Example usage for org.apache.hadoop.io.compress DirectDecompressor decompress

Introduction

In this page you can find the example usage for org.apache.hadoop.io.compress DirectDecompressor decompress.

Prototype

public void decompress(ByteBuffer src, ByteBuffer dst) throws IOException;

Source Link

Usage

From source file:parquet.hadoop.CodecFactoryExposer.java

License:Apache License

public BytesInput decompress(CompressionCodecName codecName, ByteBuf compressedByteBuf,
        ByteBuf uncompressedByteBuf, int compressedSize, int uncompressedSize) throws IOException {
    ByteBuffer inpBuffer = compressedByteBuf.nioBuffer(0, compressedSize);
    ByteBuffer outBuffer = uncompressedByteBuf.nioBuffer(0, uncompressedSize);
    CompressionCodec c = getCodec(codecName);
    //TODO: Create the decompressor only once at init time.
    Class<?> cx = c.getClass();

    DirectDecompressionCodec d = null;//ww w  .  java 2 s  .c  o  m
    DirectDecompressor decompr = null;

    if (DirectDecompressionCodec.class.isAssignableFrom(cx)) {
        d = (DirectDecompressionCodec) c;
    }

    if (d != null) {
        decompr = d.createDirectDecompressor();
    }

    if (d != null && decompr != null) {
        decompr.decompress(inpBuffer, outBuffer);
    } else {
        logger.warn("This Hadoop implementation does not support a " + codecName
                + " direct decompression codec interface. "
                + "Direct decompression is available only on *nix systems with Hadoop 2.3 or greater. "
                + "Read operations will be a little slower. ");
        BytesInput outBytesInp = this.decompress(new HadoopByteBufBytesInput(inpBuffer, 0, inpBuffer.limit()),
                uncompressedSize, codecName);
        // COPY the data back into the output buffer.
        // (DrillBufs can only refer to direct memory, so we cannot pass back a BytesInput backed
        // by a byte array).
        outBuffer.put(outBytesInp.toByteArray());
    }
    return new HadoopByteBufBytesInput(outBuffer, 0, outBuffer.limit());
}

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