ceph/src/rocksdb/java/rocksjni/transaction_notifier_jnicallback.h

   1 // Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5 //
   6 // This file implements the callback "bridge" between Java and C++ for
   7 // rocksdb::TransactionNotifier.
   8
   9 #ifndef JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_
  10 #define JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_
  11
  12 #include <jni.h>
  13
  14 #include "rocksdb/utilities/transaction.h"
  15 #include "rocksjni/jnicallback.h"
  16
  17 namespace rocksdb {
  18
  19 /**
  20  * This class acts as a bridge between C++
  21  * and Java. The methods in this class will be
  22  * called back from the RocksDB TransactionDB or OptimisticTransactionDB (C++),
  23  * we then callback to the appropriate Java method
  24  * this enables TransactionNotifier to be implemented in Java.
  25  *
  26  * Unlike RocksJava's Comparator JNI Callback, we do not attempt
  27  * to reduce Java object allocations by caching the Snapshot object
  28  * presented to the callback. This could be revisited in future
  29  * if performance is lacking.
  30  */
  31 class TransactionNotifierJniCallback: public JniCallback,
  32     public TransactionNotifier {
  33  public:
  34   TransactionNotifierJniCallback(JNIEnv* env, jobject jtransaction_notifier);
  35   virtual void SnapshotCreated(const Snapshot* newSnapshot);
  36
  37  private:
  38   jmethodID m_jsnapshot_created_methodID;
  39 };
  40 }  // namespace rocksdb
  41
  42 #endif  // JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_