Summary: Added support for the merge operation to RocksJava. You can specify a merge function to be used on the current database. The merge function can either be one of the functions defined in utilities/merge_operators.h, which can be specified through its corresponding name, or a user-created function that needs to be encapsulated in a JNI object in order to be used. Examples are provided for both use cases. Test Plan: There are unit test in MergeTest.java Reviewers: ankgup87 Subscribers: vladb38 Differential Revision: https://reviews.facebook.net/D24525main
Vlad Balan
10 years ago
committed by
Vlad Balan
parent
b5dd7eed68
commit
a40ce219b9
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// Copyright (c) 2014, Vlad Balan (vlad.gm@gmail.com). All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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package org.rocksdb; |
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import java.util.*; |
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/** |
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* MergeOperator holds an operator to be applied when compacting |
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* two values held under the same key in order to obtain a single |
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* value. |
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*/ |
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public abstract class MergeOperator { |
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abstract protected long newMergeOperatorHandle(); |
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} |
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// Copyright (c) 2014, Vlad Balan (vlad.gm@gmail.com). All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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package org.rocksdb; |
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/** |
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* MergeOperator holds an operator to be applied when compacting |
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* two values held under the same key in order to obtain a single |
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* value. |
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*/ |
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public class StringAppendOperator extends MergeOperator { |
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@Override protected long newMergeOperatorHandle() { |
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return newMergeOperatorHandleImpl(); |
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} |
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private native long newMergeOperatorHandleImpl(); |
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} |
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// Copyright (c) 2014, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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package org.rocksdb.test; |
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import java.util.Collections; |
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import org.rocksdb.*; |
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public class MergeTest { |
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static final String db_path_string = "/tmp/mergestringjni_db"; |
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static final String db_path_function = "/tmp/mergefunctionjni_db"; |
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static { |
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RocksDB.loadLibrary(); |
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} |
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public static void testStringOption() |
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throws InterruptedException, RocksDBException { |
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System.out.println("Testing merge function string option ==="); |
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Options opt = new Options(); |
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opt.setCreateIfMissing(true); |
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opt.setMergeOperatorName("stringappend"); |
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RocksDB db = RocksDB.open(opt, db_path_string); |
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System.out.println("Writing aa under key..."); |
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db.put("key".getBytes(), "aa".getBytes()); |
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System.out.println("Writing bb under key..."); |
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db.merge("key".getBytes(), "bb".getBytes()); |
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byte[] value = db.get("key".getBytes()); |
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String strValue = new String(value); |
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System.out.println("Retrieved value: " + strValue); |
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db.close(); |
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opt.dispose(); |
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assert(strValue.equals("aa,bb")); |
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System.out.println("Merge function string option passed!"); |
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} |
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public static void testOperatorOption() |
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throws InterruptedException, RocksDBException { |
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System.out.println("Testing merge function operator option ==="); |
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Options opt = new Options(); |
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opt.setCreateIfMissing(true); |
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StringAppendOperator stringAppendOperator = new StringAppendOperator(); |
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opt.setMergeOperator(stringAppendOperator); |
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RocksDB db = RocksDB.open(opt, db_path_string); |
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System.out.println("Writing aa under key..."); |
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db.put("key".getBytes(), "aa".getBytes()); |
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System.out.println("Writing bb under key..."); |
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db.merge("key".getBytes(), "bb".getBytes()); |
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byte[] value = db.get("key".getBytes()); |
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String strValue = new String(value); |
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System.out.println("Retrieved value: " + strValue); |
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db.close(); |
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opt.dispose(); |
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assert(strValue.equals("aa,bb")); |
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System.out.println("Merge function operator option passed!"); |
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} |
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public static void main(String[] args) |
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throws InterruptedException, RocksDBException { |
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testStringOption(); |
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testOperatorOption(); |
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} |
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} |
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// Copyright (c) 2014, Vlad Balan (vlad.gm@gmail.com). All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// This file implements the "bridge" between Java and C++ for rocksdb::MergeOperator.
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <jni.h> |
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#include <string> |
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#include <memory> |
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#include "include/org_rocksdb_StringAppendOperator.h" |
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#include "rocksjni/portal.h" |
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#include "rocksdb/db.h" |
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#include "rocksdb/options.h" |
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#include "rocksdb/statistics.h" |
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#include "rocksdb/memtablerep.h" |
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#include "rocksdb/table.h" |
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#include "rocksdb/slice_transform.h" |
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#include "rocksdb/merge_operator.h" |
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#include "utilities/merge_operators.h" |
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/*
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* Class: org_rocksdb_StringAppendOperator |
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* Method: newMergeOperatorHandle |
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* Signature: ()J |
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*/ |
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jlong Java_org_rocksdb_StringAppendOperator_newMergeOperatorHandleImpl(JNIEnv* env, jobject jobj) { |
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std::shared_ptr<rocksdb::MergeOperator> *op = new std::shared_ptr<rocksdb::MergeOperator>(); |
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*op = rocksdb::MergeOperators::CreateFromStringId("stringappend"); |
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return reinterpret_cast<jlong>(op); |
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} |
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