org.apache.hadoop.io.compress.DirectDecompressor Maven / Gradle / Ivy
/*
* 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.hadoop.io.compress;
import java.io.IOException;
import java.nio.ByteBuffer;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* Specification of a direct ByteBuffer 'de-compressor'.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public interface DirectDecompressor {
/*
* This exposes a direct interface for record decompression with direct byte
* buffers.
*
* The decompress() function need not always consume the buffers provided,
* it will need to be called multiple times to decompress an entire buffer
* and the object will hold the compression context internally.
*
* Codecs such as {@link SnappyCodec} may or may not support partial
* decompression of buffers and will need enough space in the destination
* buffer to decompress an entire block.
*
* The operation is modelled around dst.put(src);
*
* The end result will move src.position() by the bytes-read and
* dst.position() by the bytes-written. It should not modify the src.limit()
* or dst.limit() to maintain consistency of operation between codecs.
*
* @param src Source direct {@link ByteBuffer} for reading from. Requires src
* != null and src.remaining() > 0
*
* @param dst Destination direct {@link ByteBuffer} for storing the results
* into. Requires dst != null and dst.remaining() to be > 0
*
* @throws IOException if compression fails
*/
public void decompress(ByteBuffer src, ByteBuffer dst) throws IOException;
}