Add RestoreBackupableDB and RestoreOptions

java/org/rocksdb/RestoreBackupableDB.java

+// 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;
+
+/**
+ * This class is used to access information about backups and restore from them.
+ * 
+ * Note that dispose() must be called before this instance become out-of-scope 
+ * to release the allocated memory in c++.
+ * 
+ * @param options Instance of BackupableDBOptions.
+ */
+public class RestoreBackupableDB extends RocksObject {
+  public RestoreBackupableDB(BackupableDBOptions options) {
+    super();
+    newRestoreBackupableDB(options.nativeHandle_);
+  }
+  
+  /**
+   * Restore from backup with backup_id
+   * IMPORTANT -- if options_.share_table_files == true and you restore DB
+   * from some backup that is not the latest, and you start creating new
+   * backups from the new DB, they will probably fail.
+   * 
+   * Example: Let's say you have backups 1, 2, 3, 4, 5 and you restore 3.
+   * If you add new data to the DB and try creating a new backup now, the
+   * database will diverge from backups 4 and 5 and the new backup will fail.
+   * If you want to create new backup, you will first have to delete backups 4
+   * and 5.
+   */
+  public void restoreDBFromBackup(long backupId, String dbDir, String walDir,
+      RestoreOptions restoreOptions) throws RocksDBException {
+    restoreDBFromBackup0(nativeHandle_, backupId, dbDir, walDir,
+        restoreOptions.nativeHandle_);
+  }
+  
+  /**
+   * Restore from the latest backup.
+   */
+  public void restoreDBFromLatestBackup(String dbDir, String walDir,
+      RestoreOptions restoreOptions) throws RocksDBException {
+    restoreDBFromLatestBackup0(nativeHandle_, dbDir, walDir,
+        restoreOptions.nativeHandle_);
+  }
+  
+  /**
+   * Deletes old backups, keeping latest numBackupsToKeep alive.
+   * 
+   * @param Number of latest backups to keep
+   */
+  public void purgeOldBackups(int numBackupsToKeep) throws RocksDBException {
+    purgeOldBackups0(nativeHandle_, numBackupsToKeep);
+  }
+  
+  /**
+   * Deletes a specific backup.
+   * 
+   * @param ID of backup to delete.
+   */
+  public void deleteBackup(long backupId) throws RocksDBException {
+    deleteBackup0(nativeHandle_, backupId);
+  }
+  
+  /**
+   * Release the memory allocated for the current instance
+   * in the c++ side.
+   */
+  @Override public synchronized void dispose() {
+    if (isInitialized()) {
+      dispose(nativeHandle_);
+    }
+  }
+  
+  private native void newRestoreBackupableDB(long options);
+  private native void restoreDBFromBackup0(long nativeHandle, long backupId,
+      String dbDir, String walDir, long restoreOptions) throws RocksDBException;
+  private native void restoreDBFromLatestBackup0(long nativeHandle,
+      String dbDir, String walDir, long restoreOptions) throws RocksDBException;
+  private native void purgeOldBackups0(long nativeHandle, int numBackupsToKeep);
+  private native void deleteBackup0(long nativeHandle, long backupId);
+  private native void dispose(long nativeHandle);
+}
\ No newline at end of file

java/org/rocksdb/RestoreOptions.java

+// 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;
+
+/**
+ * RestoreOptions to control the behavior of restore.
+ *
+ * Note that dispose() must be called before this instance become out-of-scope 
+ * to release the allocated memory in c++.
+ * 
+ * @param If true, restore won't overwrite the existing log files in wal_dir. It
+ *     will also move all log files from archive directory to wal_dir. Use this
+ *     option in combination with BackupableDBOptions::backup_log_files = false 
+ *     for persisting in-memory databases.
+ *     Default: false
+ */
+public class RestoreOptions extends RocksObject {
+  public RestoreOptions(boolean keepLogFiles) {
+    super();
+    newRestoreOptions(keepLogFiles);
+  }
+  
+  /**
+   * Release the memory allocated for the current instance
+   * in the c++ side.
+   */
+  @Override public synchronized void dispose() {
+    if (isInitialized()) {
+      dispose(nativeHandle_);
+    }
+  }
+  
+  private native void newRestoreOptions(boolean keepLogFiles);
+  private native void dispose(long handle);
+}
\ No newline at end of file

java/rocksjni/restorejni.cc

+// 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 "utilities/backupable_db.h"
+/*
+ * Class:     org_rocksdb_RestoreOptions
+ * Method:    newRestoreOptions
+ * Signature: (Z)V
+ */
+void Java_org_rocksdb_RestoreOptions_newRestoreOptions(JNIEnv* env,
+    jobject jobj, jboolean keep_log_files) {
+  auto ropt = new rocksdb::RestoreOptions(keep_log_files);
+  rocksdb::RestoreOptionsJni::setHandle(env, jobj, 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;
+
+  rocksdb::RestoreOptionsJni::setHandle(env, jobj, nullptr);
+}
+
+/*
+ * Class:     org_rocksdb_RestoreBackupableDB
+ * Method:    newRestoreBackupableDB
+ * Signature: (J)V
+ */
+void 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);
+  rocksdb::RestoreBackupableDBJni::setHandle(env, jobj, 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;
+
+  rocksdb::RestoreBackupableDBJni::setHandle(env, jobj, nullptr);
+}
\ No newline at end of file