Delta filter decoder. More...

#include "delta_decoder.h"
#include "delta_private.h"

Functions
static void	decode_buffer (lzma_delta_coder coder, uint8_t buffer, size_t size)

static lzma_ret	delta_decode (void coder_ptr, const lzma_allocator allocator, const uint8_t restrict in, size_t restrict in_pos, size_t in_size, uint8_t restrict out, size_t restrict out_pos, size_t out_size, lzma_action action)

lzma_ret	lzma_delta_decoder_init (lzma_next_coder next, const lzma_allocator allocator, const lzma_filter_info *filters)

lzma_ret	lzma_delta_props_decode (void *options, const lzma_allocator allocator, const uint8_t *props, size_t props_size)

Detailed Description

Delta filter decoder.

Definition in file delta_decoder.c.

Function Documentation

◆ decode_buffer()

static void decode_buffer	(	lzma_delta_coder *	coder,
		uint8_t *	buffer,
		size_t	size
	)

static

Definition at line 18 of file delta_decoder.c.

 {
     const size_t distance = coder->distance;
  
     for (size_t i = 0; i < size; ++i) {
         buffer[i] += coder->history[(distance + coder->pos) & 0xFF];
         coder->history[coder->pos-- & 0xFF] = buffer[i];
     }
 }

References lzma_delta_coder::distance, lzma_delta_coder::history, i, and lzma_delta_coder::pos.

Referenced by delta_decode().

◆ delta_decode()

static lzma_ret delta_decode	(	void *	coder_ptr,
		const lzma_allocator *	allocator,
		const uint8_t *restrict	in,
		size_t *restrict	in_pos,
		size_t	in_size,
		uint8_t *restrict	out,
		size_t *restrict	out_pos,
		size_t	out_size,
		lzma_action	action
	)

static

Definition at line 30 of file delta_decoder.c.

 {
     lzma_delta_coder *coder = coder_ptr;
  
     assert(coder->next.code != NULL);
  
     const size_t out_start = *out_pos;
  
     const lzma_ret ret = coder->next.code(coder->next.coder, allocator,
             in, in_pos, in_size, out, out_pos, out_size,
             action);
  
     decode_buffer(coder, out + out_start, *out_pos - out_start);
  
     return ret;
 }

References test-lz4-speed::action, allocator, assert(), lzma_next_coder_s::code, lzma_next_coder_s::coder, decode_buffer(), in, in_pos, in_size, lzma_delta_coder::next, NULL, out, and out_pos.

Referenced by lzma_delta_decoder_init().

◆ lzma_delta_decoder_init()

lzma_ret lzma_delta_decoder_init	(	lzma_next_coder *	next,
		const lzma_allocator *	allocator,
		const lzma_filter_info *	filters
	)

Definition at line 52 of file delta_decoder.c.

 {
     next->code = &delta_decode;
     return lzma_delta_coder_init(next, allocator, filters);
 }

References allocator, lzma_next_coder_s::code, delta_decode(), filters, and lzma_delta_coder_init().

◆ lzma_delta_props_decode()

lzma_ret lzma_delta_props_decode	(	void **	options,
		const lzma_allocator *	allocator,
		const uint8_t *	props,
		size_t	props_size
	)

Definition at line 61 of file delta_decoder.c.

 {
     if (props_size != 1)
         return LZMA_OPTIONS_ERROR;
  
     lzma_options_delta *opt
             = lzma_alloc(sizeof(lzma_options_delta), allocator);
     if (opt == NULL)
         return LZMA_MEM_ERROR;
  
     opt->type = LZMA_DELTA_TYPE_BYTE;
     opt->dist = props[0] + 1U;
  
     *options = opt;
  
     return LZMA_OK;
 }