java/core/src/java/org/apache/orc/impl/SnappyCodec.java

/**
 * 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.orc.impl;

import io.airlift.compress.snappy.SnappyCompressor;
import io.airlift.compress.snappy.SnappyDecompressor;
import org.apache.orc.CompressionKind;

import java.io.IOException;
import java.nio.ByteBuffer;

public class SnappyCodec extends AircompressorCodec
    implements DirectDecompressionCodec{
  private static final HadoopShims SHIMS = HadoopShimsFactory.get();

  Boolean direct = null;
  HadoopShims.DirectDecompressor decompressShim = null;

  SnappyCodec() {
    super(CompressionKind.SNAPPY, new SnappyCompressor(), new SnappyDecompressor());
  }

  @Override
  public void decompress(ByteBuffer in, ByteBuffer out) throws IOException {
    if(in.isDirect() && out.isDirect()) {
      directDecompress(in, out);
      return;
    }
    super.decompress(in, out);
  }

  @Override
  public boolean isAvailable() {
    if (direct == null) {
      try {
        ensureShim();
        direct = (decompressShim != null);
      } catch (UnsatisfiedLinkError ule) {
        direct = Boolean.valueOf(false);
      }
    }
    return direct.booleanValue();
  }

  @Override
  public void directDecompress(ByteBuffer in, ByteBuffer out)
      throws IOException {
    ensureShim();
    decompressShim.decompress(in, out);
    out.flip(); // flip for read
  }

  private void ensureShim() {
    if (decompressShim == null) {
      decompressShim = SHIMS.getDirectDecompressor(HadoopShims.DirectCompressionType.SNAPPY);
    }
  }

  @Override
  public void reset() {
    super.reset();
    if (decompressShim != null) {
      decompressShim.reset();
    }
  }

  @Override
  public void destroy() {
    super.destroy();
    if (decompressShim != null) {
      decompressShim.end();
    }
  }
}