pcompress/lzma_compress.c
2012-07-07 22:18:29 +05:30

199 lines
4.6 KiB
C

/*
* This file is a part of Pcompress, a chunked parallel multi-
* algorithm lossless compression and decompression program.
*
* Copyright (C) 2012 Moinak Ghosh. All rights reserved.
* Use is subject to license terms.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* moinakg@belenix.org, http://moinakg.wordpress.com/
*
* This program includes partly-modified public domain source
* code from the LZMA SDK: http://www.7-zip.org/sdk.html
*/
#include <sys/types.h>
#include <stdio.h>
#include <strings.h>
#include <LzmaEnc.h>
#include <LzmaDec.h>
#include <utils.h>
#include <pcompress.h>
#include <allocator.h>
#define SZ_ERROR_DESTLEN 100
#define LZMA_MAX_DICT (1 << 30)
#define LZMA_DICT_THRESH (1 << 29)
#define LZMA_DEFAULT_DICT (1 << 24)
CLzmaEncProps *p = NULL;
static ISzAlloc g_Alloc = {
slab_alloc,
slab_free,
NULL
};
void
lzma_stats(int show)
{
}
/*
* The two functions below are not thread-safe, by design.
*/
int
lzma_init(void **data, int *level, ssize_t chunksize)
{
if (!p) {
p = (CLzmaEncProps *)slab_alloc(NULL, sizeof (CLzmaEncProps));
LzmaEncProps_Init(p);
/*
* Set the dictionary size and fast bytes based on level.
*/
if (*level < 8) {
/*
* Choose a dict size with a balance between perf and
* compression.
*/
p->dictSize = LZMA_DEFAULT_DICT;
} else {
/*
* Let LZMA determine best dict size.
*/
p->dictSize = 0;
}
/* Determine the fast bytes value. */
if (*level < 7)
p->fb = 32;
else if (*level < 10)
p->fb = 64;
else
p->fb = 128;
p->level = *level;
LzmaEncProps_Normalize(p);
slab_cache_add(p->litprob_sz);
}
if (*level > 9) *level = 9;
*data = p;
return (0);
}
int
lzma_deinit(void **data)
{
if (p) {
slab_free(NULL, p);
p = NULL;
}
*data = NULL;
return (0);
}
static void
lzerr(int err)
{
switch (err) {
case SZ_ERROR_MEM:
fprintf(stderr, "LZMA: Memory allocation error\n");
break;
case SZ_ERROR_PARAM:
fprintf(stderr, "LZMA: Incorrect paramater\n");
break;
case SZ_ERROR_WRITE:
fprintf(stderr, "LZMA: Write callback error\n");
break;
case SZ_ERROR_PROGRESS:
fprintf(stderr, "LZMA: Progress callback errored\n");
break;
case SZ_ERROR_INPUT_EOF:
fprintf(stderr, "LZMA: More compressed input bytes expected\n");
break;
case SZ_ERROR_OUTPUT_EOF:
fprintf(stderr, "LZMA: Output buffer overflow\n");
break;
case SZ_ERROR_UNSUPPORTED:
fprintf(stderr, "LZMA: Unsupported properties\n");
break;
case SZ_ERROR_DESTLEN:
fprintf(stderr, "LZMA: Output chunk size too small\n");
break;
case SZ_ERROR_DATA:
fprintf(stderr, "LZMA: Data Error\n");
break;
default:
fprintf(stderr, "LZMA: Unknown error code: %d\n", err);
}
}
/*
* LZMA compressed segment format(simplified)
* ------------------------------------------
* Offset Size Description
* 0 1 Special LZMA properties for compressed data
* 1 4 Dictionary size (little endian)
* 13 Compressed data
*
* Derived from http://docs.bugaco.com/7zip/lzma.txt
* We do not store the uncompressed chunk size here. It is stored in
* our chunk header.
*/
int
lzma_compress(void *src, size_t srclen, void *dst,
size_t *dstlen, int level, uchar_t chdr, void *data)
{
size_t props_len = LZMA_PROPS_SIZE;
SRes res;
Byte *_dst;
CLzmaEncProps *props = (CLzmaEncProps *)data;
if (*dstlen < LZMA_PROPS_SIZE) {
lzerr(SZ_ERROR_DESTLEN);
return (-1);
}
props->level = level;
_dst = (Byte *)dst;
*dstlen -= LZMA_PROPS_SIZE;
res = LzmaEncode(_dst + LZMA_PROPS_SIZE, dstlen, src, srclen,
props, _dst, &props_len, 0, NULL, &g_Alloc, &g_Alloc);
if (res != 0) {
lzerr(res);
return (-1);
}
*dstlen += LZMA_PROPS_SIZE;
return (0);
}
int
lzma_decompress(void *src, size_t srclen, void *dst,
size_t *dstlen, int level, uchar_t chdr, void *data)
{
size_t _srclen;
const uchar_t *_src;
SRes res;
ELzmaStatus status;
_srclen = srclen - LZMA_PROPS_SIZE;
_src = (uchar_t *)src + LZMA_PROPS_SIZE;
if ((res = LzmaDecode((uchar_t *)dst, dstlen, _src, &_srclen,
src, LZMA_PROPS_SIZE, LZMA_FINISH_ANY,
&status, &g_Alloc)) != SZ_OK) {
lzerr(res);
return (-1);
}
return (0);
}