Summary: This diff contains a simple jni library for rocksdb which supports open, get, put and closeusing default options (including Options, ReadOptions, and WriteOptions.) In the usual case, Java developers can use the c++ rocksdb library in the way similar to the following: RocksDB db = RocksDB.open(path_to_db); ... db.put("hello".getBytes(), "world".getBytes(); byte[] value = db.get("hello".getBytes()); ... db.close(); Specifically, this diff has the following major classes: * RocksDB: a Java wrapper class which forwards the operations from the java side to c++ rocksdb library. * RocksDBException: ncapsulates the error of an operation. This exception type is used to describe an internal error from the c++ rocksdb library. This diff also include a simple java sample code calling c++ rocksdb library. To build the rocksdb jni library, simply run make jni, and make jtest will try to build and run the sample code. Note that if the rocksdb is not built with the default glibc that Java uses, java will try to load the wrong glibc during the run time. As a result, the sample code might not work properly during the run time. Test Plan: * make jni * make jtest Reviewers: haobo, dhruba, sdong, igor, ljin Reviewed By: dhruba CC: leveldb, xjin Differential Revision: https://reviews.facebook.net/D17109
80 lines
2.4 KiB
Java
80 lines
2.4 KiB
Java
// 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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import java.util.*;
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import java.lang.*;
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import org.rocksdb.*;
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import java.io.IOException;
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public class RocksDBSample {
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static {
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System.loadLibrary("rocksdbjni");
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}
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public static void main(String[] args) {
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if (args.length < 1) {
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System.out.println("usage: RocksDBSample db_path");
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return;
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}
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String db_path = args[0];
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System.out.println("RocksDBSample");
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try {
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RocksDB db = RocksDB.open(db_path);
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db.put("hello".getBytes(), "world".getBytes());
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byte[] value = db.get("hello".getBytes());
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System.out.format("Get('hello') = %s\n",
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new String(value));
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for (int i = 1; i <= 9; ++i) {
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for (int j = 1; j <= 9; ++j) {
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db.put(String.format("%dx%d", i, j).getBytes(),
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String.format("%d", i * j).getBytes());
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}
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}
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for (int i = 1; i <= 9; ++i) {
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for (int j = 1; j <= 9; ++j) {
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System.out.format("%s ", new String(db.get(
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String.format("%dx%d", i, j).getBytes())));
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}
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System.out.println("");
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}
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value = db.get("1x1".getBytes());
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assert(value != null);
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value = db.get("world".getBytes());
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assert(value == null);
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byte[] testKey = "asdf".getBytes();
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byte[] testValue =
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"asdfghjkl;'?><MNBVCXZQWERTYUIOP{+_)(*&^%$#@".getBytes();
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db.put(testKey, testValue);
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byte[] testResult = db.get(testKey);
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assert(testResult != null);
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assert(Arrays.equals(testValue, testResult));
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assert(new String(testValue).equals(new String(testResult)));
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byte[] insufficientArray = new byte[10];
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byte[] enoughArray = new byte[50];
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int len;
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len = db.get(testKey, insufficientArray);
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assert(len > testKey.length);
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len = db.get("asdfjkl;".getBytes(), enoughArray);
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assert(len == RocksDB.NOT_FOUND);
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len = db.get(testKey, enoughArray);
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assert(len == testValue.length);
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try {
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db.close();
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} catch (IOException e) {
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System.err.println(e);
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}
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} catch (RocksDBException e) {
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System.err.println(e);
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}
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}
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}
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