Compression / decompression context. More...

#include <zxc_internal.h>

Data Fields
uint32_t *	hash_table
	Hash table for LZ77 match positions (epoch\|pos).

uint8_t *	hash_tags
	Split tag table for fast match rejection (8-bit tags).

uint16_t *	chain_table
	Chain table for collision resolution.

void *	memory_block
	Single allocation block owner.

uint32_t	epoch
	Current epoch for lazy hash table invalidation.

uint32_t *	buf_sequences
	Buffer for sequence records (packed: LL(8)\|ML(8)\|Offset(16)).

uint8_t *	buf_tokens
	Buffer for token sequences.

uint16_t *	buf_offsets
	Buffer for offsets.

uint8_t *	buf_extras
	Buffer for extra lengths (vbytes for LL/ML).

uint8_t *	buf_split
	Match-splitting scratch, one byte per sequence.

zxc_glo_split_hist_t *	buf_split_hist
	Match-splitting escape histograms.

uint8_t *	literals
	Buffer for literal bytes.

uint8_t *	lit_buffer
	Scratch buffer for literals (RLE / Huffman).

size_t	lit_buffer_cap
	Current capacity of the scratch buffer.

uint8_t *	work_buf
	Padded scratch buffer for buffer-API decompression.

size_t	work_buf_cap
	Capacity of the work buffer.

uint8_t *	tok_buffer
	Decode scratch for a Huffman-coded GLO token section (enc_tok == HUFFMAN); NULL on compress.

size_t	tok_buffer_cap
	Capacity of tok_buffer in bytes.

uint8_t *	pivco_scratch
	Level ping-pong scratch for PivCo decode.

size_t	pivco_scratch_cap
	Capacity of pivco_scratch in bytes.

void *	entropy_block
	Lazy allocation backing tok_buffer + pivco_scratch (heap decode contexts, first entropy block only).

uint8_t *	opt_scratch
	Optimal-parser DP scratch (level >= 6 only, lazy-allocated, packs dp/parent_len/parent_off/actions).

size_t	opt_scratch_cap
	Current capacity of opt_scratch in bytes.

int	checksum_enabled
	1 if checksum calculation/verification is enabled.

int	compression_level
	Compression level.

size_t	dict_size
	Dictionary prefill size (0 = no dictionary).

uint8_t *	dict_buffer
	[dict \| data] concat scratch carved from memory_block when dict_size > 0 (NULL otherwise).

size_t	dict_buffer_cap
	Capacity of dict_buffer in bytes (0 = none).

zxc_dict_huf_state_t *	dict_huf
	Tree-at-attach state (PivCo tree + codes + code lengths), carved from the workspace only when dict_size > 0 (NULL otherwise); built once by zxc_cctx_attach_dict_huf.

int	dict_huf_tree_ok
	1 when *dict_huf is built and valid.

uint32_t *	lit_freq_acc
	Trainer hook: when non-NULL, the GLO encoder accumulates post-LZ literal byte frequencies here (256 entries).

size_t	chunk_size
	Effective block size in bytes.

uint32_t	offset_bits
	log2(chunk_size) - governs epoch_mark shift.

uint32_t	offset_mask
	(1U << offset_bits) - 1

uint32_t	max_epoch
	1U << (32 - offset_bits)

Detailed Description

Compression / decompression context.

Holds the buffers reused across blocks to avoid repeated allocations.

Key fields:

hash_table: epoch-tagged positions (ZXC_LZ_HASH_SIZE * 4 bytes).
hash_tags: 8-bit tags for fast match rejection (ZXC_LZ_HASH_SIZE * 1 byte).
chain_table: collision chain storing the previous occurrence of a hash, forming a linked list per bucket and enabling history traversal.
epoch: drives "lazy hash table invalidation". Instead of memset-ing the hash table for every block, we store (epoch << offset_bits) | offset; an entry whose stored epoch differs from ctx->epoch is treated as empty.

Definition at line 1884 of file zxc_internal.h.

Field Documentation

◆ buf_extras

uint8_t* zxc_cctx_t::buf_extras

Buffer for extra lengths (vbytes for LL/ML).

Definition at line 1897 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ buf_offsets

uint16_t* zxc_cctx_t::buf_offsets

Buffer for offsets.

Definition at line 1896 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ buf_sequences

uint32_t* zxc_cctx_t::buf_sequences

Buffer for sequence records (packed: LL(8)|ML(8)|Offset(16)).

Definition at line 1894 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ buf_split

uint8_t* zxc_cctx_t::buf_split

Match-splitting scratch, one byte per sequence.

Definition at line 1898 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ buf_split_hist

zxc_glo_split_hist_t* zxc_cctx_t::buf_split_hist

Match-splitting escape histograms.

Definition at line 1899 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ buf_tokens

uint8_t* zxc_cctx_t::buf_tokens

Buffer for token sequences.

Definition at line 1895 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ chain_table

uint16_t* zxc_cctx_t::chain_table

Chain table for collision resolution.

Definition at line 1889 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ checksum_enabled

int zxc_cctx_t::checksum_enabled

1 if checksum calculation/verification is enabled.

Definition at line 1923 of file zxc_internal.h.

Referenced by zxc_seek_mt_worker(), zxc_static_decompress_block(), and zxc_stream_worker().

◆ chunk_size

size_t zxc_cctx_t::chunk_size

Effective block size in bytes.

Definition at line 1939 of file zxc_internal.h.

Referenced by zxc_seek_mt_worker().

◆ compression_level

int zxc_cctx_t::compression_level

Compression level.

Definition at line 1924 of file zxc_internal.h.

Referenced by zxc_stream_worker().

◆ dict_buffer

uint8_t* zxc_cctx_t::dict_buffer

[dict | data] concat scratch carved from memory_block when dict_size > 0 (NULL otherwise).

Definition at line 1926 of file zxc_internal.h.

Referenced by zxc_cctx_free(), zxc_compress(), zxc_compress_cctx(), zxc_dctx_decode_frame(), zxc_decompress_block(), zxc_seek_mt_worker(), zxc_seek_use_dict(), zxc_stream_worker(), and zxc_train_dict_huf().

◆ dict_buffer_cap

size_t zxc_cctx_t::dict_buffer_cap

Capacity of dict_buffer in bytes (0 = none).

Definition at line 1928 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ dict_huf

zxc_dict_huf_state_t* zxc_cctx_t::dict_huf

Tree-at-attach state (PivCo tree + codes + code lengths), carved from the workspace only when dict_size > 0 (NULL otherwise); built once by zxc_cctx_attach_dict_huf.

Valid iff dict_huf_tree_ok.

Definition at line 1929 of file zxc_internal.h.

Referenced by zxc_cctx_free(), and zxc_stream_worker().

◆ dict_huf_tree_ok

int zxc_cctx_t::dict_huf_tree_ok

1 when *dict_huf is built and valid.

Definition at line 1933 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ dict_size

size_t zxc_cctx_t::dict_size

Dictionary prefill size (0 = no dictionary).

Definition at line 1925 of file zxc_internal.h.

Referenced by zxc_cctx_free(), zxc_compress_cctx(), zxc_decompress_block(), zxc_seek_mt_worker(), zxc_seek_use_dict(), and zxc_static_decompress_block().

◆ entropy_block

void* zxc_cctx_t::entropy_block

Lazy allocation backing tok_buffer + pivco_scratch (heap decode contexts, first entropy block only).

NULL on compress contexts and static workspaces. Freed by zxc_cctx_free.

Definition at line 1914 of file zxc_internal.h.

Referenced by zxc_cctx_alloc_entropy_scratch(), and zxc_cctx_free().

◆ epoch

uint32_t zxc_cctx_t::epoch

Current epoch for lazy hash table invalidation.

Definition at line 1891 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ hash_table

uint32_t* zxc_cctx_t::hash_table

Hash table for LZ77 match positions (epoch|pos).

Definition at line 1887 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ hash_tags

uint8_t* zxc_cctx_t::hash_tags

Split tag table for fast match rejection (8-bit tags).

Definition at line 1888 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ lit_buffer

uint8_t* zxc_cctx_t::lit_buffer

Scratch buffer for literals (RLE / Huffman).

Definition at line 1903 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ lit_buffer_cap

size_t zxc_cctx_t::lit_buffer_cap

Current capacity of the scratch buffer.

Definition at line 1904 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ lit_freq_acc

uint32_t* zxc_cctx_t::lit_freq_acc

Trainer hook: when non-NULL, the GLO encoder accumulates post-LZ literal byte frequencies here (256 entries).

NULL outside dictionary training.

Definition at line 1934 of file zxc_internal.h.

Referenced by zxc_cctx_free(), and zxc_train_dict_huf().

◆ literals

uint8_t* zxc_cctx_t::literals

Buffer for literal bytes.

Definition at line 1900 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ max_epoch

uint32_t zxc_cctx_t::max_epoch

1U << (32 - offset_bits)

Definition at line 1942 of file zxc_internal.h.

◆ memory_block

void* zxc_cctx_t::memory_block

Single allocation block owner.

Definition at line 1890 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ offset_bits

uint32_t zxc_cctx_t::offset_bits

log2(chunk_size) - governs epoch_mark shift.

Definition at line 1940 of file zxc_internal.h.

◆ offset_mask

uint32_t zxc_cctx_t::offset_mask

(1U << offset_bits) - 1

Definition at line 1941 of file zxc_internal.h.

◆ opt_scratch

uint8_t* zxc_cctx_t::opt_scratch

Optimal-parser DP scratch (level >= 6 only, lazy-allocated, packs dp/parent_len/parent_off/actions).

Also the Huffman code-length builder's and nudge's scratch (ZXC_HUF_NUDGE_SCRATCH_SIZE).

Definition at line 1918 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ opt_scratch_cap

size_t zxc_cctx_t::opt_scratch_cap

Current capacity of opt_scratch in bytes.

Definition at line 1922 of file zxc_internal.h.

Referenced by zxc_cctx_free().

◆ pivco_scratch

uint8_t* zxc_cctx_t::pivco_scratch

Level ping-pong scratch for PivCo decode.

Definition at line 1912 of file zxc_internal.h.

Referenced by zxc_cctx_alloc_entropy_scratch(), and zxc_cctx_free().

◆ pivco_scratch_cap

size_t zxc_cctx_t::pivco_scratch_cap

Capacity of pivco_scratch in bytes.

Definition at line 1913 of file zxc_internal.h.

Referenced by zxc_cctx_alloc_entropy_scratch(), and zxc_cctx_free().

◆ tok_buffer

uint8_t* zxc_cctx_t::tok_buffer

Decode scratch for a Huffman-coded GLO token section (enc_tok == HUFFMAN); NULL on compress.

Heap decode contexts defer it (with pivco_scratch) to the first entropy section, see entropy_block.

Definition at line 1907 of file zxc_internal.h.

Referenced by zxc_cctx_alloc_entropy_scratch(), and zxc_cctx_free().

◆ tok_buffer_cap

size_t zxc_cctx_t::tok_buffer_cap

Capacity of tok_buffer in bytes.

Definition at line 1911 of file zxc_internal.h.

Referenced by zxc_cctx_alloc_entropy_scratch(), and zxc_cctx_free().

◆ work_buf

uint8_t* zxc_cctx_t::work_buf

Padded scratch buffer for buffer-API decompression.

Definition at line 1905 of file zxc_internal.h.

Referenced by zxc_cctx_free(), zxc_dctx_decode_frame(), and zxc_seek_mt_worker().

◆ work_buf_cap

size_t zxc_cctx_t::work_buf_cap

Capacity of the work buffer.

Definition at line 1906 of file zxc_internal.h.

Referenced by zxc_cctx_alloc_entropy_scratch(), zxc_cctx_free(), and zxc_dctx_decode_frame().

The documentation for this struct was generated from the following file:

src/lib/zxc_internal.h

Data Fields

Detailed Description

Field Documentation

◆ buf_extras

◆ buf_offsets

◆ buf_sequences

◆ buf_split

◆ buf_split_hist

◆ buf_tokens

◆ chain_table

◆ checksum_enabled

◆ chunk_size

◆ compression_level

◆ dict_buffer

◆ dict_buffer_cap

◆ dict_huf

◆ dict_huf_tree_ok

◆ dict_size

◆ entropy_block

◆ epoch

◆ hash_table

◆ hash_tags

◆ lit_buffer

◆ lit_buffer_cap

◆ lit_freq_acc

◆ literals

◆ max_epoch

◆ memory_block

◆ offset_bits

◆ offset_mask

◆ opt_scratch

◆ opt_scratch_cap

◆ pivco_scratch

◆ pivco_scratch_cap

◆ tok_buffer

◆ tok_buffer_cap

◆ work_buf

◆ work_buf_cap