Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/src/rocksdb/java/rocksjni/transaction_notifier_jnicallback.h b/src/rocksdb/java/rocksjni/transaction_notifier_jnicallback.h
new file mode 100644
index 000000000..089a5ee4a
--- /dev/null
+++ b/src/rocksdb/java/rocksjni/transaction_notifier_jnicallback.h
@@ -0,0 +1,42 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the callback "bridge" between Java and C++ for
+// ROCKSDB_NAMESPACE::TransactionNotifier.
+
+#ifndef JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_
+#define JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_
+
+#include <jni.h>
+
+#include "rocksdb/utilities/transaction.h"
+#include "rocksjni/jnicallback.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+/**
+ * This class acts as a bridge between C++
+ * and Java. The methods in this class will be
+ * called back from the RocksDB TransactionDB or OptimisticTransactionDB (C++),
+ * we then callback to the appropriate Java method
+ * this enables TransactionNotifier to be implemented in Java.
+ *
+ * Unlike RocksJava's Comparator JNI Callback, we do not attempt
+ * to reduce Java object allocations by caching the Snapshot object
+ * presented to the callback. This could be revisited in future
+ * if performance is lacking.
+ */
+class TransactionNotifierJniCallback : public JniCallback,
+                                       public TransactionNotifier {
+ public:
+  TransactionNotifierJniCallback(JNIEnv* env, jobject jtransaction_notifier);
+  virtual void SnapshotCreated(const Snapshot* newSnapshot);
+
+ private:
+  jmethodID m_jsnapshot_created_methodID;
+};
+}  // namespace ROCKSDB_NAMESPACE
+
+#endif  // JAVA_ROCKSJNI_TRANSACTION_NOTIFIER_JNICALLBACK_H_