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 #include "bzlib_stdio.h"
91 #include "bzlib_stdio_private.h"
92 
93 /*---------------------------------------------------*/
94 /*--
95    Code contributed by Yoshioka Tsuneo
96    (QWF00133@niftyserve.or.jp/tsuneo-y@is.aist-nara.ac.jp),
97    to support better zlib compatibility.
98    This code is not _officially_ part of libbzip2 (yet);
99    I haven't tested it, documented it, or considered the
100    threading-safeness of it.
101    If this code breaks, please contact both Yoshioka and me.
102 --*/
103 /*---------------------------------------------------*/
104 
105 /*---------------------------------------------------*/
106 
107 #if defined(_WIN32) || defined(OS2) || defined(MSDOS)
108 #   include <fcntl.h>
109 #   include <io.h>
110 #   define SET_BINARY_MODE(file) setmode(fileno(file),O_BINARY)
111 #else
112 #   define SET_BINARY_MODE(file)
113 #endif
114 static
115 BZFILE * bzopen_or_bzdopen
116                ( const char *path,   /* no use when bzdopen */
117                  int fd,             /* no use when bzdopen */
118                  const char *mode,
119                  int open_mode)      /* bzopen: 0, bzdopen:1 */
120 {
121    int    bzerr;
122    char   unused[BZ_MAX_UNUSED];
123    int    blockSize100k = 9;
124    int    writing       = 0;
125    char   mode2[10]     = "";
126    FILE   *fp           = NULL;
127    BZFILE *bzfp         = NULL;
128    int    verbosity     = 0;
129    int    workFactor    = 30;
130    int    smallMode     = 0;
131    int    nUnused       = 0; 
132 
133    if (mode == NULL) return NULL;
134    while (*mode) {
135       switch (*mode) {
136       case 'r':
137          writing = 0; break;
138       case 'w':
139          writing = 1; break;
140       case 's':
141          smallMode = 1; break;
142       default:
143          if (isdigit((int)(*mode))) {
144             blockSize100k = *mode-'0';
145          }
146       }
147       mode++;
148    }
149    strcat(mode2, writing ? "w" : "r" );
150    strcat(mode2,"b");   /* binary mode */
151 
152    if (open_mode==0) {
153       if (path==NULL || strcmp(path,"")==0) {
154         fp = (writing ? stdout : stdin);
155         SET_BINARY_MODE(fp);
156       } else {
157         fp = fopen(path,mode2);
158       }
159    } else {
160 #ifdef BZ_STRICT_ANSI
161       fp = NULL;
162 #else
163       fp = fdopen(fd,mode2);
164 #endif
165    }
166    if (fp == NULL) return NULL;
167 
168    if (writing) {
169       /* Guard against total chaos and anarchy -- JRS */
170       if (blockSize100k < 1) blockSize100k = 1;
171       if (blockSize100k > 9) blockSize100k = 9; 
172       bzfp = BZ2_bzWriteOpen(&bzerr,fp,blockSize100k,
173                              verbosity,workFactor);
174    } else {
175       bzfp = BZ2_bzReadOpen(&bzerr,fp,verbosity,smallMode,
176                             unused,nUnused);
177    }
178    if (bzfp == NULL) {
179       if (fp != stdin && fp != stdout) fclose(fp);
180       return NULL;
181    }
182    return bzfp;
183 }
184 
185 
186 /*---------------------------------------------------*/
187 /*--
188    open file for read or write.
189       ex) bzopen("file","w9")
190       case path="" or NULL => use stdin or stdout.
191 --*/
192 BZFILE * BZ_API(BZ2_bzopen)
193                ( const char *path,
194                  const char *mode )
195 {
196    return bzopen_or_bzdopen(path,-1,mode,/*bzopen*/0);
197 }
198 
199 
200 /*---------------------------------------------------*/
201 BZFILE * BZ_API(BZ2_bzdopen)
202                ( int fd,
203                  const char *mode )
204 {
205    return bzopen_or_bzdopen(NULL,fd,mode,/*bzdopen*/1);
206 }
207 
208 
209 /*---------------------------------------------------*/
210 int BZ_API(BZ2_bzread) (BZFILE* b, void* buf, int len )
211 {
212    int bzerr, nread;
213    if (((bzFile*)b)->lastErr == BZ_STREAM_END) return 0;
214    nread = BZ2_bzRead(&bzerr,b,buf,len);
215    if (bzerr == BZ_OK || bzerr == BZ_STREAM_END) {
216       return nread;
217    } else {
218       return -1;
219    }
220 }
221 
222 
223 /*---------------------------------------------------*/
224 int BZ_API(BZ2_bzwrite) (BZFILE* b, void* buf, int len )
225 {
226    int bzerr;
227 
228    BZ2_bzWrite(&bzerr,b,buf,len);
229    if(bzerr == BZ_OK){
230       return len;
231    }else{
232       return -1;
233    }
234 }
235 
236 
237 /*---------------------------------------------------*/
238 int BZ_API(BZ2_bzflush) (BZFILE *b)
239 {
240    /* do nothing now... */
241    return 0;
242 }
243 
244 
245 /*---------------------------------------------------*/
246 void BZ_API(BZ2_bzclose) (BZFILE* b)
247 {
248    int bzerr;
249    FILE *fp = ((bzFile *)b)->handle;
250    
251    if (b==NULL) {return;}
252    if(((bzFile*)b)->writing){
253       BZ2_bzWriteClose(&bzerr,b,0,NULL,NULL);
254       if(bzerr != BZ_OK){
255          BZ2_bzWriteClose(NULL,b,1,NULL,NULL);
256       }
257    }else{
258       BZ2_bzReadClose(&bzerr,b);
259    }
260    if(fp!=stdin && fp!=stdout){
261       fclose(fp);
262    }
263 }
264 
265 
266 /*---------------------------------------------------*/
267 /*--
268    return last error code 
269 --*/
270 static char *bzerrorstrings[] = {
271        "OK"
272       ,"SEQUENCE_ERROR"
273       ,"PARAM_ERROR"
274       ,"MEM_ERROR"
275       ,"DATA_ERROR"
276       ,"DATA_ERROR_MAGIC"
277       ,"IO_ERROR"
278       ,"UNEXPECTED_EOF"
279       ,"OUTBUFF_FULL"
280       ,"CONFIG_ERROR"
281       ,"???"   /* for future */
282       ,"???"   /* for future */
283       ,"???"   /* for future */
284       ,"???"   /* for future */
285       ,"???"   /* for future */
286       ,"???"   /* for future */
287 };
288 
289 
290 const char * BZ_API(BZ2_bzerror) (BZFILE *b, int *errnum)
291 {
292    int err = ((bzFile *)b)->lastErr;
293 
294    if(err>0) err = 0;
295    *errnum = err;
296    return bzerrorstrings[err*-1];
297 }