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

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one or more
   3  * contributor license agreements.  See the NOTICE file distributed with
   4  * this work for additional information regarding copyright ownership.
   5  * The ASF licenses this file to You under the Apache License, Version 2.0
   6  * (the "License"); you may not use this file except in compliance with
   7  * the License.  You may obtain a copy of the License at
   8  *
   9  *    http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 package org.apache.arrow.dataset.jni;
  19
  20 /**
  21  * C++ memory pool(arrow::MemoryPool)'s Java mapped instance.
  22  */
  23 public class NativeMemoryPool implements AutoCloseable {
  24   private final long nativeInstanceId;
  25
  26   static {
  27     JniLoader.get().ensureLoaded();
  28   }
  29
  30   private NativeMemoryPool(long nativeInstanceId) {
  31     this.nativeInstanceId = nativeInstanceId;
  32   }
  33
  34   /**
  35    * Get the default memory pool. This will return arrow::default_memory_pool() directly.
  36    */
  37   public static NativeMemoryPool getDefault() {
  38     return new NativeMemoryPool(getDefaultMemoryPool());
  39   }
  40
  41   /**
  42    * Create a listenable memory pool (see also: arrow::ReservationListenableMemoryPool) with
  43    * a specific listener. All buffers created from the memory pool should take enough reservation
  44    * from the listener in advance.
  45    */
  46   public static NativeMemoryPool createListenable(ReservationListener listener) {
  47     return new NativeMemoryPool(createListenableMemoryPool(listener));
  48   }
  49
  50   /**
  51    * Return native instance ID of this memory pool.
  52    */
  53   public long getNativeInstanceId() {
  54     return nativeInstanceId;
  55   }
  56
  57   /**
  58    * Get current allocated bytes.
  59    */
  60   public long getBytesAllocated() {
  61     return bytesAllocated(nativeInstanceId);
  62   }
  63
  64   @Override
  65   public void close() throws Exception {
  66     releaseMemoryPool(nativeInstanceId);
  67   }
  68
  69   private static native long getDefaultMemoryPool();
  70
  71   private static native long createListenableMemoryPool(ReservationListener listener);
  72
  73   private static native void releaseMemoryPool(long id);
  74
  75   private static native long bytesAllocated(long id);
  76 }