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annotate deps/glpk/src/zlib/gzread.c @ 9:33de93886c88

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Import GLPK 4.47
author Alpar Juttner <alpar@cs.elte.hu>
date Sun, 06 Nov 2011 20:59:10 +0100
parents
children
rev   line source
alpar@9 1 /* gzread.c -- zlib functions for reading gzip files
alpar@9 2 * Copyright (C) 2004, 2005, 2010 Mark Adler
alpar@9 3 * For conditions of distribution and use, see copyright notice in zlib.h
alpar@9 4 */
alpar@9 5
alpar@9 6 #include "gzguts.h"
alpar@9 7
alpar@9 8 /* Local functions */
alpar@9 9 local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *));
alpar@9 10 local int gz_avail OF((gz_statep));
alpar@9 11 local int gz_next4 OF((gz_statep, unsigned long *));
alpar@9 12 local int gz_head OF((gz_statep));
alpar@9 13 local int gz_decomp OF((gz_statep));
alpar@9 14 local int gz_make OF((gz_statep));
alpar@9 15 local int gz_skip OF((gz_statep, z_off64_t));
alpar@9 16
alpar@9 17 /* Use read() to load a buffer -- return -1 on error, otherwise 0. Read from
alpar@9 18 state->fd, and update state->eof, state->err, and state->msg as appropriate.
alpar@9 19 This function needs to loop on read(), since read() is not guaranteed to
alpar@9 20 read the number of bytes requested, depending on the type of descriptor. */
alpar@9 21 local int gz_load(state, buf, len, have)
alpar@9 22 gz_statep state;
alpar@9 23 unsigned char *buf;
alpar@9 24 unsigned len;
alpar@9 25 unsigned *have;
alpar@9 26 {
alpar@9 27 int ret;
alpar@9 28
alpar@9 29 *have = 0;
alpar@9 30 do {
alpar@9 31 ret = read(state->fd, buf + *have, len - *have);
alpar@9 32 if (ret <= 0)
alpar@9 33 break;
alpar@9 34 *have += ret;
alpar@9 35 } while (*have < len);
alpar@9 36 if (ret < 0) {
alpar@9 37 gz_error(state, Z_ERRNO, zstrerror());
alpar@9 38 return -1;
alpar@9 39 }
alpar@9 40 if (ret == 0)
alpar@9 41 state->eof = 1;
alpar@9 42 return 0;
alpar@9 43 }
alpar@9 44
alpar@9 45 /* Load up input buffer and set eof flag if last data loaded -- return -1 on
alpar@9 46 error, 0 otherwise. Note that the eof flag is set when the end of the input
alpar@9 47 file is reached, even though there may be unused data in the buffer. Once
alpar@9 48 that data has been used, no more attempts will be made to read the file.
alpar@9 49 gz_avail() assumes that strm->avail_in == 0. */
alpar@9 50 local int gz_avail(state)
alpar@9 51 gz_statep state;
alpar@9 52 {
alpar@9 53 z_streamp strm = &(state->strm);
alpar@9 54
alpar@9 55 if (state->err != Z_OK)
alpar@9 56 return -1;
alpar@9 57 if (state->eof == 0) {
alpar@9 58 if (gz_load(state, state->in, state->size,
alpar@9 59 (unsigned *)&(strm->avail_in)) == -1)
alpar@9 60 return -1;
alpar@9 61 strm->next_in = state->in;
alpar@9 62 }
alpar@9 63 return 0;
alpar@9 64 }
alpar@9 65
alpar@9 66 /* Get next byte from input, or -1 if end or error. */
alpar@9 67 #define NEXT() ((strm->avail_in == 0 && gz_avail(state) == -1) ? -1 : \
alpar@9 68 (strm->avail_in == 0 ? -1 : \
alpar@9 69 (strm->avail_in--, *(strm->next_in)++)))
alpar@9 70
alpar@9 71 /* Get a four-byte little-endian integer and return 0 on success and the value
alpar@9 72 in *ret. Otherwise -1 is returned and *ret is not modified. */
alpar@9 73 local int gz_next4(state, ret)
alpar@9 74 gz_statep state;
alpar@9 75 unsigned long *ret;
alpar@9 76 {
alpar@9 77 int ch;
alpar@9 78 unsigned long val;
alpar@9 79 z_streamp strm = &(state->strm);
alpar@9 80
alpar@9 81 val = NEXT();
alpar@9 82 val += (unsigned)NEXT() << 8;
alpar@9 83 val += (unsigned long)NEXT() << 16;
alpar@9 84 ch = NEXT();
alpar@9 85 if (ch == -1)
alpar@9 86 return -1;
alpar@9 87 val += (unsigned long)ch << 24;
alpar@9 88 *ret = val;
alpar@9 89 return 0;
alpar@9 90 }
alpar@9 91
alpar@9 92 /* Look for gzip header, set up for inflate or copy. state->have must be zero.
alpar@9 93 If this is the first time in, allocate required memory. state->how will be
alpar@9 94 left unchanged if there is no more input data available, will be set to COPY
alpar@9 95 if there is no gzip header and direct copying will be performed, or it will
alpar@9 96 be set to GZIP for decompression, and the gzip header will be skipped so
alpar@9 97 that the next available input data is the raw deflate stream. If direct
alpar@9 98 copying, then leftover input data from the input buffer will be copied to
alpar@9 99 the output buffer. In that case, all further file reads will be directly to
alpar@9 100 either the output buffer or a user buffer. If decompressing, the inflate
alpar@9 101 state and the check value will be initialized. gz_head() will return 0 on
alpar@9 102 success or -1 on failure. Failures may include read errors or gzip header
alpar@9 103 errors. */
alpar@9 104 local int gz_head(state)
alpar@9 105 gz_statep state;
alpar@9 106 {
alpar@9 107 z_streamp strm = &(state->strm);
alpar@9 108 int flags;
alpar@9 109 unsigned len;
alpar@9 110
alpar@9 111 /* allocate read buffers and inflate memory */
alpar@9 112 if (state->size == 0) {
alpar@9 113 /* allocate buffers */
alpar@9 114 state->in = malloc(state->want);
alpar@9 115 state->out = malloc(state->want << 1);
alpar@9 116 if (state->in == NULL || state->out == NULL) {
alpar@9 117 if (state->out != NULL)
alpar@9 118 free(state->out);
alpar@9 119 if (state->in != NULL)
alpar@9 120 free(state->in);
alpar@9 121 gz_error(state, Z_MEM_ERROR, "out of memory");
alpar@9 122 return -1;
alpar@9 123 }
alpar@9 124 state->size = state->want;
alpar@9 125
alpar@9 126 /* allocate inflate memory */
alpar@9 127 state->strm.zalloc = Z_NULL;
alpar@9 128 state->strm.zfree = Z_NULL;
alpar@9 129 state->strm.opaque = Z_NULL;
alpar@9 130 state->strm.avail_in = 0;
alpar@9 131 state->strm.next_in = Z_NULL;
alpar@9 132 if (inflateInit2(&(state->strm), -15) != Z_OK) { /* raw inflate */
alpar@9 133 free(state->out);
alpar@9 134 free(state->in);
alpar@9 135 state->size = 0;
alpar@9 136 gz_error(state, Z_MEM_ERROR, "out of memory");
alpar@9 137 return -1;
alpar@9 138 }
alpar@9 139 }
alpar@9 140
alpar@9 141 /* get some data in the input buffer */
alpar@9 142 if (strm->avail_in == 0) {
alpar@9 143 if (gz_avail(state) == -1)
alpar@9 144 return -1;
alpar@9 145 if (strm->avail_in == 0)
alpar@9 146 return 0;
alpar@9 147 }
alpar@9 148
alpar@9 149 /* look for the gzip magic header bytes 31 and 139 */
alpar@9 150 if (strm->next_in[0] == 31) {
alpar@9 151 strm->avail_in--;
alpar@9 152 strm->next_in++;
alpar@9 153 if (strm->avail_in == 0 && gz_avail(state) == -1)
alpar@9 154 return -1;
alpar@9 155 if (strm->avail_in && strm->next_in[0] == 139) {
alpar@9 156 /* we have a gzip header, woo hoo! */
alpar@9 157 strm->avail_in--;
alpar@9 158 strm->next_in++;
alpar@9 159
alpar@9 160 /* skip rest of header */
alpar@9 161 if (NEXT() != 8) { /* compression method */
alpar@9 162 gz_error(state, Z_DATA_ERROR, "unknown compression method");
alpar@9 163 return -1;
alpar@9 164 }
alpar@9 165 flags = NEXT();
alpar@9 166 if (flags & 0xe0) { /* reserved flag bits */
alpar@9 167 gz_error(state, Z_DATA_ERROR, "unknown header flags set");
alpar@9 168 return -1;
alpar@9 169 }
alpar@9 170 NEXT(); /* modification time */
alpar@9 171 NEXT();
alpar@9 172 NEXT();
alpar@9 173 NEXT();
alpar@9 174 NEXT(); /* extra flags */
alpar@9 175 NEXT(); /* operating system */
alpar@9 176 if (flags & 4) { /* extra field */
alpar@9 177 len = (unsigned)NEXT();
alpar@9 178 len += (unsigned)NEXT() << 8;
alpar@9 179 while (len--)
alpar@9 180 if (NEXT() < 0)
alpar@9 181 break;
alpar@9 182 }
alpar@9 183 if (flags & 8) /* file name */
alpar@9 184 while (NEXT() > 0)
alpar@9 185 ;
alpar@9 186 if (flags & 16) /* comment */
alpar@9 187 while (NEXT() > 0)
alpar@9 188 ;
alpar@9 189 if (flags & 2) { /* header crc */
alpar@9 190 NEXT();
alpar@9 191 NEXT();
alpar@9 192 }
alpar@9 193 /* an unexpected end of file is not checked for here -- it will be
alpar@9 194 noticed on the first request for uncompressed data */
alpar@9 195
alpar@9 196 /* set up for decompression */
alpar@9 197 inflateReset(strm);
alpar@9 198 strm->adler = crc32(0L, Z_NULL, 0);
alpar@9 199 state->how = GZIP;
alpar@9 200 state->direct = 0;
alpar@9 201 return 0;
alpar@9 202 }
alpar@9 203 else {
alpar@9 204 /* not a gzip file -- save first byte (31) and fall to raw i/o */
alpar@9 205 state->out[0] = 31;
alpar@9 206 state->have = 1;
alpar@9 207 }
alpar@9 208 }
alpar@9 209
alpar@9 210 /* doing raw i/o, save start of raw data for seeking, copy any leftover
alpar@9 211 input to output -- this assumes that the output buffer is larger than
alpar@9 212 the input buffer, which also assures space for gzungetc() */
alpar@9 213 state->raw = state->pos;
alpar@9 214 state->next = state->out;
alpar@9 215 if (strm->avail_in) {
alpar@9 216 memcpy(state->next + state->have, strm->next_in, strm->avail_in);
alpar@9 217 state->have += strm->avail_in;
alpar@9 218 strm->avail_in = 0;
alpar@9 219 }
alpar@9 220 state->how = COPY;
alpar@9 221 state->direct = 1;
alpar@9 222 return 0;
alpar@9 223 }
alpar@9 224
alpar@9 225 /* Decompress from input to the provided next_out and avail_out in the state.
alpar@9 226 If the end of the compressed data is reached, then verify the gzip trailer
alpar@9 227 check value and length (modulo 2^32). state->have and state->next are set
alpar@9 228 to point to the just decompressed data, and the crc is updated. If the
alpar@9 229 trailer is verified, state->how is reset to LOOK to look for the next gzip
alpar@9 230 stream or raw data, once state->have is depleted. Returns 0 on success, -1
alpar@9 231 on failure. Failures may include invalid compressed data or a failed gzip
alpar@9 232 trailer verification. */
alpar@9 233 local int gz_decomp(state)
alpar@9 234 gz_statep state;
alpar@9 235 {
alpar@9 236 int ret;
alpar@9 237 unsigned had;
alpar@9 238 unsigned long crc, len;
alpar@9 239 z_streamp strm = &(state->strm);
alpar@9 240
alpar@9 241 /* fill output buffer up to end of deflate stream */
alpar@9 242 had = strm->avail_out;
alpar@9 243 do {
alpar@9 244 /* get more input for inflate() */
alpar@9 245 if (strm->avail_in == 0 && gz_avail(state) == -1)
alpar@9 246 return -1;
alpar@9 247 if (strm->avail_in == 0) {
alpar@9 248 gz_error(state, Z_DATA_ERROR, "unexpected end of file");
alpar@9 249 return -1;
alpar@9 250 }
alpar@9 251
alpar@9 252 /* decompress and handle errors */
alpar@9 253 ret = inflate(strm, Z_NO_FLUSH);
alpar@9 254 if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
alpar@9 255 gz_error(state, Z_STREAM_ERROR,
alpar@9 256 "internal error: inflate stream corrupt");
alpar@9 257 return -1;
alpar@9 258 }
alpar@9 259 if (ret == Z_MEM_ERROR) {
alpar@9 260 gz_error(state, Z_MEM_ERROR, "out of memory");
alpar@9 261 return -1;
alpar@9 262 }
alpar@9 263 if (ret == Z_DATA_ERROR) { /* deflate stream invalid */
alpar@9 264 gz_error(state, Z_DATA_ERROR,
alpar@9 265 strm->msg == NULL ? "compressed data error" : strm->msg);
alpar@9 266 return -1;
alpar@9 267 }
alpar@9 268 } while (strm->avail_out && ret != Z_STREAM_END);
alpar@9 269
alpar@9 270 /* update available output and crc check value */
alpar@9 271 state->have = had - strm->avail_out;
alpar@9 272 state->next = strm->next_out - state->have;
alpar@9 273 strm->adler = crc32(strm->adler, state->next, state->have);
alpar@9 274
alpar@9 275 /* check gzip trailer if at end of deflate stream */
alpar@9 276 if (ret == Z_STREAM_END) {
alpar@9 277 if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
alpar@9 278 gz_error(state, Z_DATA_ERROR, "unexpected end of file");
alpar@9 279 return -1;
alpar@9 280 }
alpar@9 281 if (crc != strm->adler) {
alpar@9 282 gz_error(state, Z_DATA_ERROR, "incorrect data check");
alpar@9 283 return -1;
alpar@9 284 }
alpar@9 285 if (len != (strm->total_out & 0xffffffffL)) {
alpar@9 286 gz_error(state, Z_DATA_ERROR, "incorrect length check");
alpar@9 287 return -1;
alpar@9 288 }
alpar@9 289 state->how = LOOK; /* ready for next stream, once have is 0 (leave
alpar@9 290 state->direct unchanged to remember how) */
alpar@9 291 }
alpar@9 292
alpar@9 293 /* good decompression */
alpar@9 294 return 0;
alpar@9 295 }
alpar@9 296
alpar@9 297 /* Make data and put in the output buffer. Assumes that state->have == 0.
alpar@9 298 Data is either copied from the input file or decompressed from the input
alpar@9 299 file depending on state->how. If state->how is LOOK, then a gzip header is
alpar@9 300 looked for (and skipped if found) to determine wither to copy or decompress.
alpar@9 301 Returns -1 on error, otherwise 0. gz_make() will leave state->have as COPY
alpar@9 302 or GZIP unless the end of the input file has been reached and all data has
alpar@9 303 been processed. */
alpar@9 304 local int gz_make(state)
alpar@9 305 gz_statep state;
alpar@9 306 {
alpar@9 307 z_streamp strm = &(state->strm);
alpar@9 308
alpar@9 309 if (state->how == LOOK) { /* look for gzip header */
alpar@9 310 if (gz_head(state) == -1)
alpar@9 311 return -1;
alpar@9 312 if (state->have) /* got some data from gz_head() */
alpar@9 313 return 0;
alpar@9 314 }
alpar@9 315 if (state->how == COPY) { /* straight copy */
alpar@9 316 if (gz_load(state, state->out, state->size << 1, &(state->have)) == -1)
alpar@9 317 return -1;
alpar@9 318 state->next = state->out;
alpar@9 319 }
alpar@9 320 else if (state->how == GZIP) { /* decompress */
alpar@9 321 strm->avail_out = state->size << 1;
alpar@9 322 strm->next_out = state->out;
alpar@9 323 if (gz_decomp(state) == -1)
alpar@9 324 return -1;
alpar@9 325 }
alpar@9 326 return 0;
alpar@9 327 }
alpar@9 328
alpar@9 329 /* Skip len uncompressed bytes of output. Return -1 on error, 0 on success. */
alpar@9 330 local int gz_skip(state, len)
alpar@9 331 gz_statep state;
alpar@9 332 z_off64_t len;
alpar@9 333 {
alpar@9 334 unsigned n;
alpar@9 335
alpar@9 336 /* skip over len bytes or reach end-of-file, whichever comes first */
alpar@9 337 while (len)
alpar@9 338 /* skip over whatever is in output buffer */
alpar@9 339 if (state->have) {
alpar@9 340 n = GT_OFF(state->have) || (z_off64_t)state->have > len ?
alpar@9 341 (unsigned)len : state->have;
alpar@9 342 state->have -= n;
alpar@9 343 state->next += n;
alpar@9 344 state->pos += n;
alpar@9 345 len -= n;
alpar@9 346 }
alpar@9 347
alpar@9 348 /* output buffer empty -- return if we're at the end of the input */
alpar@9 349 else if (state->eof && state->strm.avail_in == 0)
alpar@9 350 break;
alpar@9 351
alpar@9 352 /* need more data to skip -- load up output buffer */
alpar@9 353 else {
alpar@9 354 /* get more output, looking for header if required */
alpar@9 355 if (gz_make(state) == -1)
alpar@9 356 return -1;
alpar@9 357 }
alpar@9 358 return 0;
alpar@9 359 }
alpar@9 360
alpar@9 361 /* -- see zlib.h -- */
alpar@9 362 int ZEXPORT gzread(file, buf, len)
alpar@9 363 gzFile file;
alpar@9 364 voidp buf;
alpar@9 365 unsigned len;
alpar@9 366 {
alpar@9 367 unsigned got, n;
alpar@9 368 gz_statep state;
alpar@9 369 z_streamp strm;
alpar@9 370
alpar@9 371 /* get internal structure */
alpar@9 372 if (file == NULL)
alpar@9 373 return -1;
alpar@9 374 state = (gz_statep)file;
alpar@9 375 strm = &(state->strm);
alpar@9 376
alpar@9 377 /* check that we're reading and that there's no error */
alpar@9 378 if (state->mode != GZ_READ || state->err != Z_OK)
alpar@9 379 return -1;
alpar@9 380
alpar@9 381 /* since an int is returned, make sure len fits in one, otherwise return
alpar@9 382 with an error (this avoids the flaw in the interface) */
alpar@9 383 if ((int)len < 0) {
alpar@9 384 gz_error(state, Z_BUF_ERROR, "requested length does not fit in int");
alpar@9 385 return -1;
alpar@9 386 }
alpar@9 387
alpar@9 388 /* if len is zero, avoid unnecessary operations */
alpar@9 389 if (len == 0)
alpar@9 390 return 0;
alpar@9 391
alpar@9 392 /* process a skip request */
alpar@9 393 if (state->seek) {
alpar@9 394 state->seek = 0;
alpar@9 395 if (gz_skip(state, state->skip) == -1)
alpar@9 396 return -1;
alpar@9 397 }
alpar@9 398
alpar@9 399 /* get len bytes to buf, or less than len if at the end */
alpar@9 400 got = 0;
alpar@9 401 do {
alpar@9 402 /* first just try copying data from the output buffer */
alpar@9 403 if (state->have) {
alpar@9 404 n = state->have > len ? len : state->have;
alpar@9 405 memcpy(buf, state->next, n);
alpar@9 406 state->next += n;
alpar@9 407 state->have -= n;
alpar@9 408 }
alpar@9 409
alpar@9 410 /* output buffer empty -- return if we're at the end of the input */
alpar@9 411 else if (state->eof && strm->avail_in == 0)
alpar@9 412 break;
alpar@9 413
alpar@9 414 /* need output data -- for small len or new stream load up our output
alpar@9 415 buffer */
alpar@9 416 else if (state->how == LOOK || len < (state->size << 1)) {
alpar@9 417 /* get more output, looking for header if required */
alpar@9 418 if (gz_make(state) == -1)
alpar@9 419 return -1;
alpar@9 420 continue; /* no progress yet -- go back to memcpy() above */
alpar@9 421 /* the copy above assures that we will leave with space in the
alpar@9 422 output buffer, allowing at least one gzungetc() to succeed */
alpar@9 423 }
alpar@9 424
alpar@9 425 /* large len -- read directly into user buffer */
alpar@9 426 else if (state->how == COPY) { /* read directly */
alpar@9 427 if (gz_load(state, buf, len, &n) == -1)
alpar@9 428 return -1;
alpar@9 429 }
alpar@9 430
alpar@9 431 /* large len -- decompress directly into user buffer */
alpar@9 432 else { /* state->how == GZIP */
alpar@9 433 strm->avail_out = len;
alpar@9 434 strm->next_out = buf;
alpar@9 435 if (gz_decomp(state) == -1)
alpar@9 436 return -1;
alpar@9 437 n = state->have;
alpar@9 438 state->have = 0;
alpar@9 439 }
alpar@9 440
alpar@9 441 /* update progress */
alpar@9 442 len -= n;
alpar@9 443 buf = (char *)buf + n;
alpar@9 444 got += n;
alpar@9 445 state->pos += n;
alpar@9 446 } while (len);
alpar@9 447
alpar@9 448 /* return number of bytes read into user buffer (will fit in int) */
alpar@9 449 return (int)got;
alpar@9 450 }
alpar@9 451
alpar@9 452 /* -- see zlib.h -- */
alpar@9 453 int ZEXPORT gzgetc(file)
alpar@9 454 gzFile file;
alpar@9 455 {
alpar@9 456 int ret;
alpar@9 457 unsigned char buf[1];
alpar@9 458 gz_statep state;
alpar@9 459
alpar@9 460 /* get internal structure */
alpar@9 461 if (file == NULL)
alpar@9 462 return -1;
alpar@9 463 state = (gz_statep)file;
alpar@9 464
alpar@9 465 /* check that we're reading and that there's no error */
alpar@9 466 if (state->mode != GZ_READ || state->err != Z_OK)
alpar@9 467 return -1;
alpar@9 468
alpar@9 469 /* try output buffer (no need to check for skip request) */
alpar@9 470 if (state->have) {
alpar@9 471 state->have--;
alpar@9 472 state->pos++;
alpar@9 473 return *(state->next)++;
alpar@9 474 }
alpar@9 475
alpar@9 476 /* nothing there -- try gzread() */
alpar@9 477 ret = gzread(file, buf, 1);
alpar@9 478 return ret < 1 ? -1 : buf[0];
alpar@9 479 }
alpar@9 480
alpar@9 481 /* -- see zlib.h -- */
alpar@9 482 int ZEXPORT gzungetc(c, file)
alpar@9 483 int c;
alpar@9 484 gzFile file;
alpar@9 485 {
alpar@9 486 gz_statep state;
alpar@9 487
alpar@9 488 /* get internal structure */
alpar@9 489 if (file == NULL)
alpar@9 490 return -1;
alpar@9 491 state = (gz_statep)file;
alpar@9 492
alpar@9 493 /* check that we're reading and that there's no error */
alpar@9 494 if (state->mode != GZ_READ || state->err != Z_OK)
alpar@9 495 return -1;
alpar@9 496
alpar@9 497 /* process a skip request */
alpar@9 498 if (state->seek) {
alpar@9 499 state->seek = 0;
alpar@9 500 if (gz_skip(state, state->skip) == -1)
alpar@9 501 return -1;
alpar@9 502 }
alpar@9 503
alpar@9 504 /* can't push EOF */
alpar@9 505 if (c < 0)
alpar@9 506 return -1;
alpar@9 507
alpar@9 508 /* if output buffer empty, put byte at end (allows more pushing) */
alpar@9 509 if (state->have == 0) {
alpar@9 510 state->have = 1;
alpar@9 511 state->next = state->out + (state->size << 1) - 1;
alpar@9 512 state->next[0] = c;
alpar@9 513 state->pos--;
alpar@9 514 return c;
alpar@9 515 }
alpar@9 516
alpar@9 517 /* if no room, give up (must have already done a gzungetc()) */
alpar@9 518 if (state->have == (state->size << 1)) {
alpar@9 519 gz_error(state, Z_BUF_ERROR, "out of room to push characters");
alpar@9 520 return -1;
alpar@9 521 }
alpar@9 522
alpar@9 523 /* slide output data if needed and insert byte before existing data */
alpar@9 524 if (state->next == state->out) {
alpar@9 525 unsigned char *src = state->out + state->have;
alpar@9 526 unsigned char *dest = state->out + (state->size << 1);
alpar@9 527 while (src > state->out)
alpar@9 528 *--dest = *--src;
alpar@9 529 state->next = dest;
alpar@9 530 }
alpar@9 531 state->have++;
alpar@9 532 state->next--;
alpar@9 533 state->next[0] = c;
alpar@9 534 state->pos--;
alpar@9 535 return c;
alpar@9 536 }
alpar@9 537
alpar@9 538 /* -- see zlib.h -- */
alpar@9 539 char * ZEXPORT gzgets(file, buf, len)
alpar@9 540 gzFile file;
alpar@9 541 char *buf;
alpar@9 542 int len;
alpar@9 543 {
alpar@9 544 unsigned left, n;
alpar@9 545 char *str;
alpar@9 546 unsigned char *eol;
alpar@9 547 gz_statep state;
alpar@9 548
alpar@9 549 /* check parameters and get internal structure */
alpar@9 550 if (file == NULL || buf == NULL || len < 1)
alpar@9 551 return NULL;
alpar@9 552 state = (gz_statep)file;
alpar@9 553
alpar@9 554 /* check that we're reading and that there's no error */
alpar@9 555 if (state->mode != GZ_READ || state->err != Z_OK)
alpar@9 556 return NULL;
alpar@9 557
alpar@9 558 /* process a skip request */
alpar@9 559 if (state->seek) {
alpar@9 560 state->seek = 0;
alpar@9 561 if (gz_skip(state, state->skip) == -1)
alpar@9 562 return NULL;
alpar@9 563 }
alpar@9 564
alpar@9 565 /* copy output bytes up to new line or len - 1, whichever comes first --
alpar@9 566 append a terminating zero to the string (we don't check for a zero in
alpar@9 567 the contents, let the user worry about that) */
alpar@9 568 str = buf;
alpar@9 569 left = (unsigned)len - 1;
alpar@9 570 if (left) do {
alpar@9 571 /* assure that something is in the output buffer */
alpar@9 572 if (state->have == 0) {
alpar@9 573 if (gz_make(state) == -1)
alpar@9 574 return NULL; /* error */
alpar@9 575 if (state->have == 0) { /* end of file */
alpar@9 576 if (buf == str) /* got bupkus */
alpar@9 577 return NULL;
alpar@9 578 break; /* got something -- return it */
alpar@9 579 }
alpar@9 580 }
alpar@9 581
alpar@9 582 /* look for end-of-line in current output buffer */
alpar@9 583 n = state->have > left ? left : state->have;
alpar@9 584 eol = memchr(state->next, '\n', n);
alpar@9 585 if (eol != NULL)
alpar@9 586 n = (unsigned)(eol - state->next) + 1;
alpar@9 587
alpar@9 588 /* copy through end-of-line, or remainder if not found */
alpar@9 589 memcpy(buf, state->next, n);
alpar@9 590 state->have -= n;
alpar@9 591 state->next += n;
alpar@9 592 state->pos += n;
alpar@9 593 left -= n;
alpar@9 594 buf += n;
alpar@9 595 } while (left && eol == NULL);
alpar@9 596
alpar@9 597 /* found end-of-line or out of space -- terminate string and return it */
alpar@9 598 buf[0] = 0;
alpar@9 599 return str;
alpar@9 600 }
alpar@9 601
alpar@9 602 /* -- see zlib.h -- */
alpar@9 603 int ZEXPORT gzdirect(file)
alpar@9 604 gzFile file;
alpar@9 605 {
alpar@9 606 gz_statep state;
alpar@9 607
alpar@9 608 /* get internal structure */
alpar@9 609 if (file == NULL)
alpar@9 610 return 0;
alpar@9 611 state = (gz_statep)file;
alpar@9 612
alpar@9 613 /* check that we're reading */
alpar@9 614 if (state->mode != GZ_READ)
alpar@9 615 return 0;
alpar@9 616
alpar@9 617 /* if the state is not known, but we can find out, then do so (this is
alpar@9 618 mainly for right after a gzopen() or gzdopen()) */
alpar@9 619 if (state->how == LOOK && state->have == 0)
alpar@9 620 (void)gz_head(state);
alpar@9 621
alpar@9 622 /* return 1 if reading direct, 0 if decompressing a gzip stream */
alpar@9 623 return state->direct;
alpar@9 624 }
alpar@9 625
alpar@9 626 /* -- see zlib.h -- */
alpar@9 627 int ZEXPORT gzclose_r(file)
alpar@9 628 gzFile file;
alpar@9 629 {
alpar@9 630 int ret;
alpar@9 631 gz_statep state;
alpar@9 632
alpar@9 633 /* get internal structure */
alpar@9 634 if (file == NULL)
alpar@9 635 return Z_STREAM_ERROR;
alpar@9 636 state = (gz_statep)file;
alpar@9 637
alpar@9 638 /* check that we're reading */
alpar@9 639 if (state->mode != GZ_READ)
alpar@9 640 return Z_STREAM_ERROR;
alpar@9 641
alpar@9 642 /* free memory and close file */
alpar@9 643 if (state->size) {
alpar@9 644 inflateEnd(&(state->strm));
alpar@9 645 free(state->out);
alpar@9 646 free(state->in);
alpar@9 647 }
alpar@9 648 gz_error(state, Z_OK, NULL);
alpar@9 649 free(state->path);
alpar@9 650 ret = close(state->fd);
alpar@9 651 free(state);
alpar@9 652 return ret ? Z_ERRNO : Z_OK;
alpar@9 653 }