ref: 585365f5bbffae93eac3f1a4ba476aa0cab3f95d
dir: /sys/src/cmd/bzip2/lib/bzcompress.c/
/*
* THIS FILE IS NOT IDENTICAL TO THE ORIGINAL
* FROM THE BZIP2 DISTRIBUTION.
*
* It has been modified, mainly to break the library
* into smaller pieces.
*
* Russ Cox
* rsc@plan9.bell-labs.com
* July 2000
*/
/*-------------------------------------------------------------*/
/*--- Library top-level functions. ---*/
/*--- bzlib.c ---*/
/*-------------------------------------------------------------*/
/*--
This file is a part of bzip2 and/or libbzip2, a program and
library for lossless, block-sorting data compression.
Copyright (C) 1996-2000 Julian R Seward. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. The origin of this software must not be misrepresented; you must
not claim that you wrote the original software. If you use this
software in a product, an acknowledgment in the product
documentation would be appreciated but is not required.
3. Altered source versions must be plainly marked as such, and must
not be misrepresented as being the original software.
4. The name of the author may not be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Julian Seward, Cambridge, UK.
jseward@acm.org
bzip2/libbzip2 version 1.0 of 21 March 2000
This program is based on (at least) the work of:
Mike Burrows
David Wheeler
Peter Fenwick
Alistair Moffat
Radford Neal
Ian H. Witten
Robert Sedgewick
Jon L. Bentley
For more information on these sources, see the manual.
--*/
/*--
CHANGES
~~~~~~~
0.9.0 -- original version.
0.9.0a/b -- no changes in this file.
0.9.0c
* made zero-length BZ_FLUSH work correctly in bzCompress().
* fixed bzWrite/bzRead to ignore zero-length requests.
* fixed bzread to correctly handle read requests after EOF.
* wrong parameter order in call to bzDecompressInit in
bzBuffToBuffDecompress. Fixed.
--*/
#include "os.h"
#include "bzlib.h"
#include "bzlib_private.h"
/*---------------------------------------------------*/
/*--- Compression stuff ---*/
/*---------------------------------------------------*/
/*---------------------------------------------------*/
static
void prepare_new_block ( EState* s )
{
Int32 i;
s->nblock = 0;
s->numZ = 0;
s->state_out_pos = 0;
BZ_INITIALISE_CRC ( s->blockCRC );
for (i = 0; i < 256; i++) s->inUse[i] = False;
s->blockNo++;
}
/*---------------------------------------------------*/
static
void init_RL ( EState* s )
{
s->state_in_ch = 256;
s->state_in_len = 0;
}
static
Bool isempty_RL ( EState* s )
{
if (s->state_in_ch < 256 && s->state_in_len > 0)
return False; else
return True;
}
/*---------------------------------------------------*/
int BZ_API(BZ2_bzCompressInit)
( bz_stream* strm,
int blockSize100k,
int verbosity,
int workFactor )
{
Int32 n;
EState* s;
if (!bz_config_ok()) return BZ_CONFIG_ERROR;
if (strm == NULL ||
blockSize100k < 1 || blockSize100k > 9 ||
workFactor < 0 || workFactor > 250)
return BZ_PARAM_ERROR;
if (workFactor == 0) workFactor = 30;
if (strm->bzalloc == NULL) strm->bzalloc = default_bzalloc;
if (strm->bzfree == NULL) strm->bzfree = default_bzfree;
s = BZALLOC( sizeof(EState) );
if (s == NULL) return BZ_MEM_ERROR;
s->strm = strm;
s->arr1 = NULL;
s->arr2 = NULL;
s->ftab = NULL;
n = 100000 * blockSize100k;
s->arr1 = BZALLOC( n * sizeof(UInt32) );
s->arr2 = BZALLOC( (n+BZ_N_OVERSHOOT) * sizeof(UInt32) );
s->ftab = BZALLOC( 65537 * sizeof(UInt32) );
if (s->arr1 == NULL || s->arr2 == NULL || s->ftab == NULL) {
if (s->arr1 != NULL) BZFREE(s->arr1);
if (s->arr2 != NULL) BZFREE(s->arr2);
if (s->ftab != NULL) BZFREE(s->ftab);
if (s != NULL) BZFREE(s);
return BZ_MEM_ERROR;
}
s->blockNo = 0;
s->state = BZ_S_INPUT;
s->mode = BZ_M_RUNNING;
s->combinedCRC = 0;
s->blockSize100k = blockSize100k;
s->nblockMAX = 100000 * blockSize100k - 19;
s->verbosity = verbosity;
s->workFactor = workFactor;
s->block = (UChar*)s->arr2;
s->mtfv = (UInt16*)s->arr1;
s->zbits = NULL;
s->ptr = (UInt32*)s->arr1;
strm->state = s;
strm->total_in_lo32 = 0;
strm->total_in_hi32 = 0;
strm->total_out_lo32 = 0;
strm->total_out_hi32 = 0;
init_RL ( s );
prepare_new_block ( s );
return BZ_OK;
}
/*---------------------------------------------------*/
static
void add_pair_to_block ( EState* s )
{
Int32 i;
UChar ch = (UChar)(s->state_in_ch);
for (i = 0; i < s->state_in_len; i++) {
BZ_UPDATE_CRC( s->blockCRC, ch );
}
s->inUse[s->state_in_ch] = True;
switch (s->state_in_len) {
case 1:
s->block[s->nblock] = (UChar)ch; s->nblock++;
break;
case 2:
s->block[s->nblock] = (UChar)ch; s->nblock++;
s->block[s->nblock] = (UChar)ch; s->nblock++;
break;
case 3:
s->block[s->nblock] = (UChar)ch; s->nblock++;
s->block[s->nblock] = (UChar)ch; s->nblock++;
s->block[s->nblock] = (UChar)ch; s->nblock++;
break;
default:
s->inUse[s->state_in_len-4] = True;
s->block[s->nblock] = (UChar)ch; s->nblock++;
s->block[s->nblock] = (UChar)ch; s->nblock++;
s->block[s->nblock] = (UChar)ch; s->nblock++;
s->block[s->nblock] = (UChar)ch; s->nblock++;
s->block[s->nblock] = ((UChar)(s->state_in_len-4));
s->nblock++;
break;
}
}
/*---------------------------------------------------*/
static
void flush_RL ( EState* s )
{
if (s->state_in_ch < 256) add_pair_to_block ( s );
init_RL ( s );
}
/*---------------------------------------------------*/
#define ADD_CHAR_TO_BLOCK(zs,zchh0) \
{ \
UInt32 zchh = (UInt32)(zchh0); \
/*-- fast track the common case --*/ \
if (zchh != zs->state_in_ch && \
zs->state_in_len == 1) { \
UChar ch = (UChar)(zs->state_in_ch); \
BZ_UPDATE_CRC( zs->blockCRC, ch ); \
zs->inUse[zs->state_in_ch] = True; \
zs->block[zs->nblock] = (UChar)ch; \
zs->nblock++; \
zs->state_in_ch = zchh; \
} \
else \
/*-- general, uncommon cases --*/ \
if (zchh != zs->state_in_ch || \
zs->state_in_len == 255) { \
if (zs->state_in_ch < 256) \
add_pair_to_block ( zs ); \
zs->state_in_ch = zchh; \
zs->state_in_len = 1; \
} else { \
zs->state_in_len++; \
} \
}
/*---------------------------------------------------*/
static
Bool copy_input_until_stop ( EState* s )
{
Bool progress_in = False;
if (s->mode == BZ_M_RUNNING) {
/*-- fast track the common case --*/
while (True) {
/*-- block full? --*/
if (s->nblock >= s->nblockMAX) break;
/*-- no input? --*/
if (s->strm->avail_in == 0) break;
progress_in = True;
ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) );
s->strm->next_in++;
s->strm->avail_in--;
s->strm->total_in_lo32++;
if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++;
}
} else {
/*-- general, uncommon case --*/
while (True) {
/*-- block full? --*/
if (s->nblock >= s->nblockMAX) break;
/*-- no input? --*/
if (s->strm->avail_in == 0) break;
/*-- flush/finish end? --*/
if (s->avail_in_expect == 0) break;
progress_in = True;
ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) );
s->strm->next_in++;
s->strm->avail_in--;
s->strm->total_in_lo32++;
if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++;
s->avail_in_expect--;
}
}
return progress_in;
}
/*---------------------------------------------------*/
static
Bool copy_output_until_stop ( EState* s )
{
Bool progress_out = False;
while (True) {
/*-- no output space? --*/
if (s->strm->avail_out == 0) break;
/*-- block done? --*/
if (s->state_out_pos >= s->numZ) break;
progress_out = True;
*(s->strm->next_out) = s->zbits[s->state_out_pos];
s->state_out_pos++;
s->strm->avail_out--;
s->strm->next_out++;
s->strm->total_out_lo32++;
if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
}
return progress_out;
}
/*---------------------------------------------------*/
static
Bool handle_compress ( bz_stream* strm )
{
Bool progress_in = False;
Bool progress_out = False;
EState* s = strm->state;
while (True) {
if (s->state == BZ_S_OUTPUT) {
progress_out |= copy_output_until_stop ( s );
if (s->state_out_pos < s->numZ) break;
if (s->mode == BZ_M_FINISHING &&
s->avail_in_expect == 0 &&
isempty_RL(s)) break;
prepare_new_block ( s );
s->state = BZ_S_INPUT;
if (s->mode == BZ_M_FLUSHING &&
s->avail_in_expect == 0 &&
isempty_RL(s)) break;
}
if (s->state == BZ_S_INPUT) {
progress_in |= copy_input_until_stop ( s );
if (s->mode != BZ_M_RUNNING && s->avail_in_expect == 0) {
flush_RL ( s );
BZ2_compressBlock ( s, (Bool)(s->mode == BZ_M_FINISHING) );
s->state = BZ_S_OUTPUT;
}
else
if (s->nblock >= s->nblockMAX) {
BZ2_compressBlock ( s, False );
s->state = BZ_S_OUTPUT;
}
else
if (s->strm->avail_in == 0) {
break;
}
}
}
return progress_in || progress_out;
}
/*---------------------------------------------------*/
int BZ_API(BZ2_bzCompress) ( bz_stream *strm, int action )
{
Bool progress;
EState* s;
if (strm == NULL) return BZ_PARAM_ERROR;
s = strm->state;
if (s == NULL) return BZ_PARAM_ERROR;
if (s->strm != strm) return BZ_PARAM_ERROR;
preswitch:
switch (s->mode) {
case BZ_M_IDLE:
return BZ_SEQUENCE_ERROR;
case BZ_M_RUNNING:
if (action == BZ_RUN) {
progress = handle_compress ( strm );
return progress ? BZ_RUN_OK : BZ_PARAM_ERROR;
}
else
if (action == BZ_FLUSH) {
s->avail_in_expect = strm->avail_in;
s->mode = BZ_M_FLUSHING;
goto preswitch;
}
else
if (action == BZ_FINISH) {
s->avail_in_expect = strm->avail_in;
s->mode = BZ_M_FINISHING;
goto preswitch;
}
else
return BZ_PARAM_ERROR;
case BZ_M_FLUSHING:
if (action != BZ_FLUSH) return BZ_SEQUENCE_ERROR;
if (s->avail_in_expect != s->strm->avail_in)
return BZ_SEQUENCE_ERROR;
progress = handle_compress ( strm );
if (!progress) return BZ_SEQUENCE_ERROR; //rsc added
if (s->avail_in_expect > 0 || !isempty_RL(s) ||
s->state_out_pos < s->numZ) return BZ_FLUSH_OK;
s->mode = BZ_M_RUNNING;
return BZ_RUN_OK;
case BZ_M_FINISHING:
if (action != BZ_FINISH) return BZ_SEQUENCE_ERROR;
if (s->avail_in_expect != s->strm->avail_in)
return BZ_SEQUENCE_ERROR;
progress = handle_compress ( strm );
if (!progress) return BZ_SEQUENCE_ERROR;
if (s->avail_in_expect > 0 || !isempty_RL(s) ||
s->state_out_pos < s->numZ) return BZ_FINISH_OK;
s->mode = BZ_M_IDLE;
return BZ_STREAM_END;
}
return BZ_OK; /*--not reached--*/
}
/*---------------------------------------------------*/
int BZ_API(BZ2_bzCompressEnd) ( bz_stream *strm )
{
EState* s;
if (strm == NULL) return BZ_PARAM_ERROR;
s = strm->state;
if (s == NULL) return BZ_PARAM_ERROR;
if (s->strm != strm) return BZ_PARAM_ERROR;
if (s->arr1 != NULL) BZFREE(s->arr1);
if (s->arr2 != NULL) BZFREE(s->arr2);
if (s->ftab != NULL) BZFREE(s->ftab);
BZFREE(strm->state);
strm->state = NULL;
return BZ_OK;
}