648db22b |
1 | /* gzread.c contains minimal changes required to be compiled with zlibWrapper: |
2 | * - gz_statep was converted to union to work with -Wstrict-aliasing=1 */ |
3 | |
4 | /* gzread.c -- zlib functions for reading gzip files |
5 | * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler |
6 | * For conditions of distribution and use, see https://www.zlib.net/zlib_license.html |
b24e7fce |
7 | */ |
8 | |
9 | #include "gzguts.h" |
10 | |
648db22b |
11 | /* fix for Visual Studio, which doesn't support ssize_t type. |
12 | * see https://github.com/facebook/zstd/issues/1800#issuecomment-545945050 */ |
13 | #if defined(_MSC_VER) && !defined(ssize_t) |
14 | # include <BaseTsd.h> |
15 | typedef SSIZE_T ssize_t; |
16 | #endif |
17 | |
18 | |
b24e7fce |
19 | /* Local functions */ |
648db22b |
20 | local int gz_load _Z_OF((gz_statep, unsigned char *, unsigned, unsigned *)); |
21 | local int gz_avail _Z_OF((gz_statep)); |
22 | local int gz_look _Z_OF((gz_statep)); |
23 | local int gz_decomp _Z_OF((gz_statep)); |
24 | local int gz_fetch _Z_OF((gz_statep)); |
25 | local int gz_skip _Z_OF((gz_statep, z_off64_t)); |
26 | local z_size_t gz_read _Z_OF((gz_statep, voidp, z_size_t)); |
b24e7fce |
27 | |
28 | /* Use read() to load a buffer -- return -1 on error, otherwise 0. Read from |
648db22b |
29 | state.state->fd, and update state.state->eof, state.state->err, and state.state->msg as appropriate. |
b24e7fce |
30 | This function needs to loop on read(), since read() is not guaranteed to |
31 | read the number of bytes requested, depending on the type of descriptor. */ |
32 | local int gz_load(state, buf, len, have) |
33 | gz_statep state; |
34 | unsigned char *buf; |
35 | unsigned len; |
36 | unsigned *have; |
37 | { |
648db22b |
38 | ssize_t ret; |
b24e7fce |
39 | unsigned get, max = ((unsigned)-1 >> 2) + 1; |
40 | |
41 | *have = 0; |
42 | do { |
43 | get = len - *have; |
44 | if (get > max) |
45 | get = max; |
648db22b |
46 | ret = read(state.state->fd, buf + *have, get); |
b24e7fce |
47 | if (ret <= 0) |
48 | break; |
49 | *have += (unsigned)ret; |
50 | } while (*have < len); |
51 | if (ret < 0) { |
52 | gz_error(state, Z_ERRNO, zstrerror()); |
53 | return -1; |
54 | } |
55 | if (ret == 0) |
648db22b |
56 | state.state->eof = 1; |
b24e7fce |
57 | return 0; |
58 | } |
59 | |
60 | /* Load up input buffer and set eof flag if last data loaded -- return -1 on |
61 | error, 0 otherwise. Note that the eof flag is set when the end of the input |
62 | file is reached, even though there may be unused data in the buffer. Once |
63 | that data has been used, no more attempts will be made to read the file. |
64 | If strm->avail_in != 0, then the current data is moved to the beginning of |
65 | the input buffer, and then the remainder of the buffer is loaded with the |
66 | available data from the input file. */ |
67 | local int gz_avail(state) |
68 | gz_statep state; |
69 | { |
70 | unsigned got; |
648db22b |
71 | z_streamp strm = &(state.state->strm); |
b24e7fce |
72 | |
648db22b |
73 | if (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR) |
b24e7fce |
74 | return -1; |
648db22b |
75 | if (state.state->eof == 0) { |
b24e7fce |
76 | if (strm->avail_in) { /* copy what's there to the start */ |
648db22b |
77 | unsigned char *p = state.state->in; |
b24e7fce |
78 | unsigned const char *q = strm->next_in; |
79 | unsigned n = strm->avail_in; |
80 | do { |
81 | *p++ = *q++; |
82 | } while (--n); |
83 | } |
648db22b |
84 | if (gz_load(state, state.state->in + strm->avail_in, |
85 | state.state->size - strm->avail_in, &got) == -1) |
b24e7fce |
86 | return -1; |
87 | strm->avail_in += got; |
648db22b |
88 | strm->next_in = state.state->in; |
b24e7fce |
89 | } |
90 | return 0; |
91 | } |
92 | |
648db22b |
93 | /* Look for gzip header, set up for inflate or copy. state.state->x.have must be 0. |
94 | If this is the first time in, allocate required memory. state.state->how will be |
b24e7fce |
95 | left unchanged if there is no more input data available, will be set to COPY |
96 | if there is no gzip header and direct copying will be performed, or it will |
97 | be set to GZIP for decompression. If direct copying, then leftover input |
98 | data from the input buffer will be copied to the output buffer. In that |
99 | case, all further file reads will be directly to either the output buffer or |
100 | a user buffer. If decompressing, the inflate state will be initialized. |
101 | gz_look() will return 0 on success or -1 on failure. */ |
102 | local int gz_look(state) |
103 | gz_statep state; |
104 | { |
648db22b |
105 | z_streamp strm = &(state.state->strm); |
b24e7fce |
106 | |
107 | /* allocate read buffers and inflate memory */ |
648db22b |
108 | if (state.state->size == 0) { |
b24e7fce |
109 | /* allocate buffers */ |
648db22b |
110 | state.state->in = (unsigned char *)malloc(state.state->want); |
111 | state.state->out = (unsigned char *)malloc(state.state->want << 1); |
112 | if (state.state->in == NULL || state.state->out == NULL) { |
113 | free(state.state->out); |
114 | free(state.state->in); |
b24e7fce |
115 | gz_error(state, Z_MEM_ERROR, "out of memory"); |
116 | return -1; |
117 | } |
648db22b |
118 | state.state->size = state.state->want; |
b24e7fce |
119 | |
120 | /* allocate inflate memory */ |
648db22b |
121 | state.state->strm.zalloc = Z_NULL; |
122 | state.state->strm.zfree = Z_NULL; |
123 | state.state->strm.opaque = Z_NULL; |
124 | state.state->strm.avail_in = 0; |
125 | state.state->strm.next_in = Z_NULL; |
126 | if (inflateInit2(&(state.state->strm), 15 + 16) != Z_OK) { /* gunzip */ |
127 | free(state.state->out); |
128 | free(state.state->in); |
129 | state.state->size = 0; |
b24e7fce |
130 | gz_error(state, Z_MEM_ERROR, "out of memory"); |
131 | return -1; |
132 | } |
133 | } |
134 | |
135 | /* get at least the magic bytes in the input buffer */ |
136 | if (strm->avail_in < 2) { |
137 | if (gz_avail(state) == -1) |
138 | return -1; |
139 | if (strm->avail_in == 0) |
140 | return 0; |
141 | } |
142 | |
143 | /* look for gzip magic bytes -- if there, do gzip decoding (note: there is |
144 | a logical dilemma here when considering the case of a partially written |
145 | gzip file, to wit, if a single 31 byte is written, then we cannot tell |
146 | whether this is a single-byte file, or just a partially written gzip |
147 | file -- for here we assume that if a gzip file is being written, then |
148 | the header will be written in a single operation, so that reading a |
149 | single byte is sufficient indication that it is not a gzip file) */ |
150 | if (strm->avail_in > 1 && |
648db22b |
151 | ((strm->next_in[0] == 31 && strm->next_in[1] == 139) /* gz header */ |
152 | || (strm->next_in[0] == 40 && strm->next_in[1] == 181))) { /* zstd header */ |
b24e7fce |
153 | inflateReset(strm); |
648db22b |
154 | state.state->how = GZIP; |
155 | state.state->direct = 0; |
b24e7fce |
156 | return 0; |
157 | } |
158 | |
159 | /* no gzip header -- if we were decoding gzip before, then this is trailing |
160 | garbage. Ignore the trailing garbage and finish. */ |
648db22b |
161 | if (state.state->direct == 0) { |
b24e7fce |
162 | strm->avail_in = 0; |
648db22b |
163 | state.state->eof = 1; |
164 | state.state->x.have = 0; |
b24e7fce |
165 | return 0; |
166 | } |
167 | |
168 | /* doing raw i/o, copy any leftover input to output -- this assumes that |
169 | the output buffer is larger than the input buffer, which also assures |
170 | space for gzungetc() */ |
648db22b |
171 | state.state->x.next = state.state->out; |
172 | if (strm->avail_in) { |
173 | memcpy(state.state->x.next, strm->next_in, strm->avail_in); |
174 | state.state->x.have = strm->avail_in; |
175 | strm->avail_in = 0; |
176 | } |
177 | state.state->how = COPY; |
178 | state.state->direct = 1; |
b24e7fce |
179 | return 0; |
180 | } |
181 | |
182 | /* Decompress from input to the provided next_out and avail_out in the state. |
648db22b |
183 | On return, state.state->x.have and state.state->x.next point to the just decompressed |
184 | data. If the gzip stream completes, state.state->how is reset to LOOK to look for |
185 | the next gzip stream or raw data, once state.state->x.have is depleted. Returns 0 |
b24e7fce |
186 | on success, -1 on failure. */ |
187 | local int gz_decomp(state) |
188 | gz_statep state; |
189 | { |
190 | int ret = Z_OK; |
191 | unsigned had; |
648db22b |
192 | z_streamp strm = &(state.state->strm); |
b24e7fce |
193 | |
194 | /* fill output buffer up to end of deflate stream */ |
195 | had = strm->avail_out; |
196 | do { |
197 | /* get more input for inflate() */ |
198 | if (strm->avail_in == 0 && gz_avail(state) == -1) |
199 | return -1; |
200 | if (strm->avail_in == 0) { |
201 | gz_error(state, Z_BUF_ERROR, "unexpected end of file"); |
202 | break; |
203 | } |
204 | |
205 | /* decompress and handle errors */ |
206 | ret = inflate(strm, Z_NO_FLUSH); |
207 | if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) { |
208 | gz_error(state, Z_STREAM_ERROR, |
209 | "internal error: inflate stream corrupt"); |
210 | return -1; |
211 | } |
212 | if (ret == Z_MEM_ERROR) { |
213 | gz_error(state, Z_MEM_ERROR, "out of memory"); |
214 | return -1; |
215 | } |
216 | if (ret == Z_DATA_ERROR) { /* deflate stream invalid */ |
217 | gz_error(state, Z_DATA_ERROR, |
218 | strm->msg == NULL ? "compressed data error" : strm->msg); |
219 | return -1; |
220 | } |
221 | } while (strm->avail_out && ret != Z_STREAM_END); |
222 | |
223 | /* update available output */ |
648db22b |
224 | state.state->x.have = had - strm->avail_out; |
225 | state.state->x.next = strm->next_out - state.state->x.have; |
b24e7fce |
226 | |
227 | /* if the gzip stream completed successfully, look for another */ |
228 | if (ret == Z_STREAM_END) |
648db22b |
229 | state.state->how = LOOK; |
b24e7fce |
230 | |
231 | /* good decompression */ |
232 | return 0; |
233 | } |
234 | |
648db22b |
235 | /* Fetch data and put it in the output buffer. Assumes state.state->x.have is 0. |
b24e7fce |
236 | Data is either copied from the input file or decompressed from the input |
648db22b |
237 | file depending on state.state->how. If state.state->how is LOOK, then a gzip header is |
b24e7fce |
238 | looked for to determine whether to copy or decompress. Returns -1 on error, |
648db22b |
239 | otherwise 0. gz_fetch() will leave state.state->how as COPY or GZIP unless the |
b24e7fce |
240 | end of the input file has been reached and all data has been processed. */ |
241 | local int gz_fetch(state) |
242 | gz_statep state; |
243 | { |
648db22b |
244 | z_streamp strm = &(state.state->strm); |
b24e7fce |
245 | |
246 | do { |
648db22b |
247 | switch(state.state->how) { |
b24e7fce |
248 | case LOOK: /* -> LOOK, COPY (only if never GZIP), or GZIP */ |
249 | if (gz_look(state) == -1) |
250 | return -1; |
648db22b |
251 | if (state.state->how == LOOK) |
b24e7fce |
252 | return 0; |
253 | break; |
254 | case COPY: /* -> COPY */ |
648db22b |
255 | if (gz_load(state, state.state->out, state.state->size << 1, &(state.state->x.have)) |
b24e7fce |
256 | == -1) |
257 | return -1; |
648db22b |
258 | state.state->x.next = state.state->out; |
b24e7fce |
259 | return 0; |
260 | case GZIP: /* -> GZIP or LOOK (if end of gzip stream) */ |
648db22b |
261 | strm->avail_out = state.state->size << 1; |
262 | strm->next_out = state.state->out; |
b24e7fce |
263 | if (gz_decomp(state) == -1) |
264 | return -1; |
265 | } |
648db22b |
266 | } while (state.state->x.have == 0 && (!state.state->eof || strm->avail_in)); |
b24e7fce |
267 | return 0; |
268 | } |
269 | |
270 | /* Skip len uncompressed bytes of output. Return -1 on error, 0 on success. */ |
271 | local int gz_skip(state, len) |
272 | gz_statep state; |
273 | z_off64_t len; |
274 | { |
275 | unsigned n; |
276 | |
277 | /* skip over len bytes or reach end-of-file, whichever comes first */ |
278 | while (len) |
279 | /* skip over whatever is in output buffer */ |
648db22b |
280 | if (state.state->x.have) { |
281 | n = GT_OFF(state.state->x.have) || (z_off64_t)state.state->x.have > len ? |
282 | (unsigned)len : state.state->x.have; |
283 | state.state->x.have -= n; |
284 | state.state->x.next += n; |
285 | state.state->x.pos += n; |
b24e7fce |
286 | len -= n; |
287 | } |
288 | |
289 | /* output buffer empty -- return if we're at the end of the input */ |
648db22b |
290 | else if (state.state->eof && state.state->strm.avail_in == 0) |
b24e7fce |
291 | break; |
292 | |
293 | /* need more data to skip -- load up output buffer */ |
294 | else { |
295 | /* get more output, looking for header if required */ |
296 | if (gz_fetch(state) == -1) |
297 | return -1; |
298 | } |
299 | return 0; |
300 | } |
301 | |
302 | /* Read len bytes into buf from file, or less than len up to the end of the |
303 | input. Return the number of bytes read. If zero is returned, either the |
648db22b |
304 | end of file was reached, or there was an error. state.state->err must be |
b24e7fce |
305 | consulted in that case to determine which. */ |
306 | local z_size_t gz_read(state, buf, len) |
307 | gz_statep state; |
308 | voidp buf; |
309 | z_size_t len; |
310 | { |
311 | z_size_t got; |
312 | unsigned n; |
313 | |
314 | /* if len is zero, avoid unnecessary operations */ |
315 | if (len == 0) |
316 | return 0; |
317 | |
318 | /* process a skip request */ |
648db22b |
319 | if (state.state->seek) { |
320 | state.state->seek = 0; |
321 | if (gz_skip(state, state.state->skip) == -1) |
b24e7fce |
322 | return 0; |
323 | } |
324 | |
325 | /* get len bytes to buf, or less than len if at the end */ |
326 | got = 0; |
327 | do { |
328 | /* set n to the maximum amount of len that fits in an unsigned int */ |
648db22b |
329 | n = -1; |
b24e7fce |
330 | if (n > len) |
9e052883 |
331 | n = (unsigned)len; |
b24e7fce |
332 | |
333 | /* first just try copying data from the output buffer */ |
648db22b |
334 | if (state.state->x.have) { |
335 | if (state.state->x.have < n) |
336 | n = state.state->x.have; |
337 | memcpy(buf, state.state->x.next, n); |
338 | state.state->x.next += n; |
339 | state.state->x.have -= n; |
b24e7fce |
340 | } |
341 | |
342 | /* output buffer empty -- return if we're at the end of the input */ |
648db22b |
343 | else if (state.state->eof && state.state->strm.avail_in == 0) { |
344 | state.state->past = 1; /* tried to read past end */ |
b24e7fce |
345 | break; |
346 | } |
347 | |
348 | /* need output data -- for small len or new stream load up our output |
349 | buffer */ |
648db22b |
350 | else if (state.state->how == LOOK || n < (state.state->size << 1)) { |
b24e7fce |
351 | /* get more output, looking for header if required */ |
352 | if (gz_fetch(state) == -1) |
353 | return 0; |
354 | continue; /* no progress yet -- go back to copy above */ |
355 | /* the copy above assures that we will leave with space in the |
356 | output buffer, allowing at least one gzungetc() to succeed */ |
357 | } |
358 | |
359 | /* large len -- read directly into user buffer */ |
648db22b |
360 | else if (state.state->how == COPY) { /* read directly */ |
b24e7fce |
361 | if (gz_load(state, (unsigned char *)buf, n, &n) == -1) |
362 | return 0; |
363 | } |
364 | |
365 | /* large len -- decompress directly into user buffer */ |
648db22b |
366 | else { /* state.state->how == GZIP */ |
367 | state.state->strm.avail_out = n; |
368 | state.state->strm.next_out = (unsigned char *)buf; |
b24e7fce |
369 | if (gz_decomp(state) == -1) |
370 | return 0; |
648db22b |
371 | n = state.state->x.have; |
372 | state.state->x.have = 0; |
b24e7fce |
373 | } |
374 | |
375 | /* update progress */ |
376 | len -= n; |
377 | buf = (char *)buf + n; |
378 | got += n; |
648db22b |
379 | state.state->x.pos += n; |
b24e7fce |
380 | } while (len); |
381 | |
382 | /* return number of bytes read into user buffer */ |
383 | return got; |
384 | } |
385 | |
386 | /* -- see zlib.h -- */ |
387 | int ZEXPORT gzread(file, buf, len) |
388 | gzFile file; |
389 | voidp buf; |
390 | unsigned len; |
391 | { |
392 | gz_statep state; |
393 | |
394 | /* get internal structure */ |
395 | if (file == NULL) |
396 | return -1; |
648db22b |
397 | state.file = file; |
b24e7fce |
398 | |
399 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
400 | if (state.state->mode != GZ_READ || |
401 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
402 | return -1; |
403 | |
404 | /* since an int is returned, make sure len fits in one, otherwise return |
405 | with an error (this avoids a flaw in the interface) */ |
406 | if ((int)len < 0) { |
407 | gz_error(state, Z_STREAM_ERROR, "request does not fit in an int"); |
408 | return -1; |
409 | } |
410 | |
411 | /* read len or fewer bytes to buf */ |
9e052883 |
412 | len = (unsigned)gz_read(state, buf, len); |
b24e7fce |
413 | |
414 | /* check for an error */ |
648db22b |
415 | if (len == 0 && state.state->err != Z_OK && state.state->err != Z_BUF_ERROR) |
b24e7fce |
416 | return -1; |
417 | |
418 | /* return the number of bytes read (this is assured to fit in an int) */ |
419 | return (int)len; |
420 | } |
421 | |
422 | /* -- see zlib.h -- */ |
423 | z_size_t ZEXPORT gzfread(buf, size, nitems, file) |
424 | voidp buf; |
425 | z_size_t size; |
426 | z_size_t nitems; |
427 | gzFile file; |
428 | { |
429 | z_size_t len; |
430 | gz_statep state; |
431 | |
432 | /* get internal structure */ |
433 | if (file == NULL) |
434 | return 0; |
648db22b |
435 | state.file = file; |
b24e7fce |
436 | |
437 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
438 | if (state.state->mode != GZ_READ || |
439 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
440 | return 0; |
441 | |
442 | /* compute bytes to read -- error on overflow */ |
443 | len = nitems * size; |
444 | if (size && len / size != nitems) { |
445 | gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t"); |
446 | return 0; |
447 | } |
448 | |
449 | /* read len or fewer bytes to buf, return the number of full items read */ |
450 | return len ? gz_read(state, buf, len) / size : 0; |
451 | } |
452 | |
453 | /* -- see zlib.h -- */ |
648db22b |
454 | #if ZLIB_VERNUM >= 0x1261 |
b24e7fce |
455 | #ifdef Z_PREFIX_SET |
456 | # undef z_gzgetc |
457 | #else |
458 | # undef gzgetc |
459 | #endif |
648db22b |
460 | #endif |
461 | |
462 | #if ZLIB_VERNUM == 0x1260 |
463 | # undef gzgetc |
464 | #endif |
465 | |
466 | #if ZLIB_VERNUM <= 0x1250 |
467 | ZEXTERN int ZEXPORT gzgetc _Z_OF((gzFile file)); |
468 | ZEXTERN int ZEXPORT gzgetc_ _Z_OF((gzFile file)); |
469 | #endif |
470 | |
b24e7fce |
471 | int ZEXPORT gzgetc(file) |
472 | gzFile file; |
473 | { |
648db22b |
474 | int ret; |
b24e7fce |
475 | unsigned char buf[1]; |
476 | gz_statep state; |
477 | |
478 | /* get internal structure */ |
479 | if (file == NULL) |
480 | return -1; |
648db22b |
481 | state.file = file; |
b24e7fce |
482 | |
483 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
484 | if (state.state->mode != GZ_READ || |
485 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
486 | return -1; |
487 | |
488 | /* try output buffer (no need to check for skip request) */ |
648db22b |
489 | if (state.state->x.have) { |
490 | state.state->x.have--; |
491 | state.state->x.pos++; |
492 | return *(state.state->x.next)++; |
b24e7fce |
493 | } |
494 | |
495 | /* nothing there -- try gz_read() */ |
648db22b |
496 | ret = (int)gz_read(state, buf, 1); |
497 | return ret < 1 ? -1 : buf[0]; |
b24e7fce |
498 | } |
499 | |
500 | int ZEXPORT gzgetc_(file) |
501 | gzFile file; |
502 | { |
503 | return gzgetc(file); |
504 | } |
505 | |
506 | /* -- see zlib.h -- */ |
507 | int ZEXPORT gzungetc(c, file) |
508 | int c; |
509 | gzFile file; |
510 | { |
511 | gz_statep state; |
512 | |
513 | /* get internal structure */ |
514 | if (file == NULL) |
515 | return -1; |
648db22b |
516 | state.file = file; |
b24e7fce |
517 | |
518 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
519 | if (state.state->mode != GZ_READ || |
520 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
521 | return -1; |
522 | |
523 | /* process a skip request */ |
648db22b |
524 | if (state.state->seek) { |
525 | state.state->seek = 0; |
526 | if (gz_skip(state, state.state->skip) == -1) |
b24e7fce |
527 | return -1; |
528 | } |
529 | |
530 | /* can't push EOF */ |
531 | if (c < 0) |
532 | return -1; |
533 | |
534 | /* if output buffer empty, put byte at end (allows more pushing) */ |
648db22b |
535 | if (state.state->x.have == 0) { |
536 | state.state->x.have = 1; |
537 | state.state->x.next = state.state->out + (state.state->size << 1) - 1; |
538 | state.state->x.next[0] = (unsigned char)c; |
539 | state.state->x.pos--; |
540 | state.state->past = 0; |
b24e7fce |
541 | return c; |
542 | } |
543 | |
544 | /* if no room, give up (must have already done a gzungetc()) */ |
648db22b |
545 | if (state.state->x.have == (state.state->size << 1)) { |
b24e7fce |
546 | gz_error(state, Z_DATA_ERROR, "out of room to push characters"); |
547 | return -1; |
548 | } |
549 | |
550 | /* slide output data if needed and insert byte before existing data */ |
648db22b |
551 | if (state.state->x.next == state.state->out) { |
552 | unsigned char *src = state.state->out + state.state->x.have; |
553 | unsigned char *dest = state.state->out + (state.state->size << 1); |
554 | while (src > state.state->out) |
b24e7fce |
555 | *--dest = *--src; |
648db22b |
556 | state.state->x.next = dest; |
b24e7fce |
557 | } |
648db22b |
558 | state.state->x.have++; |
559 | state.state->x.next--; |
560 | state.state->x.next[0] = (unsigned char)c; |
561 | state.state->x.pos--; |
562 | state.state->past = 0; |
b24e7fce |
563 | return c; |
564 | } |
565 | |
566 | /* -- see zlib.h -- */ |
567 | char * ZEXPORT gzgets(file, buf, len) |
568 | gzFile file; |
569 | char *buf; |
570 | int len; |
571 | { |
572 | unsigned left, n; |
573 | char *str; |
574 | unsigned char *eol; |
575 | gz_statep state; |
576 | |
577 | /* check parameters and get internal structure */ |
578 | if (file == NULL || buf == NULL || len < 1) |
579 | return NULL; |
648db22b |
580 | state.file = file; |
b24e7fce |
581 | |
582 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
583 | if (state.state->mode != GZ_READ || |
584 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
585 | return NULL; |
586 | |
587 | /* process a skip request */ |
648db22b |
588 | if (state.state->seek) { |
589 | state.state->seek = 0; |
590 | if (gz_skip(state, state.state->skip) == -1) |
b24e7fce |
591 | return NULL; |
592 | } |
593 | |
594 | /* copy output bytes up to new line or len - 1, whichever comes first -- |
595 | append a terminating zero to the string (we don't check for a zero in |
596 | the contents, let the user worry about that) */ |
597 | str = buf; |
598 | left = (unsigned)len - 1; |
599 | if (left) do { |
600 | /* assure that something is in the output buffer */ |
648db22b |
601 | if (state.state->x.have == 0 && gz_fetch(state) == -1) |
b24e7fce |
602 | return NULL; /* error */ |
648db22b |
603 | if (state.state->x.have == 0) { /* end of file */ |
604 | state.state->past = 1; /* read past end */ |
b24e7fce |
605 | break; /* return what we have */ |
606 | } |
607 | |
608 | /* look for end-of-line in current output buffer */ |
648db22b |
609 | n = state.state->x.have > left ? left : state.state->x.have; |
610 | eol = (unsigned char *)memchr(state.state->x.next, '\n', n); |
b24e7fce |
611 | if (eol != NULL) |
648db22b |
612 | n = (unsigned)(eol - state.state->x.next) + 1; |
b24e7fce |
613 | |
614 | /* copy through end-of-line, or remainder if not found */ |
648db22b |
615 | memcpy(buf, state.state->x.next, n); |
616 | state.state->x.have -= n; |
617 | state.state->x.next += n; |
618 | state.state->x.pos += n; |
b24e7fce |
619 | left -= n; |
620 | buf += n; |
621 | } while (left && eol == NULL); |
622 | |
623 | /* return terminated string, or if nothing, end of file */ |
624 | if (buf == str) |
625 | return NULL; |
626 | buf[0] = 0; |
627 | return str; |
628 | } |
629 | |
630 | /* -- see zlib.h -- */ |
631 | int ZEXPORT gzdirect(file) |
632 | gzFile file; |
633 | { |
634 | gz_statep state; |
635 | |
636 | /* get internal structure */ |
637 | if (file == NULL) |
638 | return 0; |
648db22b |
639 | state.file = file; |
b24e7fce |
640 | |
641 | /* if the state is not known, but we can find out, then do so (this is |
642 | mainly for right after a gzopen() or gzdopen()) */ |
648db22b |
643 | if (state.state->mode == GZ_READ && state.state->how == LOOK && state.state->x.have == 0) |
b24e7fce |
644 | (void)gz_look(state); |
645 | |
646 | /* return 1 if transparent, 0 if processing a gzip stream */ |
648db22b |
647 | return state.state->direct; |
b24e7fce |
648 | } |
649 | |
650 | /* -- see zlib.h -- */ |
651 | int ZEXPORT gzclose_r(file) |
652 | gzFile file; |
653 | { |
654 | int ret, err; |
655 | gz_statep state; |
656 | |
657 | /* get internal structure */ |
658 | if (file == NULL) |
659 | return Z_STREAM_ERROR; |
648db22b |
660 | state.file = file; |
b24e7fce |
661 | |
662 | /* check that we're reading */ |
648db22b |
663 | if (state.state->mode != GZ_READ) |
b24e7fce |
664 | return Z_STREAM_ERROR; |
665 | |
666 | /* free memory and close file */ |
648db22b |
667 | if (state.state->size) { |
668 | inflateEnd(&(state.state->strm)); |
669 | free(state.state->out); |
670 | free(state.state->in); |
b24e7fce |
671 | } |
648db22b |
672 | err = state.state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK; |
b24e7fce |
673 | gz_error(state, Z_OK, NULL); |
648db22b |
674 | free(state.state->path); |
675 | ret = close(state.state->fd); |
676 | free(state.state); |
b24e7fce |
677 | return ret ? Z_ERRNO : err; |
678 | } |