XerialSnappyCompressedStreamInput.java

/*
 * Licensed to ElasticSearch and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. ElasticSearch 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.elasticsearch.common.compress.snappy.xerial;

import org.elasticsearch.common.compress.snappy.SnappyCompressedStreamInput;
import org.elasticsearch.common.compress.snappy.SnappyCompressorContext;
import org.elasticsearch.common.io.stream.StreamInput;
import org.xerial.snappy.Snappy;

import java.io.IOException;

/**
 */
public class XerialSnappyCompressedStreamInput extends SnappyCompressedStreamInput {

    public XerialSnappyCompressedStreamInput(StreamInput in, SnappyCompressorContext context) throws IOException {
        super(in, context);
    }

    @Override
    protected int uncompress(StreamInput in, byte[] out) throws IOException {
        int compressedByte = in.read();
        // if we are on the "tip", just return 0 uncompressed data...
        if (compressedByte == -1) {
            return 0;
        }
        boolean compressed = compressedByte == 1;
        int length = in.readVInt();
        if (!compressed) {
            in.readBytes(out, 0, length);
            return length;
        } else {
            in.readBytes(inputBuffer, 0, length);
            return Snappy.rawUncompress(inputBuffer, 0, length, out, 0);
        }
    }
}