Add newer WBWI::NewIteratorWithBase functions to RocksJava (#6872)

Summary:
Exposes the `ReadOptions` arguments to `NewIteratorWithBase`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6872

Reviewed By: ajkr

Differential Revision: D21725867

Pulled By: pdillinger

fbshipit-source-id: 4079ba590cc13ba7a6244ed91439d89c40a543b6

java/rocksjni/write_batch_with_index.cc

@@ -533,20 +533,24 @@ jlong Java_org_rocksdb_WriteBatchWithIndex_iterator1(JNIEnv* /*env*/,
 /*
  * Class:     org_rocksdb_WriteBatchWithIndex
  * Method:    iteratorWithBase
- * Signature: (JJJ)J
+ * Signature: (JJJJ)J
  */
-jlong Java_org_rocksdb_WriteBatchWithIndex_iteratorWithBase(JNIEnv* /*env*/,
-                                                            jobject /*jobj*/,
-                                                            jlong jwbwi_handle,
-                                                            jlong jcf_handle,
-                                                            jlong jbi_handle) {
+jlong Java_org_rocksdb_WriteBatchWithIndex_iteratorWithBase(
+    JNIEnv*, jobject, jlong jwbwi_handle, jlong jcf_handle,
+    jlong jbase_iterator_handle, jlong jread_opts_handle) {
   auto* wbwi =
       reinterpret_cast<ROCKSDB_NAMESPACE::WriteBatchWithIndex*>(jwbwi_handle);
   auto* cf_handle =
       reinterpret_cast<ROCKSDB_NAMESPACE::ColumnFamilyHandle*>(jcf_handle);
   auto* base_iterator =
-      reinterpret_cast<ROCKSDB_NAMESPACE::Iterator*>(jbi_handle);
-  auto* iterator = wbwi->NewIteratorWithBase(cf_handle, base_iterator);
+      reinterpret_cast<ROCKSDB_NAMESPACE::Iterator*>(jbase_iterator_handle);
+  ROCKSDB_NAMESPACE::ReadOptions* read_opts =
+      jread_opts_handle == 0
+          ? nullptr
+          : reinterpret_cast<ROCKSDB_NAMESPACE::ReadOptions*>(
+                jread_opts_handle);
+  auto* iterator =
+      wbwi->NewIteratorWithBase(cf_handle, base_iterator, read_opts);
   return reinterpret_cast<jlong>(iterator);
 }
 

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

@@ -131,11 +131,36 @@ public class WriteBatchWithIndex extends AbstractWriteBatch {
   public RocksIterator newIteratorWithBase(
       final ColumnFamilyHandle columnFamilyHandle,
       final RocksIterator baseIterator) {
-    RocksIterator iterator = new RocksIterator(baseIterator.parent_,
-        iteratorWithBase(
-            nativeHandle_, columnFamilyHandle.nativeHandle_, baseIterator.nativeHandle_));
+    return newIteratorWithBase(columnFamilyHandle, baseIterator, null);
+  }
+
+  /**
+   * Provides Read-Your-Own-Writes like functionality by
+   * creating a new Iterator that will use {@link org.rocksdb.WBWIRocksIterator}
+   * as a delta and baseIterator as a base
+   *
+   * Updating write batch with the current key of the iterator is not safe.
+   * We strongly recommand users not to do it. It will invalidate the current
+   * key() and value() of the iterator. This invalidation happens even before
+   * the write batch update finishes. The state may recover after Next() is
+   * called.
+   *
+   * @param columnFamilyHandle The column family to iterate over
+   * @param baseIterator The base iterator,
+   *   e.g. {@link org.rocksdb.RocksDB#newIterator()}
+   * @param readOptions the read options, or null
+   * @return An iterator which shows a view comprised of both the database
+   * point-in-time from baseIterator and modifications made in this write batch.
+   */
+  public RocksIterator newIteratorWithBase(final ColumnFamilyHandle columnFamilyHandle,
+      final RocksIterator baseIterator, /* @Nullable */ final ReadOptions readOptions) {
+    final RocksIterator iterator = new RocksIterator(baseIterator.parent_,
+        iteratorWithBase(nativeHandle_, columnFamilyHandle.nativeHandle_,
+            baseIterator.nativeHandle_, readOptions == null ? 0 : readOptions.nativeHandle_));
+
     // when the iterator is deleted it will also delete the baseIterator
     baseIterator.disOwnNativeHandle();
+
     return iterator;
   }
 
@@ -151,7 +176,25 @@ public class WriteBatchWithIndex extends AbstractWriteBatch {
    * point-in-timefrom baseIterator and modifications made in this write batch.
    */
   public RocksIterator newIteratorWithBase(final RocksIterator baseIterator) {
-    return newIteratorWithBase(baseIterator.parent_.getDefaultColumnFamily(), baseIterator);
+    return newIteratorWithBase(baseIterator.parent_.getDefaultColumnFamily(), baseIterator, null);
+  }
+
+  /**
+   * Provides Read-Your-Own-Writes like functionality by
+   * creating a new Iterator that will use {@link org.rocksdb.WBWIRocksIterator}
+   * as a delta and baseIterator as a base. Operates on the default column
+   * family.
+   *
+   * @param baseIterator The base iterator,
+   *   e.g. {@link org.rocksdb.RocksDB#newIterator()}
+   * @param readOptions the read options, or null
+   * @return An iterator which shows a view comprised of both the database
+   * point-in-timefrom baseIterator and modifications made in this write batch.
+   */
+  public RocksIterator newIteratorWithBase(final RocksIterator baseIterator,
+      /* @Nullable */ final ReadOptions readOptions) {
+    return newIteratorWithBase(
+        baseIterator.parent_.getDefaultColumnFamily(), baseIterator, readOptions);
   }
 
   /**
@@ -200,7 +243,7 @@ public class WriteBatchWithIndex extends AbstractWriteBatch {
    * the results using the DB's merge operator (if the batch contains any
    * merge requests).
    *
-   * Setting {@link ReadOptions#setSnapshot(long, long)} will affect what is
+   * Setting {@link ReadOptions#setSnapshot(Snapshot)} will affect what is
    * read from the DB but will NOT change which keys are read from the batch
    * (the keys in this batch do not yet belong to any snapshot and will be
    * fetched regardless).
@@ -230,7 +273,7 @@ public class WriteBatchWithIndex extends AbstractWriteBatch {
    * the results using the DB's merge operator (if the batch contains any
    * merge requests).
    *
-   * Setting {@link ReadOptions#setSnapshot(long, long)} will affect what is
+   * Setting {@link ReadOptions#setSnapshot(Snapshot)} will affect what is
    * read from the DB but will NOT change which keys are read from the batch
    * (the keys in this batch do not yet belong to any snapshot and will be
    * fetched regardless).
@@ -303,8 +346,8 @@ public class WriteBatchWithIndex extends AbstractWriteBatch {
       final boolean overwriteKey);
   private native long iterator0(final long handle);
   private native long iterator1(final long handle, final long cfHandle);
-  private native long iteratorWithBase(
-      final long handle, final long baseIteratorHandle, final long cfHandle);
+  private native long iteratorWithBase(final long handle, final long baseIteratorHandle,
+      final long cfHandle, final long readOptionsHandle);
   private native byte[] getFromBatch(final long handle, final long optHandle,
       final byte[] key, final int keyLen);
   private native byte[] getFromBatch(final long handle, final long optHandle,

java/src/test/java/org/rocksdb/WriteBatchWithIndexTest.java

@@ -13,7 +13,9 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.nio.ByteBuffer;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
@@ -101,6 +103,95 @@ public class WriteBatchWithIndexTest {
     }
   }
 
+  @Test
+  public void readYourOwnWritesCf() throws RocksDBException {
+    final List<ColumnFamilyDescriptor> cfNames =
+        Arrays.asList(new ColumnFamilyDescriptor(RocksDB.DEFAULT_COLUMN_FAMILY),
+            new ColumnFamilyDescriptor("new_cf".getBytes()));
+
+    final List<ColumnFamilyHandle> columnFamilyHandleList = new ArrayList<>();
+
+    // Test open database with column family names
+    try (final DBOptions options =
+             new DBOptions().setCreateIfMissing(true).setCreateMissingColumnFamilies(true);
+         final RocksDB db = RocksDB.open(
+             options, dbFolder.getRoot().getAbsolutePath(), cfNames, columnFamilyHandleList)) {
+      final ColumnFamilyHandle newCf = columnFamilyHandleList.get(1);
+
+      try {
+        final byte[] k1 = "key1".getBytes();
+        final byte[] v1 = "value1".getBytes();
+        final byte[] k2 = "key2".getBytes();
+        final byte[] v2 = "value2".getBytes();
+
+        db.put(newCf, k1, v1);
+        db.put(newCf, k2, v2);
+
+        try (final WriteBatchWithIndex wbwi = new WriteBatchWithIndex(true);
+             final ReadOptions readOptions = new ReadOptions();
+             final RocksIterator base = db.newIterator(newCf, readOptions);
+             final RocksIterator it = wbwi.newIteratorWithBase(newCf, base, readOptions)) {
+          it.seek(k1);
+          assertThat(it.isValid()).isTrue();
+          assertThat(it.key()).isEqualTo(k1);
+          assertThat(it.value()).isEqualTo(v1);
+
+          it.seek(k2);
+          assertThat(it.isValid()).isTrue();
+          assertThat(it.key()).isEqualTo(k2);
+          assertThat(it.value()).isEqualTo(v2);
+
+          // put data to the write batch and make sure we can read it.
+          final byte[] k3 = "key3".getBytes();
+          final byte[] v3 = "value3".getBytes();
+          wbwi.put(newCf, k3, v3);
+          it.seek(k3);
+          assertThat(it.isValid()).isTrue();
+          assertThat(it.key()).isEqualTo(k3);
+          assertThat(it.value()).isEqualTo(v3);
+
+          // update k2 in the write batch and check the value
+          final byte[] v2Other = "otherValue2".getBytes();
+          wbwi.put(newCf, k2, v2Other);
+          it.seek(k2);
+          assertThat(it.isValid()).isTrue();
+          assertThat(it.key()).isEqualTo(k2);
+          assertThat(it.value()).isEqualTo(v2Other);
+
+          // delete k1 and make sure we can read back the write
+          wbwi.delete(newCf, k1);
+          it.seek(k1);
+          assertThat(it.key()).isNotEqualTo(k1);
+
+          // reinsert k1 and make sure we see the new value
+          final byte[] v1Other = "otherValue1".getBytes();
+          wbwi.put(newCf, k1, v1Other);
+          it.seek(k1);
+          assertThat(it.isValid()).isTrue();
+          assertThat(it.key()).isEqualTo(k1);
+          assertThat(it.value()).isEqualTo(v1Other);
+
+          // single remove k3 and make sure we can read back the write
+          wbwi.singleDelete(newCf, k3);
+          it.seek(k3);
+          assertThat(it.isValid()).isEqualTo(false);
+
+          // reinsert k3 and make sure we see the new value
+          final byte[] v3Other = "otherValue3".getBytes();
+          wbwi.put(newCf, k3, v3Other);
+          it.seek(k3);
+          assertThat(it.isValid()).isTrue();
+          assertThat(it.key()).isEqualTo(k3);
+          assertThat(it.value()).isEqualTo(v3Other);
+        }
+      } finally {
+        for (final ColumnFamilyHandle columnFamilyHandle : columnFamilyHandleList) {
+          columnFamilyHandle.close();
+        }
+      }
+    }
+  }
+
   @Test
   public void writeBatchWithIndex() throws RocksDBException {
     try (final Options options = new Options().setCreateIfMissing(true);