrown: OutOfMemoryError
+        env->ReleaseStringUTFChars(jdb_path, db_path);
+        return nullptr;
+    }
+
+    for (int i = 0; i < len_cols; i++) {
+        const jobject jcn = env->GetObjectArrayElement(jcolumn_names, i);
+        if (env->ExceptionCheck()) {
+            // exception thrown: ArrayIndexOutOfBoundsException
+            env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+            env->ReleaseStringUTFChars(jdb_path, db_path);
+            return nullptr;
+        }
+
+        const jbyteArray jcn_ba = reinterpret_cast<jbyteArray>(jcn);
+        const jsize jcf_name_len = env->GetArrayLength(jcn_ba);
+        if (env->EnsureLocalCapacity(jcf_name_len) != 0) {
+          // out of memory
+          env->DeleteLocalRef(jcn);
+          env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+          env->ReleaseStringUTFChars(jdb_path, db_path);
+          return nullptr;
+        }
+
+        jbyte* jcf_name = env->GetByteArrayElements(jcn_ba, nullptr);
+        if (jcf_name == nullptr) {
+            // exception thrown: OutOfMemoryError
+            env->DeleteLocalRef(jcn);
+            env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+            env->ReleaseStringUTFChars(jdb_path, db_path);
+            return nullptr;
+        }
+
+        const std::string cf_name(reinterpret_cast<char *>(jcf_name), jcf_name_len);
+        const rocksdb::ColumnFamilyOptions* cf_options =
+            reinterpret_cast<rocksdb::ColumnFamilyOptions*>(jco[i]);
+        column_families.push_back(
+            rocksdb::ColumnFamilyDescriptor(cf_name, *cf_options));
+
+        env->ReleaseByteArrayElements(jcn_ba, jcf_name, JNI_ABORT);
+        env->DeleteLocalRef(jcn);
+    }
+    env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+  }
+
+  auto* db_options = reinterpret_cast<rocksdb::DBOptions*>(jdb_options_handle);
+  std::vector<rocksdb::ColumnFamilyHandle*> handles;
+  rocksdb::OptimisticTransactionDB* otdb = nullptr;
+  const rocksdb::Status s = rocksdb::OptimisticTransactionDB::Open(*db_options,
+      db_path, column_families, &handles, &otdb);
+
+  env->ReleaseStringUTFChars(jdb_path, db_path);
+
+  // check if open operation was successful
+  if (s.ok()) {
+    const jsize resultsLen = 1 + len_cols;  // db handle + column family handles
+    std::unique_ptr<jlong[]> results =
+        std::unique_ptr<jlong[]>(new jlong[resultsLen]);
+    results[0] = reinterpret_cast<jlong>(otdb);
+    for (int i = 1; i <= len_cols; i++) {
+      results[i] = reinterpret_cast<jlong>(handles[i - 1]);
+    }
+
+    jlongArray jresults = env->NewLongArray(resultsLen);
+    if (jresults == nullptr) {
+        // exception thrown: OutOfMemoryError
+        return nullptr;
+    }
+    env->SetLongArrayRegion(jresults, 0, resultsLen, results.get());
+    if (env->ExceptionCheck()) {
+        // exception thrown: ArrayIndexOutOfBoundsException
+        return nullptr;
+    }
+    return jresults;
+  }
+
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  return nullptr;
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    beginTransaction
+ * Signature: (JJ)J
+ */
+jlong Java_org_rocksdb_OptimisticTransactionDB_beginTransaction__JJ(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jwrite_options_handle) {
+  auto* optimistic_txn_db =
+      reinterpret_cast<rocksdb::OptimisticTransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  rocksdb::Transaction* txn =
+      optimistic_txn_db->BeginTransaction(*write_options);
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    beginTransaction
+ * Signature: (JJJ)J
+ */
+jlong Java_org_rocksdb_OptimisticTransactionDB_beginTransaction__JJJ(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jwrite_options_handle,
+    jlong joptimistic_txn_options_handle) {
+  auto* optimistic_txn_db =
+      reinterpret_cast<rocksdb::OptimisticTransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  auto* optimistic_txn_options =
+      reinterpret_cast<rocksdb::OptimisticTransactionOptions*>(
+      joptimistic_txn_options_handle);
+  rocksdb::Transaction* txn =
+      optimistic_txn_db->BeginTransaction(*write_options,
+      *optimistic_txn_options);
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    beginTransaction_withOld
+ * Signature: (JJJ)J
+ */
+jlong Java_org_rocksdb_OptimisticTransactionDB_beginTransaction_1withOld__JJJ(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jwrite_options_handle,
+    jlong jold_txn_handle) {
+  auto* optimistic_txn_db =
+      reinterpret_cast<rocksdb::OptimisticTransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  auto* old_txn =
+      reinterpret_cast<rocksdb::Transaction*>(
+      jold_txn_handle);
+  rocksdb::OptimisticTransactionOptions optimistic_txn_options;
+  rocksdb::Transaction* txn =
+      optimistic_txn_db->BeginTransaction(*write_options,
+          optimistic_txn_options, old_txn);
+
+  // RocksJava relies on the assumption that
+  // we do not allocate a new Transaction object
+  // when providing an old_optimistic_txn
+  assert(txn == old_txn);
+
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    beginTransaction_withOld
+ * Signature: (JJJJ)J
+ */
+jlong Java_org_rocksdb_OptimisticTransactionDB_beginTransaction_1withOld__JJJJ(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jwrite_options_handle,
+    jlong joptimistic_txn_options_handle, jlong jold_txn_handle) {
+  auto* optimistic_txn_db =
+      reinterpret_cast<rocksdb::OptimisticTransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  auto* optimistic_txn_options =
+      reinterpret_cast<rocksdb::OptimisticTransactionOptions*>(
+        joptimistic_txn_options_handle);
+  auto* old_txn =
+      reinterpret_cast<rocksdb::Transaction*>(
+      jold_txn_handle);
+  rocksdb::Transaction* txn =
+      optimistic_txn_db->BeginTransaction(*write_options,
+      *optimistic_txn_options, old_txn);
+
+  // RocksJava relies on the assumption that
+  // we do not allocate a new Transaction object
+  // when providing an old_optimisic_txn
+  assert(txn == old_txn);
+
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    getBaseDB
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_OptimisticTransactionDB_getBaseDB(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* optimistic_txn_db =
+      reinterpret_cast<rocksdb::OptimisticTransactionDB*>(jhandle);
+  return reinterpret_cast<jlong>(optimistic_txn_db->GetBaseDB());
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionDB
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_OptimisticTransactionDB_disposeInternal(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  delete reinterpret_cast<rocksdb::OptimisticTransactionDB*>(jhandle);
+}

java/rocksjni/optimistic_transaction_options.cc

@@ -0,0 +1,72 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the "bridge" between Java and C++
+// for rocksdb::OptimisticTransactionOptions.
+
+#include <jni.h>
+
+#include "include/org_rocksdb_OptimisticTransactionOptions.h"
+
+#include "rocksdb/comparator.h"
+#include "rocksdb/utilities/optimistic_transaction_db.h"
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionOptions
+ * Method:    newOptimisticTransactionOptions
+ * Signature: ()J
+ */
+jlong Java_org_rocksdb_OptimisticTransactionOptions_newOptimisticTransactionOptions(
+    JNIEnv* env, jclass jcls) {
+  rocksdb::OptimisticTransactionOptions* opts =
+      new rocksdb::OptimisticTransactionOptions();
+  return reinterpret_cast<jlong>(opts);
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionOptions
+ * Method:    isSetSnapshot
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_OptimisticTransactionOptions_isSetSnapshot(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* opts =
+      reinterpret_cast<rocksdb::OptimisticTransactionOptions*>(jhandle);
+  return opts->set_snapshot;
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionOptions
+ * Method:    setSetSnapshot
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_OptimisticTransactionOptions_setSetSnapshot(JNIEnv* env,
+    jobject jobj, jlong jhandle, jboolean jset_snapshot) {
+  auto* opts =
+      reinterpret_cast<rocksdb::OptimisticTransactionOptions*>(jhandle);
+  opts->set_snapshot = jset_snapshot;
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionOptions
+ * Method:    setComparator
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_OptimisticTransactionOptions_setComparator(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jcomparator_handle) {
+  auto* opts =
+      reinterpret_cast<rocksdb::OptimisticTransactionOptions*>(jhandle);
+  opts->cmp = reinterpret_cast<rocksdb::Comparator*>(jcomparator_handle);
+}
+
+/*
+ * Class:     org_rocksdb_OptimisticTransactionOptions
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_OptimisticTransactionOptions_disposeInternal(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  delete reinterpret_cast<rocksdb::OptimisticTransactionOptions*>(jhandle);
+}

java/rocksjni/portal.h

@@ -14,9 +14,11 @@
 #include <jni.h>
 #include <functional>
 #include <iostream>
+#include <iterator>
 #include <limits>
 #include <memory>
 #include <string>
+#include <type_traits>
 #include <vector>
 
 #include "rocksdb/db.h"
@@ -24,10 +26,12 @@
 #include "rocksdb/rate_limiter.h"
 #include "rocksdb/status.h"
 #include "rocksdb/utilities/backupable_db.h"
+#include "rocksdb/utilities/transaction_db.h"
 #include "rocksdb/utilities/write_batch_with_index.h"
 #include "rocksjni/compaction_filter_factory_jnicallback.h"
 #include "rocksjni/comparatorjnicallback.h"
 #include "rocksjni/loggerjnicallback.h"
+#include "rocksjni/transaction_notifier_jnicallback.h"
 #include "rocksjni/writebatchhandlerjnicallback.h"
 
 // Remove macro on windows
@@ -1087,6 +1091,31 @@ class AbstractCompactionFilterFactoryJni : public RocksDBNativeClass<
   }
 };
 
+// The portal class for org.rocksdb.AbstractTransactionNotifier
+class AbstractTransactionNotifierJni : public RocksDBNativeClass<
+    const rocksdb::TransactionNotifierJniCallback*,
+    AbstractTransactionNotifierJni> {
+ public:
+  static jclass getJClass(JNIEnv* env) {
+    return RocksDBNativeClass::getJClass(env,
+        "org/rocksdb/AbstractTransactionNotifier");
+  }
+
+  // Get the java method `snapshotCreated`
+  // of org.rocksdb.AbstractTransactionNotifier.
+  static jmethodID getSnapshotCreatedMethodId(JNIEnv* env) {
+    jclass jclazz = getJClass(env);
+    if(jclazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    static jmethodID mid = env->GetMethodID(jclazz, "snapshotCreated", "(J)V");
+    assert(mid != nullptr);
+    return mid;
+  }
+};
+
 // The portal class for org.rocksdb.AbstractComparator
 class AbstractComparatorJni : public RocksDBNativeClass<
     const rocksdb::BaseComparatorJniCallback*,
@@ -2974,6 +3003,334 @@ class RateLimiterModeJni {
   }
 };
 
+// The portal class for org.rocksdb.Transaction
+class TransactionJni : public JavaClass {
+ public:
+  /**
+   * Get the Java Class org.rocksdb.Transaction
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Class or nullptr if one of the
+   *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+   *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+   */
+  static jclass getJClass(JNIEnv* env) {
+    return JavaClass::getJClass(env,
+        "org/rocksdb/Transaction");
+  }
+
+  /**
+   * Create a new Java org.rocksdb.Transaction.WaitingTransactions object
+   *
+   * @param env A pointer to the Java environment
+   * @param jtransaction A Java org.rocksdb.Transaction object
+   * @param column_family_id The id of the column family
+   * @param key The key
+   * @param transaction_ids The transaction ids
+   *
+   * @return A reference to a Java
+   *     org.rocksdb.Transaction.WaitingTransactions object,
+   *     or nullptr if an an exception occurs
+   */
+  static jobject newWaitingTransactions(JNIEnv* env, jobject jtransaction,
+      const uint32_t column_family_id, const std::string &key,
+      const std::vector<TransactionID> &transaction_ids) {
+    jclass jclazz = getJClass(env);
+    if(jclazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    jmethodID mid = env->GetMethodID(
+      jclazz, "newWaitingTransactions", "(JLjava/lang/String;[J)Lorg/rocksdb/Transaction$WaitingTransactions;");
+    if(mid == nullptr) {
+      // exception thrown: NoSuchMethodException or OutOfMemoryError
+      return nullptr;
+    }
+
+    jstring jkey = env->NewStringUTF(key.c_str());
+    if(jkey == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return nullptr;
+    }
+
+    const size_t len = transaction_ids.size();
+    jlongArray jtransaction_ids = env->NewLongArray(static_cast<jsize>(len));
+    if(jtransaction_ids == nullptr) {
+      // exception thrown: OutOfMemoryError
+      env->DeleteLocalRef(jkey);
+      return nullptr;
+    }
+
+    jlong *body = env->GetLongArrayElements(jtransaction_ids, nullptr);
+    if(body == nullptr) {
+        // exception thrown: OutOfMemoryError
+        env->DeleteLocalRef(jkey);
+        env->DeleteLocalRef(jtransaction_ids);
+        return nullptr;
+    }
+    for(size_t i = 0; i < len; ++i) {
+      body[i] = static_cast<jlong>(transaction_ids[i]);
+    }
+    env->ReleaseLongArrayElements(jtransaction_ids, body, 0);
+
+    jobject jwaiting_transactions = env->CallObjectMethod(jtransaction,
+      mid, static_cast<jlong>(column_family_id), jkey, jtransaction_ids);
+    if(env->ExceptionCheck()) {
+      // exception thrown: InstantiationException or OutOfMemoryError
+      env->DeleteLocalRef(jkey);
+      env->DeleteLocalRef(jtransaction_ids);
+      return nullptr;
+    }
+
+    return jwaiting_transactions;
+  }
+};
+
+// The portal class for org.rocksdb.TransactionDB
+class TransactionDBJni : public JavaClass {
+ public:
+ /**
+  * Get the Java Class org.rocksdb.TransactionDB
+  *
+  * @param env A pointer to the Java environment
+  *
+  * @return The Java Class or nullptr if one of the
+  *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+  *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+  */
+  static jclass getJClass(JNIEnv* env) {
+    return JavaClass::getJClass(env,
+       "org/rocksdb/TransactionDB");
+  }
+
+  /**
+   * Create a new Java org.rocksdb.TransactionDB.DeadlockInfo object
+   *
+   * @param env A pointer to the Java environment
+   * @param jtransaction A Java org.rocksdb.Transaction object
+   * @param column_family_id The id of the column family
+   * @param key The key
+   * @param transaction_ids The transaction ids
+   *
+   * @return A reference to a Java
+   *     org.rocksdb.Transaction.WaitingTransactions object,
+   *     or nullptr if an an exception occurs
+   */
+  static jobject newDeadlockInfo(JNIEnv* env, jobject jtransaction_db,
+      const rocksdb::TransactionID transaction_id,
+      const uint32_t column_family_id, const std::string &waiting_key,
+      const bool exclusive) {
+    jclass jclazz = getJClass(env);
+    if(jclazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    jmethodID mid = env->GetMethodID(
+        jclazz, "newDeadlockInfo", "(JJLjava/lang/String;Z)Lorg/rocksdb/TransactionDB$DeadlockInfo;");
+    if(mid == nullptr) {
+      // exception thrown: NoSuchMethodException or OutOfMemoryError
+      return nullptr;
+    }
+
+    jstring jwaiting_key = env->NewStringUTF(waiting_key.c_str());
+    if(jwaiting_key == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return nullptr;
+    }
+
+    // resolve the column family id to a ColumnFamilyHandle
+    jobject jdeadlock_info = env->CallObjectMethod(jtransaction_db,
+        mid, transaction_id, static_cast<jlong>(column_family_id),
+        jwaiting_key, exclusive);
+    if(env->ExceptionCheck()) {
+      // exception thrown: InstantiationException or OutOfMemoryError
+      env->DeleteLocalRef(jwaiting_key);
+      return nullptr;
+    }
+
+    return jdeadlock_info;
+  }
+};
+
+// The portal class for org.rocksdb.TxnDBWritePolicy
+class TxnDBWritePolicyJni {
+ public:
+ // Returns the equivalent org.rocksdb.TxnDBWritePolicy for the provided
+ // C++ rocksdb::TxnDBWritePolicy enum
+ static jbyte toJavaTxnDBWritePolicy(
+     const rocksdb::TxnDBWritePolicy& txndb_write_policy) {
+   switch(txndb_write_policy) {
+     case rocksdb::TxnDBWritePolicy::WRITE_COMMITTED:
+       return 0x0;
+     case rocksdb::TxnDBWritePolicy::WRITE_PREPARED:
+       return 0x1;
+    case rocksdb::TxnDBWritePolicy::WRITE_UNPREPARED:
+       return 0x2;
+     default:
+       return 0x7F;  // undefined
+   }
+ }
+
+ // Returns the equivalent C++ rocksdb::TxnDBWritePolicy enum for the
+ // provided Java org.rocksdb.TxnDBWritePolicy
+ static rocksdb::TxnDBWritePolicy toCppTxnDBWritePolicy(
+     jbyte jtxndb_write_policy) {
+   switch(jtxndb_write_policy) {
+     case 0x0:
+       return rocksdb::TxnDBWritePolicy::WRITE_COMMITTED;
+     case 0x1:
+       return rocksdb::TxnDBWritePolicy::WRITE_PREPARED;
+     case 0x2:
+       return rocksdb::TxnDBWritePolicy::WRITE_UNPREPARED;
+     default:
+       // undefined/default
+       return rocksdb::TxnDBWritePolicy::WRITE_COMMITTED;
+   }
+ }
+};
+
+// The portal class for org.rocksdb.TransactionDB.KeyLockInfo
+class KeyLockInfoJni : public JavaClass {
+ public:
+  /**
+   * Get the Java Class org.rocksdb.TransactionDB.KeyLockInfo
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Class or nullptr if one of the
+   *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+   *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+   */
+  static jclass getJClass(JNIEnv* env) {
+    return JavaClass::getJClass(env,
+        "org/rocksdb/TransactionDB$KeyLockInfo");
+  }
+
+  /**
+   * Create a new Java org.rocksdb.TransactionDB.KeyLockInfo object
+   * with the same properties as the provided C++ rocksdb::KeyLockInfo object
+   *
+   * @param env A pointer to the Java environment
+   * @param key_lock_info The rocksdb::KeyLockInfo object
+   *
+   * @return A reference to a Java
+   *     org.rocksdb.TransactionDB.KeyLockInfo object,
+   *     or nullptr if an an exception occurs
+   */
+  static jobject construct(JNIEnv* env,
+      const rocksdb::KeyLockInfo& key_lock_info) {
+    jclass jclazz = getJClass(env);
+    if(jclazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    jmethodID mid = env->GetMethodID(
+      jclazz, "<init>", "(Ljava/lang/String;[JZ)V");
+    if (mid == nullptr) {
+      // exception thrown: NoSuchMethodException or OutOfMemoryError
+      return nullptr;
+    }
+
+    jstring jkey = env->NewStringUTF(key_lock_info.key.c_str());
+    if (jkey == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return nullptr;
+    }
+
+    const jsize jtransaction_ids_len = static_cast<jsize>(key_lock_info.ids.size());
+    jlongArray jtransactions_ids = env->NewLongArray(jtransaction_ids_len);
+    if (jtransactions_ids == nullptr) {
+      // exception thrown: OutOfMemoryError
+      env->DeleteLocalRef(jkey);
+      return nullptr;
+    }
+
+    const jobject jkey_lock_info = env->NewObject(jclazz, mid,
+      jkey, jtransactions_ids, key_lock_info.exclusive);
+    if(jkey_lock_info == nullptr) {
+      // exception thrown: InstantiationException or OutOfMemoryError
+      env->DeleteLocalRef(jtransactions_ids);
+      env->DeleteLocalRef(jkey);
+      return nullptr;
+    }
+
+    return jkey_lock_info;
+  }
+};
+
+// The portal class for org.rocksdb.TransactionDB.DeadlockInfo
+class DeadlockInfoJni : public JavaClass {
+ public:
+  /**
+   * Get the Java Class org.rocksdb.TransactionDB.DeadlockInfo
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Class or nullptr if one of the
+   *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+   *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+   */
+   static jclass getJClass(JNIEnv* env) {
+     return JavaClass::getJClass(env,"org/rocksdb/TransactionDB$DeadlockInfo");
+  }
+};
+
+// The portal class for org.rocksdb.TransactionDB.DeadlockPath
+class DeadlockPathJni : public JavaClass {
+ public:
+  /**
+   * Get the Java Class org.rocksdb.TransactionDB.DeadlockPath
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Class or nullptr if one of the
+   *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+   *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+   */
+  static jclass getJClass(JNIEnv* env) {
+    return JavaClass::getJClass(env,
+        "org/rocksdb/TransactionDB$DeadlockPath");
+  }
+
+  /**
+   * Create a new Java org.rocksdb.TransactionDB.DeadlockPath object
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return A reference to a Java
+   *     org.rocksdb.TransactionDB.DeadlockPath object,
+   *     or nullptr if an an exception occurs
+   */
+  static jobject construct(JNIEnv* env,
+    const jobjectArray jdeadlock_infos, const bool limit_exceeded) {
+    jclass jclazz = getJClass(env);
+    if(jclazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    jmethodID mid = env->GetMethodID(
+      jclazz, "<init>", "([LDeadlockInfo;Z)V");
+    if (mid == nullptr) {
+      // exception thrown: NoSuchMethodException or OutOfMemoryError
+      return nullptr;
+    }
+
+    const jobject jdeadlock_path = env->NewObject(jclazz, mid,
+      jdeadlock_infos, limit_exceeded);
+    if(jdeadlock_path == nullptr) {
+      // exception thrown: InstantiationException or OutOfMemoryError
+      return nullptr;
+    }
+
+    return jdeadlock_path;
+  }
+};
+
 // various utility functions for working with RocksDB and JNI
 class JniUtil {
  public:
@@ -3497,7 +3854,7 @@ class ColumnFamilyDescriptorJni : public JavaClass {
    * nullptr if an an exception occurs
    */
   static jobject construct(JNIEnv* env, ColumnFamilyDescriptor* cfd) {
-    jbyteArray cfname = JniUtil::copyBytes(env, cfd->name);
+    jbyteArray jcf_name = JniUtil::copyBytes(env, cfd->name);
     jobject cfopts = ColumnFamilyOptionsJni::construct(env, &(cfd->options));
 
     jclass jclazz = getJClass(env);
@@ -3510,11 +3867,13 @@ class ColumnFamilyDescriptorJni : public JavaClass {
                                      "([BLorg/rocksdb/ColumnFamilyOptions;)V");
     if (mid == nullptr) {
       // exception thrown: NoSuchMethodException or OutOfMemoryError
+      env->DeleteLocalRef(jcf_name);
       return nullptr;
     }
 
-    jobject jcfd = env->NewObject(jclazz, mid, cfname, cfopts);
+    jobject jcfd = env->NewObject(jclazz, mid, jcf_name, cfopts);
     if (env->ExceptionCheck()) {
+      env->DeleteLocalRef(jcf_name);
       return nullptr;
     }
 
@@ -3563,5 +3922,169 @@ class ColumnFamilyDescriptorJni : public JavaClass {
   }
 };
 
+class MapJni : public JavaClass {
+ public:
+  /**
+   * Get the Java Class java.util.Map
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Class or nullptr if one of the
+   *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+   *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+   */
+  static jclass getClass(JNIEnv* env) {
+    return JavaClass::getJClass(env, "java/util/Map");
+  }
+
+  /**
+   * Get the Java Method: Map#put
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Method ID or nullptr if the class or method id could not
+   *     be retieved
+   */
+  static jmethodID getMapPutMethodId(JNIEnv* env) {
+    jclass jlist_clazz = getClass(env);
+    if(jlist_clazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    static jmethodID mid =
+        env->GetMethodID(jlist_clazz, "put", "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
+    assert(mid != nullptr);
+    return mid;
+  }
+};
+
+class HashMapJni : public JavaClass {
+ public:
+  /**
+   * Get the Java Class java.util.HashMap
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Class or nullptr if one of the
+   *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+   *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+   */
+  static jclass getJClass(JNIEnv* env) {
+    return JavaClass::getJClass(env, "java/util/HashMap");
+  }
+
+  /**
+   * Create a new Java java.util.HashMap object.
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return A reference to a Java java.util.HashMap object, or
+   * nullptr if an an exception occurs
+   */
+  static jobject construct(JNIEnv* env, const uint32_t initial_capacity = 16) {
+    jclass jclazz = getJClass(env);
+    if (jclazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    jmethodID mid = env->GetMethodID(jclazz, "<init>", "(I)V");
+    if (mid == nullptr) {
+      // exception thrown: NoSuchMethodException or OutOfMemoryError
+      return nullptr;
+    }
+
+    jobject jhash_map = env->NewObject(jclazz, mid, static_cast<jint>(initial_capacity));
+    if (env->ExceptionCheck()) {
+      return nullptr;
+    }
+
+    return jhash_map;
+  }
+
+  /**
+   * A function which maps a std::pair<K,V> to a std::pair<jobject, jobject>
+   * 
+   * @return Either a pointer to a std::pair<jobject, jobject>, or nullptr
+   *     if an error occurs during the mapping
+   */
+  template <typename K, typename V>
+  using FnMapKV = std::function<std::unique_ptr<std::pair<jobject, jobject>> (const std::pair<K, V>&)>;
+
+  // template <class I, typename K, typename V, typename K1, typename V1, typename std::enable_if<std::is_same<typename std::iterator_traits<I>::value_type, std::pair<const K,V>>::value, int32_t>::type = 0>
+  // static void putAll(JNIEnv* env, const jobject jhash_map, I iterator, const FnMapKV<const K,V,K1,V1> &fn_map_kv) {
+  /**
+   * Returns true if it succeeds, false if an error occurs
+   */
+  template<class iterator_type, typename K, typename V>
+  static bool putAll(JNIEnv* env, const jobject jhash_map, iterator_type iterator, iterator_type end, const FnMapKV<K, V> &fn_map_kv) {
+    const jmethodID jmid_put = rocksdb::MapJni::getMapPutMethodId(env);
+    if (jmid_put == nullptr) {
+      return false;
+    }
+
+    for (auto it = iterator; it != end; ++it) {
+      const std::unique_ptr<std::pair<jobject, jobject>> result = fn_map_kv(*it);
+      if (result == nullptr) {
+          // an error occurred during fn_map_kv
+          return false;
+      }
+      env->CallObjectMethod(jhash_map, jmid_put, result->first, result->second);
+      if (env->ExceptionCheck()) {
+        // exception occurred
+        env->DeleteLocalRef(result->second);
+        env->DeleteLocalRef(result->first);
+        return false;
+      }
+
+      // release local references
+      env->DeleteLocalRef(result->second);
+      env->DeleteLocalRef(result->first);
+    }
+
+    return true;
+  }
+};
+
+class LongJni : public JavaClass {
+ public:
+  /**
+   * Get the Java Class java.lang.Long
+   *
+   * @param env A pointer to the Java environment
+   *
+   * @return The Java Class or nullptr if one of the
+   *     ClassFormatError, ClassCircularityError, NoClassDefFoundError,
+   *     OutOfMemoryError or ExceptionInInitializerError exceptions is thrown
+   */
+  static jclass getJClass(JNIEnv* env) {
+    return JavaClass::getJClass(env, "java/lang/Long");
+  }
+
+  static jobject valueOf(JNIEnv* env, jlong jprimitive_long) {
+    jclass jclazz = getJClass(env);
+    if (jclazz == nullptr) {
+      // exception occurred accessing class
+      return nullptr;
+    }
+
+    jmethodID mid =
+        env->GetStaticMethodID(jclazz, "valueOf", "(J)Ljava/lang/Long;");
+    if (mid == nullptr) {
+      // exception thrown: NoSuchMethodException or OutOfMemoryError
+      return nullptr;
+    }
+
+    const jobject jlong_obj =
+        env->CallStaticObjectMethod(jclazz, mid, jprimitive_long);
+    if (env->ExceptionCheck()) {
+      // exception occurred
+      return nullptr;
+    }
+
+    return jlong_obj;
+  }
+};
 }  // namespace rocksdb
 #endif  // JAVA_ROCKSJNI_PORTAL_H_

java/rocksjni/transaction_db.cc

@@ -0,0 +1,431 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the "bridge" between Java and C++
+// for rocksdb::TransactionDB.
+
+#include <jni.h>
+#include <functional>
+#include <memory>
+#include <utility>
+
+
+#include "include/org_rocksdb_TransactionDB.h"
+
+#include "rocksdb/options.h"
+#include "rocksdb/utilities/transaction.h"
+#include "rocksdb/utilities/transaction_db.h"
+
+#include "rocksjni/portal.h"
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    open
+ * Signature: (JJLjava/lang/String;)J
+ */
+jlong Java_org_rocksdb_TransactionDB_open__JJLjava_lang_String_2(JNIEnv* env,
+    jclass jcls, jlong joptions_handle, jlong jtxn_db_options_handle,
+    jstring jdb_path) {
+  auto* options = reinterpret_cast<rocksdb::Options*>(joptions_handle);
+  auto* txn_db_options =
+      reinterpret_cast<rocksdb::TransactionDBOptions*>(jtxn_db_options_handle);
+  rocksdb::TransactionDB* tdb = nullptr;
+  const char* db_path = env->GetStringUTFChars(jdb_path, nullptr);
+  if (db_path == nullptr) {
+    // exception thrown: OutOfMemoryError
+    return 0;
+  }
+  rocksdb::Status s =
+      rocksdb::TransactionDB::Open(*options, *txn_db_options, db_path, &tdb);
+  env->ReleaseStringUTFChars(jdb_path, db_path);
+
+  if (s.ok()) {
+    return reinterpret_cast<jlong>(tdb);
+  } else {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+    return 0;
+  }
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    open
+ * Signature: (JJLjava/lang/String;[[B[J)[J
+ */
+jlongArray Java_org_rocksdb_TransactionDB_open__JJLjava_lang_String_2_3_3B_3J(
+    JNIEnv* env, jclass jcls, jlong jdb_options_handle,
+    jlong jtxn_db_options_handle, jstring jdb_path,
+    jobjectArray jcolumn_names,
+    jlongArray jcolumn_options_handles) {
+  const char* db_path = env->GetStringUTFChars(jdb_path, nullptr);
+  if (db_path == nullptr) {
+    // exception thrown: OutOfMemoryError
+    return nullptr;
+  }
+
+  const jsize len_cols = env->GetArrayLength(jcolumn_names);
+  if (env->EnsureLocalCapacity(len_cols) != 0) {
+    // out of memory
+    env->ReleaseStringUTFChars(jdb_path, db_path);
+    return nullptr;
+  }
+
+  jlong* jco = env->GetLongArrayElements(jcolumn_options_handles, nullptr);
+  if (jco == nullptr) {
+      // exception thrown: OutOfMemoryError
+      env->ReleaseStringUTFChars(jdb_path, db_path);
+      return nullptr;
+  }
+  std::vector<rocksdb::ColumnFamilyDescriptor> column_families;
+  for (int i = 0; i < len_cols; i++) {
+    const jobject jcn = env->GetObjectArrayElement(jcolumn_names, i);
+    if (env->ExceptionCheck()) {
+        // exception thrown: ArrayIndexOutOfBoundsException
+        env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+        env->ReleaseStringUTFChars(jdb_path, db_path);
+        return nullptr;
+    }
+    const jbyteArray jcn_ba = reinterpret_cast<jbyteArray>(jcn);
+    jbyte* jcf_name = env->GetByteArrayElements(jcn_ba, nullptr);
+    if (jcf_name == nullptr) {
+      // exception thrown: OutOfMemoryError
+      env->DeleteLocalRef(jcn);
+      env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+      env->ReleaseStringUTFChars(jdb_path, db_path);
+      return nullptr;
+    }
+
+    const int jcf_name_len = env->GetArrayLength(jcn_ba);
+    if (env->EnsureLocalCapacity(jcf_name_len) != 0) {
+        // out of memory
+        env->ReleaseByteArrayElements(jcn_ba, jcf_name, JNI_ABORT);
+        env->DeleteLocalRef(jcn);
+        env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+        env->ReleaseStringUTFChars(jdb_path, db_path);
+        return nullptr;
+    }
+    const std::string cf_name(reinterpret_cast<char *>(jcf_name), jcf_name_len);
+    const rocksdb::ColumnFamilyOptions* cf_options =
+      reinterpret_cast<rocksdb::ColumnFamilyOptions*>(jco[i]);
+    column_families.push_back(
+      rocksdb::ColumnFamilyDescriptor(cf_name, *cf_options));
+
+    env->ReleaseByteArrayElements(jcn_ba, jcf_name, JNI_ABORT);
+    env->DeleteLocalRef(jcn);
+  }
+  env->ReleaseLongArrayElements(jcolumn_options_handles, jco, JNI_ABORT);
+
+  auto* db_options = reinterpret_cast<rocksdb::DBOptions*>(jdb_options_handle);
+  auto* txn_db_options =
+      reinterpret_cast<rocksdb::TransactionDBOptions*>(jtxn_db_options_handle);
+  std::vector<rocksdb::ColumnFamilyHandle*> handles;
+  rocksdb::TransactionDB* tdb = nullptr;
+  const rocksdb::Status s = rocksdb::TransactionDB::Open(*db_options, *txn_db_options,
+      db_path, column_families, &handles, &tdb);
+
+  // check if open operation was successful
+  if (s.ok()) {
+    const jsize resultsLen = 1 + len_cols;  // db handle + column family handles
+    std::unique_ptr<jlong[]> results =
+        std::unique_ptr<jlong[]>(new jlong[resultsLen]);
+    results[0] = reinterpret_cast<jlong>(tdb);
+    for (int i = 1; i <= len_cols; i++) {
+      results[i] = reinterpret_cast<jlong>(handles[i - 1]);
+    }
+
+    jlongArray jresults = env->NewLongArray(resultsLen);
+    if (jresults == nullptr) {
+        // exception thrown: OutOfMemoryError
+        return nullptr;
+    }
+    env->SetLongArrayRegion(jresults, 0, resultsLen, results.get());
+    if (env->ExceptionCheck()) {
+        // exception thrown: ArrayIndexOutOfBoundsException
+        env->DeleteLocalRef(jresults);
+        return nullptr;
+    }
+    return jresults;
+  } else {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+    return nullptr;
+  }
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    beginTransaction
+ * Signature: (JJ)J
+ */
+jlong Java_org_rocksdb_TransactionDB_beginTransaction__JJ(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jwrite_options_handle) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  rocksdb::Transaction* txn = txn_db->BeginTransaction(*write_options);
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    beginTransaction
+ * Signature: (JJJ)J
+ */
+jlong Java_org_rocksdb_TransactionDB_beginTransaction__JJJ(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jwrite_options_handle,
+    jlong jtxn_options_handle) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  auto* txn_options =
+      reinterpret_cast<rocksdb::TransactionOptions*>(jtxn_options_handle);
+  rocksdb::Transaction* txn =
+      txn_db->BeginTransaction(*write_options, *txn_options);
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    beginTransaction_withOld
+ * Signature: (JJJ)J
+ */
+jlong Java_org_rocksdb_TransactionDB_beginTransaction_1withOld__JJJ(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jwrite_options_handle,
+    jlong jold_txn_handle) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  auto* old_txn = reinterpret_cast<rocksdb::Transaction*>(jold_txn_handle);
+  rocksdb::TransactionOptions txn_options;
+  rocksdb::Transaction* txn =
+      txn_db->BeginTransaction(*write_options, txn_options, old_txn);
+
+  // RocksJava relies on the assumption that
+  // we do not allocate a new Transaction object
+  // when providing an old_txn
+  assert(txn == old_txn);
+
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    beginTransaction_withOld
+ * Signature: (JJJJ)J
+ */
+jlong Java_org_rocksdb_TransactionDB_beginTransaction_1withOld__JJJJ(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jwrite_options_handle,
+    jlong jtxn_options_handle, jlong jold_txn_handle) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  auto* write_options =
+      reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options_handle);
+  auto* txn_options =
+      reinterpret_cast<rocksdb::TransactionOptions*>(jtxn_options_handle);
+  auto* old_txn = reinterpret_cast<rocksdb::Transaction*>(jold_txn_handle);
+  rocksdb::Transaction* txn = txn_db->BeginTransaction(*write_options,
+      *txn_options, old_txn);
+
+  // RocksJava relies on the assumption that
+  // we do not allocate a new Transaction object
+  // when providing an old_txn
+  assert(txn == old_txn);
+
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    getTransactionByName
+ * Signature: (JLjava/lang/String;)J
+ */
+jlong Java_org_rocksdb_TransactionDB_getTransactionByName(JNIEnv* env,
+    jobject jobj, jlong jhandle, jstring jname) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  const char* name = env->GetStringUTFChars(jname, nullptr);
+  if (name == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return 0;
+  }
+  rocksdb::Transaction* txn = txn_db->GetTransactionByName(name);
+  env->ReleaseStringUTFChars(jname, name);
+  return reinterpret_cast<jlong>(txn);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    getAllPreparedTransactions
+ * Signature: (J)[J
+ */
+jlongArray Java_org_rocksdb_TransactionDB_getAllPreparedTransactions(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  std::vector<rocksdb::Transaction*> txns;
+  txn_db->GetAllPreparedTransactions(&txns);
+
+  const size_t size = txns.size();
+  assert(size < UINT32_MAX);  // does it fit in a jint?
+
+  const jsize len = static_cast<jsize>(size);
+  jlong tmp[len];
+  for (jsize i = 0; i < len; ++i) {
+      tmp[i] = reinterpret_cast<jlong>(txns[i]);
+  }
+
+  jlongArray jtxns = env->NewLongArray(len);
+  if (jtxns == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return nullptr;
+  }
+  env->SetLongArrayRegion(jtxns, 0, len, tmp);
+  if (env->ExceptionCheck()) {
+      // exception thrown: ArrayIndexOutOfBoundsException
+      env->DeleteLocalRef(jtxns);
+      return nullptr;
+  }
+
+  return jtxns;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    getLockStatusData
+ * Signature: (J)Ljava/util/Map;
+ */
+jobject Java_org_rocksdb_TransactionDB_getLockStatusData(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  const std::unordered_multimap<uint32_t, rocksdb::KeyLockInfo> lock_status_data =
+      txn_db->GetLockStatusData();
+  const jobject jlock_status_data = rocksdb::HashMapJni::construct(env,
+        static_cast<uint32_t>(lock_status_data.size()));
+  if (jlock_status_data == nullptr) {
+      // exception occurred
+      return nullptr;
+  }
+
+  const rocksdb::HashMapJni::FnMapKV<const int32_t, const rocksdb::KeyLockInfo> fn_map_kv =
+      [env, txn_db, &lock_status_data](const std::pair<const int32_t, const rocksdb::KeyLockInfo>& pair) {
+          const jobject jlong_column_family_id =
+              rocksdb::LongJni::valueOf(env, pair.first);
+          if (jlong_column_family_id == nullptr) {
+              // an error occurred
+              return std::unique_ptr<std::pair<jobject, jobject>>(nullptr);
+          }
+          const jobject jkey_lock_info =
+              rocksdb::KeyLockInfoJni::construct(env, pair.second);
+          if (jkey_lock_info == nullptr) {
+             // an error occurred
+             return std::unique_ptr<std::pair<jobject, jobject>>(nullptr);
+          }
+          return std::unique_ptr<std::pair<jobject, jobject>>(new std::pair<jobject, jobject>(jlong_column_family_id,
+              jkey_lock_info));
+      };
+
+  if(!rocksdb::HashMapJni::putAll(env, jlock_status_data,
+      lock_status_data.begin(), lock_status_data.end(), fn_map_kv)) {
+    // exception occcurred
+    return nullptr;
+  }
+
+  return jlock_status_data;
+}
+
+/*
+* Class:     org_rocksdb_TransactionDB
+* Method:    getDeadlockInfoBuffer
+* Signature: (J)[Lorg/rocksdb/TransactionDB/DeadlockPath;
+*/
+jobjectArray Java_org_rocksdb_TransactionDB_getDeadlockInfoBuffer(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  const std::vector<rocksdb::DeadlockPath> deadlock_info_buffer =
+      txn_db->GetDeadlockInfoBuffer();
+
+  const jsize deadlock_info_buffer_len =
+      static_cast<jsize>(deadlock_info_buffer.size());
+  jobjectArray jdeadlock_info_buffer =
+      env->NewObjectArray(deadlock_info_buffer_len,
+        rocksdb::DeadlockPathJni::getJClass(env), nullptr);
+  if (jdeadlock_info_buffer == nullptr) {
+      // exception thrown: OutOfMemoryError
+      return nullptr;
+  }
+  jsize jdeadlock_info_buffer_offset = 0;
+
+  auto buf_end = deadlock_info_buffer.end();
+  for (auto buf_it = deadlock_info_buffer.begin(); buf_it != buf_end; ++buf_it) {
+    const rocksdb::DeadlockPath deadlock_path = *buf_it;
+    const std::vector<rocksdb::DeadlockInfo> deadlock_infos
+        = deadlock_path.path;
+    const jsize deadlock_infos_len =
+        static_cast<jsize>(deadlock_info_buffer.size());
+    jobjectArray jdeadlock_infos = env->NewObjectArray(deadlock_infos_len,
+        rocksdb::DeadlockInfoJni::getJClass(env), nullptr);
+    if (jdeadlock_infos == nullptr) {
+        // exception thrown: OutOfMemoryError
+        env->DeleteLocalRef(jdeadlock_info_buffer);
+        return nullptr;
+    }
+    jsize jdeadlock_infos_offset = 0;
+
+    auto infos_end = deadlock_infos.end();
+    for (auto infos_it = deadlock_infos.begin(); infos_it != infos_end; ++infos_it) {
+        const rocksdb::DeadlockInfo deadlock_info = *infos_it;
+        const jobject jdeadlock_info = rocksdb::TransactionDBJni::newDeadlockInfo(
+            env, jobj, deadlock_info.m_txn_id, deadlock_info.m_cf_id,
+            deadlock_info.m_waiting_key, deadlock_info.m_exclusive);
+        if (jdeadlock_info == nullptr) {
+            // exception occcurred
+            env->DeleteLocalRef(jdeadlock_info_buffer);
+            return nullptr;
+        }
+        env->SetObjectArrayElement(jdeadlock_infos, jdeadlock_infos_offset++, jdeadlock_info);
+        if (env->ExceptionCheck()) {
+            // exception thrown: ArrayIndexOutOfBoundsException or ArrayStoreException
+            env->DeleteLocalRef(jdeadlock_info);
+            env->DeleteLocalRef(jdeadlock_info_buffer);
+            return nullptr;
+        }
+    }
+
+    const jobject jdeadlock_path =
+        rocksdb::DeadlockPathJni::construct(env, jdeadlock_infos,
+            deadlock_path.limit_exceeded);
+    if(jdeadlock_path == nullptr) {
+        // exception occcurred
+        env->DeleteLocalRef(jdeadlock_info_buffer);
+        return nullptr;
+    }
+    env->SetObjectArrayElement(jdeadlock_info_buffer, jdeadlock_info_buffer_offset++, jdeadlock_path);
+    if (env->ExceptionCheck()) {
+        // exception thrown: ArrayIndexOutOfBoundsException or ArrayStoreException
+        env->DeleteLocalRef(jdeadlock_path);
+        env->DeleteLocalRef(jdeadlock_info_buffer);
+        return nullptr;
+    }
+  }
+
+  return jdeadlock_info_buffer;
+}
+
+/*
+* Class:     org_rocksdb_TransactionDB
+* Method:    setDeadlockInfoBufferSize
+* Signature: (JI)V
+*/
+void Java_org_rocksdb_TransactionDB_setDeadlockInfoBufferSize(
+    JNIEnv* env, jobject jobj, jlong jhandle, jint jdeadlock_info_buffer_size) {
+  auto* txn_db = reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+  txn_db->SetDeadlockInfoBufferSize(jdeadlock_info_buffer_size);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDB
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_TransactionDB_disposeInternal(JNIEnv* env, jobject jobj,
+    jlong jhandle) {
+  delete reinterpret_cast<rocksdb::TransactionDB*>(jhandle);
+}

java/rocksjni/transaction_db_options.cc

@@ -0,0 +1,147 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the "bridge" between Java and C++
+// for rocksdb::TransactionDBOptions.
+
+#include <jni.h>
+
+#include "include/org_rocksdb_TransactionDBOptions.h"
+
+#include "rocksdb/utilities/transaction_db.h"
+
+#include "rocksjni/portal.h"
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    newTransactionDBOptions
+ * Signature: ()J
+ */
+jlong Java_org_rocksdb_TransactionDBOptions_newTransactionDBOptions(
+    JNIEnv* env, jclass jcls) {
+  rocksdb::TransactionDBOptions* opts = new rocksdb::TransactionDBOptions();
+  return reinterpret_cast<jlong>(opts);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    getMaxNumLocks
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_TransactionDBOptions_getMaxNumLocks(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  return opts->max_num_locks;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    setMaxNumLocks
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_TransactionDBOptions_setMaxNumLocks(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jmax_num_locks) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  opts->max_num_locks = jmax_num_locks;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    getNumStripes
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_TransactionDBOptions_getNumStripes(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  return opts->num_stripes;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    setNumStripes
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_TransactionDBOptions_setNumStripes(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jnum_stripes) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  opts->num_stripes = jnum_stripes;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    getTransactionLockTimeout
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_TransactionDBOptions_getTransactionLockTimeout(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  return opts->transaction_lock_timeout;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    setTransactionLockTimeout
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_TransactionDBOptions_setTransactionLockTimeout(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jtransaction_lock_timeout) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  opts->transaction_lock_timeout = jtransaction_lock_timeout;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    getDefaultLockTimeout
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_TransactionDBOptions_getDefaultLockTimeout(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  return opts->default_lock_timeout;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    setDefaultLockTimeout
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_TransactionDBOptions_setDefaultLockTimeout(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jdefault_lock_timeout) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  opts->default_lock_timeout = jdefault_lock_timeout;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    getWritePolicy
+ * Signature: (J)B
+ */
+jbyte Java_org_rocksdb_TransactionDBOptions_getWritePolicy(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  return rocksdb::TxnDBWritePolicyJni::toJavaTxnDBWritePolicy(opts->write_policy);
+}
+
+/*
+* Class:     org_rocksdb_TransactionDBOptions
+* Method:    setWritePolicy
+* Signature: (JB)V
+*/
+void Java_org_rocksdb_TransactionDBOptions_setWritePolicy(
+    JNIEnv* env, jobject jobj, jlong jhandle, jbyte jwrite_policy) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+  opts->write_policy =
+      rocksdb::TxnDBWritePolicyJni::toCppTxnDBWritePolicy(jwrite_policy);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionDBOptions
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_TransactionDBOptions_disposeInternal(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  delete reinterpret_cast<rocksdb::TransactionDBOptions*>(jhandle);
+}

java/rocksjni/transaction_notifier.cc

@@ -0,0 +1,42 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the "bridge" between Java and C++
+// for rocksdb::TransactionNotifier.
+
+#include <jni.h>
+
+#include "include/org_rocksdb_AbstractTransactionNotifier.h"
+#include "rocksjni/transaction_notifier_jnicallback.h"
+
+/*
+ * Class:     org_rocksdb_AbstractTransactionNotifier
+ * Method:    createNewTransactionNotifier
+ * Signature: ()J
+ */
+jlong Java_org_rocksdb_AbstractTransactionNotifier_createNewTransactionNotifier(
+    JNIEnv* env, jobject jobj) {
+  auto* transaction_notifier =
+      new rocksdb::TransactionNotifierJniCallback(env, jobj);
+  auto* sptr_transaction_notifier =
+      new std::shared_ptr<rocksdb::TransactionNotifierJniCallback>(
+          transaction_notifier);
+  return reinterpret_cast<jlong>(sptr_transaction_notifier);
+}
+
+/*
+ * Class:     org_rocksdb_AbstractTransactionNotifier
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_AbstractTransactionNotifier_disposeInternal(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  // TODO(AR) refactor to use JniCallback::JniCallback
+  // when https://github.com/facebook/rocksdb/pull/1241/ is merged
+  std::shared_ptr<rocksdb::TransactionNotifierJniCallback>* handle =
+      reinterpret_cast<std::shared_ptr<
+          rocksdb::TransactionNotifierJniCallback>*>(jhandle);
+  delete handle;
+}

java/rocksjni/transaction_notifier_jnicallback.cc

@@ -0,0 +1,39 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the callback "bridge" between Java and C++ for
+// rocksdb::TransactionNotifier.
+
+#include "rocksjni/transaction_notifier_jnicallback.h"
+#include "rocksjni/portal.h"
+
+namespace rocksdb {
+
+TransactionNotifierJniCallback::TransactionNotifierJniCallback(JNIEnv* env,
+    jobject jtransaction_notifier) : JniCallback(env, jtransaction_notifier) {
+  // we cache the method id for the JNI callback
+  m_jsnapshot_created_methodID =
+      AbstractTransactionNotifierJni::getSnapshotCreatedMethodId(env);
+}
+
+void TransactionNotifierJniCallback::SnapshotCreated(
+    const Snapshot* newSnapshot) {
+  jboolean attached_thread = JNI_FALSE;
+  JNIEnv* env = getJniEnv(&attached_thread);
+  assert(env != nullptr);
+
+  env->CallVoidMethod(m_jcallback_obj,
+      m_jsnapshot_created_methodID, reinterpret_cast<jlong>(newSnapshot));
+
+  if(env->ExceptionCheck()) {
+    // exception thrown from CallVoidMethod
+    env->ExceptionDescribe();  // print out exception to stderr
+    releaseJniEnv(attached_thread);
+    return;
+  }
+
+  releaseJniEnv(attached_thread);
+}
+}  // namespace rocksdb

java/rocksjni/transaction_notifier_jnicallback.h

@@ -0,0 +1,42 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the callback "bridge" between Java and C++ for
+// rocksdb::TransactionNotifier.
+
+#ifndef JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_
+#define JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_
+
+#include <jni.h>
+
+#include "rocksdb/utilities/transaction.h"
+#include "rocksjni/jnicallback.h"
+
+namespace rocksdb {
+
+/**
+ * This class acts as a bridge between C++
+ * and Java. The methods in this class will be
+ * called back from the RocksDB TransactionDB or OptimisticTransactionDB (C++),
+ * we then callback to the appropriate Java method
+ * this enables TransactionNotifier to be implemented in Java.
+ *
+ * Unlike RocksJava's Comparator JNI Callback, we do not attempt
+ * to reduce Java object allocations by caching the Snapshot object
+ * presented to the callback. This could be revisited in future
+ * if performance is lacking.
+ */
+class TransactionNotifierJniCallback: public JniCallback,
+    public TransactionNotifier {
+ public:
+  TransactionNotifierJniCallback(JNIEnv* env, jobject jtransaction_notifier);
+  virtual void SnapshotCreated(const Snapshot* newSnapshot);
+
+ private:
+  jmethodID m_jsnapshot_created_methodID;
+};
+}  // namespace rocksdb
+
+#endif  // JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_

java/rocksjni/transaction_options.cc

@@ -0,0 +1,166 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the "bridge" between Java and C++
+// for rocksdb::TransactionOptions.
+
+#include <jni.h>
+
+#include "include/org_rocksdb_TransactionOptions.h"
+
+#include "rocksdb/utilities/transaction_db.h"
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    newTransactionOptions
+ * Signature: ()J
+ */
+jlong Java_org_rocksdb_TransactionOptions_newTransactionOptions(JNIEnv* env,
+    jclass jcls) {
+  auto* opts = new rocksdb::TransactionOptions();
+  return reinterpret_cast<jlong>(opts);
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    isSetSnapshot
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_TransactionOptions_isSetSnapshot(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  return opts->set_snapshot;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    setSetSnapshot
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_TransactionOptions_setSetSnapshot(JNIEnv* env,
+    jobject jobj, jlong jhandle, jboolean jset_snapshot) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  opts->set_snapshot = jset_snapshot;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    isDeadlockDetect
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_TransactionOptions_isDeadlockDetect(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  return opts->deadlock_detect;
+}
+
+/*
+* Class:     org_rocksdb_TransactionOptions
+* Method:    setDeadlockDetect
+* Signature: (JZ)V
+*/
+void Java_org_rocksdb_TransactionOptions_setDeadlockDetect(
+    JNIEnv* env, jobject jobj, jlong jhandle, jboolean jdeadlock_detect) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  opts->deadlock_detect = jdeadlock_detect;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    getLockTimeout
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_TransactionOptions_getLockTimeout(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  return opts->lock_timeout;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    setLockTimeout
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_TransactionOptions_setLockTimeout(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jlock_timeout) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  opts->lock_timeout = jlock_timeout;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    getExpiration
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_TransactionOptions_getExpiration(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  return opts->expiration;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    setExpiration
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_TransactionOptions_setExpiration(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jexpiration) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  opts->expiration = jexpiration;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    getDeadlockDetectDepth
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_TransactionOptions_getDeadlockDetectDepth(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  return opts->deadlock_detect_depth;
+}
+
+/*
+* Class:     org_rocksdb_TransactionOptions
+* Method:    setDeadlockDetectDepth
+* Signature: (JJ)V
+*/
+void Java_org_rocksdb_TransactionOptions_setDeadlockDetectDepth(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jdeadlock_detect_depth) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  opts->deadlock_detect_depth = jdeadlock_detect_depth;
+}
+
+/*
+* Class:     org_rocksdb_TransactionOptions
+* Method:    getMaxWriteBatchSize
+* Signature: (J)J
+*/
+jlong Java_org_rocksdb_TransactionOptions_getMaxWriteBatchSize(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  return opts->max_write_batch_size;
+}
+
+/*
+* Class:     org_rocksdb_TransactionOptions
+* Method:    setMaxWriteBatchSize
+* Signature: (JJ)V
+*/
+void Java_org_rocksdb_TransactionOptions_setMaxWriteBatchSize(
+    JNIEnv* env, jobject jobj, jlong jhandle, jlong jmax_write_batch_size) {
+  auto* opts = reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+  opts->max_write_batch_size = jmax_write_batch_size;
+}
+
+/*
+ * Class:     org_rocksdb_TransactionOptions
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_TransactionOptions_disposeInternal(JNIEnv* env,
+    jobject jobj, jlong jhandle) {
+  delete reinterpret_cast<rocksdb::TransactionOptions*>(jhandle);
+}

java/samples/src/main/java/OptimisticTransactionSample.java

@@ -0,0 +1,184 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+import org.rocksdb.*;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+/**
+ * Demonstrates using Transactions on an OptimisticTransactionDB with
+ * varying isolation guarantees
+ */
+public class OptimisticTransactionSample {
+  private static final String dbPath = "/tmp/rocksdb_optimistic_transaction_example";
+
+  public static final void main(final String args[]) throws RocksDBException {
+
+    try(final Options options = new Options()
+        .setCreateIfMissing(true);
+        final OptimisticTransactionDB txnDb =
+            OptimisticTransactionDB.open(options, dbPath)) {
+
+      try (final WriteOptions writeOptions = new WriteOptions();
+           final ReadOptions readOptions = new ReadOptions()) {
+
+        ////////////////////////////////////////////////////////
+        //
+        // Simple OptimisticTransaction Example ("Read Committed")
+        //
+        ////////////////////////////////////////////////////////
+        readCommitted(txnDb, writeOptions, readOptions);
+
+
+        ////////////////////////////////////////////////////////
+        //
+        // "Repeatable Read" (Snapshot Isolation) Example
+        //   -- Using a single Snapshot
+        //
+        ////////////////////////////////////////////////////////
+        repeatableRead(txnDb, writeOptions, readOptions);
+
+
+        ////////////////////////////////////////////////////////
+        //
+        // "Read Committed" (Monotonic Atomic Views) Example
+        //   --Using multiple Snapshots
+        //
+        ////////////////////////////////////////////////////////
+        readCommitted_monotonicAtomicViews(txnDb, writeOptions, readOptions);
+      }
+    }
+  }
+
+  /**
+   * Demonstrates "Read Committed" isolation
+   */
+  private static void readCommitted(final OptimisticTransactionDB txnDb,
+      final WriteOptions writeOptions, final ReadOptions readOptions)
+      throws RocksDBException {
+    final byte key1[] = "abc".getBytes(UTF_8);
+    final byte value1[] = "def".getBytes(UTF_8);
+
+    final byte key2[] = "xyz".getBytes(UTF_8);
+    final byte value2[] = "zzz".getBytes(UTF_8);
+
+    // Start a transaction
+    try(final Transaction txn = txnDb.beginTransaction(writeOptions)) {
+      // Read a key in this transaction
+      byte[] value = txn.get(readOptions, key1);
+      assert(value == null);
+
+      // Write a key in this transaction
+      txn.put(key1, value1);
+
+      // Read a key OUTSIDE this transaction. Does not affect txn.
+      value = txnDb.get(readOptions, key1);
+      assert(value == null);
+
+      // Write a key OUTSIDE of this transaction.
+      // Does not affect txn since this is an unrelated key.
+      // If we wrote key 'abc' here, the transaction would fail to commit.
+      txnDb.put(writeOptions, key2, value2);
+
+      // Commit transaction
+      txn.commit();
+    }
+  }
+
+  /**
+   * Demonstrates "Repeatable Read" (Snapshot Isolation) isolation
+   */
+  private static void repeatableRead(final OptimisticTransactionDB txnDb,
+      final WriteOptions writeOptions, final ReadOptions readOptions)
+      throws RocksDBException {
+
+    final byte key1[] = "ghi".getBytes(UTF_8);
+    final byte value1[] = "jkl".getBytes(UTF_8);
+
+    // Set a snapshot at start of transaction by setting setSnapshot(true)
+    try(final OptimisticTransactionOptions txnOptions =
+            new OptimisticTransactionOptions().setSetSnapshot(true);
+        final Transaction txn =
+            txnDb.beginTransaction(writeOptions, txnOptions)) {
+
+      final Snapshot snapshot = txn.getSnapshot();
+
+      // Write a key OUTSIDE of transaction
+      txnDb.put(writeOptions, key1, value1);
+
+      // Read a key using the snapshot.
+      readOptions.setSnapshot(snapshot);
+      final byte[] value = txn.getForUpdate(readOptions, key1, true);
+      assert(value == value1);
+
+      try {
+        // Attempt to commit transaction
+        txn.commit();
+        throw new IllegalStateException();
+      } catch(final RocksDBException e) {
+        // Transaction could not commit since the write outside of the txn
+        // conflicted with the read!
+        assert(e.getStatus().getCode() == Status.Code.Busy);
+      }
+
+      txn.rollback();
+    } finally {
+      // Clear snapshot from read options since it is no longer valid
+      readOptions.setSnapshot(null);
+    }
+  }
+
+  /**
+   * Demonstrates "Read Committed" (Monotonic Atomic Views) isolation
+   *
+   * In this example, we set the snapshot multiple times.  This is probably
+   * only necessary if you have very strict isolation requirements to
+   * implement.
+   */
+  private static void readCommitted_monotonicAtomicViews(
+      final OptimisticTransactionDB txnDb, final WriteOptions writeOptions,
+      final ReadOptions readOptions) throws RocksDBException {
+
+    final byte keyX[] = "x".getBytes(UTF_8);
+    final byte valueX[] = "x".getBytes(UTF_8);
+
+    final byte keyY[] = "y".getBytes(UTF_8);
+    final byte valueY[] = "y".getBytes(UTF_8);
+
+    try (final OptimisticTransactionOptions txnOptions =
+             new OptimisticTransactionOptions().setSetSnapshot(true);
+         final Transaction txn =
+             txnDb.beginTransaction(writeOptions, txnOptions)) {
+
+      // Do some reads and writes to key "x"
+      Snapshot snapshot = txnDb.getSnapshot();
+      readOptions.setSnapshot(snapshot);
+      byte[] value = txn.get(readOptions, keyX);
+      txn.put(valueX, valueX);
+
+      // Do a write outside of the transaction to key "y"
+      txnDb.put(writeOptions, keyY, valueY);
+
+      // Set a new snapshot in the transaction
+      txn.setSnapshot();
+      snapshot = txnDb.getSnapshot();
+      readOptions.setSnapshot(snapshot);
+
+      // Do some reads and writes to key "y"
+      // Since the snapshot was advanced, the write done outside of the
+      // transaction does not conflict.
+      value = txn.getForUpdate(readOptions, keyY, true);
+      txn.put(keyY, valueY);
+
+      // Commit.  Since the snapshot was advanced, the write done outside of the
+      // transaction does not prevent this transaction from Committing.
+      txn.commit();
+
+    } finally {
+      // Clear snapshot from read options since it is no longer valid
+      readOptions.setSnapshot(null);
+    }
+  }
+}

java/samples/src/main/java/TransactionSample.java

@@ -0,0 +1,183 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+import org.rocksdb.*;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+/**
+ * Demonstrates using Transactions on a TransactionDB with
+ * varying isolation guarantees
+ */
+public class TransactionSample {
+  private static final String dbPath = "/tmp/rocksdb_transaction_example";
+
+  public static final void main(final String args[]) throws RocksDBException {
+
+    try(final Options options = new Options()
+        .setCreateIfMissing(true);
+        final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+        final TransactionDB txnDb =
+            TransactionDB.open(options, txnDbOptions, dbPath)) {
+
+      try (final WriteOptions writeOptions = new WriteOptions();
+           final ReadOptions readOptions = new ReadOptions()) {
+
+        ////////////////////////////////////////////////////////
+        //
+        // Simple Transaction Example ("Read Committed")
+        //
+        ////////////////////////////////////////////////////////
+        readCommitted(txnDb, writeOptions, readOptions);
+
+
+        ////////////////////////////////////////////////////////
+        //
+        // "Repeatable Read" (Snapshot Isolation) Example
+        //   -- Using a single Snapshot
+        //
+        ////////////////////////////////////////////////////////
+        repeatableRead(txnDb, writeOptions, readOptions);
+
+
+        ////////////////////////////////////////////////////////
+        //
+        // "Read Committed" (Monotonic Atomic Views) Example
+        //   --Using multiple Snapshots
+        //
+        ////////////////////////////////////////////////////////
+        readCommitted_monotonicAtomicViews(txnDb, writeOptions, readOptions);
+      }
+    }
+  }
+
+  /**
+   * Demonstrates "Read Committed" isolation
+   */
+  private static void readCommitted(final TransactionDB txnDb,
+      final WriteOptions writeOptions, final ReadOptions readOptions)
+      throws RocksDBException {
+    final byte key1[] = "abc".getBytes(UTF_8);
+    final byte value1[] = "def".getBytes(UTF_8);
+
+    final byte key2[] = "xyz".getBytes(UTF_8);
+    final byte value2[] = "zzz".getBytes(UTF_8);
+
+    // Start a transaction
+    try(final Transaction txn = txnDb.beginTransaction(writeOptions)) {
+      // Read a key in this transaction
+      byte[] value = txn.get(readOptions, key1);
+      assert(value == null);
+
+      // Write a key in this transaction
+      txn.put(key1, value1);
+
+      // Read a key OUTSIDE this transaction. Does not affect txn.
+      value = txnDb.get(readOptions, key1);
+      assert(value == null);
+
+      // Write a key OUTSIDE of this transaction.
+      // Does not affect txn since this is an unrelated key.
+      // If we wrote key 'abc' here, the transaction would fail to commit.
+      txnDb.put(writeOptions, key2, value2);
+
+      // Commit transaction
+      txn.commit();
+    }
+  }
+
+  /**
+   * Demonstrates "Repeatable Read" (Snapshot Isolation) isolation
+   */
+  private static void repeatableRead(final TransactionDB txnDb,
+      final WriteOptions writeOptions, final ReadOptions readOptions)
+      throws RocksDBException {
+
+    final byte key1[] = "ghi".getBytes(UTF_8);
+    final byte value1[] = "jkl".getBytes(UTF_8);
+
+    // Set a snapshot at start of transaction by setting setSnapshot(true)
+    try(final TransactionOptions txnOptions = new TransactionOptions()
+          .setSetSnapshot(true);
+        final Transaction txn =
+            txnDb.beginTransaction(writeOptions, txnOptions)) {
+
+      final Snapshot snapshot = txn.getSnapshot();
+
+      // Write a key OUTSIDE of transaction
+      txnDb.put(writeOptions, key1, value1);
+
+      // Attempt to read a key using the snapshot.  This will fail since
+      // the previous write outside this txn conflicts with this read.
+      readOptions.setSnapshot(snapshot);
+
+      try {
+        final byte[] value = txn.getForUpdate(readOptions, key1, true);
+        throw new IllegalStateException();
+      } catch(final RocksDBException e) {
+        assert(e.getStatus().getCode() == Status.Code.Busy);
+      }
+
+      txn.rollback();
+    } finally {
+      // Clear snapshot from read options since it is no longer valid
+      readOptions.setSnapshot(null);
+    }
+  }
+
+  /**
+   * Demonstrates "Read Committed" (Monotonic Atomic Views) isolation
+   *
+   * In this example, we set the snapshot multiple times.  This is probably
+   * only necessary if you have very strict isolation requirements to
+   * implement.
+   */
+  private static void readCommitted_monotonicAtomicViews(
+      final TransactionDB txnDb, final WriteOptions writeOptions,
+      final ReadOptions readOptions) throws RocksDBException {
+
+    final byte keyX[] = "x".getBytes(UTF_8);
+    final byte valueX[] = "x".getBytes(UTF_8);
+
+    final byte keyY[] = "y".getBytes(UTF_8);
+    final byte valueY[] = "y".getBytes(UTF_8);
+
+    try (final TransactionOptions txnOptions = new TransactionOptions()
+        .setSetSnapshot(true);
+         final Transaction txn =
+             txnDb.beginTransaction(writeOptions, txnOptions)) {
+
+      // Do some reads and writes to key "x"
+      Snapshot snapshot = txnDb.getSnapshot();
+      readOptions.setSnapshot(snapshot);
+      byte[] value = txn.get(readOptions, keyX);
+      txn.put(valueX, valueX);
+
+      // Do a write outside of the transaction to key "y"
+      txnDb.put(writeOptions, keyY, valueY);
+
+      // Set a new snapshot in the transaction
+      txn.setSnapshot();
+      txn.setSavePoint();
+      snapshot = txnDb.getSnapshot();
+      readOptions.setSnapshot(snapshot);
+
+      // Do some reads and writes to key "y"
+      // Since the snapshot was advanced, the write done outside of the
+      // transaction does not conflict.
+      value = txn.getForUpdate(readOptions, keyY, true);
+      txn.put(keyY, valueY);
+
+      // Decide we want to revert the last write from this transaction.
+      txn.rollbackToSavePoint();
+
+      // Commit.
+      txn.commit();
+    } finally {
+      // Clear snapshot from read options since it is no longer valid
+      readOptions.setSnapshot(null);
+    }
+  }
+}

java/src/main/java/org/rocksdb/AbstractTransactionNotifier.java

@@ -0,0 +1,54 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+/**
+ * Provides notification to the caller of SetSnapshotOnNextOperation when
+ * the actual snapshot gets created
+ */
+public abstract class AbstractTransactionNotifier
+    extends RocksCallbackObject {
+
+  protected AbstractTransactionNotifier() {
+    super();
+  }
+
+  /**
+   * Implement this method to receive notification when a snapshot is
+   * requested via {@link Transaction#setSnapshotOnNextOperation()}.
+   *
+   * @param newSnapshot the snapshot that has been created.
+   */
+  public abstract void snapshotCreated(final Snapshot newSnapshot);
+
+  /**
+   * This is intentionally private as it is the callback hook
+   * from JNI
+   */
+  private void snapshotCreated(final long snapshotHandle) {
+    snapshotCreated(new Snapshot(snapshotHandle));
+  }
+
+  @Override
+  protected long initializeNative(final long... nativeParameterHandles) {
+    return createNewTransactionNotifier();
+  }
+
+  private native long createNewTransactionNotifier();
+
+  /**
+   * Deletes underlying C++ TransactionNotifier pointer.
+   *
+   * Note that this function should be called only after all
+   * Transactions referencing the comparator are closed.
+   * Otherwise an undefined behavior will occur.
+   */
+  @Override
+  protected void disposeInternal() {
+    disposeInternal(nativeHandle_);
+  }
+  protected final native void disposeInternal(final long handle);
+}

java/src/main/java/org/rocksdb/ColumnFamilyDescriptor.java

@@ -5,6 +5,8 @@
 
 package org.rocksdb;
 
+import java.util.Arrays;
+
 /**
  * <p>Describes a column family with a
  * name and respective Options.</p>
@@ -32,7 +34,7 @@ public class ColumnFamilyDescriptor {
    * @since 3.10.0
    */
   public ColumnFamilyDescriptor(final byte[] columnFamilyName,
-      final ColumnFamilyOptions columnFamilyOptions) {
+                                final ColumnFamilyOptions columnFamilyOptions) {
     columnFamilyName_ = columnFamilyName;
     columnFamilyOptions_ = columnFamilyOptions;
   }
@@ -43,19 +45,65 @@ public class ColumnFamilyDescriptor {
    * @return column family name.
    * @since 3.10.0
    */
-  public byte[] columnFamilyName() {
+  public byte[] getName() {
     return columnFamilyName_;
   }
 
+  /**
+   * Retrieve name of column family.
+   *
+   * @return column family name.
+   * @since 3.10.0
+   *
+   * @deprecated Use {@link #getName()} instead.
+   */
+  @Deprecated
+  public byte[] columnFamilyName() {
+    return getName();
+  }
+
   /**
    * Retrieve assigned options instance.
    *
    * @return Options instance assigned to this instance.
    */
-  public ColumnFamilyOptions columnFamilyOptions() {
+  public ColumnFamilyOptions getOptions() {
     return columnFamilyOptions_;
   }
 
+  /**
+   * Retrieve assigned options instance.
+   *
+   * @return Options instance assigned to this instance.
+   *
+   * @deprecated Use {@link #getOptions()} instead.
+   */
+  @Deprecated
+  public ColumnFamilyOptions columnFamilyOptions() {
+    return getOptions();
+  }
+
+  @Override
+  public boolean equals(final Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    final ColumnFamilyDescriptor that = (ColumnFamilyDescriptor) o;
+    return Arrays.equals(columnFamilyName_, that.columnFamilyName_)
+            && columnFamilyOptions_.nativeHandle_ == that.columnFamilyOptions_.nativeHandle_;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = (int) (columnFamilyOptions_.nativeHandle_ ^ (columnFamilyOptions_.nativeHandle_ >>> 32));
+    result = 31 * result + Arrays.hashCode(columnFamilyName_);
+    return result;
+  }
+
   private final byte[] columnFamilyName_;
   private final ColumnFamilyOptions columnFamilyOptions_;
 }

java/src/main/java/org/rocksdb/ColumnFamilyHandle.java

@@ -5,6 +5,9 @@
 
 package org.rocksdb;
 
+import java.util.Arrays;
+import java.util.Objects;
+
 /**
  * ColumnFamilyHandle class to hold handles to underlying rocksdb
  * ColumnFamily Pointers.
@@ -21,6 +24,63 @@ public class ColumnFamilyHandle extends RocksObject {
     this.rocksDB_ = rocksDB;
   }
 
+  /**
+   * Gets the name of the Column Family.
+   *
+   * @return The name of the Column Family.
+   */
+  public byte[] getName() {
+    return getName(nativeHandle_);
+  }
+
+  /**
+   * Gets the ID of the Column Family.
+   *
+   * @return the ID of the Column Family.
+   */
+  public int getID() {
+    return getID(nativeHandle_);
+  }
+
+  /**
+   * Gets the up-to-date descriptor of the column family
+   * associated with this handle. Since it fills "*desc" with the up-to-date
+   * information, this call might internally lock and release DB mutex to
+   * access the up-to-date CF options. In addition, all the pointer-typed
+   * options cannot be referenced any longer than the original options exist.
+   *
+   * Note that this function is not supported in RocksDBLite.
+   *
+   * @return the up-to-date descriptor.
+   *
+   * @throws RocksDBException if an error occurs whilst retrieving the
+   *     descriptor.
+   */
+  public ColumnFamilyDescriptor getDescriptor() throws RocksDBException {
+    assert(isOwningHandle());
+    return getDescriptor(nativeHandle_);
+  }
+
+  @Override
+  public boolean equals(final Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    final ColumnFamilyHandle that = (ColumnFamilyHandle) o;
+    return rocksDB_.nativeHandle_ == that.rocksDB_.nativeHandle_ &&
+        getID() == that.getID() &&
+        Arrays.equals(getName(), that.getName());
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(getName(), getID(), rocksDB_.nativeHandle_);
+  }
+
   /**
    * <p>Deletes underlying C++ iterator pointer.</p>
    *
@@ -36,6 +96,9 @@ public class ColumnFamilyHandle extends RocksObject {
     }
   }
 
+  private native byte[] getName(final long handle);
+  private native int getID(final long handle);
+  private native ColumnFamilyDescriptor getDescriptor(final long handle) throws RocksDBException;
   @Override protected final native void disposeInternal(final long handle);
 
   private final RocksDB rocksDB_;

java/src/main/java/org/rocksdb/ColumnFamilyOptions.java

@@ -53,6 +53,18 @@ public class ColumnFamilyOptions extends RocksObject
     this.compressionOptions_ = other.compressionOptions_;
   }
 
+  /**
+   * <p>Constructor to be used by
+   * {@link #getColumnFamilyOptionsFromProps(java.util.Properties)},
+   * {@link ColumnFamilyDescriptor#columnFamilyOptions()}
+   * and also called via JNI.</p>
+   *
+   * @param handle native handle to ColumnFamilyOptions instance.
+   */
+  ColumnFamilyOptions(final long handle) {
+    super(handle);
+  }
+
   /**
    * <p>Method to get a options instance by using pre-configured
    * property values. If one or many values are undefined in
@@ -788,17 +800,6 @@ public class ColumnFamilyOptions extends RocksObject
     return forceConsistencyChecks(nativeHandle_);
   }
 
-  /**
-   * <p>Constructor to be used by
-   * {@link #getColumnFamilyOptionsFromProps(java.util.Properties)}</p>
-   * and also called via JNI.
-   *
-   * @param handle native handle to ColumnFamilyOptions instance.
-   */
-  public ColumnFamilyOptions(final long handle) {
-    super(handle);
-  }
-
   private static native long getColumnFamilyOptionsFromProps(
       String optString);
 

java/src/main/java/org/rocksdb/DBOptionsInterface.java

@@ -269,7 +269,10 @@ public interface DBOptionsInterface<T extends DBOptionsInterface> {
    * Statistics objects should not be shared between DB instances as
    * it does not use any locks to prevent concurrent updates.</p>
    *
+   * @param statistics The statistics to set
+   *
    * @return the instance of the current object.
+   *
    * @see RocksDB#open(org.rocksdb.Options, String)
    */
   T setStatistics(final Statistics statistics);
@@ -277,7 +280,9 @@ public interface DBOptionsInterface<T extends DBOptionsInterface> {
   /**
    * <p>Returns statistics object.</p>
    *
-   * @return the instance of the statistics object or null if there is no statistics object.
+   * @return the instance of the statistics object or null if there is no
+   * statistics object.
+   *
    * @see #setStatistics(Statistics)
    */
   Statistics statistics();

java/src/main/java/org/rocksdb/OptimisticTransactionDB.java

@@ -0,0 +1,175 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import java.util.List;
+
+/**
+ * Database with Transaction support.
+ */
+public class OptimisticTransactionDB extends RocksDB
+    implements TransactionalDB<OptimisticTransactionOptions> {
+
+  /**
+   * Private constructor.
+   *
+   * @param nativeHandle The native handle of the C++ OptimisticTransactionDB
+   *     object
+   */
+  private OptimisticTransactionDB(final long nativeHandle) {
+    super(nativeHandle);
+  }
+
+  /**
+   * Open an OptimisticTransactionDB similar to
+   * {@link RocksDB#open(Options, String)}.
+   *
+   * @param options {@link org.rocksdb.Options} instance.
+   * @param path the path to the rocksdb.
+   *
+   * @return a {@link OptimisticTransactionDB} instance on success, null if the
+   * specified {@link OptimisticTransactionDB} can not be opened.
+   *
+   * @throws RocksDBException if an error occurs whilst opening the database.
+   */
+  public static OptimisticTransactionDB open(final Options options,
+      final String path) throws RocksDBException {
+    final OptimisticTransactionDB otdb = new OptimisticTransactionDB(open(
+        options.nativeHandle_, path));
+
+    // when non-default Options is used, keeping an Options reference
+    // in RocksDB can prevent Java to GC during the life-time of
+    // the currently-created RocksDB.
+    otdb.storeOptionsInstance(options);
+
+    return otdb;
+  }
+
+  /**
+   * Open an OptimisticTransactionDB similar to
+   * {@link RocksDB#open(DBOptions, String, List, List)}.
+   *
+   * @param dbOptions {@link org.rocksdb.DBOptions} instance.
+   * @param path the path to the rocksdb.
+   * @param columnFamilyDescriptors list of column family descriptors
+   * @param columnFamilyHandles will be filled with ColumnFamilyHandle instances
+   *
+   * @return a {@link OptimisticTransactionDB} instance on success, null if the
+   *     specified {@link OptimisticTransactionDB} can not be opened.
+   *
+   * @throws RocksDBException if an error occurs whilst opening the database.
+   */
+  public static OptimisticTransactionDB open(final DBOptions dbOptions,
+      final String path,
+      final List<ColumnFamilyDescriptor> columnFamilyDescriptors,
+      final List<ColumnFamilyHandle> columnFamilyHandles)
+      throws RocksDBException {
+
+    final byte[][] cfNames = new byte[columnFamilyDescriptors.size()][];
+    final long[] cfOptionHandles = new long[columnFamilyDescriptors.size()];
+    for (int i = 0; i < columnFamilyDescriptors.size(); i++) {
+      final ColumnFamilyDescriptor cfDescriptor = columnFamilyDescriptors
+          .get(i);
+      cfNames[i] = cfDescriptor.columnFamilyName();
+      cfOptionHandles[i] = cfDescriptor.columnFamilyOptions().nativeHandle_;
+    }
+
+    final long[] handles = open(dbOptions.nativeHandle_, path, cfNames,
+        cfOptionHandles);
+    final OptimisticTransactionDB otdb =
+        new OptimisticTransactionDB(handles[0]);
+
+    // when non-default Options is used, keeping an Options reference
+    // in RocksDB can prevent Java to GC during the life-time of
+    // the currently-created RocksDB.
+    otdb.storeOptionsInstance(dbOptions);
+
+    for (int i = 1; i < handles.length; i++) {
+      columnFamilyHandles.add(new ColumnFamilyHandle(otdb, handles[i]));
+    }
+
+    return otdb;
+  }
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions) {
+    return new Transaction(this, beginTransaction(nativeHandle_,
+        writeOptions.nativeHandle_));
+  }
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions,
+      final OptimisticTransactionOptions optimisticTransactionOptions) {
+    return new Transaction(this, beginTransaction(nativeHandle_,
+        writeOptions.nativeHandle_,
+        optimisticTransactionOptions.nativeHandle_));
+  }
+
+  // TODO(AR) consider having beingTransaction(... oldTransaction) set a
+  // reference count inside Transaction, so that we can always call
+  // Transaction#close but the object is only disposed when there are as many
+  // closes as beginTransaction. Makes the try-with-resources paradigm easier for
+  // java developers
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions,
+      final Transaction oldTransaction) {
+    final long jtxn_handle = beginTransaction_withOld(nativeHandle_,
+        writeOptions.nativeHandle_, oldTransaction.nativeHandle_);
+
+    // RocksJava relies on the assumption that
+    // we do not allocate a new Transaction object
+    // when providing an old_txn
+    assert(jtxn_handle == oldTransaction.nativeHandle_);
+
+    return oldTransaction;
+  }
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions,
+      final OptimisticTransactionOptions optimisticTransactionOptions,
+      final Transaction oldTransaction) {
+    final long jtxn_handle = beginTransaction_withOld(nativeHandle_,
+        writeOptions.nativeHandle_, optimisticTransactionOptions.nativeHandle_,
+        oldTransaction.nativeHandle_);
+
+    // RocksJava relies on the assumption that
+    // we do not allocate a new Transaction object
+    // when providing an old_txn
+    assert(jtxn_handle == oldTransaction.nativeHandle_);
+
+    return oldTransaction;
+  }
+
+  /**
+   * Get the underlying database that was opened.
+   *
+   * @return The underlying database that was opened.
+   */
+  public RocksDB getBaseDB() {
+    final RocksDB db = new RocksDB(getBaseDB(nativeHandle_));
+    db.disOwnNativeHandle();
+    return db;
+  }
+
+  protected static native long open(final long optionsHandle,
+      final String path) throws RocksDBException;
+  protected static native long[] open(final long handle, final String path,
+      final byte[][] columnFamilyNames, final long[] columnFamilyOptions);
+  private native long beginTransaction(final long handle,
+      final long writeOptionsHandle);
+  private native long beginTransaction(final long handle,
+      final long writeOptionsHandle,
+      final long optimisticTransactionOptionsHandle);
+  private native long beginTransaction_withOld(final long handle,
+      final long writeOptionsHandle, final long oldTransactionHandle);
+  private native long beginTransaction_withOld(final long handle,
+      final long writeOptionsHandle,
+      final long optimisticTransactionOptionsHandle,
+      final long oldTransactionHandle);
+  private native long getBaseDB(final long handle);
+  @Override protected final native void disposeInternal(final long handle);
+}

java/src/main/java/org/rocksdb/OptimisticTransactionOptions.java

@@ -0,0 +1,53 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+public class OptimisticTransactionOptions extends RocksObject
+    implements TransactionalOptions {
+
+  public OptimisticTransactionOptions() {
+    super(newOptimisticTransactionOptions());
+  }
+
+  @Override
+  public boolean isSetSnapshot() {
+    assert(isOwningHandle());
+    return isSetSnapshot(nativeHandle_);
+  }
+
+  @Override
+  public OptimisticTransactionOptions setSetSnapshot(
+      final boolean setSnapshot) {
+    assert(isOwningHandle());
+    setSetSnapshot(nativeHandle_, setSnapshot);
+    return this;
+  }
+
+  /**
+   * Should be set if the DB has a non-default comparator.
+   * See comment in
+   * {@link WriteBatchWithIndex#WriteBatchWithIndex(AbstractComparator, int, boolean)}
+   * constructor.
+   *
+   * @param comparator The comparator to use for the transaction.
+   *
+   * @return this OptimisticTransactionOptions instance
+   */
+  public OptimisticTransactionOptions setComparator(
+      final AbstractComparator<? extends AbstractSlice<?>> comparator) {
+    assert(isOwningHandle());
+    setComparator(nativeHandle_, comparator.nativeHandle_);
+    return this;
+  }
+
+  private native static long newOptimisticTransactionOptions();
+  private native boolean isSetSnapshot(final long handle);
+  private native void setSetSnapshot(final long handle,
+      final boolean setSnapshot);
+  private native void setComparator(final long handle,
+      final long comparatorHandle);
+  @Override protected final native void disposeInternal(final long handle);
+}

java/src/main/java/org/rocksdb/RocksDB.java

@@ -435,7 +435,7 @@ public class RocksDB extends RocksObject {
         path));
   }
 
-  private void storeOptionsInstance(DBOptionsInterface options) {
+  protected void storeOptionsInstance(DBOptionsInterface options) {
     options_ = options;
   }
 
@@ -1683,7 +1683,7 @@ public class RocksDB extends RocksObject {
    * @return The handle of the default column family
    */
   public ColumnFamilyHandle getDefaultColumnFamily() {
-    ColumnFamilyHandle cfHandle = new ColumnFamilyHandle(this,
+    final ColumnFamilyHandle cfHandle = new ColumnFamilyHandle(this,
         getDefaultColumnFamily(nativeHandle_));
     cfHandle.disOwnNativeHandle();
     return cfHandle;
@@ -2359,8 +2359,9 @@ public class RocksDB extends RocksObject {
       final long[] columnFamilyHandles, final long readOptHandle)
       throws RocksDBException;
   protected native long getSnapshot(long nativeHandle);
-  protected native void releaseSnapshot(long nativeHandle, long snapshotHandle);
-  @Override protected final native void disposeInternal(final long handle);
+  protected native void releaseSnapshot(
+      long nativeHandle, long snapshotHandle);
+  @Override protected native void disposeInternal(final long handle);
   private native long getDefaultColumnFamily(long handle);
   private native long createColumnFamily(final long handle,
       final byte[] columnFamilyName, final long columnFamilyOptions)

java/src/main/java/org/rocksdb/Snapshot.java

@@ -11,6 +11,10 @@ package org.rocksdb;
 public class Snapshot extends RocksObject {
   Snapshot(final long nativeHandle) {
     super(nativeHandle);
+
+    // The pointer to the snapshot is always released
+    // by the database instance.
+    disOwnNativeHandle();
   }
 
   /**
@@ -20,17 +24,17 @@ public class Snapshot extends RocksObject {
    *     this snapshot.
    */
   public long getSequenceNumber() {
-    assert(isOwningHandle());
     return getSequenceNumber(nativeHandle_);
   }
 
-  /**
-   * Dont release C++ Snapshot pointer. The pointer
-   * to the snapshot is released by the database
-   * instance.
-   */
   @Override
   protected final void disposeInternal(final long handle) {
+    /**
+     * Nothing to release, we never own the pointer for a
+     * Snapshot. The pointer
+     * to the snapshot is released by the database
+     * instance.
+     */
   }
 
   private native long getSequenceNumber(long handle);

java/src/main/java/org/rocksdb/Statistics.java

@@ -117,6 +117,8 @@ public class Statistics extends RocksObject {
 
   /**
    * Resets all ticker and histogram stats.
+   *
+   * @throws RocksDBException if an error occurs when resetting the statistics.
    */
   public void reset() throws RocksDBException {
     assert(isOwningHandle());
@@ -126,6 +128,7 @@ public class Statistics extends RocksObject {
   /**
    * String representation of the statistic object.
    */
+  @Override
   public String toString() {
     assert(isOwningHandle());
     return toString(nativeHandle_);

java/src/main/java/org/rocksdb/TransactionDB.java

@@ -0,0 +1,354 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Database with Transaction support
+ */
+public class TransactionDB extends RocksDB
+    implements TransactionalDB<TransactionOptions> {
+
+  private TransactionDBOptions transactionDbOptions_;
+
+  /**
+   * Private constructor.
+   *
+   * @param nativeHandle The native handle of the C++ TransactionDB object
+   */
+  private TransactionDB(final long nativeHandle) {
+    super(nativeHandle);
+  }
+
+  /**
+   * Open a TransactionDB, similar to {@link RocksDB#open(Options, String)}.
+   *
+   * @param options {@link org.rocksdb.Options} instance.
+   * @param transactionDbOptions {@link org.rocksdb.TransactionDBOptions}
+   *     instance.
+   * @param path the path to the rocksdb.
+   *
+   * @return a {@link TransactionDB} instance on success, null if the specified
+   *     {@link TransactionDB} can not be opened.
+   *
+   * @throws RocksDBException if an error occurs whilst opening the database.
+   */
+  public static TransactionDB open(final Options options,
+      final TransactionDBOptions transactionDbOptions, final String path)
+      throws RocksDBException {
+    final TransactionDB tdb = new TransactionDB(open(options.nativeHandle_,
+        transactionDbOptions.nativeHandle_, path));
+
+    // when non-default Options is used, keeping an Options reference
+    // in RocksDB can prevent Java to GC during the life-time of
+    // the currently-created RocksDB.
+    tdb.storeOptionsInstance(options);
+    tdb.storeTransactionDbOptions(transactionDbOptions);
+
+    return tdb;
+  }
+
+  /**
+   * Open a TransactionDB, similar to
+   * {@link RocksDB#open(DBOptions, String, List, List)}.
+   *
+   * @param dbOptions {@link org.rocksdb.DBOptions} instance.
+   * @param transactionDbOptions {@link org.rocksdb.TransactionDBOptions}
+   *     instance.
+   * @param path the path to the rocksdb.
+   * @param columnFamilyDescriptors list of column family descriptors
+   * @param columnFamilyHandles will be filled with ColumnFamilyHandle instances
+   *
+   * @return a {@link TransactionDB} instance on success, null if the specified
+   *     {@link TransactionDB} can not be opened.
+   *
+   * @throws RocksDBException if an error occurs whilst opening the database.
+   */
+  public static TransactionDB open(final DBOptions dbOptions,
+      final TransactionDBOptions transactionDbOptions,
+      final String path,
+      final List<ColumnFamilyDescriptor> columnFamilyDescriptors,
+      final List<ColumnFamilyHandle> columnFamilyHandles)
+      throws RocksDBException {
+
+    final byte[][] cfNames = new byte[columnFamilyDescriptors.size()][];
+    final long[] cfOptionHandles = new long[columnFamilyDescriptors.size()];
+    for (int i = 0; i < columnFamilyDescriptors.size(); i++) {
+      final ColumnFamilyDescriptor cfDescriptor = columnFamilyDescriptors
+          .get(i);
+      cfNames[i] = cfDescriptor.columnFamilyName();
+      cfOptionHandles[i] = cfDescriptor.columnFamilyOptions().nativeHandle_;
+    }
+
+    final long[] handles = open(dbOptions.nativeHandle_,
+        transactionDbOptions.nativeHandle_, path, cfNames, cfOptionHandles);
+    final TransactionDB tdb = new TransactionDB(handles[0]);
+
+    // when non-default Options is used, keeping an Options reference
+    // in RocksDB can prevent Java to GC during the life-time of
+    // the currently-created RocksDB.
+    tdb.storeOptionsInstance(dbOptions);
+    tdb.storeTransactionDbOptions(transactionDbOptions);
+
+    for (int i = 1; i < handles.length; i++) {
+      columnFamilyHandles.add(new ColumnFamilyHandle(tdb, handles[i]));
+    }
+
+    return tdb;
+  }
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions) {
+    return new Transaction(this, beginTransaction(nativeHandle_,
+        writeOptions.nativeHandle_));
+  }
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions,
+      final TransactionOptions transactionOptions) {
+    return new Transaction(this, beginTransaction(nativeHandle_,
+        writeOptions.nativeHandle_, transactionOptions.nativeHandle_));
+  }
+
+  // TODO(AR) consider having beingTransaction(... oldTransaction) set a
+  // reference count inside Transaction, so that we can always call
+  // Transaction#close but the object is only disposed when there are as many
+  // closes as beginTransaction. Makes the try-with-resources paradigm easier for
+  // java developers
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions,
+      final Transaction oldTransaction) {
+    final long jtxnHandle = beginTransaction_withOld(nativeHandle_,
+        writeOptions.nativeHandle_, oldTransaction.nativeHandle_);
+
+    // RocksJava relies on the assumption that
+    // we do not allocate a new Transaction object
+    // when providing an old_txn
+    assert(jtxnHandle == oldTransaction.nativeHandle_);
+
+    return oldTransaction;
+  }
+
+  @Override
+  public Transaction beginTransaction(final WriteOptions writeOptions,
+      final TransactionOptions transactionOptions,
+      final Transaction oldTransaction) {
+    final long jtxn_handle = beginTransaction_withOld(nativeHandle_,
+        writeOptions.nativeHandle_, transactionOptions.nativeHandle_,
+        oldTransaction.nativeHandle_);
+
+    // RocksJava relies on the assumption that
+    // we do not allocate a new Transaction object
+    // when providing an old_txn
+    assert(jtxn_handle == oldTransaction.nativeHandle_);
+
+    return oldTransaction;
+  }
+
+  public Transaction getTransactionByName(final String transactionName) {
+    final long jtxnHandle = getTransactionByName(nativeHandle_, transactionName);
+    if(jtxnHandle == 0) {
+      return null;
+    }
+
+    final Transaction txn = new Transaction(this, jtxnHandle);
+
+    // this instance doesn't own the underlying C++ object
+    txn.disOwnNativeHandle();
+
+    return txn;
+  }
+
+  public List<Transaction> getAllPreparedTransactions() {
+    final long[] jtxnHandles = getAllPreparedTransactions(nativeHandle_);
+
+    final List<Transaction> txns = new ArrayList<>();
+    for(final long jtxnHandle : jtxnHandles) {
+      final Transaction txn = new Transaction(this, jtxnHandle);
+
+      // this instance doesn't own the underlying C++ object
+      txn.disOwnNativeHandle();
+
+      txns.add(txn);
+    }
+    return txns;
+  }
+
+  public static class KeyLockInfo {
+    private final String key;
+    private final long[] transactionIDs;
+    private final boolean exclusive;
+
+    public KeyLockInfo(final String key, final long transactionIDs[],
+        final boolean exclusive) {
+      this.key = key;
+      this.transactionIDs = transactionIDs;
+      this.exclusive = exclusive;
+    }
+
+    /**
+     * Get the key.
+     *
+     * @return the key
+     */
+    public String getKey() {
+      return key;
+    }
+
+    /**
+     * Get the Transaction IDs.
+     *
+     * @return the Transaction IDs.
+     */
+    public long[] getTransactionIDs() {
+      return transactionIDs;
+    }
+
+    /**
+     * Get the Lock status.
+     *
+     * @return true if the lock is exclusive, false if the lock is shared.
+     */
+    public boolean isExclusive() {
+      return exclusive;
+    }
+  }
+
+  /**
+   * Returns map of all locks held.
+   *
+   * @return a map of all the locks held.
+   */
+  public Map<Long, KeyLockInfo> getLockStatusData() {
+    return getLockStatusData(nativeHandle_);
+  }
+
+  /**
+   * Called from C++ native method {@link #getDeadlockInfoBuffer(long)}
+   * to construct a DeadlockInfo object.
+   *
+   * @param transactionID The transaction id
+   * @param columnFamilyId The id of the {@link ColumnFamilyHandle}
+   * @param waitingKey the key that we are waiting on
+   * @param exclusive true if the lock is exclusive, false if the lock is shared
+   *
+   * @return The waiting transactions
+   */
+  private DeadlockInfo newDeadlockInfo(
+      final long transactionID, final long columnFamilyId,
+      final String waitingKey, final boolean exclusive) {
+    return new DeadlockInfo(transactionID, columnFamilyId,
+        waitingKey, exclusive);
+  }
+
+  public static class DeadlockInfo {
+    private final long transactionID;
+    private final long columnFamilyId;
+    private final String waitingKey;
+    private final boolean exclusive;
+
+    private DeadlockInfo(final long transactionID, final long columnFamilyId,
+      final String waitingKey, final boolean exclusive) {
+      this.transactionID = transactionID;
+      this.columnFamilyId = columnFamilyId;
+      this.waitingKey = waitingKey;
+      this.exclusive = exclusive;
+    }
+
+    /**
+     * Get the Transaction ID.
+     *
+     * @return the transaction ID
+     */
+    public long getTransactionID() {
+      return transactionID;
+    }
+
+    /**
+     * Get the Column Family ID.
+     *
+     * @return The column family ID
+     */
+    public long getColumnFamilyId() {
+      return columnFamilyId;
+    }
+
+    /**
+     * Get the key that we are waiting on.
+     *
+     * @return the key that we are waiting on
+     */
+    public String getWaitingKey() {
+      return waitingKey;
+    }
+
+    /**
+     * Get the Lock status.
+     *
+     * @return true if the lock is exclusive, false if the lock is shared.
+     */
+    public boolean isExclusive() {
+      return exclusive;
+    }
+  }
+
+  public static class DeadlockPath {
+    final DeadlockInfo[] path;
+    final boolean limitExceeded;
+
+    public DeadlockPath(final DeadlockInfo[] path, final boolean limitExceeded) {
+      this.path = path;
+      this.limitExceeded = limitExceeded;
+    }
+
+    public boolean isEmpty() {
+      return path.length == 0 && !limitExceeded;
+    }
+  }
+
+  public DeadlockPath[] getDeadlockInfoBuffer() {
+    return getDeadlockInfoBuffer(nativeHandle_);
+  }
+
+  public void setDeadlockInfoBufferSize(final int targetSize) {
+    setDeadlockInfoBufferSize(nativeHandle_, targetSize);
+  }
+
+  private void storeTransactionDbOptions(
+      final TransactionDBOptions transactionDbOptions) {
+    this.transactionDbOptions_ = transactionDbOptions;
+  }
+
+  private static native long open(final long optionsHandle,
+      final long transactionDbOptionsHandle, final String path)
+      throws RocksDBException;
+  private static native long[] open(final long dbOptionsHandle,
+      final long transactionDbOptionsHandle, final String path,
+      final byte[][] columnFamilyNames, final long[] columnFamilyOptions);
+  private native long beginTransaction(final long handle,
+      final long writeOptionsHandle);
+  private native long beginTransaction(final long handle,
+      final long writeOptionsHandle, final long transactionOptionsHandle);
+  private native long beginTransaction_withOld(final long handle,
+      final long writeOptionsHandle, final long oldTransactionHandle);
+  private native long beginTransaction_withOld(final long handle,
+      final long writeOptionsHandle, final long transactionOptionsHandle,
+      final long oldTransactionHandle);
+  private native long getTransactionByName(final long handle,
+      final String name);
+  private native long[] getAllPreparedTransactions(final long handle);
+  private native Map<Long, KeyLockInfo> getLockStatusData(
+      final long handle);
+  private native DeadlockPath[] getDeadlockInfoBuffer(final long handle);
+  private native void setDeadlockInfoBufferSize(final long handle,
+      final int targetSize);
+  @Override protected final native void disposeInternal(final long handle);
+}

java/src/main/java/org/rocksdb/TransactionDBOptions.java

@@ -0,0 +1,217 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+public class TransactionDBOptions extends RocksObject {
+
+  public TransactionDBOptions() {
+    super(newTransactionDBOptions());
+  }
+
+  /**
+   * Specifies the maximum number of keys that can be locked at the same time
+   * per column family.
+   *
+   * If the number of locked keys is greater than {@link #getMaxNumLocks()},
+   * transaction writes (or GetForUpdate) will return an error.
+   *
+   * @return The maximum number of keys that can be locked
+   */
+  public long getMaxNumLocks() {
+    assert(isOwningHandle());
+    return getMaxNumLocks(nativeHandle_);
+  }
+
+  /**
+   * Specifies the maximum number of keys that can be locked at the same time
+   * per column family.
+   *
+   * If the number of locked keys is greater than {@link #getMaxNumLocks()},
+   * transaction writes (or GetForUpdate) will return an error.
+   *
+   * @param maxNumLocks The maximum number of keys that can be locked;
+   *     If this value is not positive, no limit will be enforced.
+   *
+   * @return this TransactionDBOptions instance
+   */
+  public TransactionDBOptions setMaxNumLocks(final long maxNumLocks) {
+    assert(isOwningHandle());
+    setMaxNumLocks(nativeHandle_, maxNumLocks);
+    return this;
+  }
+
+  /**
+   * The number of sub-tables per lock table (per column family)
+   *
+   * @return The number of sub-tables
+   */
+  public long getNumStripes() {
+    assert(isOwningHandle());
+    return getNumStripes(nativeHandle_);
+  }
+
+  /**
+   * Increasing this value will increase the concurrency by dividing the lock
+   * table (per column family) into more sub-tables, each with their own
+   * separate mutex.
+   *
+   * Default: 16
+   *
+   * @param numStripes The number of sub-tables
+   *
+   * @return this TransactionDBOptions instance
+   */
+  public TransactionDBOptions setNumStripes(final long numStripes) {
+    assert(isOwningHandle());
+    setNumStripes(nativeHandle_, numStripes);
+    return this;
+  }
+
+  /**
+   * The default wait timeout in milliseconds when
+   * a transaction attempts to lock a key if not specified by
+   * {@link TransactionOptions#setLockTimeout(long)}
+   *
+   * If 0, no waiting is done if a lock cannot instantly be acquired.
+   * If negative, there is no timeout.
+   *
+   * @return the default wait timeout in milliseconds
+   */
+  public long getTransactionLockTimeout() {
+    assert(isOwningHandle());
+    return getTransactionLockTimeout(nativeHandle_);
+  }
+
+  /**
+   * If positive, specifies the default wait timeout in milliseconds when
+   * a transaction attempts to lock a key if not specified by
+   * {@link TransactionOptions#setLockTimeout(long)}
+   *
+   * If 0, no waiting is done if a lock cannot instantly be acquired.
+   * If negative, there is no timeout. Not using a timeout is not recommended
+   * as it can lead to deadlocks.  Currently, there is no deadlock-detection to
+   * recover from a deadlock.
+   *
+   * Default: 1000
+   *
+   * @param transactionLockTimeout the default wait timeout in milliseconds
+   *
+   * @return this TransactionDBOptions instance
+   */
+  public TransactionDBOptions setTransactionLockTimeout(
+      final long transactionLockTimeout) {
+    assert(isOwningHandle());
+    setTransactionLockTimeout(nativeHandle_, transactionLockTimeout);
+    return this;
+  }
+
+  /**
+   * The wait timeout in milliseconds when writing a key
+   * OUTSIDE of a transaction (ie by calling {@link RocksDB#put},
+   * {@link RocksDB#merge}, {@link RocksDB#remove} or {@link RocksDB#write}
+   * directly).
+   *
+   * If 0, no waiting is done if a lock cannot instantly be acquired.
+   * If negative, there is no timeout and will block indefinitely when acquiring
+   * a lock.
+   *
+   * @return the timeout in milliseconds when writing a key OUTSIDE of a
+   *     transaction
+   */
+  public long getDefaultLockTimeout() {
+    assert(isOwningHandle());
+    return getDefaultLockTimeout(nativeHandle_);
+  }
+
+  /**
+   * If positive, specifies the wait timeout in milliseconds when writing a key
+   * OUTSIDE of a transaction (ie by calling {@link RocksDB#put},
+   * {@link RocksDB#merge}, {@link RocksDB#remove} or {@link RocksDB#write}
+   * directly).
+   *
+   * If 0, no waiting is done if a lock cannot instantly be acquired.
+   * If negative, there is no timeout and will block indefinitely when acquiring
+   * a lock.
+   *
+   * Not using a timeout can lead to deadlocks. Currently, there
+   * is no deadlock-detection to recover from a deadlock.  While DB writes
+   * cannot deadlock with other DB writes, they can deadlock with a transaction.
+   * A negative timeout should only be used if all transactions have a small
+   * expiration set.
+   *
+   * Default: 1000
+   *
+   * @param defaultLockTimeout the timeout in milliseconds when writing a key
+   *     OUTSIDE of a transaction
+   * @return this TransactionDBOptions instance
+   */
+   public TransactionDBOptions setDefaultLockTimeout(
+       final long defaultLockTimeout) {
+     assert(isOwningHandle());
+     setDefaultLockTimeout(nativeHandle_, defaultLockTimeout);
+     return this;
+   }
+
+//  /**
+//   * If set, the {@link TransactionDB} will use this implementation of a mutex
+//   * and condition variable for all transaction locking instead of the default
+//   * mutex/condvar implementation.
+//   *
+//   * @param transactionDbMutexFactory the mutex factory for the transactions
+//   *
+//   * @return this TransactionDBOptions instance
+//   */
+//  public TransactionDBOptions setCustomMutexFactory(
+//      final TransactionDBMutexFactory transactionDbMutexFactory) {
+//
+//  }
+
+  /**
+   * The policy for when to write the data into the DB. The default policy is to
+   * write only the committed data {@link TxnDBWritePolicy#WRITE_COMMITTED}.
+   * The data could be written before the commit phase. The DB then needs to
+   * provide the mechanisms to tell apart committed from uncommitted data.
+   *
+   * @return The write policy.
+   */
+  public TxnDBWritePolicy getWritePolicy() {
+    assert(isOwningHandle());
+    return TxnDBWritePolicy.getTxnDBWritePolicy(getWritePolicy(nativeHandle_));
+  }
+
+  /**
+   * The policy for when to write the data into the DB. The default policy is to
+   * write only the committed data {@link TxnDBWritePolicy#WRITE_COMMITTED}.
+   * The data could be written before the commit phase. The DB then needs to
+   * provide the mechanisms to tell apart committed from uncommitted data.
+   *
+   * @param writePolicy The write policy.
+   *
+   * @return this TransactionDBOptions instance
+   */
+  public TransactionDBOptions setWritePolicy(
+      final TxnDBWritePolicy writePolicy) {
+    assert(isOwningHandle());
+    setWritePolicy(nativeHandle_, writePolicy.getValue());
+    return this;
+  }
+
+  private native static long newTransactionDBOptions();
+  private native long getMaxNumLocks(final long handle);
+  private native void setMaxNumLocks(final long handle,
+      final long maxNumLocks);
+  private native long getNumStripes(final long handle);
+  private native void setNumStripes(final long handle, final long numStripes);
+  private native long getTransactionLockTimeout(final long handle);
+  private native void setTransactionLockTimeout(final long handle,
+      final long transactionLockTimeout);
+  private native long getDefaultLockTimeout(final long handle);
+  private native void setDefaultLockTimeout(final long handle,
+      final long transactionLockTimeout);
+  private native byte getWritePolicy(final long handle);
+  private native void setWritePolicy(final long handle, final byte writePolicy);
+  @Override protected final native void disposeInternal(final long handle);
+}

java/src/main/java/org/rocksdb/TransactionOptions.java

@@ -0,0 +1,189 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+public class TransactionOptions extends RocksObject
+    implements TransactionalOptions {
+
+  public TransactionOptions() {
+    super(newTransactionOptions());
+  }
+
+  @Override
+  public boolean isSetSnapshot() {
+    assert(isOwningHandle());
+    return isSetSnapshot(nativeHandle_);
+  }
+
+  @Override
+  public TransactionOptions setSetSnapshot(final boolean setSnapshot) {
+    assert(isOwningHandle());
+    setSetSnapshot(nativeHandle_, setSnapshot);
+    return this;
+  }
+
+  /**
+   * True means that before acquiring locks, this transaction will
+   * check if doing so will cause a deadlock. If so, it will return with
+   * {@link Status.Code#Busy}. The user should retry their transaction.
+   *
+   * @return true if a deadlock is detected.
+   */
+  public boolean isDeadlockDetect() {
+    assert(isOwningHandle());
+    return isDeadlockDetect(nativeHandle_);
+  }
+
+  /**
+   * Setting to true means that before acquiring locks, this transaction will
+   * check if doing so will cause a deadlock. If so, it will return with
+   * {@link Status.Code#Busy}. The user should retry their transaction.
+   *
+   * @param deadlockDetect true if we should detect deadlocks.
+   *
+   * @return this TransactionOptions instance
+   */
+  public TransactionOptions setDeadlockDetect(final boolean deadlockDetect) {
+    assert(isOwningHandle());
+    setDeadlockDetect(nativeHandle_, deadlockDetect);
+    return this;
+  }
+
+  /**
+   * The wait timeout in milliseconds when a transaction attempts to lock a key.
+   *
+   * If 0, no waiting is done if a lock cannot instantly be acquired.
+   * If negative, {@link TransactionDBOptions#getTransactionLockTimeout(long)}
+   * will be used
+   *
+   * @return the lock tiemout in milliseconds
+   */
+  public long getLockTimeout() {
+    assert(isOwningHandle());
+    return getLockTimeout(nativeHandle_);
+  }
+
+  /**
+   * If positive, specifies the wait timeout in milliseconds when
+   * a transaction attempts to lock a key.
+   *
+   * If 0, no waiting is done if a lock cannot instantly be acquired.
+   * If negative, {@link TransactionDBOptions#getTransactionLockTimeout(long)}
+   * will be used
+   *
+   * Default: -1
+   *
+   * @param lockTimeout the lock tiemout in milliseconds
+   *
+   * @return this TransactionOptions instance
+   */
+  public TransactionOptions setLockTimeout(final long lockTimeout) {
+    assert(isOwningHandle());
+    setLockTimeout(nativeHandle_, lockTimeout);
+    return this;
+  }
+
+  /**
+   * Expiration duration in milliseconds.
+   *
+   * If non-negative, transactions that last longer than this many milliseconds
+   * will fail to commit. If not set, a forgotten transaction that is never
+   * committed, rolled back, or deleted will never relinquish any locks it
+   * holds. This could prevent keys from being written by other writers.
+   *
+   * @return expiration the expiration duration in milliseconds
+   */
+  public long getExpiration() {
+    assert(isOwningHandle());
+    return getExpiration(nativeHandle_);
+  }
+
+  /**
+   * Expiration duration in milliseconds.
+   *
+   * If non-negative, transactions that last longer than this many milliseconds
+   * will fail to commit. If not set, a forgotten transaction that is never
+   * committed, rolled back, or deleted will never relinquish any locks it
+   * holds. This could prevent keys from being written by other writers.
+   *
+   * Default: -1
+   *
+   * @param expiration the expiration duration in milliseconds
+   *
+   * @return this TransactionOptions instance
+   */
+  public TransactionOptions setExpiration(final long expiration) {
+    assert(isOwningHandle());
+    setExpiration(nativeHandle_, expiration);
+    return this;
+  }
+
+  /**
+   * Gets the number of traversals to make during deadlock detection.
+   *
+   * @return the number of traversals to make during
+   *     deadlock detection
+   */
+  public long getDeadlockDetectDepth() {
+    return getDeadlockDetectDepth(nativeHandle_);
+  }
+
+  /**
+   * Sets the number of traversals to make during deadlock detection.
+   *
+   * Default: 50
+   *
+   * @param deadlockDetectDepth the the number of traversals to make during
+   *     deadlock detection
+   *
+   * @return this TransactionOptions instance
+   */
+  public TransactionOptions setDeadlockDetectDepth(
+      final long deadlockDetectDepth) {
+    setDeadlockDetectDepth(nativeHandle_, deadlockDetectDepth);
+    return this;
+  }
+
+  /**
+   * Get the maximum number of bytes that may be used for the write batch.
+   *
+   * @return the maximum number of bytes, 0 means no limit.
+   */
+  public long getMaxWriteBatchSize() {
+    return getMaxWriteBatchSize(nativeHandle_);
+  }
+
+  /**
+   * Set the maximum number of bytes that may be used for the write batch.
+   *
+   * @param maxWriteBatchSize the maximum number of bytes, 0 means no limit.
+   *
+   * @return this TransactionOptions instance
+   */
+  public TransactionOptions setMaxWriteBatchSize(final long maxWriteBatchSize) {
+    setMaxWriteBatchSize(nativeHandle_, maxWriteBatchSize);
+    return this;
+  }
+
+  private native static long newTransactionOptions();
+  private native boolean isSetSnapshot(final long handle);
+  private native void setSetSnapshot(final long handle,
+      final boolean setSnapshot);
+  private native boolean isDeadlockDetect(final long handle);
+  private native void setDeadlockDetect(final long handle,
+      final boolean deadlockDetect);
+  private native long getLockTimeout(final long handle);
+  private native void setLockTimeout(final long handle, final long lockTimeout);
+  private native long getExpiration(final long handle);
+  private native void setExpiration(final long handle, final long expiration);
+  private native long getDeadlockDetectDepth(final long handle);
+  private native void setDeadlockDetectDepth(final long handle,
+      final long deadlockDetectDepth);
+  private native long getMaxWriteBatchSize(final long handle);
+  private native void setMaxWriteBatchSize(final long handle,
+      final long maxWriteBatchSize);
+  @Override protected final native void disposeInternal(final long handle);
+}

java/src/main/java/org/rocksdb/TransactionalDB.java

@@ -0,0 +1,68 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+
+interface TransactionalDB<T extends TransactionalOptions>
+    extends AutoCloseable {
+
+  /**
+   * Starts a new Transaction.
+   *
+   * Caller is responsible for calling {@link #close()} on the returned
+   * transaction when it is no longer needed.
+   *
+   * @param writeOptions Any write options for the transaction
+   * @return a new transaction
+   */
+  Transaction beginTransaction(final WriteOptions writeOptions);
+
+  /**
+   * Starts a new Transaction.
+   *
+   * Caller is responsible for calling {@link #close()} on the returned
+   * transaction when it is no longer needed.
+   *
+   * @param writeOptions Any write options for the transaction
+   * @param transactionOptions Any options for the transaction
+   * @return a new transaction
+   */
+  Transaction beginTransaction(final WriteOptions writeOptions,
+      final T transactionOptions);
+
+  /**
+   * Starts a new Transaction.
+   *
+   * Caller is responsible for calling {@link #close()} on the returned
+   * transaction when it is no longer needed.
+   *
+   * @param writeOptions Any write options for the transaction
+   * @param oldTransaction this Transaction will be reused instead of allocating
+   *     a new one. This is an optimization to avoid extra allocations
+   *     when repeatedly creating transactions.
+   * @return The oldTransaction which has been reinitialized as a new
+   *     transaction
+   */
+  Transaction beginTransaction(final WriteOptions writeOptions,
+      final Transaction oldTransaction);
+
+  /**
+   * Starts a new Transaction.
+   *
+   * Caller is responsible for calling {@link #close()} on the returned
+   * transaction when it is no longer needed.
+   *
+   * @param writeOptions Any write options for the transaction
+   * @param transactionOptions Any options for the transaction
+   * @param oldTransaction this Transaction will be reused instead of allocating
+   *     a new one. This is an optimization to avoid extra allocations
+   *     when repeatedly creating transactions.
+   * @return The oldTransaction which has been reinitialized as a new
+   *     transaction
+   */
+  Transaction beginTransaction(final WriteOptions writeOptions,
+      final T transactionOptions, final Transaction oldTransaction);
+}

java/src/main/java/org/rocksdb/TransactionalOptions.java

@@ -0,0 +1,31 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+
+interface TransactionalOptions extends AutoCloseable {
+
+  /**
+   * True indicates snapshots will be set, just like if
+   * {@link Transaction#setSnapshot()} had been called
+   *
+   * @return whether a snapshot will be set
+   */
+  boolean isSetSnapshot();
+
+  /**
+   * Setting the setSnapshot to true is the same as calling
+   * {@link Transaction#setSnapshot()}.
+   *
+   * Default: false
+   *
+   * @param <T> The type of transactional options.
+   * @param setSnapshot Whether to set a snapshot
+   *
+   * @return this TransactionalOptions instance
+   */
+  <T extends TransactionalOptions> T setSetSnapshot(final boolean setSnapshot);
+}

java/src/main/java/org/rocksdb/TxnDBWritePolicy.java

@@ -0,0 +1,62 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+package org.rocksdb;
+
+/**
+ * The transaction db write policy.
+ */
+public enum TxnDBWritePolicy {
+  /**
+   * Write only the committed data.
+   */
+  WRITE_COMMITTED((byte)0x00),
+
+  /**
+   * Write data after the prepare phase of 2pc.
+   */
+  WRITE_PREPARED((byte)0x1),
+
+  /**
+   * Write data before the prepare phase of 2pc.
+   */
+  WRITE_UNPREPARED((byte)0x2);
+
+  private byte value;
+
+  TxnDBWritePolicy(final byte value) {
+    this.value = value;
+  }
+
+  /**
+   * <p>Returns the byte value of the enumerations value.</p>
+   *
+   * @return byte representation
+   */
+  public byte getValue() {
+    return value;
+  }
+
+  /**
+   * <p>Get the TxnDBWritePolicy enumeration value by
+   * passing the byte identifier to this method.</p>
+   *
+   * @param byteIdentifier of TxnDBWritePolicy.
+   *
+   * @return TxnDBWritePolicy instance.
+   *
+   * @throws IllegalArgumentException If TxnDBWritePolicy cannot be found for
+   *     the provided byteIdentifier
+   */
+  public static TxnDBWritePolicy getTxnDBWritePolicy(final byte byteIdentifier) {
+    for (final TxnDBWritePolicy txnDBWritePolicy : TxnDBWritePolicy.values()) {
+      if (txnDBWritePolicy.getValue() == byteIdentifier) {
+        return txnDBWritePolicy;
+      }
+    }
+
+    throw new IllegalArgumentException(
+        "Illegal value provided for TxnDBWritePolicy.");
+  }
+}

java/src/main/java/org/rocksdb/WALRecoveryMode.java

@@ -65,7 +65,7 @@ public enum WALRecoveryMode {
    *
    * @param byteIdentifier of WALRecoveryMode.
    *
-   * @return CompressionType instance.
+   * @return WALRecoveryMode instance.
    *
    * @throws IllegalArgumentException If WALRecoveryMode cannot be found for the
    *   provided byteIdentifier

java/src/main/java/org/rocksdb/WriteBatchWithIndex.java

@@ -64,6 +64,18 @@ public class WriteBatchWithIndex extends AbstractWriteBatch {
         fallbackIndexComparator instanceof DirectComparator, reservedBytes, overwriteKey));
   }
 
+  /**
+   * <p>Private WriteBatchWithIndex constructor which is used to construct
+   * WriteBatchWithIndex instances from C++ side. As the reference to this
+   * object is also managed from C++ side the handle will be disowned.</p>
+   *
+   * @param nativeHandle address of native instance.
+   */
+  WriteBatchWithIndex(final long nativeHandle) {
+    super(nativeHandle);
+    disOwnNativeHandle();
+  }
+
   /**
    * Create an iterator of a column family. User can call
    * {@link org.rocksdb.RocksIteratorInterface#seek(byte[])} to

java/src/main/java/org/rocksdb/WriteOptions.java

@@ -20,6 +20,12 @@ public class WriteOptions extends RocksObject {
 
   }
 
+  // TODO(AR) consider ownership
+  WriteOptions(final long nativeHandle) {
+    super(nativeHandle);
+    disOwnNativeHandle();
+  }
+
   /**
    * Copy constructor for WriteOptions.
    *

java/src/test/java/org/rocksdb/AbstractTransactionTest.java

@@ -0,0 +1,903 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.fail;
+
+/**
+ * Base class of {@link TransactionTest} and {@link OptimisticTransactionTest}
+ */
+public abstract class AbstractTransactionTest {
+
+  protected final static byte[] TXN_TEST_COLUMN_FAMILY = "txn_test_cf"
+      .getBytes();
+
+  protected static final Random rand = PlatformRandomHelper.
+      getPlatformSpecificRandomFactory();
+
+  @Rule
+  public TemporaryFolder dbFolder = new TemporaryFolder();
+
+  public abstract DBContainer startDb()
+      throws RocksDBException;
+
+  @Test
+  public void setSnapshot() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.setSnapshot();
+    }
+  }
+
+  @Test
+  public void setSnapshotOnNextOperation() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.setSnapshotOnNextOperation();
+      txn.put("key1".getBytes(), "value1".getBytes());
+    }
+  }
+
+  @Test
+  public void setSnapshotOnNextOperation_transactionNotifier() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      try(final TestTransactionNotifier notifier = new TestTransactionNotifier()) {
+        txn.setSnapshotOnNextOperation(notifier);
+        txn.put("key1".getBytes(), "value1".getBytes());
+
+        txn.setSnapshotOnNextOperation(notifier);
+        txn.put("key2".getBytes(), "value2".getBytes());
+
+        assertThat(notifier.getCreatedSnapshots().size()).isEqualTo(2);
+      }
+    }
+  }
+
+  @Test
+  public void getSnapshot() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.setSnapshot();
+      final Snapshot snapshot = txn.getSnapshot();
+      assertThat(snapshot.isOwningHandle()).isFalse();
+    }
+  }
+
+  @Test
+  public void getSnapshot_null() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final Snapshot snapshot = txn.getSnapshot();
+      assertThat(snapshot).isNull();
+    }
+  }
+
+  @Test
+  public void clearSnapshot() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.setSnapshot();
+      txn.clearSnapshot();
+    }
+  }
+
+  @Test
+  public void clearSnapshot_none() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.clearSnapshot();
+    }
+  }
+
+  @Test
+  public void commit() throws RocksDBException {
+    final byte k1[] = "rollback-key1".getBytes(UTF_8);
+    final byte v1[] = "rollback-value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb()) {
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(k1, v1);
+        txn.commit();
+      }
+
+      try(final ReadOptions readOptions = new ReadOptions();
+          final Transaction txn2 = dbContainer.beginTransaction()) {
+        assertThat(txn2.get(readOptions, k1)).isEqualTo(v1);
+      }
+    }
+  }
+
+  @Test
+  public void rollback() throws RocksDBException {
+    final byte k1[] = "rollback-key1".getBytes(UTF_8);
+    final byte v1[] = "rollback-value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb()) {
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(k1, v1);
+        txn.rollback();
+      }
+
+      try(final ReadOptions readOptions = new ReadOptions();
+          final Transaction txn2 = dbContainer.beginTransaction()) {
+        assertThat(txn2.get(readOptions, k1)).isNull();
+      }
+    }
+  }
+
+  @Test
+  public void savePoint() throws RocksDBException {
+    final byte k1[] = "savePoint-key1".getBytes(UTF_8);
+    final byte v1[] = "savePoint-value1".getBytes(UTF_8);
+    final byte k2[] = "savePoint-key2".getBytes(UTF_8);
+    final byte v2[] = "savePoint-value2".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(k1, v1);
+
+        assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+
+        txn.setSavePoint();
+
+        txn.put(k2, v2);
+
+        assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+        assertThat(txn.get(readOptions, k2)).isEqualTo(v2);
+
+        txn.rollbackToSavePoint();
+
+        assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+        assertThat(txn.get(readOptions, k2)).isNull();
+
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        assertThat(txn2.get(readOptions, k1)).isEqualTo(v1);
+        assertThat(txn2.get(readOptions, k2)).isNull();
+      }
+    }
+  }
+
+  @Test
+  public void getPut_cf() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      assertThat(txn.get(testCf, readOptions, k1)).isNull();
+      txn.put(testCf, k1, v1);
+      assertThat(txn.get(testCf, readOptions, k1)).isEqualTo(v1);
+    }
+  }
+
+  @Test
+  public void getPut() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.get(readOptions, k1)).isNull();
+      txn.put(k1, v1);
+      assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+    }
+  }
+
+  @Test
+  public void multiGetPut_cf() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      final List<ColumnFamilyHandle> cfList = Arrays.asList(testCf, testCf);
+
+      assertThat(txn.multiGet(readOptions, cfList, keys)).isEqualTo(new byte[][] { null, null });
+
+      txn.put(testCf, keys[0], values[0]);
+      txn.put(testCf, keys[1], values[1]);
+      assertThat(txn.multiGet(readOptions, cfList, keys)).isEqualTo(values);
+    }
+  }
+
+  @Test
+  public void multiGetPut() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      assertThat(txn.multiGet(readOptions, keys)).isEqualTo(new byte[][] { null, null });
+
+      txn.put(keys[0], values[0]);
+      txn.put(keys[1], values[1]);
+      assertThat(txn.multiGet(readOptions, keys)).isEqualTo(values);
+    }
+  }
+
+  @Test
+  public void getForUpdate_cf() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      assertThat(txn.getForUpdate(readOptions, testCf, k1, true)).isNull();
+      txn.put(testCf, k1, v1);
+      assertThat(txn.getForUpdate(readOptions, testCf, k1, true)).isEqualTo(v1);
+    }
+  }
+
+  @Test
+  public void getForUpdate() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getForUpdate(readOptions, k1, true)).isNull();
+      txn.put(k1, v1);
+      assertThat(txn.getForUpdate(readOptions, k1, true)).isEqualTo(v1);
+    }
+  }
+
+  @Test
+  public void multiGetForUpdate_cf() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      final List<ColumnFamilyHandle> cfList = Arrays.asList(testCf, testCf);
+
+      assertThat(txn.multiGetForUpdate(readOptions, cfList, keys))
+          .isEqualTo(new byte[][] { null, null });
+
+      txn.put(testCf, keys[0], values[0]);
+      txn.put(testCf, keys[1], values[1]);
+      assertThat(txn.multiGetForUpdate(readOptions, cfList, keys))
+          .isEqualTo(values);
+    }
+  }
+
+  @Test
+  public void multiGetForUpdate() throws RocksDBException {
+    final byte keys[][] = new byte[][]{
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][]{
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+
+    try (final DBContainer dbContainer = startDb();
+         final ReadOptions readOptions = new ReadOptions();
+         final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.multiGetForUpdate(readOptions, keys)).isEqualTo(new byte[][]{null, null});
+
+      txn.put(keys[0], values[0]);
+      txn.put(keys[1], values[1]);
+      assertThat(txn.multiGetForUpdate(readOptions, keys)).isEqualTo(values);
+    }
+  }
+
+  @Test
+  public void getIterator() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      final byte[] k1 = "key1".getBytes(UTF_8);
+      final byte[] v1 = "value1".getBytes(UTF_8);
+
+      txn.put(k1, v1);
+
+      try(final RocksIterator iterator = txn.getIterator(readOptions)) {
+        iterator.seek(k1);
+        assertThat(iterator.isValid()).isTrue();
+        assertThat(iterator.key()).isEqualTo(k1);
+        assertThat(iterator.value()).isEqualTo(v1);
+      }
+    }
+  }
+
+  @Test
+  public void getIterator_cf() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+
+      final byte[] k1 = "key1".getBytes(UTF_8);
+      final byte[] v1 = "value1".getBytes(UTF_8);
+
+      txn.put(testCf, k1, v1);
+
+      try(final RocksIterator iterator = txn.getIterator(readOptions, testCf)) {
+        iterator.seek(k1);
+        assertThat(iterator.isValid()).isTrue();
+        assertThat(iterator.key()).isEqualTo(k1);
+        assertThat(iterator.value()).isEqualTo(v1);
+      }
+    }
+  }
+
+  @Test
+  public void merge_cf() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      txn.merge(testCf, k1, v1);
+    }
+  }
+
+  @Test
+  public void merge() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.merge(k1, v1);
+    }
+  }
+
+
+  @Test
+  public void delete_cf() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      txn.put(testCf, k1, v1);
+      assertThat(txn.get(testCf, readOptions, k1)).isEqualTo(v1);
+
+      txn.delete(testCf, k1);
+      assertThat(txn.get(testCf, readOptions, k1)).isNull();
+    }
+  }
+
+  @Test
+  public void delete() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.put(k1, v1);
+      assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+
+      txn.delete(k1);
+      assertThat(txn.get(readOptions, k1)).isNull();
+    }
+  }
+
+  @Test
+  public void delete_parts_cf() throws RocksDBException {
+    final byte keyParts[][] = new byte[][] {
+        "ke".getBytes(UTF_8),
+        "y1".getBytes(UTF_8)};
+    final byte valueParts[][] = new byte[][] {
+        "val".getBytes(UTF_8),
+        "ue1".getBytes(UTF_8)};
+    final byte[] key = concat(keyParts);
+    final byte[] value = concat(valueParts);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      txn.put(testCf, keyParts, valueParts);
+      assertThat(txn.get(testCf, readOptions, key)).isEqualTo(value);
+
+      txn.delete(testCf, keyParts);
+
+      assertThat(txn.get(testCf, readOptions, key))
+          .isNull();
+    }
+  }
+
+  @Test
+  public void delete_parts() throws RocksDBException {
+    final byte keyParts[][] = new byte[][] {
+        "ke".getBytes(UTF_8),
+        "y1".getBytes(UTF_8)};
+    final byte valueParts[][] = new byte[][] {
+        "val".getBytes(UTF_8),
+        "ue1".getBytes(UTF_8)};
+    final byte[] key = concat(keyParts);
+    final byte[] value = concat(valueParts);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      txn.put(keyParts, valueParts);
+
+      assertThat(txn.get(readOptions, key)).isEqualTo(value);
+
+      txn.delete(keyParts);
+
+      assertThat(txn.get(readOptions, key)).isNull();
+    }
+  }
+
+  @Test
+  public void getPutUntracked_cf() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      assertThat(txn.get(testCf, readOptions, k1)).isNull();
+      txn.putUntracked(testCf, k1, v1);
+      assertThat(txn.get(testCf, readOptions, k1)).isEqualTo(v1);
+    }
+  }
+
+  @Test
+  public void getPutUntracked() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.get(readOptions, k1)).isNull();
+      txn.putUntracked(k1, v1);
+      assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+    }
+  }
+
+  @Test
+  public void multiGetPutUntracked_cf() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+
+      final List<ColumnFamilyHandle> cfList = Arrays.asList(testCf, testCf);
+
+      assertThat(txn.multiGet(readOptions, cfList, keys)).isEqualTo(new byte[][] { null, null });
+      txn.putUntracked(testCf, keys[0], values[0]);
+      txn.putUntracked(testCf, keys[1], values[1]);
+      assertThat(txn.multiGet(readOptions, cfList, keys)).isEqualTo(values);
+    }
+  }
+
+  @Test
+  public void multiGetPutUntracked() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      assertThat(txn.multiGet(readOptions, keys)).isEqualTo(new byte[][] { null, null });
+      txn.putUntracked(keys[0], values[0]);
+      txn.putUntracked(keys[1], values[1]);
+      assertThat(txn.multiGet(readOptions, keys)).isEqualTo(values);
+    }
+  }
+
+  @Test
+  public void mergeUntracked_cf() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      txn.mergeUntracked(testCf, k1, v1);
+    }
+  }
+
+  @Test
+  public void mergeUntracked() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.mergeUntracked(k1, v1);
+    }
+  }
+
+  @Test
+  public void deleteUntracked_cf() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      txn.put(testCf, k1, v1);
+      assertThat(txn.get(testCf, readOptions, k1)).isEqualTo(v1);
+
+      txn.deleteUntracked(testCf, k1);
+      assertThat(txn.get(testCf, readOptions, k1)).isNull();
+    }
+  }
+
+  @Test
+  public void deleteUntracked() throws RocksDBException {
+    final byte[] k1 = "key1".getBytes(UTF_8);
+    final byte[] v1 = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.put(k1, v1);
+      assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+
+      txn.deleteUntracked(k1);
+      assertThat(txn.get(readOptions, k1)).isNull();
+    }
+  }
+
+  @Test
+  public void deleteUntracked_parts_cf() throws RocksDBException {
+    final byte keyParts[][] = new byte[][] {
+        "ke".getBytes(UTF_8),
+        "y1".getBytes(UTF_8)};
+    final byte valueParts[][] = new byte[][] {
+        "val".getBytes(UTF_8),
+        "ue1".getBytes(UTF_8)};
+    final byte[] key = concat(keyParts);
+    final byte[] value = concat(valueParts);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      txn.put(testCf, keyParts, valueParts);
+      assertThat(txn.get(testCf, readOptions, key)).isEqualTo(value);
+
+      txn.deleteUntracked(testCf, keyParts);
+      assertThat(txn.get(testCf, readOptions, key)).isNull();
+    }
+  }
+
+  @Test
+  public void deleteUntracked_parts() throws RocksDBException {
+    final byte keyParts[][] = new byte[][] {
+        "ke".getBytes(UTF_8),
+        "y1".getBytes(UTF_8)};
+    final byte valueParts[][] = new byte[][] {
+        "val".getBytes(UTF_8),
+        "ue1".getBytes(UTF_8)};
+    final byte[] key = concat(keyParts);
+    final byte[] value = concat(valueParts);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.put(keyParts, valueParts);
+      assertThat(txn.get(readOptions, key)).isEqualTo(value);
+
+      txn.deleteUntracked(keyParts);
+      assertThat(txn.get(readOptions, key)).isNull();
+    }
+  }
+
+  @Test
+  public void putLogData() throws RocksDBException {
+    final byte[] blob = "blobby".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.putLogData(blob);
+    }
+  }
+
+  @Test
+  public void enabledDisableIndexing() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.disableIndexing();
+      txn.enableIndexing();
+      txn.disableIndexing();
+      txn.enableIndexing();
+    }
+  }
+
+  @Test
+  public void numKeys() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte k2[] = "key2".getBytes(UTF_8);
+    final byte v2[] = "value2".getBytes(UTF_8);
+    final byte k3[] = "key3".getBytes(UTF_8);
+    final byte v3[] = "value3".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      txn.put(k1, v1);
+      txn.put(testCf, k2, v2);
+      txn.merge(k3, v3);
+      txn.delete(testCf, k2);
+
+      assertThat(txn.getNumKeys()).isEqualTo(3);
+      assertThat(txn.getNumPuts()).isEqualTo(2);
+      assertThat(txn.getNumMerges()).isEqualTo(1);
+      assertThat(txn.getNumDeletes()).isEqualTo(1);
+    }
+  }
+
+  @Test
+  public void elapsedTime() throws RocksDBException, InterruptedException {
+    final long preStartTxnTime = System.currentTimeMillis();
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      Thread.sleep(1);
+
+      final long txnElapsedTime = txn.getElapsedTime();
+      assertThat(txnElapsedTime).isLessThan(System.currentTimeMillis()
+          - preStartTxnTime);
+      assertThat(txnElapsedTime).isGreaterThan(0);
+    }
+  }
+
+  @Test
+  public void getWriteBatch() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      txn.put(k1, v1);
+
+      final WriteBatchWithIndex writeBatch = txn.getWriteBatch();
+      assertThat(writeBatch).isNotNull();
+      assertThat(writeBatch.isOwningHandle()).isFalse();
+      assertThat(writeBatch.count()).isEqualTo(1);
+    }
+  }
+
+  @Test
+  public void setLockTimeout() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      txn.setLockTimeout(1000);
+    }
+  }
+
+  @Test
+  public void writeOptions() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final WriteOptions writeOptions = new WriteOptions()
+        .setDisableWAL(true)
+        .setSync(true);
+        final Transaction txn = dbContainer.beginTransaction(writeOptions)) {
+
+      txn.put(k1, v1);
+
+      WriteOptions txnWriteOptions = txn.getWriteOptions();
+      assertThat(txnWriteOptions).isNotNull();
+      assertThat(txnWriteOptions.isOwningHandle()).isFalse();
+      assertThat(txnWriteOptions).isNotSameAs(writeOptions);
+      assertThat(txnWriteOptions.disableWAL()).isTrue();
+      assertThat(txnWriteOptions.sync()).isTrue();
+
+      txn.setWriteOptions(txnWriteOptions.setSync(false));
+      txnWriteOptions = txn.getWriteOptions();
+      assertThat(txnWriteOptions).isNotNull();
+      assertThat(txnWriteOptions.isOwningHandle()).isFalse();
+      assertThat(txnWriteOptions).isNotSameAs(writeOptions);
+      assertThat(txnWriteOptions.disableWAL()).isTrue();
+      assertThat(txnWriteOptions.sync()).isFalse();
+    }
+  }
+
+  @Test
+  public void undoGetForUpdate_cf() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      assertThat(txn.getForUpdate(readOptions, testCf, k1, true)).isNull();
+      txn.put(testCf, k1, v1);
+      assertThat(txn.getForUpdate(readOptions, testCf, k1, true)).isEqualTo(v1);
+      txn.undoGetForUpdate(testCf, k1);
+    }
+  }
+
+  @Test
+  public void undoGetForUpdate() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getForUpdate(readOptions, k1, true)).isNull();
+      txn.put(k1, v1);
+      assertThat(txn.getForUpdate(readOptions, k1, true)).isEqualTo(v1);
+      txn.undoGetForUpdate(k1);
+    }
+  }
+
+  @Test
+  public void rebuildFromWriteBatch() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte k2[] = "key2".getBytes(UTF_8);
+    final byte v2[] = "value2".getBytes(UTF_8);
+    final byte k3[] = "key3".getBytes(UTF_8);
+    final byte v3[] = "value3".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      txn.put(k1, v1);
+
+      assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+      assertThat(txn.getNumKeys()).isEqualTo(1);
+
+      try(final WriteBatch writeBatch = new WriteBatch()) {
+        writeBatch.put(k2, v2);
+        writeBatch.put(k3, v3);
+        txn.rebuildFromWriteBatch(writeBatch);
+
+        assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+        assertThat(txn.get(readOptions, k2)).isEqualTo(v2);
+        assertThat(txn.get(readOptions, k3)).isEqualTo(v3);
+        assertThat(txn.getNumKeys()).isEqualTo(3);
+      }
+    }
+  }
+
+  @Test
+  public void getCommitTimeWriteBatch() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+
+      txn.put(k1, v1);
+      final WriteBatch writeBatch = txn.getCommitTimeWriteBatch();
+
+      assertThat(writeBatch).isNotNull();
+      assertThat(writeBatch.isOwningHandle()).isFalse();
+      assertThat(writeBatch.count()).isEqualTo(0);
+    }
+  }
+
+  @Test
+  public void logNumber() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getLogNumber()).isEqualTo(0);
+      final long logNumber = rand.nextLong();
+      txn.setLogNumber(logNumber);
+      assertThat(txn.getLogNumber()).isEqualTo(logNumber);
+    }
+  }
+
+  private static byte[] concat(final byte[][] bufs) {
+    int resultLength = 0;
+    for(final byte[] buf : bufs) {
+      resultLength += buf.length;
+    }
+
+    final byte[] result = new byte[resultLength];
+    int resultOffset = 0;
+    for(final byte[] buf : bufs) {
+      final int srcLength = buf.length;
+      System.arraycopy(buf, 0, result, resultOffset, srcLength);
+      resultOffset += srcLength;
+    }
+
+    return result;
+  }
+
+  private static class TestTransactionNotifier
+      extends AbstractTransactionNotifier {
+    private final List<Snapshot> createdSnapshots = new ArrayList<>();
+
+    @Override
+    public void snapshotCreated(final Snapshot newSnapshot) {
+      createdSnapshots.add(newSnapshot);
+    }
+
+    public List<Snapshot> getCreatedSnapshots() {
+      return createdSnapshots;
+    }
+  }
+
+  protected static abstract class DBContainer
+      implements AutoCloseable {
+    protected final WriteOptions writeOptions;
+    protected final List<ColumnFamilyHandle> columnFamilyHandles;
+    protected final ColumnFamilyOptions columnFamilyOptions;
+    protected final DBOptions options;
+
+    public DBContainer(final WriteOptions writeOptions,
+        final List<ColumnFamilyHandle> columnFamilyHandles,
+        final ColumnFamilyOptions columnFamilyOptions,
+        final DBOptions options) {
+      this.writeOptions = writeOptions;
+      this.columnFamilyHandles = columnFamilyHandles;
+      this.columnFamilyOptions = columnFamilyOptions;
+      this.options = options;
+    }
+
+    public abstract Transaction beginTransaction();
+
+    public abstract Transaction beginTransaction(
+        final WriteOptions writeOptions);
+
+    public ColumnFamilyHandle getTestColumnFamily() {
+      return columnFamilyHandles.get(1);
+    }
+
+    @Override
+    public abstract void close();
+  }
+}

java/src/test/java/org/rocksdb/ColumnFamilyTest.java

@@ -12,6 +12,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class ColumnFamilyTest {
@@ -23,6 +24,31 @@ public class ColumnFamilyTest {
   @Rule
   public TemporaryFolder dbFolder = new TemporaryFolder();
 
+  @Test
+  public void columnFamilyDescriptorName() throws RocksDBException {
+    final byte[] cfName = "some_name".getBytes(UTF_8);
+
+    try(final ColumnFamilyOptions cfOptions = new ColumnFamilyOptions()) {
+      final ColumnFamilyDescriptor cfDescriptor =
+              new ColumnFamilyDescriptor(cfName, cfOptions);
+      assertThat(cfDescriptor.getName()).isEqualTo(cfName);
+    }
+  }
+
+  @Test
+  public void columnFamilyDescriptorOptions() throws RocksDBException {
+    final byte[] cfName = "some_name".getBytes(UTF_8);
+
+    try(final ColumnFamilyOptions cfOptions = new ColumnFamilyOptions()
+            .setCompressionType(CompressionType.BZLIB2_COMPRESSION)) {
+      final ColumnFamilyDescriptor cfDescriptor =
+          new ColumnFamilyDescriptor(cfName, cfOptions);
+
+        assertThat(cfDescriptor.getOptions().compressionType())
+            .isEqualTo(CompressionType.BZLIB2_COMPRESSION);
+    }
+  }
+
   @Test
   public void listColumnFamilies() throws RocksDBException {
     try (final Options options = new Options().setCreateIfMissing(true);
@@ -47,6 +73,9 @@ public class ColumnFamilyTest {
       try {
         assertThat(cfh).isNotNull();
 
+        assertThat(cfh.getName()).isEqualTo("default".getBytes(UTF_8));
+        assertThat(cfh.getID()).isEqualTo(0);
+
         final byte[] key = "key".getBytes();
         final byte[] value = "value".getBytes();
 
@@ -64,15 +93,25 @@ public class ColumnFamilyTest {
 
   @Test
   public void createColumnFamily() throws RocksDBException {
+    final byte[] cfName = "new_cf".getBytes(UTF_8);
+    final ColumnFamilyDescriptor cfDescriptor = new ColumnFamilyDescriptor(cfName,
+            new ColumnFamilyOptions());
+
     try (final Options options = new Options().setCreateIfMissing(true);
          final RocksDB db = RocksDB.open(options,
-             dbFolder.getRoot().getAbsolutePath())) {
-      final ColumnFamilyHandle columnFamilyHandle = db.createColumnFamily(
-          new ColumnFamilyDescriptor("new_cf".getBytes(),
-              new ColumnFamilyOptions()));
+                 dbFolder.getRoot().getAbsolutePath())) {
+
+      final ColumnFamilyHandle columnFamilyHandle = db.createColumnFamily(cfDescriptor);
+
       try {
+        assertThat(columnFamilyHandle.getName()).isEqualTo(cfName);
+        assertThat(columnFamilyHandle.getID()).isEqualTo(1);
+
+        final ColumnFamilyDescriptor latestDescriptor = columnFamilyHandle.getDescriptor();
+        assertThat(latestDescriptor.getName()).isEqualTo(cfName);
+
         final List<byte[]> columnFamilyNames = RocksDB.listColumnFamilies(
-            options, dbFolder.getRoot().getAbsolutePath());
+                options, dbFolder.getRoot().getAbsolutePath());
         assertThat(columnFamilyNames).isNotNull();
         assertThat(columnFamilyNames.size()).isGreaterThan(0);
         assertThat(columnFamilyNames.size()).isEqualTo(2);

java/src/test/java/org/rocksdb/OptimisticTransactionDBTest.java

@@ -0,0 +1,131 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class OptimisticTransactionDBTest {
+
+  @Rule
+  public TemporaryFolder dbFolder = new TemporaryFolder();
+
+  @Test
+  public void open() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final OptimisticTransactionDB otdb = OptimisticTransactionDB.open(options,
+                 dbFolder.getRoot().getAbsolutePath())) {
+      assertThat(otdb).isNotNull();
+    }
+  }
+
+  @Test
+  public void open_columnFamilies() throws RocksDBException {
+    try(final DBOptions dbOptions = new DBOptions().setCreateIfMissing(true)
+          .setCreateMissingColumnFamilies(true);
+        final ColumnFamilyOptions myCfOpts = new ColumnFamilyOptions()) {
+
+      final List<ColumnFamilyDescriptor> columnFamilyDescriptors =
+          Arrays.asList(
+              new ColumnFamilyDescriptor(RocksDB.DEFAULT_COLUMN_FAMILY),
+              new ColumnFamilyDescriptor("myCf".getBytes(), myCfOpts));
+
+      final List<ColumnFamilyHandle> columnFamilyHandles = new ArrayList<>();
+
+      try (final OptimisticTransactionDB otdb = OptimisticTransactionDB.open(dbOptions,
+               dbFolder.getRoot().getAbsolutePath(),
+               columnFamilyDescriptors, columnFamilyHandles)) {
+        try {
+          assertThat(otdb).isNotNull();
+        } finally {
+          for (final ColumnFamilyHandle handle : columnFamilyHandles) {
+            handle.close();
+          }
+        }
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final OptimisticTransactionDB otdb = OptimisticTransactionDB.open(
+             options, dbFolder.getRoot().getAbsolutePath());
+        final WriteOptions writeOptions = new WriteOptions()) {
+
+      try(final Transaction txn = otdb.beginTransaction(writeOptions)) {
+        assertThat(txn).isNotNull();
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction_transactionOptions() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final OptimisticTransactionDB otdb = OptimisticTransactionDB.open(
+             options, dbFolder.getRoot().getAbsolutePath());
+         final WriteOptions writeOptions = new WriteOptions();
+         final OptimisticTransactionOptions optimisticTxnOptions =
+             new OptimisticTransactionOptions()) {
+
+      try(final Transaction txn = otdb.beginTransaction(writeOptions,
+          optimisticTxnOptions)) {
+        assertThat(txn).isNotNull();
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction_withOld() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final OptimisticTransactionDB otdb = OptimisticTransactionDB.open(
+             options, dbFolder.getRoot().getAbsolutePath());
+         final WriteOptions writeOptions = new WriteOptions()) {
+
+      try(final Transaction txn = otdb.beginTransaction(writeOptions)) {
+        final Transaction txnReused = otdb.beginTransaction(writeOptions, txn);
+        assertThat(txnReused).isSameAs(txn);
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction_withOld_transactionOptions()
+      throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final OptimisticTransactionDB otdb = OptimisticTransactionDB.open(
+             options, dbFolder.getRoot().getAbsolutePath());
+         final WriteOptions writeOptions = new WriteOptions();
+         final OptimisticTransactionOptions optimisticTxnOptions =
+             new OptimisticTransactionOptions()) {
+
+      try(final Transaction txn = otdb.beginTransaction(writeOptions)) {
+        final Transaction txnReused = otdb.beginTransaction(writeOptions,
+            optimisticTxnOptions, txn);
+        assertThat(txnReused).isSameAs(txn);
+      }
+    }
+  }
+
+  @Test
+  public void baseDB() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final OptimisticTransactionDB otdb = OptimisticTransactionDB.open(options,
+             dbFolder.getRoot().getAbsolutePath())) {
+      assertThat(otdb).isNotNull();
+      final RocksDB db = otdb.getBaseDB();
+      assertThat(db).isNotNull();
+      assertThat(db.isOwningHandle()).isFalse();
+    }
+  }
+}

java/src/test/java/org/rocksdb/OptimisticTransactionOptionsTest.java

@@ -0,0 +1,37 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Test;
+import org.rocksdb.util.DirectBytewiseComparator;
+
+import java.util.Random;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class OptimisticTransactionOptionsTest {
+
+  private static final Random rand = PlatformRandomHelper.
+      getPlatformSpecificRandomFactory();
+
+  @Test
+  public void setSnapshot() {
+    try (final OptimisticTransactionOptions opt = new OptimisticTransactionOptions()) {
+      final boolean boolValue = rand.nextBoolean();
+      opt.setSetSnapshot(boolValue);
+      assertThat(opt.isSetSnapshot()).isEqualTo(boolValue);
+    }
+  }
+
+  @Test
+  public void comparator() {
+    try (final OptimisticTransactionOptions opt = new OptimisticTransactionOptions();
+         final ComparatorOptions copt = new ComparatorOptions();
+         final DirectComparator comparator = new DirectBytewiseComparator(copt)) {
+      opt.setComparator(comparator);
+    }
+  }
+}

java/src/test/java/org/rocksdb/OptimisticTransactionTest.java

@@ -0,0 +1,350 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.fail;
+
+public class OptimisticTransactionTest extends AbstractTransactionTest {
+
+  @Test
+  public void getForUpdate_cf_conflict() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte v12[] = "value12".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(testCf, k1, v1);
+        assertThat(txn.get(testCf, readOptions, k1)).isEqualTo(v1);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.getForUpdate(readOptions, testCf, k1, true)).isEqualTo(v1);
+
+          // NOTE: txn2 updates k1, during txn3
+          txn2.put(testCf, k1, v12);
+          assertThat(txn2.get(testCf, readOptions, k1)).isEqualTo(v12);
+          txn2.commit();
+
+          try {
+            txn3.commit(); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.Busy);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void getForUpdate_conflict() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte v12[] = "value12".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(k1, v1);
+        assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.getForUpdate(readOptions, k1, true)).isEqualTo(v1);
+
+          // NOTE: txn2 updates k1, during txn3
+          txn2.put(k1, v12);
+          assertThat(txn2.get(readOptions, k1)).isEqualTo(v12);
+          txn2.commit();
+
+          try {
+            txn3.commit(); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.Busy);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void multiGetForUpdate_cf_conflict() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+    final byte[] otherValue = "otherValue".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      final List<ColumnFamilyHandle> cfList = Arrays.asList(testCf, testCf);
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(testCf, keys[0], values[0]);
+        txn.put(testCf, keys[1], values[1]);
+        assertThat(txn.multiGet(readOptions, cfList, keys)).isEqualTo(values);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.multiGetForUpdate(readOptions, cfList, keys))
+              .isEqualTo(values);
+
+          // NOTE: txn2 updates k1, during txn3
+          txn2.put(testCf, keys[0], otherValue);
+          assertThat(txn2.get(testCf, readOptions, keys[0]))
+              .isEqualTo(otherValue);
+          txn2.commit();
+
+          try {
+            txn3.commit(); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.Busy);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void multiGetForUpdate_conflict() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+    final byte[] otherValue = "otherValue".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(keys[0], values[0]);
+        txn.put(keys[1], values[1]);
+        assertThat(txn.multiGet(readOptions, keys)).isEqualTo(values);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.multiGetForUpdate(readOptions, keys))
+              .isEqualTo(values);
+
+          // NOTE: txn2 updates k1, during txn3
+          txn2.put(keys[0], otherValue);
+          assertThat(txn2.get(readOptions, keys[0]))
+              .isEqualTo(otherValue);
+          txn2.commit();
+
+          try {
+            txn3.commit(); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.Busy);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void undoGetForUpdate_cf_conflict() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte v12[] = "value12".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(testCf, k1, v1);
+        assertThat(txn.get(testCf, readOptions, k1)).isEqualTo(v1);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.getForUpdate(readOptions, testCf, k1, true)).isEqualTo(v1);
+
+          // undo the getForUpdate
+          txn3.undoGetForUpdate(testCf, k1);
+
+          // NOTE: txn2 updates k1, during txn3
+          txn2.put(testCf, k1, v12);
+          assertThat(txn2.get(testCf, readOptions, k1)).isEqualTo(v12);
+          txn2.commit();
+
+          // should not cause an exception
+          // because we undid the getForUpdate above!
+          txn3.commit();
+        }
+      }
+    }
+  }
+
+  @Test
+  public void undoGetForUpdate_conflict() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte v12[] = "value12".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(k1, v1);
+        assertThat(txn.get(readOptions, k1)).isEqualTo(v1);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.getForUpdate(readOptions, k1, true)).isEqualTo(v1);
+
+          // undo the getForUpdate
+          txn3.undoGetForUpdate(k1);
+
+          // NOTE: txn2 updates k1, during txn3
+          txn2.put(k1, v12);
+          assertThat(txn2.get(readOptions, k1)).isEqualTo(v12);
+          txn2.commit();
+
+          // should not cause an exception
+          // because we undid the getForUpdate above!
+          txn3.commit();
+        }
+      }
+    }
+  }
+
+  @Test
+  public void name() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getName()).isEmpty();
+      final String name = "my-transaction-" + rand.nextLong();
+
+      try {
+        txn.setName(name);
+      } catch(final RocksDBException e) {
+         assertThat(e.getStatus().getCode() == Status.Code.InvalidArgument);
+        return;
+      }
+
+      fail("Optimistic transactions cannot be named.");
+    }
+  }
+
+  @Override
+  public OptimisticTransactionDBContainer startDb()
+      throws RocksDBException {
+    final DBOptions options = new DBOptions()
+        .setCreateIfMissing(true)
+        .setCreateMissingColumnFamilies(true);
+
+    final ColumnFamilyOptions columnFamilyOptions = new ColumnFamilyOptions();
+    final List<ColumnFamilyDescriptor> columnFamilyDescriptors =
+        Arrays.asList(
+            new ColumnFamilyDescriptor(RocksDB.DEFAULT_COLUMN_FAMILY),
+            new ColumnFamilyDescriptor(TXN_TEST_COLUMN_FAMILY,
+                columnFamilyOptions));
+    final List<ColumnFamilyHandle> columnFamilyHandles = new ArrayList<>();
+
+    final OptimisticTransactionDB optimisticTxnDb;
+    try {
+      optimisticTxnDb = OptimisticTransactionDB.open(
+          options, dbFolder.getRoot().getAbsolutePath(),
+          columnFamilyDescriptors, columnFamilyHandles);
+    } catch(final RocksDBException e) {
+      columnFamilyOptions.close();
+      options.close();
+      throw e;
+    }
+
+    final WriteOptions writeOptions = new WriteOptions();
+    final OptimisticTransactionOptions optimisticTxnOptions =
+             new OptimisticTransactionOptions();
+
+    return new OptimisticTransactionDBContainer(optimisticTxnOptions,
+        writeOptions, columnFamilyHandles, optimisticTxnDb, columnFamilyOptions,
+        options);
+  }
+
+  private static class OptimisticTransactionDBContainer
+      extends DBContainer {
+
+    private final OptimisticTransactionOptions optimisticTxnOptions;
+    private final OptimisticTransactionDB optimisticTxnDb;
+
+    public OptimisticTransactionDBContainer(
+        final OptimisticTransactionOptions optimisticTxnOptions,
+        final WriteOptions writeOptions,
+        final List<ColumnFamilyHandle> columnFamilyHandles,
+        final OptimisticTransactionDB optimisticTxnDb,
+        final ColumnFamilyOptions columnFamilyOptions,
+        final DBOptions options) {
+      super(writeOptions, columnFamilyHandles, columnFamilyOptions,
+          options);
+      this.optimisticTxnOptions = optimisticTxnOptions;
+      this.optimisticTxnDb = optimisticTxnDb;
+    }
+
+    @Override
+    public Transaction beginTransaction() {
+      return optimisticTxnDb.beginTransaction(writeOptions,
+          optimisticTxnOptions);
+    }
+
+    @Override
+    public Transaction beginTransaction(final WriteOptions writeOptions) {
+      return optimisticTxnDb.beginTransaction(writeOptions,
+          optimisticTxnOptions);
+    }
+
+    @Override
+    public void close() {
+      optimisticTxnOptions.close();
+      writeOptions.close();
+      for(final ColumnFamilyHandle columnFamilyHandle : columnFamilyHandles) {
+        columnFamilyHandle.close();
+      }
+      optimisticTxnDb.close();
+      options.close();
+    }
+  }
+}

java/src/test/java/org/rocksdb/TransactionDBOptionsTest.java

@@ -0,0 +1,64 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Test;
+
+import java.util.Random;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class TransactionDBOptionsTest {
+
+  private static final Random rand = PlatformRandomHelper.
+      getPlatformSpecificRandomFactory();
+
+  @Test
+  public void maxNumLocks() {
+    try (final TransactionDBOptions opt = new TransactionDBOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setMaxNumLocks(longValue);
+      assertThat(opt.getMaxNumLocks()).isEqualTo(longValue);
+    }
+  }
+
+  @Test
+  public void maxNumStripes() {
+    try (final TransactionDBOptions opt = new TransactionDBOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setNumStripes(longValue);
+      assertThat(opt.getNumStripes()).isEqualTo(longValue);
+    }
+  }
+
+  @Test
+  public void transactionLockTimeout() {
+    try (final TransactionDBOptions opt = new TransactionDBOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setTransactionLockTimeout(longValue);
+      assertThat(opt.getTransactionLockTimeout()).isEqualTo(longValue);
+    }
+  }
+
+  @Test
+  public void defaultLockTimeout() {
+    try (final TransactionDBOptions opt = new TransactionDBOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setDefaultLockTimeout(longValue);
+      assertThat(opt.getDefaultLockTimeout()).isEqualTo(longValue);
+    }
+  }
+
+  @Test
+  public void writePolicy() {
+    try (final TransactionDBOptions opt = new TransactionDBOptions()) {
+      final TxnDBWritePolicy writePolicy = TxnDBWritePolicy.WRITE_UNPREPARED;  // non-default
+      opt.setWritePolicy(writePolicy);
+      assertThat(opt.getWritePolicy()).isEqualTo(writePolicy);
+    }
+  }
+
+}

java/src/test/java/org/rocksdb/TransactionDBTest.java

@@ -0,0 +1,178 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.util.*;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+public class TransactionDBTest {
+
+  @Rule
+  public TemporaryFolder dbFolder = new TemporaryFolder();
+
+  @Test
+  public void open() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+                 dbFolder.getRoot().getAbsolutePath())) {
+      assertThat(tdb).isNotNull();
+    }
+  }
+
+  @Test
+  public void open_columnFamilies() throws RocksDBException {
+    try(final DBOptions dbOptions = new DBOptions().setCreateIfMissing(true)
+          .setCreateMissingColumnFamilies(true);
+        final ColumnFamilyOptions myCfOpts = new ColumnFamilyOptions()) {
+
+      final List<ColumnFamilyDescriptor> columnFamilyDescriptors =
+          Arrays.asList(
+              new ColumnFamilyDescriptor(RocksDB.DEFAULT_COLUMN_FAMILY),
+              new ColumnFamilyDescriptor("myCf".getBytes(), myCfOpts));
+
+      final List<ColumnFamilyHandle> columnFamilyHandles = new ArrayList<>();
+
+      try (final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+           final TransactionDB tdb = TransactionDB.open(dbOptions, txnDbOptions,
+               dbFolder.getRoot().getAbsolutePath(),
+               columnFamilyDescriptors, columnFamilyHandles)) {
+        try {
+          assertThat(tdb).isNotNull();
+        } finally {
+          for (final ColumnFamilyHandle handle : columnFamilyHandles) {
+            handle.close();
+          }
+        }
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+             dbFolder.getRoot().getAbsolutePath());
+        final WriteOptions writeOptions = new WriteOptions()) {
+
+      try(final Transaction txn = tdb.beginTransaction(writeOptions)) {
+        assertThat(txn).isNotNull();
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction_transactionOptions() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+             dbFolder.getRoot().getAbsolutePath());
+         final WriteOptions writeOptions = new WriteOptions();
+         final TransactionOptions txnOptions = new TransactionOptions()) {
+
+      try(final Transaction txn = tdb.beginTransaction(writeOptions,
+          txnOptions)) {
+        assertThat(txn).isNotNull();
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction_withOld() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+             dbFolder.getRoot().getAbsolutePath());
+         final WriteOptions writeOptions = new WriteOptions()) {
+
+      try(final Transaction txn = tdb.beginTransaction(writeOptions)) {
+        final Transaction txnReused = tdb.beginTransaction(writeOptions, txn);
+        assertThat(txnReused).isSameAs(txn);
+      }
+    }
+  }
+
+  @Test
+  public void beginTransaction_withOld_transactionOptions()
+      throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+             dbFolder.getRoot().getAbsolutePath());
+         final WriteOptions writeOptions = new WriteOptions();
+         final TransactionOptions txnOptions = new TransactionOptions()) {
+
+      try(final Transaction txn = tdb.beginTransaction(writeOptions)) {
+        final Transaction txnReused = tdb.beginTransaction(writeOptions,
+            txnOptions, txn);
+        assertThat(txnReused).isSameAs(txn);
+      }
+    }
+  }
+
+  @Test
+  public void lockStatusData() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+             dbFolder.getRoot().getAbsolutePath());
+         final WriteOptions writeOptions = new WriteOptions();
+         final ReadOptions readOptions = new ReadOptions()) {
+
+      try (final Transaction txn = tdb.beginTransaction(writeOptions)) {
+
+        final byte key[] = "key".getBytes(UTF_8);
+        final byte value[] = "value".getBytes(UTF_8);
+
+        txn.put(key, value);
+        assertThat(txn.getForUpdate(readOptions, key, true)).isEqualTo(value);
+
+        final Map<Long, TransactionDB.KeyLockInfo> lockStatus =
+            tdb.getLockStatusData();
+
+        assertThat(lockStatus.size()).isEqualTo(1);
+        final Set<Map.Entry<Long, TransactionDB.KeyLockInfo>> entrySet = lockStatus.entrySet();
+        final Map.Entry<Long, TransactionDB.KeyLockInfo> entry = entrySet.iterator().next();
+        final long columnFamilyId = entry.getKey();
+        assertThat(columnFamilyId).isEqualTo(0);
+        final TransactionDB.KeyLockInfo keyLockInfo = entry.getValue();
+        assertThat(keyLockInfo.getKey()).isEqualTo(new String(key, UTF_8));
+        assertThat(keyLockInfo.getTransactionIDs().length).isEqualTo(1);
+        assertThat(keyLockInfo.getTransactionIDs()[0]).isEqualTo(txn.getId());
+        assertThat(keyLockInfo.isExclusive()).isTrue();
+      }
+    }
+  }
+
+  @Test
+  public void deadlockInfoBuffer() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+             dbFolder.getRoot().getAbsolutePath())) {
+
+      // TODO(AR) can we cause a deadlock so that we can test the output here?
+      assertThat(tdb.getDeadlockInfoBuffer()).isEmpty();
+    }
+  }
+
+  @Test
+  public void setDeadlockInfoBufferSize() throws RocksDBException {
+    try (final Options options = new Options().setCreateIfMissing(true);
+         final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+         final TransactionDB tdb = TransactionDB.open(options, txnDbOptions,
+             dbFolder.getRoot().getAbsolutePath())) {
+      tdb.setDeadlockInfoBufferSize(123);
+    }
+  }
+}

java/src/test/java/org/rocksdb/TransactionOptionsTest.java

@@ -0,0 +1,72 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Test;
+
+import java.util.Random;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class TransactionOptionsTest {
+
+  private static final Random rand = PlatformRandomHelper.
+      getPlatformSpecificRandomFactory();
+
+  @Test
+  public void snapshot() {
+    try (final TransactionOptions opt = new TransactionOptions()) {
+      final boolean boolValue = rand.nextBoolean();
+      opt.setSetSnapshot(boolValue);
+      assertThat(opt.isSetSnapshot()).isEqualTo(boolValue);
+    }
+  }
+
+  @Test
+  public void deadlockDetect() {
+    try (final TransactionOptions opt = new TransactionOptions()) {
+      final boolean boolValue = rand.nextBoolean();
+      opt.setDeadlockDetect(boolValue);
+      assertThat(opt.isDeadlockDetect()).isEqualTo(boolValue);
+    }
+  }
+
+  @Test
+  public void lockTimeout() {
+    try (final TransactionOptions opt = new TransactionOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setLockTimeout(longValue);
+      assertThat(opt.getLockTimeout()).isEqualTo(longValue);
+    }
+  }
+
+  @Test
+  public void expiration() {
+    try (final TransactionOptions opt = new TransactionOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setExpiration(longValue);
+      assertThat(opt.getExpiration()).isEqualTo(longValue);
+    }
+  }
+
+  @Test
+  public void deadlockDetectDepth() {
+    try (final TransactionOptions opt = new TransactionOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setDeadlockDetectDepth(longValue);
+      assertThat(opt.getDeadlockDetectDepth()).isEqualTo(longValue);
+    }
+  }
+
+  @Test
+  public void maxWriteBatchSize() {
+    try (final TransactionOptions opt = new TransactionOptions()) {
+      final long longValue = rand.nextLong();
+      opt.setMaxWriteBatchSize(longValue);
+      assertThat(opt.getMaxWriteBatchSize()).isEqualTo(longValue);
+    }
+  }
+}

java/src/test/java/org/rocksdb/TransactionTest.java

@@ -0,0 +1,308 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+package org.rocksdb;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.fail;
+
+public class TransactionTest extends AbstractTransactionTest {
+
+  @Test
+  public void getForUpdate_cf_conflict() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte v12[] = "value12".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(testCf, k1, v1);
+        assertThat(txn.getForUpdate(readOptions, testCf, k1, true)).isEqualTo(v1);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.getForUpdate(readOptions, testCf, k1, true)).isEqualTo(v1);
+
+          // NOTE: txn2 updates k1, during txn3
+          try {
+            txn2.put(testCf, k1, v12); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.TimedOut);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void getForUpdate_conflict() throws RocksDBException {
+    final byte k1[] = "key1".getBytes(UTF_8);
+    final byte v1[] = "value1".getBytes(UTF_8);
+    final byte v12[] = "value12".getBytes(UTF_8);
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(k1, v1);
+        assertThat(txn.getForUpdate(readOptions, k1, true)).isEqualTo(v1);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.getForUpdate(readOptions, k1, true)).isEqualTo(v1);
+
+          // NOTE: txn2 updates k1, during txn3
+          try {
+            txn2.put(k1, v12); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.TimedOut);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void multiGetForUpdate_cf_conflict() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+    final byte[] otherValue = "otherValue".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+      final ColumnFamilyHandle testCf = dbContainer.getTestColumnFamily();
+      final List<ColumnFamilyHandle> cfList = Arrays.asList(testCf, testCf);
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(testCf, keys[0], values[0]);
+        txn.put(testCf, keys[1], values[1]);
+        assertThat(txn.multiGet(readOptions, cfList, keys)).isEqualTo(values);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.multiGetForUpdate(readOptions, cfList, keys))
+              .isEqualTo(values);
+
+          // NOTE: txn2 updates k1, during txn3
+          try {
+            txn2.put(testCf, keys[0], otherValue); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.TimedOut);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void multiGetForUpdate_conflict() throws RocksDBException {
+    final byte keys[][] = new byte[][] {
+        "key1".getBytes(UTF_8),
+        "key2".getBytes(UTF_8)};
+    final byte values[][] = new byte[][] {
+        "value1".getBytes(UTF_8),
+        "value2".getBytes(UTF_8)};
+    final byte[] otherValue = "otherValue".getBytes(UTF_8);
+
+    try(final DBContainer dbContainer = startDb();
+        final ReadOptions readOptions = new ReadOptions()) {
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        txn.put(keys[0], values[0]);
+        txn.put(keys[1], values[1]);
+        assertThat(txn.multiGet(readOptions, keys)).isEqualTo(values);
+        txn.commit();
+      }
+
+      try(final Transaction txn2 = dbContainer.beginTransaction()) {
+        try(final Transaction txn3 = dbContainer.beginTransaction()) {
+          assertThat(txn3.multiGetForUpdate(readOptions, keys))
+              .isEqualTo(values);
+
+          // NOTE: txn2 updates k1, during txn3
+          try {
+            txn2.put(keys[0], otherValue); // should cause an exception!
+          } catch(final RocksDBException e) {
+            assertThat(e.getStatus().getCode()).isSameAs(Status.Code.TimedOut);
+            return;
+          }
+        }
+      }
+
+      fail("Expected an exception for put after getForUpdate from conflicting" +
+          "transactions");
+    }
+  }
+
+  @Test
+  public void name() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getName()).isEmpty();
+      final String name = "my-transaction-" + rand.nextLong();
+      txn.setName(name);
+      assertThat(txn.getName()).isEqualTo(name);
+    }
+  }
+
+  @Test
+  public void ID() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getID()).isGreaterThan(0);
+    }
+  }
+
+  @Test
+  public void deadlockDetect() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.isDeadlockDetect()).isFalse();
+    }
+  }
+
+  @Test
+  public void waitingTxns() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getWaitingTxns().getTransactionIds().length).isEqualTo(0);
+    }
+  }
+
+  @Test
+  public void state() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb()) {
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        assertThat(txn.getState())
+            .isSameAs(Transaction.TransactionState.STARTED);
+        txn.commit();
+        assertThat(txn.getState())
+            .isSameAs(Transaction.TransactionState.COMMITED);
+      }
+
+      try(final Transaction txn = dbContainer.beginTransaction()) {
+        assertThat(txn.getState())
+            .isSameAs(Transaction.TransactionState.STARTED);
+        txn.rollback();
+        assertThat(txn.getState())
+            .isSameAs(Transaction.TransactionState.STARTED);
+      }
+    }
+  }
+
+  @Test
+  public void Id() throws RocksDBException {
+    try(final DBContainer dbContainer = startDb();
+        final Transaction txn = dbContainer.beginTransaction()) {
+      assertThat(txn.getId()).isNotNull();
+    }
+  }
+
+  @Override
+  public TransactionDBContainer startDb() throws RocksDBException {
+    final DBOptions options = new DBOptions()
+        .setCreateIfMissing(true)
+        .setCreateMissingColumnFamilies(true);
+    final TransactionDBOptions txnDbOptions = new TransactionDBOptions();
+    final ColumnFamilyOptions columnFamilyOptions = new ColumnFamilyOptions();
+    final List<ColumnFamilyDescriptor> columnFamilyDescriptors =
+        Arrays.asList(
+            new ColumnFamilyDescriptor(RocksDB.DEFAULT_COLUMN_FAMILY),
+            new ColumnFamilyDescriptor(TXN_TEST_COLUMN_FAMILY,
+                columnFamilyOptions));
+    final List<ColumnFamilyHandle> columnFamilyHandles = new ArrayList<>();
+
+    final TransactionDB txnDb;
+    try {
+      txnDb = TransactionDB.open(options, txnDbOptions,
+          dbFolder.getRoot().getAbsolutePath(), columnFamilyDescriptors,
+              columnFamilyHandles);
+    } catch(final RocksDBException e) {
+      columnFamilyOptions.close();
+      txnDbOptions.close();
+      options.close();
+      throw e;
+    }
+
+    final WriteOptions writeOptions = new WriteOptions();
+    final TransactionOptions txnOptions = new TransactionOptions();
+
+    return new TransactionDBContainer(txnOptions, writeOptions,
+        columnFamilyHandles, txnDb, txnDbOptions, columnFamilyOptions, options);
+  }
+
+  private static class TransactionDBContainer
+      extends DBContainer {
+    private final TransactionOptions txnOptions;
+    private final TransactionDB txnDb;
+    private final TransactionDBOptions txnDbOptions;
+
+    public TransactionDBContainer(
+        final TransactionOptions txnOptions, final WriteOptions writeOptions,
+        final List<ColumnFamilyHandle> columnFamilyHandles,
+        final TransactionDB txnDb, final TransactionDBOptions txnDbOptions,
+        final ColumnFamilyOptions columnFamilyOptions,
+        final DBOptions options) {
+      super(writeOptions, columnFamilyHandles, columnFamilyOptions,
+          options);
+      this.txnOptions = txnOptions;
+      this.txnDb = txnDb;
+      this.txnDbOptions = txnDbOptions;
+    }
+
+    @Override
+    public Transaction beginTransaction() {
+      return txnDb.beginTransaction(writeOptions, txnOptions);
+    }
+
+    @Override
+    public Transaction beginTransaction(final WriteOptions writeOptions) {
+      return txnDb.beginTransaction(writeOptions, txnOptions);
+    }
+
+    @Override
+    public void close() {
+      txnOptions.close();
+      writeOptions.close();
+      for(final ColumnFamilyHandle columnFamilyHandle : columnFamilyHandles) {
+        columnFamilyHandle.close();
+      }
+      txnDb.close();
+      txnDbOptions.close();
+      options.close();
+    }
+  }
+
+}

src.mk

@@ -396,6 +396,8 @@ JNI_NATIVE_SOURCES =                                          \
   java/rocksjni/lru_cache.cc                                  \
   java/rocksjni/memtablejni.cc                                \
   java/rocksjni/merge_operator.cc                             \
+  java/rocksjni/optimistic_transaction_db.cc                   \
+  java/rocksjni/optimistic_transaction_options.cc             \
   java/rocksjni/options.cc                                    \
   java/rocksjni/options_util.cc                               \
   java/rocksjni/ratelimiterjni.cc                             \
@@ -412,7 +414,13 @@ JNI_NATIVE_SOURCES =                                          \
   java/rocksjni/statistics.cc                                 \
   java/rocksjni/statisticsjni.cc                              \
   java/rocksjni/table.cc                                      \
+  java/rocksjni/transaction.cc                                \
+  java/rocksjni/transaction_db.cc                             \
+  java/rocksjni/transaction_options.cc                        \
+  java/rocksjni/transaction_db_options.cc                     \
   java/rocksjni/transaction_log.cc                            \
+  java/rocksjni/transaction_notifier.cc                       \
+  java/rocksjni/transaction_notifier_jnicallback.cc           \
   java/rocksjni/ttl.cc                                        \
   java/rocksjni/write_batch.cc                                \
   java/rocksjni/writebatchhandlerjnicallback.cc               \