[JNI] Add java api and java tests for WriteBatch and WriteOptions, add put() and remove() to RocksDB.

Summary:
* Add java api for rocksdb::WriteBatch and rocksdb::WriteOptions, which are necessary components
  for running benchmark.
* Add java test for org.rocksdb.WriteBatch and org.rocksdb.WriteOptions.
* Add remove() to org.rocksdb.RocksDB, and add put() and remove() to RocksDB which take
  org.rocksdb.WriteOptions.

Test Plan: make jtest

Reviewers: haobo, sdong, dhruba

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17373

java/org/rocksdb/RocksDB.java

@@ -1,4 +1,4 @@
-// Copyright (c) 2013, Facebook, Inc.  All rights reserved.
+// Copyright (c) 2014, Facebook, Inc.  All rights reserved.
 // This source code is licensed under the BSD-style license found in the
 // LICENSE file in the root directory of this source tree. An additional grant
 // of patent rights can be found in the PATENTS file in the same directory.
@@ -64,6 +64,17 @@ public class RocksDB {
     put(key, key.length, value, value.length);
   }
 
+  /**
+   * Set the database entry for "key" to "value".
+   *
+   * @param key the specified key to be inserted.
+   * @param value the value associated with the specified key.
+   */
+  public void put(WriteOptions writeOpts, byte[] key, byte[] value)
+      throws RocksDBException {
+    put(writeOpts.nativeHandle_, key, key.length, value, value.length);
+  }
+
   /**
    * Get the value associated with the specified key.
    *
@@ -95,6 +106,25 @@ public class RocksDB {
     return get(key, key.length);
   }
 
+  /**
+   * Remove the database entry (if any) for "key".  Returns OK on
+   * success, and a non-OK status on error.  It is not an error if "key"
+   * did not exist in the database.
+   */
+  public void remove(byte[] key) throws RocksDBException {
+    remove(key, key.length);
+  }
+
+  /**
+   * Remove the database entry (if any) for "key".  Returns OK on
+   * success, and a non-OK status on error.  It is not an error if "key"
+   * did not exist in the database.
+   */
+  public void remove(WriteOptions writeOpt, byte[] key)
+      throws RocksDBException {
+    remove(writeOpt.nativeHandle_, key, key.length);
+  }
+
   @Override protected void finalize() {
     close();
   }
@@ -108,15 +138,23 @@ public class RocksDB {
 
   // native methods
   private native void open0(String path) throws RocksDBException;
-  private native void open(long optionsHandle, String path) throws RocksDBException;
+  private native void open(
+      long optionsHandle, String path) throws RocksDBException;
   private native void put(
       byte[] key, int keyLen,
       byte[] value, int valueLen) throws RocksDBException;
+  private native void put(
+      long writeOptHandle, byte[] key, int keyLen,
+      byte[] value, int valueLen) throws RocksDBException;
   private native int get(
       byte[] key, int keyLen,
       byte[] value, int valueLen) throws RocksDBException;
   private native byte[] get(
       byte[] key, int keyLen) throws RocksDBException;
+  private native void remove(
+      byte[] key, int keyLen) throws RocksDBException;
+  private native void remove(
+      long writeOptHandle, byte[] key, int keyLen) throws RocksDBException;
   private native void close0();
 
   private long nativeHandle_;

java/org/rocksdb/WriteBatch.java

@@ -0,0 +1,121 @@
+// Copyright (c) 2014, Facebook, Inc.  All rights reserved.
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree. An additional grant
+// of patent rights can be found in the PATENTS file in the same directory.
+
+package org.rocksdb;
+
+import java.lang.*;
+import java.util.*;
+
+/**
+ * WriteBatch holds a collection of updates to apply atomically to a DB.
+ *
+ * The updates are applied in the order in which they are added
+ * to the WriteBatch.  For example, the value of "key" will be "v3"
+ * after the following batch is written:
+ *
+ *    batch.put("key", "v1");
+ *    batch.remove("key");
+ *    batch.put("key", "v2");
+ *    batch.put("key", "v3");
+ *
+ * Multiple threads can invoke const methods on a WriteBatch without
+ * external synchronization, but if any of the threads may call a
+ * non-const method, all threads accessing the same WriteBatch must use
+ * external synchronization.
+ */
+public class WriteBatch {
+  public WriteBatch() {
+    nativeHandle_ = 0;
+    newWriteBatch(0);
+  }
+
+  public WriteBatch(int reserved_bytes) {
+    nativeHandle_ = 0;
+    newWriteBatch(reserved_bytes);
+  }
+
+  /**
+   * Returns the number of updates in the batch.
+   */
+  public native int count();
+
+  /**
+   * Store the mapping "key->value" in the database.
+   */
+  public void put(byte[] key, byte[] value) {
+    put(key, key.length, value, value.length);
+  }
+
+  /**
+   * Merge "value" with the existing value of "key" in the database.
+   * "key->merge(existing, value)"
+   */
+  public void merge(byte[] key, byte[] value) {
+    merge(key, key.length, value, value.length);
+  }
+
+  /**
+   * If the database contains a mapping for "key", erase it.  Else do nothing.
+   */
+  public void remove(byte[] key) {
+    remove(key, key.length);
+  }
+
+  /**
+   * Append a blob of arbitrary size to the records in this batch. The blob will
+   * be stored in the transaction log but not in any other file. In particular,
+   * it will not be persisted to the SST files. When iterating over this
+   * WriteBatch, WriteBatch::Handler::LogData will be called with the contents
+   * of the blob as it is encountered. Blobs, puts, deletes, and merges will be
+   * encountered in the same order in thich they were inserted. The blob will
+   * NOT consume sequence number(s) and will NOT increase the count of the batch
+   *
+   * Example application: add timestamps to the transaction log for use in
+   * replication.
+   */
+  public void putLogData(byte[] blob) {
+    putLogData(blob, blob.length);
+  }
+
+  /**
+   * Clear all updates buffered in this batch
+   */
+  public native void clear();
+
+  /**
+   * Delete the c++ side pointer.
+   */
+  public synchronized void dispose() {
+    if (nativeHandle_ != 0) {
+      dispose0();
+    }
+  }
+
+  @Override protected void finalize() {
+    dispose();
+  }
+
+  private native void newWriteBatch(int reserved_bytes);
+  private native void put(byte[] key, int keyLen,
+                          byte[] value, int valueLen);
+  private native void merge(byte[] key, int keyLen,
+                            byte[] value, int valueLen);
+  private native void remove(byte[] key, int keyLen);
+  private native void putLogData(byte[] blob, int blobLen);
+  private native void dispose0();
+
+  private long nativeHandle_;
+}
+
+/**
+ * Package-private class which provides java api to access
+ * c++ WriteBatchInternal.
+ */
+class WriteBatchInternal {
+  static native void setSequence(WriteBatch batch, long sn);
+  static native long sequence(WriteBatch batch);
+  static native void append(WriteBatch b1, WriteBatch b2);
+}
+

java/org/rocksdb/WriteBatchTest.java

@@ -0,0 +1,125 @@
+//  Copyright (c) 2014, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+package org.rocksdb;
+
+import java.util.*;
+import java.lang.*;
+import java.io.UnsupportedEncodingException;
+
+/**
+ * This class mimics the db/write_batch_test.cc in the c++ rocksdb library.
+ */
+public class WriteBatchTest {
+  static {
+    System.loadLibrary("rocksdbjni");
+  }
+
+  public static void main(String args[]) {
+    System.out.println("Testing WriteBatchTest.Empty ===");
+    Empty();
+
+    System.out.println("Testing WriteBatchTest.Multiple ===");
+    Multiple();
+
+    System.out.println("Testing WriteBatchTest.Append ===");
+    Append();
+
+    System.out.println("Testing WriteBatchTest.Blob ===");
+    Blob();
+
+    // The following tests have not yet ported.
+    // Continue();
+    // PutGatherSlices();
+
+    System.out.println("Passed all WriteBatchTest!");
+  }
+
+  static void Empty() {
+    WriteBatch batch = new WriteBatch();
+    assert(batch.count() == 0);
+  }
+
+  static void Multiple() {
+    try {
+      WriteBatch batch =  new WriteBatch();
+      batch.put("foo".getBytes("US-ASCII"), "bar".getBytes("US-ASCII"));
+      batch.remove("box".getBytes("US-ASCII"));
+      batch.put("baz".getBytes("US-ASCII"), "boo".getBytes("US-ASCII"));
+      WriteBatchInternal.setSequence(batch, 100);
+      assert(100 == WriteBatchInternal.sequence(batch));
+      assert(3 == batch.count());
+      assert(new String("Put(baz, boo)@102" +
+                        "Delete(box)@101" +
+                        "Put(foo, bar)@100")
+                .equals(new String(getContents(batch), "US-ASCII")));
+    } catch (UnsupportedEncodingException e) {
+      System.err.println(e);
+      assert(false);
+    }
+  }
+
+  static void Append() {
+    WriteBatch b1 = new WriteBatch();
+    WriteBatch b2 = new WriteBatch();
+    WriteBatchInternal.setSequence(b1, 200);
+    WriteBatchInternal.setSequence(b2, 300);
+    WriteBatchInternal.append(b1, b2);
+    assert(getContents(b1).length == 0);
+    assert(b1.count() == 0);
+    try {
+      b2.put("a".getBytes("US-ASCII"), "va".getBytes("US-ASCII"));
+      WriteBatchInternal.append(b1, b2);
+      assert("Put(a, va)@200".equals(new String(getContents(b1), "US-ASCII")));
+      assert(1 == b1.count());
+      b2.clear();
+      b2.put("b".getBytes("US-ASCII"), "vb".getBytes("US-ASCII"));
+      WriteBatchInternal.append(b1, b2);
+      assert(new String("Put(a, va)@200" +
+                        "Put(b, vb)@201")
+                .equals(new String(getContents(b1), "US-ASCII")));
+      assert(2 == b1.count());
+      b2.remove("foo".getBytes("US-ASCII"));
+      WriteBatchInternal.append(b1, b2);
+      assert(new String("Put(a, va)@200" +
+                        "Put(b, vb)@202" +
+                        "Put(b, vb)@201" +
+                        "Delete(foo)@203")
+                 .equals(new String(getContents(b1), "US-ASCII")));
+      assert(4 == b1.count());
+    } catch (UnsupportedEncodingException e) {
+      System.err.println(e);
+      assert(false);
+    }
+  }
+
+  static void Blob() {
+    WriteBatch batch = new WriteBatch();
+    try {
+      batch.put("k1".getBytes("US-ASCII"), "v1".getBytes("US-ASCII"));
+      batch.put("k2".getBytes("US-ASCII"), "v2".getBytes("US-ASCII"));
+      batch.put("k3".getBytes("US-ASCII"), "v3".getBytes("US-ASCII"));
+      batch.putLogData("blob1".getBytes("US-ASCII"));
+      batch.remove("k2".getBytes("US-ASCII"));
+      batch.putLogData("blob2".getBytes("US-ASCII"));
+      batch.merge("foo".getBytes("US-ASCII"), "bar".getBytes("US-ASCII"));
+      assert(5 == batch.count());
+      assert(new String("Merge(foo, bar)@4" +
+                        "Put(k1, v1)@0" +
+                        "Delete(k2)@3" +
+                        "Put(k2, v2)@1" +
+                        "Put(k3, v3)@2")
+                .equals(new String(getContents(batch), "US-ASCII")));
+    } catch (UnsupportedEncodingException e) {
+      System.err.println(e);
+      assert(false);
+    }
+  }
+
+  static native byte[] getContents(WriteBatch batch);
+}

java/org/rocksdb/WriteOptions.java

@@ -0,0 +1,96 @@
+// Copyright (c) 2014, Facebook, Inc.  All rights reserved.
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree. An additional grant
+// of patent rights can be found in the PATENTS file in the same directory.
+
+package org.rocksdb;
+
+/**
+ * Options that control write operations.
+ *
+ * Note that developers should call WriteOptions.dispose() to release the
+ * c++ side memory before a WriteOptions instance runs out of scope.
+ */
+public class WriteOptions {
+  public WriteOptions() {
+    nativeHandle_ = 0;
+    newWriteOptions();
+  }
+
+  public synchronized void dispose() {
+    if (nativeHandle_ != 0) {
+      dispose0(nativeHandle_);
+    }
+  }
+
+  /**
+   * If true, the write will be flushed from the operating system
+   * buffer cache (by calling WritableFile::Sync()) before the write
+   * is considered complete.  If this flag is true, writes will be
+   * slower.
+   *
+   * If this flag is false, and the machine crashes, some recent
+   * writes may be lost.  Note that if it is just the process that
+   * crashes (i.e., the machine does not reboot), no writes will be
+   * lost even if sync==false.
+   *
+   * In other words, a DB write with sync==false has similar
+   * crash semantics as the "write()" system call.  A DB write
+   * with sync==true has similar crash semantics to a "write()"
+   * system call followed by "fdatasync()".
+   *
+   * Default: false
+   */
+  public void setSync(boolean flag) {
+    setSync(nativeHandle_, flag);
+  }
+
+  /**
+   * If true, the write will be flushed from the operating system
+   * buffer cache (by calling WritableFile::Sync()) before the write
+   * is considered complete.  If this flag is true, writes will be
+   * slower.
+   *
+   * If this flag is false, and the machine crashes, some recent
+   * writes may be lost.  Note that if it is just the process that
+   * crashes (i.e., the machine does not reboot), no writes will be
+   * lost even if sync==false.
+   *
+   * In other words, a DB write with sync==false has similar
+   * crash semantics as the "write()" system call.  A DB write
+   * with sync==true has similar crash semantics to a "write()"
+   * system call followed by "fdatasync()".
+   */
+  public boolean sync() {
+    return sync(nativeHandle_);
+  }
+
+  /**
+   * If true, writes will not first go to the write ahead log,
+   * and the write may got lost after a crash.
+   */
+  public void setDisableWAL(boolean flag) {
+    setDisableWAL(nativeHandle_, flag);
+  }
+
+  /**
+   * If true, writes will not first go to the write ahead log,
+   * and the write may got lost after a crash.
+   */
+  public boolean disableWAL() {
+    return disableWAL(nativeHandle_);
+  }
+
+  @Override protected void finalize() {
+    dispose();
+  }
+
+  private native void newWriteOptions();
+  private native void setSync(long handle, boolean flag);
+  private native boolean sync(long handle);
+  private native void setDisableWAL(long handle, boolean flag);
+  private native boolean disableWAL(long handle);
+  private native void dispose0(long handle);
+
+  protected  long nativeHandle_;
+}