Java Code Examples for net.jpountz.lz4.LZ4Factory#fastCompressor()

/**
     * Creates a new customizable LZ4 encoder.创建一个新的可定制的LZ4编码器。
     *
     * @param factory         user customizable {@link LZ4Factory} instance
     *                        which may be JNI bindings to the original C implementation, a pure Java implementation
     *                        or a Java implementation that uses the {@link sun.misc.Unsafe}
     * @param highCompressor  if {@code true} codec will use compressor which requires more memory
     *                        and is slower but compresses more efficiently
     * @param blockSize       the maximum number of bytes to try to compress at once,
     *                        must be >= 64 and <= 32 M
     * @param checksum        the {@link Checksum} instance to use to check data for integrity
     * @param maxEncodeSize   the maximum size for an encode (compressed) buffer
     */
public Lz4FrameEncoder(LZ4Factory factory, boolean highCompressor, int blockSize,
                       Checksum checksum, int maxEncodeSize) {
    if (factory == null) {
        throw new NullPointerException("factory");
    }
    if (checksum == null) {
        throw new NullPointerException("checksum");
    }

    compressor = highCompressor ? factory.highCompressor() : factory.fastCompressor();
    this.checksum = ByteBufChecksum.wrapChecksum(checksum);

    compressionLevel = compressionLevel(blockSize);
    this.blockSize = blockSize;
    this.maxEncodeSize = ObjectUtil.checkPositive(maxEncodeSize, "maxEncodeSize");
    finished = false;
}
 

public static void main(String[] args) throws Exception {

        if(args.length == 0){
            System.out.println("args[0] must be data file path");
            return;
        }
        LZ4Factory factory = LZ4Factory.fastestInstance();

        byte[] data = Files.toByteArray(new File(args[0]));
        final int decompressedLength = data.length;

        // compress data
        LZ4Compressor compressor = factory.fastCompressor();
        long start = System.currentTimeMillis();
        int maxCompressedLength = compressor.maxCompressedLength(decompressedLength);
        byte[] compressed = new byte[maxCompressedLength];
        int compressedLength = compressor.compress(data, 0, decompressedLength, compressed, 0, maxCompressedLength);
        System.out.println("compress take:" + (System.currentTimeMillis() - start));
        System.out.println(compressedLength);

        // decompress data
        // - method 1: when the decompressed length is known
        LZ4FastDecompressor decompressor = factory.fastDecompressor();
        start = System.currentTimeMillis();
        byte[] restored = new byte[decompressedLength];
        int compressedLength2 = decompressor.decompress(compressed, 0, restored, 0, decompressedLength);
        System.out.println("decompress take:" + (System.currentTimeMillis() - start));
        System.out.println(decompressedLength);
        // compressedLength == compressedLength2

        // - method 2: when the compressed length is known (a little slower)
        // the destination buffer needs to be over-sized
        LZ4SafeDecompressor decompressor2 = factory.safeDecompressor();
        int decompressedLength2 = decompressor2.decompress(compressed, 0, compressedLength, restored, 0);
    }
 

@Override
public byte[] compress(byte[] data) throws IOException {
	LZ4Factory factory = LZ4Factory.fastestInstance();
	ByteArrayOutputStream byteOutput = new ByteArrayOutputStream();
	LZ4Compressor compressor = factory.fastCompressor();
	LZ4BlockOutputStream compressedOutput = new LZ4BlockOutputStream(byteOutput, 2048, compressor);
	compressedOutput.write(data);
	compressedOutput.close();
	
	return byteOutput.toByteArray();
}
 

public static void main(String[] args) throws Exception {

        if(args.length == 0){
            System.out.println("args[0] must be data file path");
            return;
        }
        LZ4Factory factory = LZ4Factory.fastestInstance();

        byte[] data = Files.toByteArray(new File(args[0]));
        final int decompressedLength = data.length;

        // compress data
        LZ4Compressor compressor = factory.fastCompressor();
        long start = System.currentTimeMillis();
        int maxCompressedLength = compressor.maxCompressedLength(decompressedLength);
        byte[] compressed = new byte[maxCompressedLength];
        int compressedLength = compressor.compress(data, 0, decompressedLength, compressed, 0, maxCompressedLength);
        System.out.println("compress take:" + (System.currentTimeMillis() - start));
        System.out.println(compressedLength);

        // decompress data
        // - method 1: when the decompressed length is known
        LZ4FastDecompressor decompressor = factory.fastDecompressor();
        start = System.currentTimeMillis();
        byte[] restored = new byte[decompressedLength];
        int compressedLength2 = decompressor.decompress(compressed, 0, restored, 0, decompressedLength);
        System.out.println("decompress take:" + (System.currentTimeMillis() - start));
        System.out.println(decompressedLength);
        // compressedLength == compressedLength2

        // - method 2: when the compressed length is known (a little slower)
        // the destination buffer needs to be over-sized
        LZ4SafeDecompressor decompressor2 = factory.safeDecompressor();
        int decompressedLength2 = decompressor2.decompress(compressed, 0, compressedLength, restored, 0);
    }
 

public Lz4Compressor(boolean unsafe, int bufferSize, boolean useHC) {
  super(bufferSize);
  LZ4Factory factory = (unsafe) ? LZ4Factory.unsafeInstance() : LZ4Factory.safeInstance();
  compressor = (useHC) ? factory.highCompressor() : factory.fastCompressor();
}
 

private LZ4Compressor()
{
    final LZ4Factory lz4Factory = LZ4Factory.fastestInstance();
    compressor = lz4Factory.fastCompressor();
    decompressor = lz4Factory.decompressor();
}
 

private LZ4Compressor()
{
    final LZ4Factory lz4Factory = LZ4Factory.fastestInstance();
    compressor = lz4Factory.fastCompressor();
    decompressor = lz4Factory.decompressor();
}