import quincy 17.2.0

[ceph.git] / ceph / src / arrow / java / dataset / src / main / java / org / apache / arrow / dataset / jni / NativeMemoryPool.java

diff --git a/ceph/src/arrow/java/dataset/src/main/java/org/apache/arrow/dataset/jni/NativeMemoryPool.java b/ceph/src/arrow/java/dataset/src/main/java/org/apache/arrow/dataset/jni/NativeMemoryPool.java
new file mode 100644 (file)
index 0000000..8382577
--- /dev/null
+++ b/ceph/src/arrow/java/dataset/src/main/java/org/apache/arrow/dataset/jni/NativeMemoryPool.java
@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.arrow.dataset.jni;
+
+/**
+ * C++ memory pool(arrow::MemoryPool)'s Java mapped instance.
+ */
+public class NativeMemoryPool implements AutoCloseable {
+  private final long nativeInstanceId;
+
+  static {
+    JniLoader.get().ensureLoaded();
+  }
+
+  private NativeMemoryPool(long nativeInstanceId) {
+    this.nativeInstanceId = nativeInstanceId;
+  }
+
+  /**
+   * Get the default memory pool. This will return arrow::default_memory_pool() directly.
+   */
+  public static NativeMemoryPool getDefault() {
+    return new NativeMemoryPool(getDefaultMemoryPool());
+  }
+
+  /**
+   * Create a listenable memory pool (see also: arrow::ReservationListenableMemoryPool) with
+   * a specific listener. All buffers created from the memory pool should take enough reservation
+   * from the listener in advance.
+   */
+  public static NativeMemoryPool createListenable(ReservationListener listener) {
+    return new NativeMemoryPool(createListenableMemoryPool(listener));
+  }
+
+  /**
+   * Return native instance ID of this memory pool.
+   */
+  public long getNativeInstanceId() {
+    return nativeInstanceId;
+  }
+
+  /**
+   * Get current allocated bytes.
+   */
+  public long getBytesAllocated() {
+    return bytesAllocated(nativeInstanceId);
+  }
+
+  @Override
+  public void close() throws Exception {
+    releaseMemoryPool(nativeInstanceId);
+  }
+
+  private static native long getDefaultMemoryPool();
+
+  private static native long createListenableMemoryPool(ReservationListener listener);
+
+  private static native void releaseMemoryPool(long id);
+
+  private static native long bytesAllocated(long id);
+}