lzma2_encoder.h File Reference

LZMA2 encoder. More...

#include "common.h"

Go to the source code of this file.

Macros
#define	LZMA2_CHUNK_MAX   (UINT32_C(1) << 16)
	Maximum number of bytes of actual data per chunk (no headers) More...
#define	LZMA2_UNCOMPRESSED_MAX   (UINT32_C(1) << 21)
	Maximum uncompressed size of LZMA chunk (no headers) More...
#define	LZMA2_HEADER_MAX   6
	Maximum size of LZMA2 headers. More...
#define	LZMA2_HEADER_UNCOMPRESSED   3
	Size of a header for uncompressed chunk. More...

Functions
lzma_ret	lzma_lzma2_encoder_init (lzma_next_coder *next, const lzma_allocator *allocator, const lzma_filter_info *filters)
uint64_t	lzma_lzma2_encoder_memusage (const void *options)
lzma_ret	lzma_lzma2_props_encode (const void *options, uint8_t *out)
uint64_t	lzma_lzma2_block_size (const void *options)

Detailed Description

LZMA2 encoder.

Definition in file lzma2_encoder.h.

Macro Definition Documentation

LZMA2_CHUNK_MAX

#define LZMA2_CHUNK_MAX   (UINT32_C(1) << 16)

Maximum number of bytes of actual data per chunk (no headers)

Definition at line 21 of file lzma2_encoder.h.

LZMA2_HEADER_MAX

#define LZMA2_HEADER_MAX   6

Maximum size of LZMA2 headers.

Definition at line 27 of file lzma2_encoder.h.

LZMA2_HEADER_UNCOMPRESSED

#define LZMA2_HEADER_UNCOMPRESSED   3

Size of a header for uncompressed chunk.

Definition at line 30 of file lzma2_encoder.h.

LZMA2_UNCOMPRESSED_MAX

#define LZMA2_UNCOMPRESSED_MAX   (UINT32_C(1) << 21)

Maximum uncompressed size of LZMA chunk (no headers)

Definition at line 24 of file lzma2_encoder.h.

Function Documentation

lzma_lzma2_block_size()

uint64_t lzma_lzma2_block_size

(

const void *

options

)

Definition at line 404 of file lzma2_encoder.c.

{
    const lzma_options_lzma *const opt = options;
 
    // Use at least 1 MiB to keep compression ratio better.
    return my_max((uint64_t)(opt->dict_size) * 3, UINT64_C(1) << 20);
}

References lzma_options_lzma::dict_size, my_max, options, and UINT64_C.

lzma_lzma2_encoder_init()

lzma_ret lzma_lzma2_encoder_init	(	lzma_next_coder *	next,
		const lzma_allocator *	allocator,
		const lzma_filter_info *	filters
	)

Definition at line 359 of file lzma2_encoder.c.

{
    return lzma_lz_encoder_init(
            next, allocator, filters, &lzma2_encoder_init);
}

References allocator, filters, lzma2_encoder_init(), and lzma_lz_encoder_init().

lzma_lzma2_encoder_memusage()

uint64_t lzma_lzma2_encoder_memusage

(

const void *

options

)

Definition at line 368 of file lzma2_encoder.c.

{
    const uint64_t lzma_mem = lzma_lzma_encoder_memusage(options);
    if (lzma_mem == UINT64_MAX)
        return UINT64_MAX;
 
    return sizeof(lzma_lzma2_coder) + lzma_mem;
}

References lzma_lzma_encoder_memusage(), options, and UINT64_MAX.

lzma_lzma2_props_encode()

lzma_ret lzma_lzma2_props_encode	(	const void *	options,
		uint8_t *	out
	)

Definition at line 379 of file lzma2_encoder.c.

{
    const lzma_options_lzma *const opt = options;
    uint32_t d = my_max(opt->dict_size, LZMA_DICT_SIZE_MIN);
 
    // Round up to the next 2^n - 1 or 2^n + 2^(n - 1) - 1 depending
    // on which one is the next:
    --d;
    d |= d >> 2;
    d |= d >> 3;
    d |= d >> 4;
    d |= d >> 8;
    d |= d >> 16;
 
    // Get the highest two bits using the proper encoding:
    if (d == UINT32_MAX)
        out[0] = 40;
    else
        out[0] = get_dist_slot(d + 1) - 24;
 
    return LZMA_OK;
}

References d, lzma_options_lzma::dict_size, get_dist_slot(), LZMA_DICT_SIZE_MIN, LZMA_OK, my_max, options, out, and UINT32_MAX.