net.jpountz.lz4.LZ4JNISafeDecompressor Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of lz4 Show documentation

Java ports and bindings of the LZ4 compression algorithm and the xxHash hashing algorithm

There is a newer version: 1.3.0

package net.jpountz.lz4;

/*
 * Licensed 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.
 */


import java.nio.ByteBuffer;

import net.jpountz.util.ByteBufferUtils;
import net.jpountz.util.SafeUtils;

/**
 * {@link LZ4SafeDecompressor} implemented with JNI bindings to the original C
 * implementation of LZ4.
 */
final class LZ4JNISafeDecompressor extends LZ4SafeDecompressor {

  public static final LZ4JNISafeDecompressor INSTANCE = new LZ4JNISafeDecompressor();
  private static LZ4SafeDecompressor SAFE_INSTANCE;

  @Override
  public final int decompress(byte[] src, int srcOff, int srcLen, byte[] dest, int destOff, int maxDestLen) {
    SafeUtils.checkRange(src, srcOff, srcLen);
    SafeUtils.checkRange(dest, destOff, maxDestLen);
    final int result = LZ4JNI.LZ4_decompress_safe(src, null, srcOff, srcLen, dest, null, destOff, maxDestLen);
    if (result < 0) {
      throw new LZ4Exception("Error decoding offset " + (srcOff - result) + " of input buffer");
    }
    return result;
  }

  @Override
  public int decompress(ByteBuffer src, int srcOff, int srcLen, ByteBuffer dest, int destOff, int maxDestLen) {
    ByteBufferUtils.checkNotReadOnly(dest);
    ByteBufferUtils.checkRange(src, srcOff, srcLen);
    ByteBufferUtils.checkRange(dest, destOff, maxDestLen);

    byte[] srcArr = null, destArr = null;
    ByteBuffer srcBuf = null, destBuf = null;
    if (src.hasArray()) {
      srcArr = src.array();
    } else if (src.isDirect()) {
      srcBuf = src;
    }
    if (dest.hasArray()) {
      destArr = dest.array();
    } else if (dest.isDirect()) {
      destBuf = dest;
    }

    if ((srcArr != null || srcBuf != null) && (destArr != null || destBuf != null)) {
      final int result = LZ4JNI.LZ4_decompress_safe(srcArr, srcBuf, srcOff, srcLen, destArr, destBuf, destOff, maxDestLen);
      if (result < 0) {
        throw new LZ4Exception("Error decoding offset " + (srcOff - result) + " of input buffer");
      }
      return result;
    } else {
      LZ4SafeDecompressor safeInstance = SAFE_INSTANCE;
      if (safeInstance == null) {
        safeInstance = SAFE_INSTANCE = LZ4Factory.safeInstance().safeDecompressor();
      }
      return safeInstance.decompress(src, srcOff, srcLen, dest, destOff, maxDestLen);
    }
  }

}