bzread.c (7038B)
1 /* THIS FILE HAS BEEN MODIFIED -- rsc split bzlib.c into bzlib.c, 2 bzlibcompress.c, bzlibdecompress.c, bzlibread.c, bzlibwrite.c 3 */ 4 /*-------------------------------------------------------------*/ 5 /*--- Library top-level functions. ---*/ 6 /*--- bzlib.c ---*/ 7 /*-------------------------------------------------------------*/ 8 9 /*-- 10 This file is a part of bzip2 and/or libbzip2, a program and 11 library for lossless, block-sorting data compression. 12 13 Copyright (C) 1996-2000 Julian R Seward. All rights reserved. 14 15 Redistribution and use in source and binary forms, with or without 16 modification, are permitted provided that the following conditions 17 are met: 18 19 1. Redistributions of source code must retain the above copyright 20 notice, this list of conditions and the following disclaimer. 21 22 2. The origin of this software must not be misrepresented; you must 23 not claim that you wrote the original software. If you use this 24 software in a product, an acknowledgment in the product 25 documentation would be appreciated but is not required. 26 27 3. Altered source versions must be plainly marked as such, and must 28 not be misrepresented as being the original software. 29 30 4. The name of the author may not be used to endorse or promote 31 products derived from this software without specific prior written 32 permission. 33 34 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 35 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 36 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 37 ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 38 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 39 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 40 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 41 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 42 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 43 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 44 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 45 46 Julian Seward, Cambridge, UK. 47 jseward@acm.org 48 bzip2/libbzip2 version 1.0 of 21 March 2000 49 50 This program is based on (at least) the work of: 51 Mike Burrows 52 David Wheeler 53 Peter Fenwick 54 Alistair Moffat 55 Radford Neal 56 Ian H. Witten 57 Robert Sedgewick 58 Jon L. Bentley 59 60 For more information on these sources, see the manual. 61 --*/ 62 63 /*-- 64 CHANGES 65 ~~~~~~~ 66 0.9.0 -- original version. 67 68 0.9.0a/b -- no changes in this file. 69 70 0.9.0c 71 * made zero-length BZ_FLUSH work correctly in bzCompress(). 72 * fixed bzWrite/bzRead to ignore zero-length requests. 73 * fixed bzread to correctly handle read requests after EOF. 74 * wrong parameter order in call to bzDecompressInit in 75 bzBuffToBuffDecompress. Fixed. 76 --*/ 77 78 #include "os.h" 79 #include "bzlib.h" 80 #include "bzlib_private.h" 81 #include "bzlib_stdio.h" 82 #include "bzlib_stdio_private.h" 83 84 /*---------------------------------------------------*/ 85 BZFILE* BZ_API(BZ2_bzReadOpen) 86 ( int* bzerror, 87 FILE* f, 88 int verbosity, 89 int small, 90 void* unused, 91 int nUnused ) 92 { 93 bzFile* bzf = NULL; 94 int ret; 95 96 BZ_SETERR(BZ_OK); 97 98 if (f == NULL || 99 (small != 0 && small != 1) || 100 (verbosity < 0 || verbosity > 4) || 101 (unused == NULL && nUnused != 0) || 102 (unused != NULL && (nUnused < 0 || nUnused > BZ_MAX_UNUSED))) 103 { BZ_SETERR(BZ_PARAM_ERROR); return NULL; }; 104 105 if (ferror(f)) 106 { BZ_SETERR(BZ_IO_ERROR); return NULL; }; 107 108 bzf = malloc ( sizeof(bzFile) ); 109 if (bzf == NULL) 110 { BZ_SETERR(BZ_MEM_ERROR); return NULL; }; 111 112 BZ_SETERR(BZ_OK); 113 114 bzf->initialisedOk = False; 115 bzf->handle = f; 116 bzf->bufN = 0; 117 bzf->writing = False; 118 bzf->strm.bzalloc = NULL; 119 bzf->strm.bzfree = NULL; 120 bzf->strm.opaque = NULL; 121 122 while (nUnused > 0) { 123 bzf->buf[bzf->bufN] = *((UChar*)(unused)); bzf->bufN++; 124 unused = ((void*)( 1 + ((UChar*)(unused)) )); 125 nUnused--; 126 } 127 128 ret = BZ2_bzDecompressInit ( &(bzf->strm), verbosity, small ); 129 if (ret != BZ_OK) 130 { BZ_SETERR(ret); free(bzf); return NULL; }; 131 132 bzf->strm.avail_in = bzf->bufN; 133 bzf->strm.next_in = bzf->buf; 134 135 bzf->initialisedOk = True; 136 return bzf; 137 } 138 139 140 /*---------------------------------------------------*/ 141 void BZ_API(BZ2_bzReadClose) ( int *bzerror, BZFILE *b ) 142 { 143 bzFile* bzf = (bzFile*)b; 144 145 BZ_SETERR(BZ_OK); 146 if (bzf == NULL) 147 { BZ_SETERR(BZ_OK); return; }; 148 149 if (bzf->writing) 150 { BZ_SETERR(BZ_SEQUENCE_ERROR); return; }; 151 152 if (bzf->initialisedOk) 153 (void)BZ2_bzDecompressEnd ( &(bzf->strm) ); 154 free ( bzf ); 155 } 156 157 158 /*---------------------------------------------------*/ 159 int BZ_API(BZ2_bzRead) 160 ( int* bzerror, 161 BZFILE* b, 162 void* buf, 163 int len ) 164 { 165 Int32 n, ret; 166 bzFile* bzf = (bzFile*)b; 167 168 BZ_SETERR(BZ_OK); 169 170 if (bzf == NULL || buf == NULL || len < 0) 171 { BZ_SETERR(BZ_PARAM_ERROR); return 0; }; 172 173 if (bzf->writing) 174 { BZ_SETERR(BZ_SEQUENCE_ERROR); return 0; }; 175 176 if (len == 0) 177 { BZ_SETERR(BZ_OK); return 0; }; 178 179 bzf->strm.avail_out = len; 180 bzf->strm.next_out = buf; 181 182 while (True) { 183 184 if (ferror(bzf->handle)) 185 { BZ_SETERR(BZ_IO_ERROR); return 0; }; 186 187 if (bzf->strm.avail_in == 0 && !bz_feof(bzf->handle)) { 188 n = fread ( bzf->buf, sizeof(UChar), 189 BZ_MAX_UNUSED, bzf->handle ); 190 if (ferror(bzf->handle)) 191 { BZ_SETERR(BZ_IO_ERROR); return 0; }; 192 bzf->bufN = n; 193 bzf->strm.avail_in = bzf->bufN; 194 bzf->strm.next_in = bzf->buf; 195 } 196 197 ret = BZ2_bzDecompress ( &(bzf->strm) ); 198 199 if (ret != BZ_OK && ret != BZ_STREAM_END) 200 { BZ_SETERR(ret); return 0; }; 201 202 if (ret == BZ_OK && bz_feof(bzf->handle) && 203 bzf->strm.avail_in == 0 && bzf->strm.avail_out > 0) 204 { BZ_SETERR(BZ_UNEXPECTED_EOF); return 0; }; 205 206 if (ret == BZ_STREAM_END) 207 { BZ_SETERR(BZ_STREAM_END); 208 return len - bzf->strm.avail_out; }; 209 if (bzf->strm.avail_out == 0) 210 { BZ_SETERR(BZ_OK); return len; }; 211 212 } 213 214 /* return 0; not reached*/ 215 } 216 217 218 /*---------------------------------------------------*/ 219 void BZ_API(BZ2_bzReadGetUnused) 220 ( int* bzerror, 221 BZFILE* b, 222 void** unused, 223 int* nUnused ) 224 { 225 bzFile* bzf = (bzFile*)b; 226 if (bzf == NULL) 227 { BZ_SETERR(BZ_PARAM_ERROR); return; }; 228 if (bzf->lastErr != BZ_STREAM_END) 229 { BZ_SETERR(BZ_SEQUENCE_ERROR); return; }; 230 if (unused == NULL || nUnused == NULL) 231 { BZ_SETERR(BZ_PARAM_ERROR); return; }; 232 233 BZ_SETERR(BZ_OK); 234 *nUnused = bzf->strm.avail_in; 235 *unused = bzf->strm.next_in; 236 }