org.rocksdb.RocksMutableObject Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rocksdbjni Show documentation

RocksDB fat jar that contains .so files for linux32 and linux64 (glibc and musl-libc), jnilib files for Mac OSX, and a .dll for Windows x64.

There is a newer version: 8.9.1.2

Show newest version

// Copyright (c) 2016, 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).

package org.rocksdb;

/**
 * RocksMutableObject is an implementation of {@link AbstractNativeReference}
 * whose reference to the underlying native C++ object can change.
 *
 * The use of {@code RocksMutableObject} should be kept to a minimum, as it
 * has synchronization overheads and introduces complexity. Instead it is
 * recommended to use {@link RocksObject} where possible.
 */
public abstract class RocksMutableObject extends AbstractNativeReference {

  /**
   * An mutable reference to the value of the C++ pointer pointing to some
   * underlying native RocksDB C++ object.
   */
  private long nativeHandle_;
  private boolean owningHandle_;

  protected RocksMutableObject() {
  }

  protected RocksMutableObject(final long nativeHandle) {
    this.nativeHandle_ = nativeHandle;
    this.owningHandle_ = true;
  }

  /**
   * Closes the existing handle, and changes the handle to the new handle
   *
   * @param newNativeHandle The C++ pointer to the new native object
   * @param owningNativeHandle true if we own the new native object
   */
  public synchronized void resetNativeHandle(final long newNativeHandle,
      final boolean owningNativeHandle) {
    close();
    setNativeHandle(newNativeHandle, owningNativeHandle);
  }

  /**
   * Sets the handle (C++ pointer) of the underlying C++ native object
   *
   * @param nativeHandle The C++ pointer to the native object
   * @param owningNativeHandle true if we own the native object
   */
  public synchronized void setNativeHandle(final long nativeHandle,
      final boolean owningNativeHandle) {
    this.nativeHandle_ = nativeHandle;
    this.owningHandle_ = owningNativeHandle;
  }

  @Override
  protected synchronized boolean isOwningHandle() {
    return this.owningHandle_;
  }

  /**
   * Gets the value of the C++ pointer pointing to the underlying
   * native C++ object
   *
   * @return the pointer value for the native object
   */
  protected synchronized long getNativeHandle() {
    assert (this.nativeHandle_ != 0);
    return this.nativeHandle_;
  }

  @Override
  public final synchronized void close() {
    if (isOwningHandle()) {
      disposeInternal();
      this.owningHandle_ = false;
      this.nativeHandle_ = 0;
    }
  }

  protected void disposeInternal() {
    disposeInternal(nativeHandle_);
  }

  protected abstract void disposeInternal(final long handle);
}