Squashed 'src/rocksdb/' content from commit 224932d

git-subtree-dir: src/rocksdb
git-subtree-split: 224932d4d0b561712107d747c662df181c39644d

java/rocksjni/backupablejni.cc

@@ -0,0 +1,95 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::BackupableDB and rocksdb::BackupableDBOptions methods
+// from Java side.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+#include <string>
+
+#include "include/org_rocksdb_BackupableDB.h"
+#include "include/org_rocksdb_BackupableDBOptions.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/utilities/backupable_db.h"
+
+/*
+ * Class:     org_rocksdb_BackupableDB
+ * Method:    open
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_BackupableDB_open(
+    JNIEnv* env, jobject jbdb, jlong jdb_handle, jlong jopt_handle) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  auto opt = reinterpret_cast<rocksdb::BackupableDBOptions*>(jopt_handle);
+  auto bdb = new rocksdb::BackupableDB(db, *opt);
+
+  // as BackupableDB extends RocksDB on the java side, we can reuse
+  // the RocksDB portal here.
+  rocksdb::RocksDBJni::setHandle(env, jbdb, bdb);
+}
+
+/*
+ * Class:     org_rocksdb_BackupableDB
+ * Method:    createNewBackup
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_BackupableDB_createNewBackup(
+    JNIEnv* env, jobject jbdb, jlong jhandle, jboolean jflag) {
+  reinterpret_cast<rocksdb::BackupableDB*>(jhandle)->CreateNewBackup(jflag);
+}
+
+///////////////////////////////////////////////////////////////////////////
+// BackupDBOptions
+
+/*
+ * Class:     org_rocksdb_BackupableDBOptions
+ * Method:    newBackupableDBOptions
+ * Signature: (Ljava/lang/String;)V
+ */
+void Java_org_rocksdb_BackupableDBOptions_newBackupableDBOptions(
+    JNIEnv* env, jobject jobj, jstring jpath, jboolean jshare_table_files,
+    jboolean jsync, jboolean jdestroy_old_data, jboolean jbackup_log_files,
+    jlong jbackup_rate_limit, jlong jrestore_rate_limit) {
+  jbackup_rate_limit = (jbackup_rate_limit <= 0) ? 0 : jbackup_rate_limit;
+  jrestore_rate_limit = (jrestore_rate_limit <= 0) ? 0 : jrestore_rate_limit;
+
+  const char* cpath = env->GetStringUTFChars(jpath, 0);
+
+  auto bopt = new rocksdb::BackupableDBOptions(cpath, nullptr,
+      jshare_table_files, nullptr, jsync, jdestroy_old_data, jbackup_log_files,
+      jbackup_rate_limit, jrestore_rate_limit);
+
+  env->ReleaseStringUTFChars(jpath, cpath);
+
+  rocksdb::BackupableDBOptionsJni::setHandle(env, jobj, bopt);
+}
+
+/*
+ * Class:     org_rocksdb_BackupableDBOptions
+ * Method:    backupDir
+ * Signature: (J)Ljava/lang/String;
+ */
+jstring Java_org_rocksdb_BackupableDBOptions_backupDir(
+    JNIEnv* env, jobject jopt, jlong jhandle, jstring jpath) {
+  auto bopt = reinterpret_cast<rocksdb::BackupableDBOptions*>(jhandle);
+  return env->NewStringUTF(bopt->backup_dir.c_str());
+}
+
+/*
+ * Class:     org_rocksdb_BackupableDBOptions
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_BackupableDBOptions_disposeInternal(
+    JNIEnv* env, jobject jopt, jlong jhandle) {
+  auto bopt = reinterpret_cast<rocksdb::BackupableDBOptions*>(jhandle);
+  assert(bopt);
+  delete bopt;
+
+  rocksdb::BackupableDBOptionsJni::setHandle(env, jopt, nullptr);
+}

java/rocksjni/env.cc

@@ -0,0 +1,66 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::Env methods from Java side.
+
+#include "include/org_rocksdb_RocksEnv.h"
+#include "rocksdb/env.h"
+
+/*
+ * Class:     org_rocksdb_RocksEnv
+ * Method:    getDefaultEnvInternal
+ * Signature: ()J
+ */
+jlong Java_org_rocksdb_RocksEnv_getDefaultEnvInternal(
+    JNIEnv* env, jclass jclass) {
+  return reinterpret_cast<jlong>(rocksdb::Env::Default());
+}
+
+/*
+ * Class:     org_rocksdb_RocksEnv
+ * Method:    setBackgroundThreads
+ * Signature: (JII)V
+ */
+void Java_org_rocksdb_RocksEnv_setBackgroundThreads(
+    JNIEnv* env, jobject jobj, jlong jhandle,
+    jint num, jint priority) {
+  auto* rocks_env = reinterpret_cast<rocksdb::Env*>(jhandle);
+  switch (priority) {
+    case org_rocksdb_RocksEnv_FLUSH_POOL:
+      rocks_env->SetBackgroundThreads(num, rocksdb::Env::Priority::LOW);
+      break;
+    case org_rocksdb_RocksEnv_COMPACTION_POOL:
+      rocks_env->SetBackgroundThreads(num, rocksdb::Env::Priority::HIGH);
+      break;
+  }
+}
+
+/*
+ * Class:     org_rocksdb_RocksEnv
+ * Method:    getThreadPoolQueueLen
+ * Signature: (JI)I
+ */
+jint Java_org_rocksdb_RocksEnv_getThreadPoolQueueLen(
+    JNIEnv* env, jobject jobj, jlong jhandle, jint pool_id) {
+  auto* rocks_env = reinterpret_cast<rocksdb::Env*>(jhandle);
+  switch (pool_id) {
+    case org_rocksdb_RocksEnv_FLUSH_POOL:
+      return rocks_env->GetThreadPoolQueueLen(rocksdb::Env::Priority::LOW);
+    case org_rocksdb_RocksEnv_COMPACTION_POOL:
+      return rocks_env->GetThreadPoolQueueLen(rocksdb::Env::Priority::HIGH);
+  }
+  return 0;
+}
+
+/*
+ * Class:     org_rocksdb_RocksEnv
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RocksEnv_disposeInternal(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  delete reinterpret_cast<rocksdb::Env*>(jhandle);
+}

java/rocksjni/filter.cc

@@ -0,0 +1,38 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ for
+// rocksdb::FilterPolicy.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+#include <string>
+
+#include "include/org_rocksdb_Filter.h"
+#include "include/org_rocksdb_BloomFilter.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/filter_policy.h"
+
+/*
+ * Class:     org_rocksdb_BloomFilter
+ * Method:    createNewFilter0
+ * Signature: (I)V
+ */
+void Java_org_rocksdb_BloomFilter_createNewFilter0(
+    JNIEnv* env, jobject jobj, jint bits_per_key) {
+  const rocksdb::FilterPolicy* fp = rocksdb::NewBloomFilterPolicy(bits_per_key);
+  rocksdb::FilterJni::setHandle(env, jobj, fp);
+}
+
+/*
+ * Class:     org_rocksdb_Filter
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_Filter_disposeInternal(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  delete reinterpret_cast<rocksdb::FilterPolicy*>(handle);
+}

java/rocksjni/iterator.cc

@@ -0,0 +1,145 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::Iterator methods from Java side.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+
+#include "include/org_rocksdb_RocksIterator.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/iterator.h"
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    isValid0
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_RocksIterator_isValid0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  return reinterpret_cast<rocksdb::Iterator*>(handle)->Valid();
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    seekToFirst0
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RocksIterator_seekToFirst0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  reinterpret_cast<rocksdb::Iterator*>(handle)->SeekToFirst();
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    seekToFirst0
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RocksIterator_seekToLast0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  reinterpret_cast<rocksdb::Iterator*>(handle)->SeekToLast();
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    seekToLast0
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RocksIterator_next0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  reinterpret_cast<rocksdb::Iterator*>(handle)->Next();
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    next0
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RocksIterator_prev0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  reinterpret_cast<rocksdb::Iterator*>(handle)->Prev();
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    prev0
+ * Signature: (J)V
+ */
+jbyteArray Java_org_rocksdb_RocksIterator_key0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  auto it = reinterpret_cast<rocksdb::Iterator*>(handle);
+  rocksdb::Slice key_slice = it->key();
+
+  jbyteArray jkey = env->NewByteArray(key_slice.size());
+  env->SetByteArrayRegion(
+      jkey, 0, key_slice.size(),
+      reinterpret_cast<const jbyte*>(key_slice.data()));
+  return jkey;
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    key0
+ * Signature: (J)[B
+ */
+jbyteArray Java_org_rocksdb_RocksIterator_value0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  auto it = reinterpret_cast<rocksdb::Iterator*>(handle);
+  rocksdb::Slice value_slice = it->value();
+
+  jbyteArray jvalue = env->NewByteArray(value_slice.size());
+  env->SetByteArrayRegion(
+      jvalue, 0, value_slice.size(),
+      reinterpret_cast<const jbyte*>(value_slice.data()));
+  return jvalue;
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    value0
+ * Signature: (J)[B
+ */
+void Java_org_rocksdb_RocksIterator_seek0(
+    JNIEnv* env, jobject jobj, jlong handle,
+    jbyteArray jtarget, jint jtarget_len) {
+  auto it = reinterpret_cast<rocksdb::Iterator*>(handle);
+  jbyte* target = env->GetByteArrayElements(jtarget, 0);
+  rocksdb::Slice target_slice(
+      reinterpret_cast<char*>(target), jtarget_len);
+
+  it->Seek(target_slice);
+
+  env->ReleaseByteArrayElements(jtarget, target, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    seek0
+ * Signature: (J[BI)V
+ */
+void Java_org_rocksdb_RocksIterator_status0(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  auto it = reinterpret_cast<rocksdb::Iterator*>(handle);
+  rocksdb::Status s = it->status();
+
+  if (s.ok()) {
+    return;
+  }
+
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+}
+
+/*
+ * Class:     org_rocksdb_RocksIterator
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RocksIterator_disposeInternal(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  auto it = reinterpret_cast<rocksdb::Iterator*>(handle);
+  delete it;
+}

java/rocksjni/memtablejni.cc

@@ -0,0 +1,58 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ for MemTables.
+
+#include "include/org_rocksdb_HashSkipListMemTableConfig.h"
+#include "include/org_rocksdb_HashLinkedListMemTableConfig.h"
+#include "include/org_rocksdb_VectorMemTableConfig.h"
+#include "include/org_rocksdb_SkipListMemTableConfig.h"
+#include "rocksdb/memtablerep.h"
+
+/*
+ * Class:     org_rocksdb_HashSkipListMemTableConfig
+ * Method:    newMemTableFactoryHandle
+ * Signature: (JII)J
+ */
+jlong Java_org_rocksdb_HashSkipListMemTableConfig_newMemTableFactoryHandle(
+    JNIEnv* env, jobject jobj, jlong jbucket_count,
+    jint jheight, jint jbranching_factor) {
+  return reinterpret_cast<jlong>(rocksdb::NewHashSkipListRepFactory(
+      static_cast<size_t>(jbucket_count),
+      static_cast<int32_t>(jheight),
+      static_cast<int32_t>(jbranching_factor)));
+}
+
+/*
+ * Class:     org_rocksdb_HashLinkedListMemTableConfig
+ * Method:    newMemTableFactoryHandle
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_HashLinkedListMemTableConfig_newMemTableFactoryHandle(
+    JNIEnv* env, jobject jobj, jlong jbucket_count) {
+  return reinterpret_cast<jlong>(rocksdb::NewHashLinkListRepFactory(
+       static_cast<size_t>(jbucket_count)));
+}
+
+/*
+ * Class:     org_rocksdb_VectorMemTableConfig
+ * Method:    newMemTableFactoryHandle
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_VectorMemTableConfig_newMemTableFactoryHandle(
+    JNIEnv* env, jobject jobj, jlong jreserved_size) {
+  return reinterpret_cast<jlong>(new rocksdb::VectorRepFactory(
+      static_cast<size_t>(jreserved_size)));
+}
+
+/*
+ * Class:     org_rocksdb_SkipListMemTableConfig
+ * Method:    newMemTableFactoryHandle0
+ * Signature: ()J
+ */
+jlong Java_org_rocksdb_SkipListMemTableConfig_newMemTableFactoryHandle0(
+    JNIEnv* env, jobject jobj) {
+  return reinterpret_cast<jlong>(new rocksdb::SkipListFactory());
+}

java/rocksjni/portal.h

@@ -0,0 +1,383 @@
+// 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.
+
+// This file is designed for caching those frequently used IDs and provide
+// efficient portal (i.e, a set of static functions) to access java code
+// from c++.
+
+#ifndef JAVA_ROCKSJNI_PORTAL_H_
+#define JAVA_ROCKSJNI_PORTAL_H_
+
+#include <jni.h>
+#include "rocksdb/db.h"
+#include "rocksdb/filter_policy.h"
+#include "rocksdb/utilities/backupable_db.h"
+
+namespace rocksdb {
+
+// The portal class for org.rocksdb.RocksDB
+class RocksDBJni {
+ public:
+  // Get the java class id of org.rocksdb.RocksDB.
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/RocksDB");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.RocksDB
+  // that stores the pointer to rocksdb::DB.
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::DB of the specified org.rocksdb.RocksDB.
+  static rocksdb::DB* getHandle(JNIEnv* env, jobject jdb) {
+    return reinterpret_cast<rocksdb::DB*>(
+        env->GetLongField(jdb, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::DB pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jdb, rocksdb::DB* db) {
+    env->SetLongField(
+        jdb, getHandleFieldID(env),
+        reinterpret_cast<jlong>(db));
+  }
+};
+
+// The portal class for org.rocksdb.RocksDBException
+class RocksDBExceptionJni {
+ public:
+  // Get the jclass of org.rocksdb.RocksDBException
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/RocksDBException");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Create and throw a java exception by converting the input
+  // Status to an RocksDBException.
+  //
+  // In case s.ok() is true, then this function will not throw any
+  // exception.
+  static void ThrowNew(JNIEnv* env, Status s) {
+    if (s.ok()) {
+      return;
+    }
+    jstring msg = env->NewStringUTF(s.ToString().c_str());
+    // get the constructor id of org.rocksdb.RocksDBException
+    static jmethodID mid = env->GetMethodID(
+        getJClass(env), "<init>", "(Ljava/lang/String;)V");
+    assert(mid != nullptr);
+
+    env->Throw((jthrowable)env->NewObject(getJClass(env), mid, msg));
+  }
+};
+
+class OptionsJni {
+ public:
+  // Get the java class id of org.rocksdb.Options.
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/Options");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.Options
+  // that stores the pointer to rocksdb::Options
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::Options
+  static rocksdb::Options* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::Options*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::Options pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jobj, rocksdb::Options* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+class WriteOptionsJni {
+ public:
+  // Get the java class id of org.rocksdb.WriteOptions.
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/WriteOptions");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.WriteOptions
+  // that stores the pointer to rocksdb::WriteOptions
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::WriteOptions
+  static rocksdb::WriteOptions* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::WriteOptions*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::WriteOptions pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jobj, rocksdb::WriteOptions* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+
+class ReadOptionsJni {
+ public:
+  // Get the java class id of org.rocksdb.ReadOptions.
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/ReadOptions");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.ReadOptions
+  // that stores the pointer to rocksdb::ReadOptions
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::ReadOptions
+  static rocksdb::ReadOptions* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::ReadOptions*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::ReadOptions pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jobj,
+                        rocksdb::ReadOptions* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+
+class WriteBatchJni {
+ public:
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/WriteBatch");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::WriteBatch of the specified
+  // org.rocksdb.WriteBatch.
+  static rocksdb::WriteBatch* getHandle(JNIEnv* env, jobject jwb) {
+    return reinterpret_cast<rocksdb::WriteBatch*>(
+        env->GetLongField(jwb, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::WriteBatch pointer to the java side.
+  static void setHandle(JNIEnv* env, jobject jwb, rocksdb::WriteBatch* wb) {
+    env->SetLongField(
+        jwb, getHandleFieldID(env),
+        reinterpret_cast<jlong>(wb));
+  }
+};
+
+class HistogramDataJni {
+ public:
+  static jmethodID getConstructorMethodId(JNIEnv* env, jclass jclazz) {
+    static jmethodID mid = env->GetMethodID(jclazz, "<init>", "(DDDDD)V");
+    assert(mid != nullptr);
+    return mid;
+  }
+};
+
+class BackupableDBOptionsJni {
+ public:
+  // Get the java class id of org.rocksdb.BackupableDBOptions.
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/BackupableDBOptions");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.BackupableDBOptions
+  // that stores the pointer to rocksdb::BackupableDBOptions
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::BackupableDBOptions
+  static rocksdb::BackupableDBOptions* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::BackupableDBOptions*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::BackupableDBOptions pointer to the java side.
+  static void setHandle(
+      JNIEnv* env, jobject jobj, rocksdb::BackupableDBOptions* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+class IteratorJni {
+ public:
+  // Get the java class id of org.rocksdb.Iteartor.
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/RocksIterator");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.Iterator
+  // that stores the pointer to rocksdb::Iterator.
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::Iterator.
+  static rocksdb::Iterator* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::Iterator*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::Iterator pointer to the java side.
+  static void setHandle(
+      JNIEnv* env, jobject jobj, rocksdb::Iterator* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+class FilterJni {
+ public:
+  // Get the java class id of org.rocksdb.FilterPolicy.
+  static jclass getJClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("org/rocksdb/Filter");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the field id of the member variable of org.rocksdb.Filter
+  // that stores the pointer to rocksdb::FilterPolicy.
+  static jfieldID getHandleFieldID(JNIEnv* env) {
+    static jfieldID fid = env->GetFieldID(
+        getJClass(env), "nativeHandle_", "J");
+    assert(fid != nullptr);
+    return fid;
+  }
+
+  // Get the pointer to rocksdb::FilterPolicy.
+  static rocksdb::FilterPolicy* getHandle(JNIEnv* env, jobject jobj) {
+    return reinterpret_cast<rocksdb::FilterPolicy*>(
+        env->GetLongField(jobj, getHandleFieldID(env)));
+  }
+
+  // Pass the rocksdb::FilterPolicy pointer to the java side.
+  static void setHandle(
+      JNIEnv* env, jobject jobj, const rocksdb::FilterPolicy* op) {
+    env->SetLongField(
+        jobj, getHandleFieldID(env),
+        reinterpret_cast<jlong>(op));
+  }
+};
+
+class ListJni {
+ public:
+  // Get the java class id of java.util.List.
+  static jclass getListClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("java/util/List");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the java class id of java.util.ArrayList.
+  static jclass getArrayListClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("java/util/ArrayList");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the java class id of java.util.Iterator.
+  static jclass getIteratorClass(JNIEnv* env) {
+    jclass jclazz = env->FindClass("java/util/Iterator");
+    assert(jclazz != nullptr);
+    return jclazz;
+  }
+
+  // Get the java method id of java.util.List.iterator().
+  static jmethodID getIteratorMethod(JNIEnv* env) {
+    static jmethodID mid = env->GetMethodID(
+        getListClass(env), "iterator", "()Ljava/util/Iterator;");
+    assert(mid != nullptr);
+    return mid;
+  }
+
+  // Get the java method id of java.util.Iterator.hasNext().
+  static jmethodID getHasNextMethod(JNIEnv* env) {
+    static jmethodID mid = env->GetMethodID(
+        getIteratorClass(env), "hasNext", "()Z");
+    assert(mid != nullptr);
+    return mid;
+  }
+
+  // Get the java method id of java.util.Iterator.next().
+  static jmethodID getNextMethod(JNIEnv* env) {
+    static jmethodID mid = env->GetMethodID(
+        getIteratorClass(env), "next", "()Ljava/lang/Object;");
+    assert(mid != nullptr);
+    return mid;
+  }
+
+  // Get the java method id of arrayList constructor.
+  static jmethodID getArrayListConstructorMethodId(JNIEnv* env, jclass jclazz) {
+    static jmethodID mid = env->GetMethodID(
+        jclazz, "<init>", "(I)V");
+    assert(mid != nullptr);
+    return mid;
+  }
+
+  // Get the java method id of java.util.List.add().
+  static jmethodID getListAddMethodId(JNIEnv* env) {
+    static jmethodID mid = env->GetMethodID(
+        getListClass(env), "add", "(Ljava/lang/Object;)Z");
+    assert(mid != nullptr);
+    return mid;
+  }
+};
+}  // namespace rocksdb
+#endif  // JAVA_ROCKSJNI_PORTAL_H_

java/rocksjni/restorejni.cc

@@ -0,0 +1,145 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::RestoreBackupableDB and rocksdb::RestoreOptions methods
+// from Java side.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+#include <iostream>
+#include <string>
+
+#include "include/org_rocksdb_RestoreOptions.h"
+#include "include/org_rocksdb_RestoreBackupableDB.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/utilities/backupable_db.h"
+/*
+ * Class:     org_rocksdb_RestoreOptions
+ * Method:    newRestoreOptions
+ * Signature: (Z)J
+ */
+jlong Java_org_rocksdb_RestoreOptions_newRestoreOptions(JNIEnv* env,
+    jobject jobj, jboolean keep_log_files) {
+  auto ropt = new rocksdb::RestoreOptions(keep_log_files);
+  return reinterpret_cast<jlong>(ropt);
+}
+
+/*
+ * Class:     org_rocksdb_RestoreOptions
+ * Method:    dispose
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RestoreOptions_dispose(JNIEnv* env, jobject jobj,
+    jlong jhandle) {
+  auto ropt = reinterpret_cast<rocksdb::RestoreOptions*>(jhandle);
+  assert(ropt);
+  delete ropt;
+}
+
+/*
+ * Class:     org_rocksdb_RestoreBackupableDB
+ * Method:    newRestoreBackupableDB
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_RestoreBackupableDB_newRestoreBackupableDB(JNIEnv* env,
+    jobject jobj, jlong jopt_handle) {
+  auto opt = reinterpret_cast<rocksdb::BackupableDBOptions*>(jopt_handle);
+  auto rdb = new rocksdb::RestoreBackupableDB(rocksdb::Env::Default(), *opt);
+  return reinterpret_cast<jlong>(rdb);
+}
+
+/*
+ * Class:     org_rocksdb_RestoreBackupableDB
+ * Method:    restoreDBFromBackup0
+ * Signature: (JJLjava/lang/String;Ljava/lang/String;J)V
+ */
+void Java_org_rocksdb_RestoreBackupableDB_restoreDBFromBackup0(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jbackup_id, jstring jdb_dir,
+    jstring jwal_dir, jlong jopt_handle) {
+  auto opt = reinterpret_cast<rocksdb::RestoreOptions*>(jopt_handle);
+
+  const char* cdb_dir = env->GetStringUTFChars(jdb_dir, 0);
+  const char* cwal_dir = env->GetStringUTFChars(jwal_dir, 0);
+
+  auto rdb = reinterpret_cast<rocksdb::RestoreBackupableDB*>(jhandle);
+  rocksdb::Status s =
+      rdb->RestoreDBFromBackup(jbackup_id, cdb_dir, cwal_dir, *opt);
+
+  env->ReleaseStringUTFChars(jdb_dir, cdb_dir);
+  env->ReleaseStringUTFChars(jwal_dir, cwal_dir);
+
+  if(!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+}
+
+/*
+ * Class:     org_rocksdb_RestoreBackupableDB
+ * Method:    restoreDBFromLatestBackup0
+ * Signature: (JLjava/lang/String;Ljava/lang/String;J)V
+ */
+void Java_org_rocksdb_RestoreBackupableDB_restoreDBFromLatestBackup0(
+    JNIEnv* env, jobject jobj, jlong jhandle, jstring jdb_dir, jstring jwal_dir,
+    jlong jopt_handle) {
+  auto opt = reinterpret_cast<rocksdb::RestoreOptions*>(jopt_handle);
+
+  const char* cdb_dir = env->GetStringUTFChars(jdb_dir, 0);
+  const char* cwal_dir = env->GetStringUTFChars(jwal_dir, 0);
+
+  auto rdb = reinterpret_cast<rocksdb::RestoreBackupableDB*>(jhandle);
+  rocksdb::Status s =
+      rdb->RestoreDBFromLatestBackup(cdb_dir, cwal_dir, *opt);
+
+  env->ReleaseStringUTFChars(jdb_dir, cdb_dir);
+  env->ReleaseStringUTFChars(jwal_dir, cwal_dir);
+
+  if(!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+}
+
+/*
+ * Class:     org_rocksdb_RestoreBackupableDB
+ * Method:    purgeOldBackups0
+ * Signature: (JI)V
+ */
+void Java_org_rocksdb_RestoreBackupableDB_purgeOldBackups0(JNIEnv* env,
+    jobject jobj, jlong jhandle, jint jnum_backups_to_keep) {
+  auto rdb = reinterpret_cast<rocksdb::RestoreBackupableDB*>(jhandle);
+  rocksdb::Status s = rdb->PurgeOldBackups(jnum_backups_to_keep);
+
+  if(!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+}
+
+/*
+ * Class:     org_rocksdb_RestoreBackupableDB
+ * Method:    deleteBackup0
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_RestoreBackupableDB_deleteBackup0(JNIEnv* env,
+    jobject jobj, jlong jhandle, jlong jbackup_id) {
+  auto rdb = reinterpret_cast<rocksdb::RestoreBackupableDB*>(jhandle);
+  rocksdb::Status s = rdb->DeleteBackup(jbackup_id);
+
+  if(!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+}
+
+/*
+ * Class:     org_rocksdb_RestoreBackupableDB
+ * Method:    dispose
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RestoreBackupableDB_dispose(JNIEnv* env, jobject jobj,
+    jlong jhandle) {
+  auto ropt = reinterpret_cast<rocksdb::RestoreBackupableDB*>(jhandle);
+  assert(ropt);
+  delete ropt;
+}

java/rocksjni/rocksjni.cc

@@ -0,0 +1,440 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::DB methods from Java side.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+#include <string>
+#include <vector>
+
+#include "include/org_rocksdb_RocksDB.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/db.h"
+#include "rocksdb/cache.h"
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Open
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    open
+ * Signature: (JLjava/lang/String;)V
+ */
+void Java_org_rocksdb_RocksDB_open(
+    JNIEnv* env, jobject jdb, jlong jopt_handle,
+    jlong jcache_size, jint jnum_shardbits, jstring jdb_path) {
+  auto opt = reinterpret_cast<rocksdb::Options*>(jopt_handle);
+  if (jcache_size > 0) {
+    opt->no_block_cache = false;
+    if (jnum_shardbits >= 1) {
+      opt->block_cache = rocksdb::NewLRUCache(jcache_size, jnum_shardbits);
+    } else {
+      opt->block_cache = rocksdb::NewLRUCache(jcache_size);
+    }
+  } else {
+    opt->no_block_cache = true;
+    opt->block_cache = nullptr;
+  }
+
+  rocksdb::DB* db = nullptr;
+  const char* db_path = env->GetStringUTFChars(jdb_path, 0);
+  rocksdb::Status s = rocksdb::DB::Open(*opt, db_path, &db);
+  env->ReleaseStringUTFChars(jdb_path, db_path);
+
+  if (s.ok()) {
+    rocksdb::RocksDBJni::setHandle(env, jdb, db);
+    return;
+  }
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Put
+
+void rocksdb_put_helper(
+    JNIEnv* env, rocksdb::DB* db, const rocksdb::WriteOptions& write_options,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+
+  jbyte* key = env->GetByteArrayElements(jkey, 0);
+  jbyte* value = env->GetByteArrayElements(jvalue, 0);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  rocksdb::Slice value_slice(reinterpret_cast<char*>(value), jvalue_len);
+
+  rocksdb::Status s = db->Put(write_options, key_slice, value_slice);
+
+  // trigger java unref on key and value.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+  env->ReleaseByteArrayElements(jvalue, value, JNI_ABORT);
+
+  if (s.ok()) {
+    return;
+  }
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    put
+ * Signature: (J[BI[BI)V
+ */
+void Java_org_rocksdb_RocksDB_put__J_3BI_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  static const rocksdb::WriteOptions default_write_options =
+      rocksdb::WriteOptions();
+
+  rocksdb_put_helper(env, db, default_write_options,
+                     jkey, jkey_len,
+                     jvalue, jvalue_len);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    put
+ * Signature: (JJ[BI[BI)V
+ */
+void Java_org_rocksdb_RocksDB_put__JJ_3BI_3BI(
+    JNIEnv* env, jobject jdb,
+    jlong jdb_handle, jlong jwrite_options_handle,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  auto write_options = reinterpret_cast<rocksdb::WriteOptions*>(
+      jwrite_options_handle);
+
+  rocksdb_put_helper(env, db, *write_options,
+                     jkey, jkey_len,
+                     jvalue, jvalue_len);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Write
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    write
+ * Signature: (JJ)V
+ */
+void Java_org_rocksdb_RocksDB_write(
+    JNIEnv* env, jobject jdb,
+    jlong jwrite_options_handle, jlong jbatch_handle) {
+  rocksdb::DB* db = rocksdb::RocksDBJni::getHandle(env, jdb);
+  auto write_options = reinterpret_cast<rocksdb::WriteOptions*>(
+      jwrite_options_handle);
+  auto batch = reinterpret_cast<rocksdb::WriteBatch*>(jbatch_handle);
+
+  rocksdb::Status s = db->Write(*write_options, batch);
+
+  if (!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Get
+
+jbyteArray rocksdb_get_helper(
+    JNIEnv* env, rocksdb::DB* db, const rocksdb::ReadOptions& read_opt,
+    jbyteArray jkey, jint jkey_len) {
+  jboolean isCopy;
+  jbyte* key = env->GetByteArrayElements(jkey, &isCopy);
+  rocksdb::Slice key_slice(
+      reinterpret_cast<char*>(key), jkey_len);
+
+  std::string value;
+  rocksdb::Status s = db->Get(
+      read_opt, key_slice, &value);
+
+  // trigger java unref on key.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+
+  if (s.IsNotFound()) {
+    return nullptr;
+  }
+
+  if (s.ok()) {
+    jbyteArray jvalue = env->NewByteArray(value.size());
+    env->SetByteArrayRegion(
+        jvalue, 0, value.size(),
+        reinterpret_cast<const jbyte*>(value.c_str()));
+    return jvalue;
+  }
+  rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+
+  return nullptr;
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    get
+ * Signature: (J[BI)[B
+ */
+jbyteArray Java_org_rocksdb_RocksDB_get__J_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len) {
+  return rocksdb_get_helper(env,
+      reinterpret_cast<rocksdb::DB*>(jdb_handle),
+      rocksdb::ReadOptions(),
+      jkey, jkey_len);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    get
+ * Signature: (JJ[BI)[B
+ */
+jbyteArray Java_org_rocksdb_RocksDB_get__JJ_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle, jlong jropt_handle,
+    jbyteArray jkey, jint jkey_len) {
+  return rocksdb_get_helper(env,
+      reinterpret_cast<rocksdb::DB*>(jdb_handle),
+      *reinterpret_cast<rocksdb::ReadOptions*>(jropt_handle),
+      jkey, jkey_len);
+}
+
+jint rocksdb_get_helper(
+    JNIEnv* env, rocksdb::DB* db, const rocksdb::ReadOptions& read_options,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  static const int kNotFound = -1;
+  static const int kStatusError = -2;
+
+  jbyte* key = env->GetByteArrayElements(jkey, 0);
+  rocksdb::Slice key_slice(
+      reinterpret_cast<char*>(key), jkey_len);
+
+  // TODO(yhchiang): we might save one memory allocation here by adding
+  // a DB::Get() function which takes preallocated jbyte* as input.
+  std::string cvalue;
+  rocksdb::Status s = db->Get(
+      read_options, key_slice, &cvalue);
+
+  // trigger java unref on key.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+
+  if (s.IsNotFound()) {
+    return kNotFound;
+  } else if (!s.ok()) {
+    // Here since we are throwing a Java exception from c++ side.
+    // As a result, c++ does not know calling this function will in fact
+    // throwing an exception.  As a result, the execution flow will
+    // not stop here, and codes after this throw will still be
+    // executed.
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+
+    // Return a dummy const value to avoid compilation error, although
+    // java side might not have a chance to get the return value :)
+    return kStatusError;
+  }
+
+  int cvalue_len = static_cast<int>(cvalue.size());
+  int length = std::min(jvalue_len, cvalue_len);
+
+  env->SetByteArrayRegion(
+      jvalue, 0, length,
+      reinterpret_cast<const jbyte*>(cvalue.c_str()));
+  return cvalue_len;
+}
+
+jobject multi_get_helper(JNIEnv* env, jobject jdb, rocksdb::DB* db,
+    const rocksdb::ReadOptions& rOpt, jobject jkey_list, jint jkeys_count) {
+  std::vector<rocksdb::Slice> keys;
+  std::vector<jbyte*> keys_to_free;
+
+  // get iterator
+  jobject iteratorObj = env->CallObjectMethod(
+      jkey_list, rocksdb::ListJni::getIteratorMethod(env));
+
+  // iterate over keys and convert java byte array to slice
+  while(env->CallBooleanMethod(
+      iteratorObj, rocksdb::ListJni::getHasNextMethod(env)) == JNI_TRUE) {
+    jbyteArray jkey = (jbyteArray) env->CallObjectMethod(
+       iteratorObj, rocksdb::ListJni::getNextMethod(env));
+    jint key_length = env->GetArrayLength(jkey);
+
+    jbyte* key = new jbyte[key_length];
+    env->GetByteArrayRegion(jkey, 0, key_length, key);
+    // store allocated jbyte to free it after multiGet call
+    keys_to_free.push_back(key);
+
+    rocksdb::Slice key_slice(
+      reinterpret_cast<char*>(key), key_length);
+    keys.push_back(key_slice);
+  }
+
+  std::vector<std::string> values;
+  std::vector<rocksdb::Status> s = db->MultiGet(rOpt, keys, &values);
+
+  // Don't reuse class pointer
+  jclass jclazz = env->FindClass("java/util/ArrayList");
+  jmethodID mid = rocksdb::ListJni::getArrayListConstructorMethodId(
+      env, jclazz);
+  jobject jvalue_list = env->NewObject(jclazz, mid, jkeys_count);
+
+  // insert in java list
+  for(std::vector<rocksdb::Status>::size_type i = 0; i != s.size(); i++) {
+    if(s[i].ok()) {
+      jbyteArray jvalue = env->NewByteArray(values[i].size());
+      env->SetByteArrayRegion(
+          jvalue, 0, values[i].size(),
+          reinterpret_cast<const jbyte*>(values[i].c_str()));
+      env->CallBooleanMethod(
+          jvalue_list, rocksdb::ListJni::getListAddMethodId(env), jvalue);
+    }
+    else {
+      env->CallBooleanMethod(
+          jvalue_list, rocksdb::ListJni::getListAddMethodId(env), nullptr);
+    }
+  }
+
+  // free up allocated byte arrays
+  for(std::vector<jbyte*>::size_type i = 0; i != keys_to_free.size(); i++) {
+    delete[] keys_to_free[i];
+  }
+  keys_to_free.clear();
+
+  return jvalue_list;
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    multiGet
+ * Signature: (JLjava/util/List;I)Ljava/util/List;
+ */
+jobject Java_org_rocksdb_RocksDB_multiGet__JLjava_util_List_2I(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jobject jkey_list, jint jkeys_count) {
+  return multi_get_helper(env, jdb, reinterpret_cast<rocksdb::DB*>(jdb_handle),
+      rocksdb::ReadOptions(), jkey_list, jkeys_count);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    multiGet
+ * Signature: (JJLjava/util/List;I)Ljava/util/List;
+ */
+jobject Java_org_rocksdb_RocksDB_multiGet__JJLjava_util_List_2I(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jlong jropt_handle, jobject jkey_list, jint jkeys_count) {
+  return multi_get_helper(env, jdb, reinterpret_cast<rocksdb::DB*>(jdb_handle),
+      *reinterpret_cast<rocksdb::ReadOptions*>(jropt_handle), jkey_list,
+      jkeys_count);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    get
+ * Signature: (J[BI[BI)I
+ */
+jint Java_org_rocksdb_RocksDB_get__J_3BI_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  return rocksdb_get_helper(env,
+      reinterpret_cast<rocksdb::DB*>(jdb_handle),
+      rocksdb::ReadOptions(),
+      jkey, jkey_len, jvalue, jvalue_len);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    get
+ * Signature: (JJ[BI[BI)I
+ */
+jint Java_org_rocksdb_RocksDB_get__JJ_3BI_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle, jlong jropt_handle,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  return rocksdb_get_helper(env,
+      reinterpret_cast<rocksdb::DB*>(jdb_handle),
+      *reinterpret_cast<rocksdb::ReadOptions*>(jropt_handle),
+      jkey, jkey_len, jvalue, jvalue_len);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::Delete()
+void rocksdb_remove_helper(
+    JNIEnv* env, rocksdb::DB* db, const rocksdb::WriteOptions& write_options,
+    jbyteArray jkey, jint jkey_len) {
+  jbyte* key = env->GetByteArrayElements(jkey, 0);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+
+  rocksdb::Status s = db->Delete(write_options, key_slice);
+
+  // trigger java unref on key and value.
+  // by passing JNI_ABORT, it will simply release the reference without
+  // copying the result back to the java byte array.
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+
+  if (!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+  return;
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    remove
+ * Signature: (J[BI)V
+ */
+void Java_org_rocksdb_RocksDB_remove__J_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jbyteArray jkey, jint jkey_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  static const rocksdb::WriteOptions default_write_options =
+      rocksdb::WriteOptions();
+
+  rocksdb_remove_helper(env, db, default_write_options, jkey, jkey_len);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    remove
+ * Signature: (JJ[BI)V
+ */
+void Java_org_rocksdb_RocksDB_remove__JJ_3BI(
+    JNIEnv* env, jobject jdb, jlong jdb_handle,
+    jlong jwrite_options, jbyteArray jkey, jint jkey_len) {
+  auto db = reinterpret_cast<rocksdb::DB*>(jdb_handle);
+  auto write_options = reinterpret_cast<rocksdb::WriteOptions*>(jwrite_options);
+
+  rocksdb_remove_helper(env, db, *write_options, jkey, jkey_len);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// rocksdb::DB::~DB()
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_RocksDB_disposeInternal(
+    JNIEnv* env, jobject java_db, jlong jhandle) {
+  delete reinterpret_cast<rocksdb::DB*>(jhandle);
+}
+
+/*
+ * Class:     org_rocksdb_RocksDB
+ * Method:    iterator0
+ * Signature: (J)J
+ */
+jlong Java_org_rocksdb_RocksDB_iterator0(
+    JNIEnv* env, jobject jdb, jlong db_handle) {
+  auto db = reinterpret_cast<rocksdb::DB*>(db_handle);
+  rocksdb::Iterator* iterator = db->NewIterator(rocksdb::ReadOptions());
+  return reinterpret_cast<jlong>(iterator);
+}

java/rocksjni/statistics.cc

@@ -0,0 +1,50 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::Statistics methods from Java side.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <jni.h>
+
+#include "include/org_rocksdb_Statistics.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/statistics.h"
+
+/*
+ * Class:     org_rocksdb_Statistics
+ * Method:    getTickerCount0
+ * Signature: (IJ)J
+ */
+jlong Java_org_rocksdb_Statistics_getTickerCount0(
+    JNIEnv* env, jobject jobj, int tickerType, jlong handle) {
+  auto st = reinterpret_cast<rocksdb::Statistics*>(handle);
+  assert(st != nullptr);
+
+  return st->getTickerCount(static_cast<rocksdb::Tickers>(tickerType));
+}
+
+/*
+ * Class:     org_rocksdb_Statistics
+ * Method:    geHistogramData0
+ * Signature: (IJ)Lorg/rocksdb/HistogramData;
+ */
+jobject Java_org_rocksdb_Statistics_geHistogramData0(
+  JNIEnv* env, jobject jobj, int histogramType, jlong handle) {
+  auto st = reinterpret_cast<rocksdb::Statistics*>(handle);
+  assert(st != nullptr);
+
+  rocksdb::HistogramData data;
+  st->histogramData(static_cast<rocksdb::Histograms>(histogramType),
+    &data);
+
+  // Don't reuse class pointer
+  jclass jclazz = env->FindClass("org/rocksdb/HistogramData");
+  jmethodID mid = rocksdb::HistogramDataJni::getConstructorMethodId(
+      env, jclazz);
+  return env->NewObject(jclazz, mid, data.median, data.percentile95,
+      data.percentile99, data.average, data.standard_deviation);
+}

java/rocksjni/table.cc

@@ -0,0 +1,26 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ for rocksdb::Options.
+
+#include <jni.h>
+#include "include/org_rocksdb_PlainTableConfig.h"
+#include "rocksdb/table.h"
+
+/*
+ * Class:     org_rocksdb_PlainTableConfig
+ * Method:    newTableFactoryHandle
+ * Signature: (IIDI)J
+ */
+jlong Java_org_rocksdb_PlainTableConfig_newTableFactoryHandle(
+    JNIEnv* env, jobject jobj, jint jkey_size, jint jbloom_bits_per_key,
+    jdouble jhash_table_ratio, jint jindex_sparseness) {
+  rocksdb::PlainTableOptions options = rocksdb::PlainTableOptions();
+  options.user_key_len = jkey_size;
+  options.bloom_bits_per_key = jbloom_bits_per_key;
+  options.hash_table_ratio = jhash_table_ratio;
+  options.index_sparseness = jindex_sparseness;
+  return reinterpret_cast<jlong>(rocksdb::NewPlainTableFactory(options));
+}

java/rocksjni/write_batch.cc

@@ -0,0 +1,261 @@
+// 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.
+//
+// This file implements the "bridge" between Java and C++ and enables
+// calling c++ rocksdb::WriteBatch methods from Java side.
+#include <memory>
+
+#include "include/org_rocksdb_WriteBatch.h"
+#include "include/org_rocksdb_WriteBatchInternal.h"
+#include "include/org_rocksdb_WriteBatchTest.h"
+#include "rocksjni/portal.h"
+#include "rocksdb/db.h"
+#include "db/memtable.h"
+#include "rocksdb/write_batch.h"
+#include "db/write_batch_internal.h"
+#include "rocksdb/env.h"
+#include "rocksdb/memtablerep.h"
+#include "util/logging.h"
+#include "util/testharness.h"
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    newWriteBatch
+ * Signature: (I)V
+ */
+void Java_org_rocksdb_WriteBatch_newWriteBatch(
+    JNIEnv* env, jobject jobj, jint jreserved_bytes) {
+  rocksdb::WriteBatch* wb = new rocksdb::WriteBatch(
+      static_cast<size_t>(jreserved_bytes));
+
+  rocksdb::WriteBatchJni::setHandle(env, jobj, wb);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    count
+ * Signature: ()I
+ */
+jint Java_org_rocksdb_WriteBatch_count(JNIEnv* env, jobject jobj) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  return static_cast<jint>(wb->Count());
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    clear
+ * Signature: ()V
+ */
+void Java_org_rocksdb_WriteBatch_clear(JNIEnv* env, jobject jobj) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  wb->Clear();
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    put
+ * Signature: ([BI[BI)V
+ */
+void Java_org_rocksdb_WriteBatch_put(
+    JNIEnv* env, jobject jobj,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* key = env->GetByteArrayElements(jkey, nullptr);
+  jbyte* value = env->GetByteArrayElements(jvalue, nullptr);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  rocksdb::Slice value_slice(reinterpret_cast<char*>(value), jvalue_len);
+  wb->Put(key_slice, value_slice);
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+  env->ReleaseByteArrayElements(jvalue, value, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    merge
+ * Signature: ([BI[BI)V
+ */
+JNIEXPORT void JNICALL Java_org_rocksdb_WriteBatch_merge(
+    JNIEnv* env, jobject jobj,
+    jbyteArray jkey, jint jkey_len,
+    jbyteArray jvalue, jint jvalue_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* key = env->GetByteArrayElements(jkey, nullptr);
+  jbyte* value = env->GetByteArrayElements(jvalue, nullptr);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  rocksdb::Slice value_slice(reinterpret_cast<char*>(value), jvalue_len);
+  wb->Merge(key_slice, value_slice);
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+  env->ReleaseByteArrayElements(jvalue, value, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    remove
+ * Signature: ([BI)V
+ */
+JNIEXPORT void JNICALL Java_org_rocksdb_WriteBatch_remove(
+    JNIEnv* env, jobject jobj,
+    jbyteArray jkey, jint jkey_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* key = env->GetByteArrayElements(jkey, nullptr);
+  rocksdb::Slice key_slice(reinterpret_cast<char*>(key), jkey_len);
+  wb->Delete(key_slice);
+  env->ReleaseByteArrayElements(jkey, key, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    putLogData
+ * Signature: ([BI)V
+ */
+void Java_org_rocksdb_WriteBatch_putLogData(
+    JNIEnv* env, jobject jobj, jbyteArray jblob, jint jblob_len) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  jbyte* blob = env->GetByteArrayElements(jblob, nullptr);
+  rocksdb::Slice blob_slice(reinterpret_cast<char*>(blob), jblob_len);
+  wb->PutLogData(blob_slice);
+  env->ReleaseByteArrayElements(jblob, blob, JNI_ABORT);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatch
+ * Method:    disposeInternal
+ * Signature: (J)V
+ */
+void Java_org_rocksdb_WriteBatch_disposeInternal(
+    JNIEnv* env, jobject jobj, jlong handle) {
+  delete reinterpret_cast<rocksdb::WriteBatch*>(handle);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchInternal
+ * Method:    setSequence
+ * Signature: (Lorg/rocksdb/WriteBatch;J)V
+ */
+void Java_org_rocksdb_WriteBatchInternal_setSequence(
+    JNIEnv* env, jclass jclazz, jobject jobj, jlong jsn) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  rocksdb::WriteBatchInternal::SetSequence(
+      wb, static_cast<rocksdb::SequenceNumber>(jsn));
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchInternal
+ * Method:    sequence
+ * Signature: (Lorg/rocksdb/WriteBatch;)J
+ */
+jlong Java_org_rocksdb_WriteBatchInternal_sequence(
+    JNIEnv* env, jclass jclazz, jobject jobj) {
+  rocksdb::WriteBatch* wb = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(wb != nullptr);
+
+  return static_cast<jlong>(rocksdb::WriteBatchInternal::Sequence(wb));
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchInternal
+ * Method:    append
+ * Signature: (Lorg/rocksdb/WriteBatch;Lorg/rocksdb/WriteBatch;)V
+ */
+void Java_org_rocksdb_WriteBatchInternal_append(
+    JNIEnv* env, jclass jclazz, jobject jwb1, jobject jwb2) {
+  rocksdb::WriteBatch* wb1 = rocksdb::WriteBatchJni::getHandle(env, jwb1);
+  assert(wb1 != nullptr);
+  rocksdb::WriteBatch* wb2 = rocksdb::WriteBatchJni::getHandle(env, jwb2);
+  assert(wb2 != nullptr);
+
+  rocksdb::WriteBatchInternal::Append(wb1, wb2);
+}
+
+/*
+ * Class:     org_rocksdb_WriteBatchTest
+ * Method:    getContents
+ * Signature: (Lorg/rocksdb/WriteBatch;)[B
+ */
+jbyteArray Java_org_rocksdb_WriteBatchTest_getContents(
+    JNIEnv* env, jclass jclazz, jobject jobj) {
+  rocksdb::WriteBatch* b = rocksdb::WriteBatchJni::getHandle(env, jobj);
+  assert(b != nullptr);
+
+  // todo: Currently the following code is directly copied from
+  // db/write_bench_test.cc.  It could be implemented in java once
+  // all the necessary components can be accessed via jni api.
+
+  rocksdb::InternalKeyComparator cmp(rocksdb::BytewiseComparator());
+  auto factory = std::make_shared<rocksdb::SkipListFactory>();
+  rocksdb::Options options;
+  options.memtable_factory = factory;
+  rocksdb::MemTable* mem = new rocksdb::MemTable(cmp, options);
+  mem->Ref();
+  std::string state;
+  rocksdb::ColumnFamilyMemTablesDefault cf_mems_default(mem, &options);
+  rocksdb::Status s =
+      rocksdb::WriteBatchInternal::InsertInto(b, &cf_mems_default);
+  int count = 0;
+  rocksdb::Iterator* iter = mem->NewIterator(rocksdb::ReadOptions());
+  for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
+    rocksdb::ParsedInternalKey ikey;
+    memset(reinterpret_cast<void*>(&ikey), 0, sizeof(ikey));
+    ASSERT_TRUE(rocksdb::ParseInternalKey(iter->key(), &ikey));
+    switch (ikey.type) {
+      case rocksdb::kTypeValue:
+        state.append("Put(");
+        state.append(ikey.user_key.ToString());
+        state.append(", ");
+        state.append(iter->value().ToString());
+        state.append(")");
+        count++;
+        break;
+      case rocksdb::kTypeMerge:
+        state.append("Merge(");
+        state.append(ikey.user_key.ToString());
+        state.append(", ");
+        state.append(iter->value().ToString());
+        state.append(")");
+        count++;
+        break;
+      case rocksdb::kTypeDeletion:
+        state.append("Delete(");
+        state.append(ikey.user_key.ToString());
+        state.append(")");
+        count++;
+        break;
+      default:
+        assert(false);
+        break;
+    }
+    state.append("@");
+    state.append(rocksdb::NumberToString(ikey.sequence));
+  }
+  delete iter;
+  if (!s.ok()) {
+    state.append(s.ToString());
+  } else if (count != rocksdb::WriteBatchInternal::Count(b)) {
+    state.append("CountMismatch()");
+  }
+  delete mem->Unref();
+
+  jbyteArray jstate = env->NewByteArray(state.size());
+  env->SetByteArrayRegion(
+      jstate, 0, state.size(),
+      reinterpret_cast<const jbyte*>(state.c_str()));
+
+  return jstate;
+}