File syn_lz4.c¶

FileList > src > syntropic > util > syn_lz4.c

Implementation of Zero-Heap LZ4 Raw Block Compression & Decompression.

#include "syn_lz4.h"
#include <string.h>

Public Functions¶

Type	Name
size_t	syn_lz4_compress (SYN_Lz4 * ctx, const void * src, size_t src_size, void * dst, size_t dst_capacity) Compress data buffer into LZ4 raw block format.
size_t	syn_lz4_compress_bound (size_t input_size) Calculate worst-case compressed output bound for a given input size.
size_t	syn_lz4_decompress (const void * src, size_t src_size, void * dst, size_t dst_capacity) Decompress LZ4 raw block buffer.
SYN_Status	syn_lz4_init (SYN_Lz4 * ctx) Initialize an LZ4 compression context.

Public Static Functions¶

Type	Name
uint32_t	lz4_hash4 (uint32_t val) Hash 4 bytes into 12-bit hash index using Knuth multiplicative hash.
uint32_t	lz4_read32 (const uint8_t * ptr) Read 32-bit little-endian word from unaligned byte pointer.

Macros¶

Type	Name
define	LZ4_HASH_BITS `12U`
define	LZ4_MIN_MATCH `4U`

Public Functions Documentation¶

function syn_lz4_compress¶

Compress data buffer into LZ4 raw block format.

size_t syn_lz4_compress (
    SYN_Lz4 * ctx,
    const void * src,
    size_t src_size,
    void * dst,
    size_t dst_capacity
)

Parameters:

ctx Pointer to initialized LZ4 context.
src Source data buffer to compress.
src_size Source data size in bytes.
dst Destination buffer for compressed output.
dst_capacity Capacity of destination buffer in bytes.

Returns:

Number of compressed bytes written to dst, or 0 on error/overflow.

function syn_lz4_compress_bound¶

Calculate worst-case compressed output bound for a given input size.

size_t syn_lz4_compress_bound (
    size_t input_size
)

Parameters:

input_size Uncompressed payload size in bytes.

Returns:

Maximum compressed buffer size required.

function syn_lz4_decompress¶

Decompress LZ4 raw block buffer.

size_t syn_lz4_decompress (
    const void * src,
    size_t src_size,
    void * dst,
    size_t dst_capacity
)

Decompression is fully stateless and requires no context workspace.

Parameters:

src Compressed source buffer.
src_size Compressed source size in bytes.
dst Destination buffer for decompressed output.
dst_capacity Capacity of destination buffer in bytes.

Returns:

Number of decompressed bytes written to dst, or 0 on corruption/overflow.

function syn_lz4_init¶

Initialize an LZ4 compression context.

SYN_Status syn_lz4_init (
    SYN_Lz4 * ctx
)

Parameters:

ctx Pointer to LZ4 context instance.

Returns:

SYN_OK on success, or SYN_INVALID_PARAM.

Public Static Functions Documentation¶

function lz4_hash4¶

Hash 4 bytes into 12-bit hash index using Knuth multiplicative hash.

static inline uint32_t lz4_hash4 (
    uint32_t val
)

Parameters:

val 32-bit integer word to hash.

Returns:

12-bit hash index (0..4095).

function lz4_read32¶

Read 32-bit little-endian word from unaligned byte pointer.

static inline uint32_t lz4_read32 (
    const uint8_t * ptr
)

Parameters:

ptr Pointer to byte stream.

Returns:

32-bit unsigned integer value.

Macro Definition Documentation¶

define LZ4_HASH_BITS¶

#define LZ4_HASH_BITS `12U`

Log2 size of 4096-entry hash table

define LZ4_MIN_MATCH¶

#define LZ4_MIN_MATCH `4U`

Minimum byte match length for LZ4 compression

The documentation for this class was generated from the following file src/syntropic/util/syn_lz4.c