plan9port

fork of plan9port with libvec, libstr and libsdb
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buffcompress.c (4556B)

      1 /*
      2  * THIS FILE IS NOT IDENTICAL TO THE ORIGINAL
      3  * FROM THE BZIP2 DISTRIBUTION.
      4  *
      5  * It has been modified, mainly to break the library
      6  * into smaller pieces.
      7  *
      8  * Russ Cox
      9  * rsc@plan9.bell-labs.com
     10  * July 2000
     11  */
     12 
     13 /*-------------------------------------------------------------*/
     14 /*--- Library top-level functions.                          ---*/
     15 /*---                                               bzlib.c ---*/
     16 /*-------------------------------------------------------------*/
     17 
     18 /*--
     19   This file is a part of bzip2 and/or libbzip2, a program and
     20   library for lossless, block-sorting data compression.
     21 
     22   Copyright (C) 1996-2000 Julian R Seward.  All rights reserved.
     23 
     24   Redistribution and use in source and binary forms, with or without
     25   modification, are permitted provided that the following conditions
     26   are met:
     27 
     28   1. Redistributions of source code must retain the above copyright
     29      notice, this list of conditions and the following disclaimer.
     30 
     31   2. The origin of this software must not be misrepresented; you must
     32      not claim that you wrote the original software.  If you use this
     33      software in a product, an acknowledgment in the product
     34      documentation would be appreciated but is not required.
     35 
     36   3. Altered source versions must be plainly marked as such, and must
     37      not be misrepresented as being the original software.
     38 
     39   4. The name of the author may not be used to endorse or promote
     40      products derived from this software without specific prior written
     41      permission.
     42 
     43   THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     44   OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     45   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     46   ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
     47   DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     48   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     49   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     50   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     51   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     52   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     53   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     54 
     55   Julian Seward, Cambridge, UK.
     56   jseward@acm.org
     57   bzip2/libbzip2 version 1.0 of 21 March 2000
     58 
     59   This program is based on (at least) the work of:
     60      Mike Burrows
     61      David Wheeler
     62      Peter Fenwick
     63      Alistair Moffat
     64      Radford Neal
     65      Ian H. Witten
     66      Robert Sedgewick
     67      Jon L. Bentley
     68 
     69   For more information on these sources, see the manual.
     70 --*/
     71 
     72 /*--
     73    CHANGES
     74    ~~~~~~~
     75    0.9.0 -- original version.
     76 
     77    0.9.0a/b -- no changes in this file.
     78 
     79    0.9.0c
     80       * made zero-length BZ_FLUSH work correctly in bzCompress().
     81       * fixed bzWrite/bzRead to ignore zero-length requests.
     82       * fixed bzread to correctly handle read requests after EOF.
     83       * wrong parameter order in call to bzDecompressInit in
     84         bzBuffToBuffDecompress.  Fixed.
     85 --*/
     86 
     87 #include "os.h"
     88 #include "bzlib.h"
     89 #include "bzlib_private.h"
     90 
     91 /*---------------------------------------------------*/
     92 int BZ_API(BZ2_bzBuffToBuffCompress)
     93                          ( char*         dest,
     94                            unsigned int* destLen,
     95                            char*         source,
     96                            unsigned int  sourceLen,
     97                            int           blockSize100k,
     98                            int           verbosity,
     99                            int           workFactor )
    100 {
    101    bz_stream strm;
    102    int ret;
    103 
    104    if (dest == NULL || destLen == NULL ||
    105        source == NULL ||
    106        blockSize100k < 1 || blockSize100k > 9 ||
    107        verbosity < 0 || verbosity > 4 ||
    108        workFactor < 0 || workFactor > 250)
    109       return BZ_PARAM_ERROR;
    110 
    111    if (workFactor == 0) workFactor = 30;
    112    strm.bzalloc = NULL;
    113    strm.bzfree = NULL;
    114    strm.opaque = NULL;
    115    ret = BZ2_bzCompressInit ( &strm, blockSize100k,
    116                               verbosity, workFactor );
    117    if (ret != BZ_OK) return ret;
    118 
    119    strm.next_in = source;
    120    strm.next_out = dest;
    121    strm.avail_in = sourceLen;
    122    strm.avail_out = *destLen;
    123 
    124    ret = BZ2_bzCompress ( &strm, BZ_FINISH );
    125    if (ret == BZ_FINISH_OK) goto output_overflow;
    126    if (ret != BZ_STREAM_END) goto errhandler;
    127 
    128    /* normal termination */
    129    *destLen -= strm.avail_out;
    130    BZ2_bzCompressEnd ( &strm );
    131    return BZ_OK;
    132 
    133    output_overflow:
    134    BZ2_bzCompressEnd ( &strm );
    135    return BZ_OUTBUFF_FULL;
    136 
    137    errhandler:
    138    BZ2_bzCompressEnd ( &strm );
    139    return ret;
    140 }