| 1 | /* Copyright (C) 1991 Aladdin Enterprises. All rights reserved. |
| 2 | Distributed by Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of Ghostscript. |
| 5 | |
| 6 | Ghostscript is distributed in the hope that it will be useful, but |
| 7 | WITHOUT ANY WARRANTY. No author or distributor accepts responsibility |
| 8 | to anyone for the consequences of using it or for whether it serves any |
| 9 | particular purpose or works at all, unless he says so in writing. Refer |
| 10 | to the Ghostscript General Public License for full details. |
| 11 | |
| 12 | Everyone is granted permission to copy, modify and redistribute |
| 13 | Ghostscript, but only under the conditions described in the Ghostscript |
| 14 | General Public License. A copy of this license is supposed to have been |
| 15 | given to you along with Ghostscript so you can know your rights and |
| 16 | responsibilities. It should be in a file named COPYING. Among other |
| 17 | things, the copyright notice and this notice must be preserved on all |
| 18 | copies. */ |
| 19 | |
| 20 | /* sfilter2.c */ |
| 21 | /* Additional stream functions for filters */ |
| 22 | #include <stdio.h> |
| 23 | #include "memory_.h" |
| 24 | #include "std.h" |
| 25 | #include "scanchar.h" |
| 26 | #include "stream.h" |
| 27 | |
| 28 | /* Generic functions in sfilter.c */ |
| 29 | extern int s_filter_flush(P1(stream *)); |
| 30 | extern int s_filter_close(P1(stream *)); |
| 31 | |
| 32 | /* ------ ASCII85Encode ------ */ |
| 33 | |
| 34 | /* Flush the buffer */ |
| 35 | private int |
| 36 | s_A85E_write_buf(register stream *s) |
| 37 | { register stream *strm = s->strm; |
| 38 | register byte *p = s->cbuf; |
| 39 | register int count = s->cptr + 1 - p; |
| 40 | while ( count >= 4 ) |
| 41 | { ulong word = |
| 42 | ((ulong)(((uint)p[0] << 8) + p[1]) << 16) + |
| 43 | (((uint)p[2] << 8) + p[3]); |
| 44 | if ( word == 0 ) |
| 45 | sputc(strm, 'z'); |
| 46 | else |
| 47 | { ulong q = word / (85L*85*85*85); |
| 48 | ushort w1; |
| 49 | sputc(strm, q + '!'); |
| 50 | word -= q * (85L*85*85*85); |
| 51 | q = word / (85L*85*85); |
| 52 | sputc(strm, q + '!'); |
| 53 | word -= q * (85L*85*85); |
| 54 | q = word / (85*85); |
| 55 | sputc(strm, q + '!'); |
| 56 | w1 = (ushort)(word - q * (85L*85)); |
| 57 | sputc(strm, w1 / 85 + '!'); |
| 58 | sputc(strm, w1 % 85 + '!'); |
| 59 | if ( !(count & 60) ) |
| 60 | sputc(strm, '\n'); |
| 61 | } |
| 62 | count -= 4, p += 4; |
| 63 | } |
| 64 | memcpy(s->cbuf, p, count); |
| 65 | s->cptr = s->cbuf + count - 1; |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | /* Close the stream, flushing a partial word. */ |
| 70 | private int |
| 71 | s_A85E_close(register stream *s) |
| 72 | { stream *strm = s->strm; |
| 73 | int count; |
| 74 | (*s->procs.write_buf)(s); |
| 75 | count = s->cptr - s->cbuf + 1; |
| 76 | if ( count > 0 ) |
| 77 | { /* Handle leftover bytes. 1 <= count <= 3. */ |
| 78 | /* All the bytes are at the beginning of the buffer. */ |
| 79 | byte ebuf[5]; |
| 80 | stream sst; |
| 81 | s->cptr[1] = s->cptr[2] = s->cptr[3] = 0xff; |
| 82 | s->cptr = s->cbuf + 3; |
| 83 | swrite_string(&sst, ebuf, 5); |
| 84 | s->strm = &sst; |
| 85 | (*s->procs.write_buf)(s); /* force out final codes */ |
| 86 | sputs(strm, ebuf, count + 1); |
| 87 | } |
| 88 | sputs(strm, (byte *)"~>", 2); |
| 89 | return s_std_close(s); |
| 90 | } |
| 91 | |
| 92 | /* Stream procedures */ |
| 93 | stream_procs s_A85E_procs = |
| 94 | { s_std_noavailable, NULL, s_filter_flush, s_A85E_close, |
| 95 | NULL, s_A85E_write_buf |
| 96 | }; |
| 97 | |
| 98 | /* ------ ASCII85Decode ------ */ |
| 99 | |
| 100 | /* Refill the buffer */ |
| 101 | private int |
| 102 | s_A85D_read_buf(register stream *s) |
| 103 | { register stream *strm = s->strm; |
| 104 | register byte *p = s->cbuf; |
| 105 | byte *limit = p + s->bsize - 4; |
| 106 | int ccount = 0; |
| 107 | ulong word = 0; |
| 108 | while ( p < limit ) |
| 109 | { int ch = sgetc(strm); |
| 110 | uint ccode = ch - '!'; |
| 111 | if ( ccode < 85 ) /* catches ch < '!' as well */ |
| 112 | { word = word * 85 + ccode; |
| 113 | if ( ++ccount == 5 ) |
| 114 | { p[0] = word >> 24; |
| 115 | p[1] = (byte)(word >> 16); |
| 116 | p[2] = (byte)((uint)word >> 8); |
| 117 | p[3] = (byte)word; |
| 118 | p += 4; |
| 119 | word = 0; |
| 120 | ccount = 0; |
| 121 | } |
| 122 | } |
| 123 | else if ( ch == 'z' && ccount == 0 ) |
| 124 | p[0] = p[1] = p[2] = p[3] = 0, |
| 125 | p += 4; |
| 126 | else if ( scan_char_decoder[ch] == ctype_space ) |
| 127 | ; |
| 128 | else if ( ch == '~' && sgetc(strm) == '>' ) |
| 129 | { /* Handle odd bytes */ |
| 130 | s->end_status = EOFC; |
| 131 | switch ( ccount ) |
| 132 | { |
| 133 | case 0: |
| 134 | break; |
| 135 | case 1: /* syntax error */ |
| 136 | s->end_status = ERRC; |
| 137 | break; |
| 138 | case 2: /* 1 odd byte */ |
| 139 | word = word * (85L+85*85) + 0xffffffL; |
| 140 | goto o1; |
| 141 | case 3: /* 2 odd bytes */ |
| 142 | word = word * (85L*85) + 0xffffL; |
| 143 | goto o2; |
| 144 | case 4: /* 3 odd bytes */ |
| 145 | word = word * 85 + 0xffL; |
| 146 | p[2] = (byte)(word >> 8); |
| 147 | o2: p[1] = (byte)(word >> 16); |
| 148 | o1: p[0] = (byte)(word >> 24); |
| 149 | p += ccount - 1; |
| 150 | } |
| 151 | break; |
| 152 | } |
| 153 | else /* syntax error */ |
| 154 | { s->end_status = ERRC; |
| 155 | break; |
| 156 | } |
| 157 | } |
| 158 | s->cptr = s->cbuf - 1; |
| 159 | s->endptr = p - 1; |
| 160 | if ( !s->end_status ) s->end_status = strm->end_status; |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | /* Stream procedures */ |
| 165 | stream_procs s_A85D_procs = |
| 166 | { s_std_noavailable, NULL, s_std_null, s_filter_close, |
| 167 | s_A85D_read_buf, NULL |
| 168 | }; |
| 169 | |
| 170 | /* ------ NullEncode ------ */ |
| 171 | |
| 172 | /* Flush the buffer */ |
| 173 | private int |
| 174 | s_NullE_write_buf(register stream *s) |
| 175 | { sputs(s->strm, s->cbuf, s->cptr - s->cbuf + 1); |
| 176 | s->cptr = s->cbuf - 1; |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | /* Close the stream */ |
| 181 | private int |
| 182 | s_NullE_close(register stream *s) |
| 183 | { sflush(s); |
| 184 | return s_filter_close(s); |
| 185 | } |
| 186 | |
| 187 | /* Stream procedures */ |
| 188 | stream_procs s_NullE_procs = |
| 189 | { s_std_noavailable, NULL, s_filter_flush, s_NullE_close, |
| 190 | NULL, s_NullE_write_buf |
| 191 | }; |
| 192 | |
| 193 | /* ------ RunLengthEncode ------ */ |
| 194 | |
| 195 | /* Initialize */ |
| 196 | void |
| 197 | s_RLE_init(register stream *s, uint rec_size) |
| 198 | { s->record_size = (rec_size == 0 ? max_uint : rec_size); |
| 199 | s->record_left = s->record_size; |
| 200 | } |
| 201 | |
| 202 | /* Empty the buffer */ |
| 203 | private int |
| 204 | s_RLE_write_buf(register stream *s) |
| 205 | { register stream *strm = s->strm; |
| 206 | register byte *p = s->cbuf; |
| 207 | while ( p <= s->cptr ) |
| 208 | { byte *beg = p, *q; |
| 209 | uint count = s->cptr - p + 1; |
| 210 | if ( count > s->record_left) |
| 211 | count = s->record_left; |
| 212 | if ( count > 127 ) |
| 213 | count = 127; |
| 214 | q = p + count; |
| 215 | if ( count > 2 && p[1] == p[0] ) |
| 216 | { /* Recognize leading repeated byte */ |
| 217 | do { p++; } |
| 218 | while ( p + 1 < q && p[1] == p[0] ); |
| 219 | p++; |
| 220 | sputc(strm, 257 - (p - beg)); |
| 221 | sputc(strm, *beg); |
| 222 | } |
| 223 | else |
| 224 | { while ( p + 2 < q && (p[1] != p[0] || p[2] != p[0]) ) |
| 225 | p++; |
| 226 | if ( p + 2 >= q ) p = q; |
| 227 | sputc(strm, p - beg - 1); |
| 228 | sputs(strm, beg, p - beg); |
| 229 | } |
| 230 | s->record_left -= p - beg; |
| 231 | if ( s->record_left == 0 ) |
| 232 | s->record_left = s->record_size; |
| 233 | } |
| 234 | s->cptr = s->cbuf - 1; |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | /* Close */ |
| 239 | private int |
| 240 | s_RLE_close(register stream *s) |
| 241 | { (*s->procs.write_buf)(s); |
| 242 | sputc(s->strm, 128); |
| 243 | return s_std_close(s); |
| 244 | } |
| 245 | |
| 246 | /* Stream procedures */ |
| 247 | stream_procs s_RLE_procs = |
| 248 | { s_std_noavailable, NULL, s_filter_flush, s_RLE_close, |
| 249 | NULL, s_RLE_write_buf |
| 250 | }; |
| 251 | |
| 252 | /* ------ RunLengthDecode ------ */ |
| 253 | |
| 254 | /* Initialize */ |
| 255 | void |
| 256 | s_RLD_init(register stream *s) |
| 257 | { s->odd = -1; |
| 258 | } |
| 259 | |
| 260 | /* Refill the buffer */ |
| 261 | private int |
| 262 | s_RLD_read_buf(register stream *s) |
| 263 | { register stream *strm = s->strm; |
| 264 | register byte *p = s->cbuf; |
| 265 | byte *limit = p + s->bsize; |
| 266 | int b = s->odd; |
| 267 | if ( b < 0 ) b = sgetc(strm); |
| 268 | for ( ; ; ) |
| 269 | { uint count; |
| 270 | if ( b < 0 ) break; /* EOF/ERR */ |
| 271 | if ( b < 128 ) |
| 272 | { if ( p + b >= limit ) break; /* data won't fit */ |
| 273 | count = sgets(s, p, b + 1); |
| 274 | p += count; |
| 275 | b = -1; |
| 276 | if ( strm->end_status ) break; /* EOF/ERR */ |
| 277 | } |
| 278 | else if ( b == 128 ) /* end of data */ |
| 279 | { s->end_status = EOFC; |
| 280 | b = -1; |
| 281 | break; |
| 282 | } |
| 283 | else if ( p + (257 - b) > limit ) |
| 284 | break; /* won't fit */ |
| 285 | else |
| 286 | { count = 257 - b; |
| 287 | b = sgetc(strm); |
| 288 | if ( b < 0 ) break; /* EOF/ERR */ |
| 289 | memset(p, b, count); |
| 290 | p += count; |
| 291 | } |
| 292 | b = sgetc(strm); |
| 293 | } |
| 294 | s->cptr = s->cbuf - 1; |
| 295 | s->endptr = p - 1; |
| 296 | s->odd = b; |
| 297 | if ( !s->end_status ) s->end_status = strm->end_status; |
| 298 | return 0; |
| 299 | } |
| 300 | |
| 301 | /* Stream procedures */ |
| 302 | stream_procs s_RLD_procs = |
| 303 | { s_std_noavailable, NULL, s_std_null, s_std_close, |
| 304 | s_RLD_read_buf, NULL |
| 305 | }; |
| 306 | |
| 307 | /* ------ SubFileDecode ------ */ |
| 308 | /* Currently equivalent to "NullDecode" */ |
| 309 | |
| 310 | /* Refill the buffer */ |
| 311 | private int |
| 312 | s_SFD_read_buf(register stream *s) |
| 313 | { stream *strm = s->strm; |
| 314 | uint count = sgets(strm, s->cbuf, s->bsize); |
| 315 | s->cptr = s->cbuf - 1; |
| 316 | s->endptr = s->cptr + count; |
| 317 | s->end_status = strm->end_status; |
| 318 | return count; |
| 319 | } |
| 320 | |
| 321 | /* Stream procedures */ |
| 322 | stream_procs s_SFD_procs = |
| 323 | { s_std_noavailable, NULL, s_std_null, s_filter_close, |
| 324 | s_SFD_read_buf, NULL |
| 325 | }; |