org.rocksdb.CompressionOptions 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.
The newest version!
// 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).

package org.rocksdb;

/**
 * Options for Compression
 */
public class CompressionOptions extends RocksObject {

  public CompressionOptions() {
    super(newCompressionOptions());
  }

  public CompressionOptions setWindowBits(final int windowBits) {
    setWindowBits(nativeHandle_, windowBits);
    return this;
  }

  public int windowBits() {
    return windowBits(nativeHandle_);
  }

  public CompressionOptions setLevel(final int level) {
    setLevel(nativeHandle_, level);
    return this;
  }

  public int level() {
    return level(nativeHandle_);
  }

  public CompressionOptions setStrategy(final int strategy) {
    setStrategy(nativeHandle_, strategy);
    return this;
  }

  public int strategy() {
    return strategy(nativeHandle_);
  }

  /**
   * Maximum size of dictionary used to prime the compression library. Currently
   * this dictionary will be constructed by sampling the first output file in a
   * subcompaction when the target level is bottommost. This dictionary will be
   * loaded into the compression library before compressing/uncompressing each
   * data block of subsequent files in the subcompaction. Effectively, this
   * improves compression ratios when there are repetitions across data blocks.
   *
   * A value of 0 indicates the feature is disabled.
   *
   * Default: 0.
   *
   * @param maxDictBytes Maximum bytes to use for the dictionary
   *
   * @return the reference to the current options
   */
  public CompressionOptions setMaxDictBytes(final int maxDictBytes) {
    setMaxDictBytes(nativeHandle_, maxDictBytes);
    return this;
  }

  /**
   * Maximum size of dictionary used to prime the compression library.
   *
   * @return The maximum bytes to use for the dictionary
   */
  public int maxDictBytes() {
    return maxDictBytes(nativeHandle_);
  }

  /**
   * Maximum size of training data passed to zstd's dictionary trainer. Using
   * zstd's dictionary trainer can achieve even better compression ratio
   * improvements than using {@link #setMaxDictBytes(int)} alone.
   *
   * The training data will be used to generate a dictionary
   * of {@link #maxDictBytes()}.
   *
   * Default: 0.
   *
   * @param zstdMaxTrainBytes Maximum bytes to use for training ZStd.
   *
   * @return the reference to the current options
   */
  public CompressionOptions setZStdMaxTrainBytes(final int zstdMaxTrainBytes) {
    setZstdMaxTrainBytes(nativeHandle_, zstdMaxTrainBytes);
    return this;
  }

  /**
   * Maximum size of training data passed to zstd's dictionary trainer.
   *
   * @return Maximum bytes to use for training ZStd
   */
  public int zstdMaxTrainBytes() {
    return zstdMaxTrainBytes(nativeHandle_);
  }

  /**
   * When the compression options are set by the user, it will be set to "true".
   * For bottommost_compression_opts, to enable it, user must set enabled=true.
   * Otherwise, bottommost compression will use compression_opts as default
   * compression options.
   *
   * For compression_opts, if compression_opts.enabled=false, it is still
   * used as compression options for compression process.
   *
   * Default: false.
   *
   * @param enabled true to use these compression options
   *     for the bottommost_compression_opts, false otherwise
   *
   * @return the reference to the current options
   */
  public CompressionOptions setEnabled(final boolean enabled) {
    setEnabled(nativeHandle_, enabled);
    return this;
  }

  /**
   * Determine whether these compression options
   * are used for the bottommost_compression_opts.
   *
   * @return true if these compression options are used
   *     for the bottommost_compression_opts, false otherwise
   */
  public boolean enabled() {
    return enabled(nativeHandle_);
  }


  private native static long newCompressionOptions();
  @Override protected final native void disposeInternal(final long handle);

  private native void setWindowBits(final long handle, final int windowBits);
  private native int windowBits(final long handle);
  private native void setLevel(final long handle, final int level);
  private native int level(final long handle);
  private native void setStrategy(final long handle, final int strategy);
  private native int strategy(final long handle);
  private native void setMaxDictBytes(final long handle, final int maxDictBytes);
  private native int maxDictBytes(final long handle);
  private native void setZstdMaxTrainBytes(final long handle,
      final int zstdMaxTrainBytes);
  private native int zstdMaxTrainBytes(final long handle);
  private native void setEnabled(final long handle, final boolean enabled);
  private native boolean enabled(final long handle);
}