blosc-java

A stateless, cross-platform, JNI-based wrapper around the c-blosc library.

The packaged JARs contain binaries for Windows, Mac OS (x86_64 and arm64) and Linux.

Usage

import dev.zarr.bloscjava.Blosc;

// Generate some random data
int SIZE = 1000000;
byte[] buf = new byte[SIZE];
for (int i = 0; i < SIZE; i++) {
    buf[i] = (int)(i % 24);
}

byte[] compressedBuf = Blosc.compress(buf, 1, Blosc.Compressor.ZSTD, 9);
byte[] decompressedBuf = Blosc.decompress(compressedBuf);

assert Arrays.equals(buf, decompressedBuf);

API

byte[] compress(
    byte[] src, 
    int typeSize, 
    Blosc.Compressor compressor, 
    int compressorLevel, 
    Blosc.Shuffle shuffle, 
    int blockSize,
    int numThreads
)

• src: Byte array to be compressed. Required.
• typeSize: Number of bytes per primitive value (e.g. 1 for int8, 2 for int16, 4 for int32). Required.
• compressor: Compression algorithm. Available choices: LZ4, LZ4HC, BLOSCLZ, ZSTD, ZLIB. Default: ZSTD
• compressorLevel: Number from 0 to 9 (0 = little compression, 9 = strongest compression). Default: 5.
• shuffle: Whether to use shuffling. Available choices: NOSHUFFLE, BIT_SHUFFLE, BYTE_SHUFFLE. Default: BIT_SHUFFLE for typeSize == 1, BYTE_SHUFFLE otherwise.
• blockSize: Requested size of compressed blocks. Use 0 for automatic block sizes.
• numThreads: Number of threads to be used internally. Default: 1.

byte[] decompress(byte[] src, int numThreads)

• src: Byte array to be decompressed. Required.
• numThreads: Number of threads to be used internally. Default: 1.

Installation

Add the dev.zarr.blosc-java dependency to your Maven project:

    <dependencies>
        <dependency>
            <groupId>dev.zarr</groupId>
            <artifactId>blosc-java</artifactId>
            <version>BLOSC_VERSION</version>
        </dependency>
    </dependencies>