delta_common.c File Reference

Common stuff for Delta encoder and decoder. More...

#include "delta_common.h"
#include "delta_private.h"

Go to the source code of this file.

Functions
static void	delta_coder_end (void *coder_ptr, const lzma_allocator *allocator)
lzma_ret	lzma_delta_coder_init (lzma_next_coder *next, const lzma_allocator *allocator, const lzma_filter_info *filters)
uint64_t	lzma_delta_coder_memusage (const void *options)

Detailed Description

Common stuff for Delta encoder and decoder.

Definition in file delta_common.c.

Function Documentation

delta_coder_end()

static void delta_coder_end ( void *  coder_ptr, const lzma_allocator *  allocator  )

static

Definition at line 18 of file delta_common.c.

{
    lzma_delta_coder *coder = coder_ptr;
    lzma_next_end(&coder->next, allocator);
    lzma_free(coder, allocator);
    return;
}

References allocator, lzma_free(), lzma_next_end(), and lzma_delta_coder::next.

Referenced by lzma_delta_coder_init().

lzma_delta_coder_init()

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

Definition at line 28 of file delta_common.c.

{
    // Allocate memory for the decoder if needed.
    lzma_delta_coder *coder = next->coder;
    if (coder == NULL) {
        coder = lzma_alloc(sizeof(lzma_delta_coder), allocator);
        if (coder == NULL)
            return LZMA_MEM_ERROR;
 
        next->coder = coder;
 
        // End function is the same for encoder and decoder.
        next->end = &delta_coder_end;
        coder->next = LZMA_NEXT_CODER_INIT;
    }
 
    // Validate the options.
    if (lzma_delta_coder_memusage(filters[0].options) == UINT64_MAX)
        return LZMA_OPTIONS_ERROR;
 
    // Set the delta distance.
    const lzma_options_delta *opt = filters[0].options;
    coder->distance = opt->dist;
 
    // Initialize the rest of the variables.
    coder->pos = 0;
    memzero(coder->history, LZMA_DELTA_DIST_MAX);
 
    // Initialize the next decoder in the chain, if any.
    return lzma_next_filter_init(&coder->next, allocator, filters + 1);
}

References allocator, lzma_next_coder_s::coder, delta_coder_end(), lzma_options_delta::dist, lzma_delta_coder::distance, lzma_next_coder_s::end, filters, lzma_delta_coder::history, lzma_alloc(), lzma_delta_coder_memusage(), LZMA_DELTA_DIST_MAX, LZMA_MEM_ERROR, LZMA_NEXT_CODER_INIT, lzma_next_filter_init(), LZMA_OPTIONS_ERROR, memzero, lzma_delta_coder::next, NULL, options, lzma_filter::options, lzma_delta_coder::pos, and UINT64_MAX.

Referenced by lzma_delta_decoder_init(), and lzma_delta_encoder_init().

lzma_delta_coder_memusage()

uint64_t lzma_delta_coder_memusage

(

const void *

options

)

Definition at line 63 of file delta_common.c.

{
    const lzma_options_delta *opt = options;
 
    if (opt == NULL || opt->type != LZMA_DELTA_TYPE_BYTE
            || opt->dist < LZMA_DELTA_DIST_MIN
            || opt->dist > LZMA_DELTA_DIST_MAX)
        return UINT64_MAX;
 
    return sizeof(lzma_delta_coder);
}

References lzma_options_delta::dist, LZMA_DELTA_DIST_MAX, LZMA_DELTA_DIST_MIN, LZMA_DELTA_TYPE_BYTE, NULL, options, lzma_options_delta::type, and UINT64_MAX.

Referenced by lzma_delta_coder_init(), and lzma_delta_props_encode().