com.github.luben.zstd

Class Zstd

java.lang.Object

com.github.luben.zstd.Zstd

public class Zstd
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
Zstd()

Method Summary

Modifier and Type	Method and Description
static int	blockSizeMax()
static int	chainLogMax()
static int	chainLogMin()
static byte[]	compress(byte[] src) Compresses the data in buffer 'src' using defaul compression level
static long	compress(byte[] dst, byte[] src, int level) Compresses buffer 'src' into buffer 'dst'.
static byte[]	compress(byte[] src, int level) Compresses the data in buffer 'src'
static byte[]	compress(byte[] src, ZstdDictCompress dict) Compresses the data in buffer 'src'
static long	compressBound(long srcSize) Maximum size of the compressed data
static long	compressFastDict(byte[] dst, int dstOffset, byte[] src, int srcOffset, int length, ZstdDictCompress dict) Compresses buffer 'src' into buffer 'dst' with dictionary.
static long	compressUsingDict(byte[] dst, byte[] src, byte[] dict, int level) Compresses buffer 'src' into buffer 'dst' with dictionary.
static long	compressUsingDict(byte[] dst, int dstOffset, byte[] src, int srcOffset, int length, byte[] dict, int level) Compresses buffer 'src' into buffer 'dst' with dictionary.
static long	decompress(byte[] dst, byte[] src) Decompresses buffer 'src' into buffer 'dst'.
static byte[]	decompress(byte[] src, int originalSize) Decompress data
static byte[]	decompress(byte[] src, ZstdDictDecompress dict, int originalSize) Decompress data
static long	decompressedSize(byte[] src) Return the original size of a compressed buffer (if known)
static long	decompressFastDict(byte[] dst, int dstOffset, byte[] src, int srcOffset, int length, ZstdDictDecompress dict) Decompresses buffer 'src' into buffer 'dst' with dictionary.
static long	decompressUsingDict(byte[] dst, byte[] src, byte[] dict) Decompresses buffer 'src' into buffer 'dst' with dictionary.
static long	decompressUsingDict(byte[] dst, int dstOffset, byte[] src, int srcOffset, int length, byte[] dict) Decompresses buffer 'src' into buffer 'dst' with dictionary.
static int	frameHeaderSizeMax()
static int	frameHeaderSizeMin()
static java.lang.String	getErrorName(long code)
static int	hashLogMax()
static int	hashLogMin()
static boolean	isError(long code) Error handling
static int	magicNumber()
static int	searchLengthMax()
static int	searchLengthMin()
static int	searchLogMax()
static int	searchLogMin()
static int	targetLengthMax()
static int	targetLengthMin()
static long	trainFromBuffer(byte[][] samples, byte[] dictBuffer) Creates a new dictionary to tune a kind of samples
static int	windowLogMax()
static int	windowLogMin()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Zstd

public Zstd()

Method Detail

compress

public static long compress(byte[] dst,
                            byte[] src,
                            int level)

Compresses buffer 'src' into buffer 'dst'. Destination buffer should be sized to handle worst cases situations (input data not compressible). Worst case size evaluation is provided by function ZSTD_compressBound().

Parameters:

dst - the destination buffer

src - the source buffer

level - compression level

Returns:

the number of bytes written into buffer 'dst' or an error code if it fails (which can be tested using ZSTD_isError())

decompress

public static long decompress(byte[] dst,
                              byte[] src)

Decompresses buffer 'src' into buffer 'dst'. Destination buffer should be sized to be larger of equal to the originalSize

Parameters:

dst - the destination buffer

src - the source buffer

Returns:

the number of bytes decompressed into destination buffer (originalSize) or an errorCode if it fails (which can be tested using ZSTD_isError())

decompressedSize

public static long decompressedSize(byte[] src)

Return the original size of a compressed buffer (if known)

Parameters:

src - the compressed buffer

Returns:

the number of bytes of the original buffer 0 if the original size is now known

compressUsingDict

public static long compressUsingDict(byte[] dst,
                                     int dstOffset,
                                     byte[] src,
                                     int srcOffset,
                                     int length,
                                     byte[] dict,
                                     int level)

Compresses buffer 'src' into buffer 'dst' with dictionary. Destination buffer should be sized to handle worst cases situations (input data not compressible). Worst case size evaluation is provided by function ZSTD_compressBound().

Parameters:

dst - the destination buffer

dstOffset - the start offset of 'dst'

src - the source buffer

srcOffset - the start offset of 'src'

length - the length of 'src'

dict - the dictionary buffer

level - compression level

Returns:

the number of bytes written into buffer 'dst' or an error code if it fails (which can be tested using ZSTD_isError())

decompressUsingDict

public static long decompressUsingDict(byte[] dst,
                                       int dstOffset,
                                       byte[] src,
                                       int srcOffset,
                                       int length,
                                       byte[] dict)

Decompresses buffer 'src' into buffer 'dst' with dictionary. Destination buffer should be sized to be larger of equal to the originalSize

Parameters:

dst - the destination buffer

dstOffset - the start offset of 'dst'

src - the source buffer

srcOffset - the start offset of 'src'

length - the length of 'src'

dict - the dictionary buffer

Returns:

the number of bytes decompressed into destination buffer (originalSize) or an errorCode if it fails (which can be tested using ZSTD_isError())

decompressFastDict

public static long decompressFastDict(byte[] dst,
                                      int dstOffset,
                                      byte[] src,
                                      int srcOffset,
                                      int length,
                                      ZstdDictDecompress dict)

Decompresses buffer 'src' into buffer 'dst' with dictionary. Destination buffer should be sized to be larger of equal to the originalSize

Parameters:

dst - the destination buffer

dstOffset - the start offset of 'dst'

src - the source buffer

srcOffset - the start offset of 'src'

length - the length of 'src'

dict - the dictionary

Returns:

the number of bytes decompressed into destination buffer (originalSize) or an errorCode if it fails (which can be tested using ZSTD_isError())

compressFastDict

public static long compressFastDict(byte[] dst,
                                    int dstOffset,
                                    byte[] src,
                                    int srcOffset,
                                    int length,
                                    ZstdDictCompress dict)

Compresses buffer 'src' into buffer 'dst' with dictionary. Destination buffer should be sized to handle worst cases situations (input data not compressible). Worst case size evaluation is provided by function ZSTD_compressBound().

Parameters:

dst - the destination buffer

dstOffset - the start offset of 'dst'

src - the source buffer

srcOffset - the start offset of 'src'

length - the length of 'src'

dict - the dictionary

Returns:

the number of bytes written into buffer 'dst' or an error code if it fails (which can be tested using ZSTD_isError())

compressBound

public static long compressBound(long srcSize)

Maximum size of the compressed data

Parameters:

srcSize - the size of the data to be compressed

Returns:

the maximum size of the compressed data

isError

public static boolean isError(long code)

Error handling

Parameters:

code - return code/size

Returns:

if the return code signals an error

getErrorName

public static java.lang.String getErrorName(long code)

trainFromBuffer

public static long trainFromBuffer(byte[][] samples,
                                   byte[] dictBuffer)

Creates a new dictionary to tune a kind of samples

Parameters:

samples - the samples buffer array

dictBuffer - the new dictionary buffer

Returns:

the number of bytes into buffer 'dictBuffer' or an error code if it fails (which can be tested using ZSTD_isError())

magicNumber

public static int magicNumber()

windowLogMin

public static int windowLogMin()

windowLogMax

public static int windowLogMax()

chainLogMin

public static int chainLogMin()

chainLogMax

public static int chainLogMax()

hashLogMin

public static int hashLogMin()

hashLogMax

public static int hashLogMax()

searchLogMin

public static int searchLogMin()

searchLogMax

public static int searchLogMax()

searchLengthMin

public static int searchLengthMin()

searchLengthMax

public static int searchLengthMax()

targetLengthMin

public static int targetLengthMin()

targetLengthMax

public static int targetLengthMax()

frameHeaderSizeMin

public static int frameHeaderSizeMin()

frameHeaderSizeMax

public static int frameHeaderSizeMax()

blockSizeMax

public static int blockSizeMax()

compress

public static byte[] compress(byte[] src,
                              int level)

Compresses the data in buffer 'src'

Parameters:

src - the source buffer

level - compression level

Returns:

byte array with the compressed data

compress

public static byte[] compress(byte[] src,
                              ZstdDictCompress dict)

Compresses the data in buffer 'src'

Parameters:

src - the source buffer

dict - dictionary to use

Returns:

byte array with the compressed data

compress

public static byte[] compress(byte[] src)

Compresses the data in buffer 'src' using defaul compression level

Parameters:

src - the source buffer

Returns:

byte array with the compressed data

decompress

public static byte[] decompress(byte[] src,
                                int originalSize)

Decompress data

Parameters:

src - the source buffer

originalSize - the maximum size of the uncompressed data

Returns:

byte array with the decompressed data

decompress

public static byte[] decompress(byte[] src,
                                ZstdDictDecompress dict,
                                int originalSize)

Decompress data

Parameters:

src - the source buffer

dict - dictionary to use

originalSize - the maximum size of the uncompressed data

Returns:

byte array with the decompressed data

compressUsingDict

public static long compressUsingDict(byte[] dst,
                                     byte[] src,
                                     byte[] dict,
                                     int level)

Compresses buffer 'src' into buffer 'dst' with dictionary. Destination buffer should be sized to handle worst cases situations (input data not compressible). Worst case size evaluation is provided by function ZSTD_compressBound().

Parameters:

dst - the destination buffer

src - the source buffer

dict - the dictionary buffer

level - compression level

Returns:

the number of bytes written into buffer 'dst' or an error code if it fails (which can be tested using ZSTD_isError())

decompressUsingDict

public static long decompressUsingDict(byte[] dst,
                                       byte[] src,
                                       byte[] dict)

Decompresses buffer 'src' into buffer 'dst' with dictionary. Destination buffer should be sized to be larger of equal to the originalSize

Parameters:

dst - the destination buffer

src - the source buffer

dict - the dictionary buffer

Returns:

the number of bytes decompressed into destination buffer (originalSize) or an errorCode if it fails (which can be tested using ZSTD_isError())