private static final HadoopShims SHIMS = HadoopShimsFactory.get();

// Note: shim path does not care about levels and strategies (only used for decompression).

private HadoopShims.DirectDecompressor decompressShim = null;

private Boolean direct = null;

static class ZlibOptions implements Options {

private int level;

private int strategy;

private final boolean FIXED;

ZlibOptions(int level, int strategy, boolean fixed) {

this.level = level;

this.strategy = strategy;

FIXED = fixed;

}

@Override

public ZlibOptions copy() {

return new ZlibOptions(level, strategy, false);

}

@Override

public ZlibOptions setSpeed(SpeedModifier newValue) {

if (FIXED) {

throw new IllegalStateException("Attempt to modify the default options");

}

switch (newValue) {

case FAST:

// deflate_fast looking for 16 byte patterns

level = Deflater.BEST_SPEED + 1;

break;

case DEFAULT:

// deflate_slow looking for 128 byte patterns

level = Deflater.DEFAULT_COMPRESSION;

break;

case FASTEST:

// deflate_fast looking for 8 byte patterns

level = Deflater.BEST_SPEED;

break;

default:

break;

}

return this;

}

@Override

public ZlibOptions setData(DataKind newValue) {

if (FIXED) {

throw new IllegalStateException("Attempt to modify the default options");

}

switch (newValue) {

case BINARY:

/* filtered == less LZ77, more huffman */

strategy = Deflater.FILTERED;

break;

case TEXT:

strategy = Deflater.DEFAULT_STRATEGY;

break;

default:

break;

}

return this;

}

@Override

public boolean equals(Object other) {

if (other == null || getClass() != other.getClass()) {

return false;

} else if (this == other) {

return true;

} else {

ZlibOptions otherOpts = (ZlibOptions) other;

return level == otherOpts.level && strategy == otherOpts.strategy;

}

}

@Override

public int hashCode() {

return level + strategy * 101;

}

}

private static final ZlibOptions DEFAULT_OPTIONS =

new ZlibOptions(Deflater.DEFAULT_COMPRESSION, Deflater.DEFAULT_STRATEGY, true);

@Override

public Options getDefaultOptions() {

return DEFAULT_OPTIONS;

}

@Override

public boolean compress(ByteBuffer in, ByteBuffer out,

ByteBuffer overflow,

Options options) {

ZlibOptions zlo = (ZlibOptions) options;

int length = in.remaining();

int outSize = 0;

Deflater deflater = new Deflater(zlo.level, true);

try {

deflater.setStrategy(zlo.strategy);

deflater.setInput(in.array(), in.arrayOffset() + in.position(), length);

deflater.finish();

int offset = out.arrayOffset() + out.position();

while (!deflater.finished() && (length > outSize)) {

int size = deflater.deflate(out.array(), offset, out.remaining());

out.position(size + out.position());

outSize += size;

offset += size;

// if we run out of space in the out buffer, use the overflow

if (out.remaining() == 0) {

if (overflow == null) {

return false;

}

out = overflow;

offset = out.arrayOffset() + out.position();

}

}

} finally {

deflater.end();

}

return length > outSize;

}

@Override

public void decompress(ByteBuffer in, ByteBuffer out) throws IOException {

if(in.isDirect() && out.isDirect()) {

directDecompress(in, out);

return;

}

Inflater inflater = new Inflater(true);

try {

inflater.setInput(in.array(), in.arrayOffset() + in.position(),

in.remaining());

while (!(inflater.finished() || inflater.needsDictionary() ||

inflater.needsInput())) {

try {

int count = inflater.inflate(out.array(),

out.arrayOffset() + out.position(),

out.remaining());

out.position(count + out.position());

if (!inflater.finished() && !inflater.needsDictionary() && !inflater.needsInput() &&

count == 0) {

if (out.remaining() == 0) {

throw new IOException("Decompress output buffer too small. in = " + in +

", out = " + out);

} else {

throw new IOException("Decompress error. in = " + in +

", out = " + out);

}

}

} catch (DataFormatException dfe) {

throw new IOException("Bad compression data", dfe);

}

}

out.flip();

} finally {

inflater.end();

}

in.position(in.limit());

}

@Override

public boolean isAvailable() {

if (direct == null) {

// see nowrap option in new Inflater(boolean) which disables zlib headers

try {

ensureShim();

direct = (decompressShim != null);

} catch (UnsatisfiedLinkError ule) {

direct = false;

}

}

return direct;

}

private void ensureShim() {

if (decompressShim == null) {

decompressShim = SHIMS.getDirectDecompressor(

HadoopShims.DirectCompressionType.ZLIB_NOHEADER);

}

}

@Override

public void directDecompress(ByteBuffer in, ByteBuffer out) throws IOException {

ensureShim();

decompressShim.decompress(in, out);

out.flip(); // flip for read

}

@Override

public void reset() {

if (decompressShim != null) {

decompressShim.reset();

}

}

@Override

public void destroy() {

if (decompressShim != null) {

decompressShim.end();

}

}

@Override

public CompressionKind getKind() {

return CompressionKind.ZLIB;

}

@Override

public void close() {

OrcCodecPool.returnCodec(CompressionKind.ZLIB, this);

}