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. */ |
f535537f |
32 | local int gz_load(gz_statep state, unsigned char *buf, unsigned len, |
33 | unsigned *have) { |
648db22b |
34 | ssize_t ret; |
b24e7fce |
35 | unsigned get, max = ((unsigned)-1 >> 2) + 1; |
36 | |
37 | *have = 0; |
38 | do { |
39 | get = len - *have; |
40 | if (get > max) |
41 | get = max; |
648db22b |
42 | ret = read(state.state->fd, buf + *have, get); |
b24e7fce |
43 | if (ret <= 0) |
44 | break; |
45 | *have += (unsigned)ret; |
46 | } while (*have < len); |
47 | if (ret < 0) { |
48 | gz_error(state, Z_ERRNO, zstrerror()); |
49 | return -1; |
50 | } |
51 | if (ret == 0) |
648db22b |
52 | state.state->eof = 1; |
b24e7fce |
53 | return 0; |
54 | } |
55 | |
56 | /* Load up input buffer and set eof flag if last data loaded -- return -1 on |
57 | error, 0 otherwise. Note that the eof flag is set when the end of the input |
58 | file is reached, even though there may be unused data in the buffer. Once |
59 | that data has been used, no more attempts will be made to read the file. |
60 | If strm->avail_in != 0, then the current data is moved to the beginning of |
61 | the input buffer, and then the remainder of the buffer is loaded with the |
62 | available data from the input file. */ |
f535537f |
63 | local int gz_avail(gz_statep state) |
b24e7fce |
64 | { |
65 | unsigned got; |
648db22b |
66 | z_streamp strm = &(state.state->strm); |
b24e7fce |
67 | |
648db22b |
68 | if (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR) |
b24e7fce |
69 | return -1; |
648db22b |
70 | if (state.state->eof == 0) { |
b24e7fce |
71 | if (strm->avail_in) { /* copy what's there to the start */ |
648db22b |
72 | unsigned char *p = state.state->in; |
b24e7fce |
73 | unsigned const char *q = strm->next_in; |
74 | unsigned n = strm->avail_in; |
75 | do { |
76 | *p++ = *q++; |
77 | } while (--n); |
78 | } |
648db22b |
79 | if (gz_load(state, state.state->in + strm->avail_in, |
80 | state.state->size - strm->avail_in, &got) == -1) |
b24e7fce |
81 | return -1; |
82 | strm->avail_in += got; |
648db22b |
83 | strm->next_in = state.state->in; |
b24e7fce |
84 | } |
85 | return 0; |
86 | } |
87 | |
648db22b |
88 | /* Look for gzip header, set up for inflate or copy. state.state->x.have must be 0. |
89 | If this is the first time in, allocate required memory. state.state->how will be |
b24e7fce |
90 | left unchanged if there is no more input data available, will be set to COPY |
91 | if there is no gzip header and direct copying will be performed, or it will |
92 | be set to GZIP for decompression. If direct copying, then leftover input |
93 | data from the input buffer will be copied to the output buffer. In that |
94 | case, all further file reads will be directly to either the output buffer or |
95 | a user buffer. If decompressing, the inflate state will be initialized. |
96 | gz_look() will return 0 on success or -1 on failure. */ |
f535537f |
97 | local int gz_look(gz_statep state) { |
648db22b |
98 | z_streamp strm = &(state.state->strm); |
b24e7fce |
99 | |
100 | /* allocate read buffers and inflate memory */ |
648db22b |
101 | if (state.state->size == 0) { |
b24e7fce |
102 | /* allocate buffers */ |
648db22b |
103 | state.state->in = (unsigned char *)malloc(state.state->want); |
104 | state.state->out = (unsigned char *)malloc(state.state->want << 1); |
105 | if (state.state->in == NULL || state.state->out == NULL) { |
106 | free(state.state->out); |
107 | free(state.state->in); |
b24e7fce |
108 | gz_error(state, Z_MEM_ERROR, "out of memory"); |
109 | return -1; |
110 | } |
648db22b |
111 | state.state->size = state.state->want; |
b24e7fce |
112 | |
113 | /* allocate inflate memory */ |
648db22b |
114 | state.state->strm.zalloc = Z_NULL; |
115 | state.state->strm.zfree = Z_NULL; |
116 | state.state->strm.opaque = Z_NULL; |
117 | state.state->strm.avail_in = 0; |
118 | state.state->strm.next_in = Z_NULL; |
119 | if (inflateInit2(&(state.state->strm), 15 + 16) != Z_OK) { /* gunzip */ |
120 | free(state.state->out); |
121 | free(state.state->in); |
122 | state.state->size = 0; |
b24e7fce |
123 | gz_error(state, Z_MEM_ERROR, "out of memory"); |
124 | return -1; |
125 | } |
126 | } |
127 | |
128 | /* get at least the magic bytes in the input buffer */ |
129 | if (strm->avail_in < 2) { |
130 | if (gz_avail(state) == -1) |
131 | return -1; |
132 | if (strm->avail_in == 0) |
133 | return 0; |
134 | } |
135 | |
136 | /* look for gzip magic bytes -- if there, do gzip decoding (note: there is |
137 | a logical dilemma here when considering the case of a partially written |
138 | gzip file, to wit, if a single 31 byte is written, then we cannot tell |
139 | whether this is a single-byte file, or just a partially written gzip |
140 | file -- for here we assume that if a gzip file is being written, then |
141 | the header will be written in a single operation, so that reading a |
142 | single byte is sufficient indication that it is not a gzip file) */ |
143 | if (strm->avail_in > 1 && |
648db22b |
144 | ((strm->next_in[0] == 31 && strm->next_in[1] == 139) /* gz header */ |
145 | || (strm->next_in[0] == 40 && strm->next_in[1] == 181))) { /* zstd header */ |
b24e7fce |
146 | inflateReset(strm); |
648db22b |
147 | state.state->how = GZIP; |
148 | state.state->direct = 0; |
b24e7fce |
149 | return 0; |
150 | } |
151 | |
152 | /* no gzip header -- if we were decoding gzip before, then this is trailing |
153 | garbage. Ignore the trailing garbage and finish. */ |
648db22b |
154 | if (state.state->direct == 0) { |
b24e7fce |
155 | strm->avail_in = 0; |
648db22b |
156 | state.state->eof = 1; |
157 | state.state->x.have = 0; |
b24e7fce |
158 | return 0; |
159 | } |
160 | |
161 | /* doing raw i/o, copy any leftover input to output -- this assumes that |
162 | the output buffer is larger than the input buffer, which also assures |
163 | space for gzungetc() */ |
648db22b |
164 | state.state->x.next = state.state->out; |
165 | if (strm->avail_in) { |
166 | memcpy(state.state->x.next, strm->next_in, strm->avail_in); |
167 | state.state->x.have = strm->avail_in; |
168 | strm->avail_in = 0; |
169 | } |
170 | state.state->how = COPY; |
171 | state.state->direct = 1; |
b24e7fce |
172 | return 0; |
173 | } |
174 | |
175 | /* Decompress from input to the provided next_out and avail_out in the state. |
648db22b |
176 | On return, state.state->x.have and state.state->x.next point to the just decompressed |
177 | data. If the gzip stream completes, state.state->how is reset to LOOK to look for |
178 | the next gzip stream or raw data, once state.state->x.have is depleted. Returns 0 |
b24e7fce |
179 | on success, -1 on failure. */ |
f535537f |
180 | local int gz_decomp(gz_statep state) { |
b24e7fce |
181 | int ret = Z_OK; |
182 | unsigned had; |
648db22b |
183 | z_streamp strm = &(state.state->strm); |
b24e7fce |
184 | |
185 | /* fill output buffer up to end of deflate stream */ |
186 | had = strm->avail_out; |
187 | do { |
188 | /* get more input for inflate() */ |
189 | if (strm->avail_in == 0 && gz_avail(state) == -1) |
190 | return -1; |
191 | if (strm->avail_in == 0) { |
192 | gz_error(state, Z_BUF_ERROR, "unexpected end of file"); |
193 | break; |
194 | } |
195 | |
196 | /* decompress and handle errors */ |
197 | ret = inflate(strm, Z_NO_FLUSH); |
198 | if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) { |
199 | gz_error(state, Z_STREAM_ERROR, |
200 | "internal error: inflate stream corrupt"); |
201 | return -1; |
202 | } |
203 | if (ret == Z_MEM_ERROR) { |
204 | gz_error(state, Z_MEM_ERROR, "out of memory"); |
205 | return -1; |
206 | } |
207 | if (ret == Z_DATA_ERROR) { /* deflate stream invalid */ |
208 | gz_error(state, Z_DATA_ERROR, |
209 | strm->msg == NULL ? "compressed data error" : strm->msg); |
210 | return -1; |
211 | } |
212 | } while (strm->avail_out && ret != Z_STREAM_END); |
213 | |
214 | /* update available output */ |
648db22b |
215 | state.state->x.have = had - strm->avail_out; |
216 | state.state->x.next = strm->next_out - state.state->x.have; |
b24e7fce |
217 | |
218 | /* if the gzip stream completed successfully, look for another */ |
219 | if (ret == Z_STREAM_END) |
648db22b |
220 | state.state->how = LOOK; |
b24e7fce |
221 | |
222 | /* good decompression */ |
223 | return 0; |
224 | } |
225 | |
648db22b |
226 | /* Fetch data and put it in the output buffer. Assumes state.state->x.have is 0. |
b24e7fce |
227 | Data is either copied from the input file or decompressed from the input |
648db22b |
228 | file depending on state.state->how. If state.state->how is LOOK, then a gzip header is |
b24e7fce |
229 | looked for to determine whether to copy or decompress. Returns -1 on error, |
648db22b |
230 | otherwise 0. gz_fetch() will leave state.state->how as COPY or GZIP unless the |
b24e7fce |
231 | end of the input file has been reached and all data has been processed. */ |
f535537f |
232 | local int gz_fetch(gz_statep state) { |
648db22b |
233 | z_streamp strm = &(state.state->strm); |
b24e7fce |
234 | |
235 | do { |
648db22b |
236 | switch(state.state->how) { |
b24e7fce |
237 | case LOOK: /* -> LOOK, COPY (only if never GZIP), or GZIP */ |
238 | if (gz_look(state) == -1) |
239 | return -1; |
648db22b |
240 | if (state.state->how == LOOK) |
b24e7fce |
241 | return 0; |
242 | break; |
243 | case COPY: /* -> COPY */ |
648db22b |
244 | if (gz_load(state, state.state->out, state.state->size << 1, &(state.state->x.have)) |
b24e7fce |
245 | == -1) |
246 | return -1; |
648db22b |
247 | state.state->x.next = state.state->out; |
b24e7fce |
248 | return 0; |
249 | case GZIP: /* -> GZIP or LOOK (if end of gzip stream) */ |
648db22b |
250 | strm->avail_out = state.state->size << 1; |
251 | strm->next_out = state.state->out; |
b24e7fce |
252 | if (gz_decomp(state) == -1) |
253 | return -1; |
254 | } |
648db22b |
255 | } while (state.state->x.have == 0 && (!state.state->eof || strm->avail_in)); |
b24e7fce |
256 | return 0; |
257 | } |
258 | |
259 | /* Skip len uncompressed bytes of output. Return -1 on error, 0 on success. */ |
f535537f |
260 | local int gz_skip(gz_statep state, z_off64_t len) { |
b24e7fce |
261 | unsigned n; |
262 | |
263 | /* skip over len bytes or reach end-of-file, whichever comes first */ |
264 | while (len) |
265 | /* skip over whatever is in output buffer */ |
648db22b |
266 | if (state.state->x.have) { |
267 | n = GT_OFF(state.state->x.have) || (z_off64_t)state.state->x.have > len ? |
268 | (unsigned)len : state.state->x.have; |
269 | state.state->x.have -= n; |
270 | state.state->x.next += n; |
271 | state.state->x.pos += n; |
b24e7fce |
272 | len -= n; |
273 | } |
274 | |
275 | /* output buffer empty -- return if we're at the end of the input */ |
648db22b |
276 | else if (state.state->eof && state.state->strm.avail_in == 0) |
b24e7fce |
277 | break; |
278 | |
279 | /* need more data to skip -- load up output buffer */ |
280 | else { |
281 | /* get more output, looking for header if required */ |
282 | if (gz_fetch(state) == -1) |
283 | return -1; |
284 | } |
285 | return 0; |
286 | } |
287 | |
288 | /* Read len bytes into buf from file, or less than len up to the end of the |
289 | input. Return the number of bytes read. If zero is returned, either the |
648db22b |
290 | end of file was reached, or there was an error. state.state->err must be |
b24e7fce |
291 | consulted in that case to determine which. */ |
f535537f |
292 | local z_size_t gz_read(gz_statep state, voidp buf, z_size_t len) { |
b24e7fce |
293 | z_size_t got; |
294 | unsigned n; |
295 | |
296 | /* if len is zero, avoid unnecessary operations */ |
297 | if (len == 0) |
298 | return 0; |
299 | |
300 | /* process a skip request */ |
648db22b |
301 | if (state.state->seek) { |
302 | state.state->seek = 0; |
303 | if (gz_skip(state, state.state->skip) == -1) |
b24e7fce |
304 | return 0; |
305 | } |
306 | |
307 | /* get len bytes to buf, or less than len if at the end */ |
308 | got = 0; |
309 | do { |
310 | /* set n to the maximum amount of len that fits in an unsigned int */ |
648db22b |
311 | n = -1; |
b24e7fce |
312 | if (n > len) |
9e052883 |
313 | n = (unsigned)len; |
b24e7fce |
314 | |
315 | /* first just try copying data from the output buffer */ |
648db22b |
316 | if (state.state->x.have) { |
317 | if (state.state->x.have < n) |
318 | n = state.state->x.have; |
319 | memcpy(buf, state.state->x.next, n); |
320 | state.state->x.next += n; |
321 | state.state->x.have -= n; |
b24e7fce |
322 | } |
323 | |
324 | /* output buffer empty -- return if we're at the end of the input */ |
648db22b |
325 | else if (state.state->eof && state.state->strm.avail_in == 0) { |
326 | state.state->past = 1; /* tried to read past end */ |
b24e7fce |
327 | break; |
328 | } |
329 | |
330 | /* need output data -- for small len or new stream load up our output |
331 | buffer */ |
648db22b |
332 | else if (state.state->how == LOOK || n < (state.state->size << 1)) { |
b24e7fce |
333 | /* get more output, looking for header if required */ |
334 | if (gz_fetch(state) == -1) |
335 | return 0; |
336 | continue; /* no progress yet -- go back to copy above */ |
337 | /* the copy above assures that we will leave with space in the |
338 | output buffer, allowing at least one gzungetc() to succeed */ |
339 | } |
340 | |
341 | /* large len -- read directly into user buffer */ |
648db22b |
342 | else if (state.state->how == COPY) { /* read directly */ |
b24e7fce |
343 | if (gz_load(state, (unsigned char *)buf, n, &n) == -1) |
344 | return 0; |
345 | } |
346 | |
347 | /* large len -- decompress directly into user buffer */ |
648db22b |
348 | else { /* state.state->how == GZIP */ |
349 | state.state->strm.avail_out = n; |
350 | state.state->strm.next_out = (unsigned char *)buf; |
b24e7fce |
351 | if (gz_decomp(state) == -1) |
352 | return 0; |
648db22b |
353 | n = state.state->x.have; |
354 | state.state->x.have = 0; |
b24e7fce |
355 | } |
356 | |
357 | /* update progress */ |
358 | len -= n; |
359 | buf = (char *)buf + n; |
360 | got += n; |
648db22b |
361 | state.state->x.pos += n; |
b24e7fce |
362 | } while (len); |
363 | |
364 | /* return number of bytes read into user buffer */ |
365 | return got; |
366 | } |
367 | |
368 | /* -- see zlib.h -- */ |
f535537f |
369 | int ZEXPORT gzread(gzFile file, voidp buf, unsigned len) { |
b24e7fce |
370 | gz_statep state; |
371 | |
372 | /* get internal structure */ |
373 | if (file == NULL) |
374 | return -1; |
648db22b |
375 | state.file = file; |
b24e7fce |
376 | |
377 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
378 | if (state.state->mode != GZ_READ || |
379 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
380 | return -1; |
381 | |
382 | /* since an int is returned, make sure len fits in one, otherwise return |
383 | with an error (this avoids a flaw in the interface) */ |
384 | if ((int)len < 0) { |
385 | gz_error(state, Z_STREAM_ERROR, "request does not fit in an int"); |
386 | return -1; |
387 | } |
388 | |
389 | /* read len or fewer bytes to buf */ |
9e052883 |
390 | len = (unsigned)gz_read(state, buf, len); |
b24e7fce |
391 | |
392 | /* check for an error */ |
648db22b |
393 | if (len == 0 && state.state->err != Z_OK && state.state->err != Z_BUF_ERROR) |
b24e7fce |
394 | return -1; |
395 | |
396 | /* return the number of bytes read (this is assured to fit in an int) */ |
397 | return (int)len; |
398 | } |
399 | |
400 | /* -- see zlib.h -- */ |
f535537f |
401 | z_size_t ZEXPORT gzfread(voidp buf, z_size_t size, z_size_t nitems, |
402 | gzFile file) { |
b24e7fce |
403 | z_size_t len; |
404 | gz_statep state; |
405 | |
406 | /* get internal structure */ |
407 | if (file == NULL) |
408 | return 0; |
648db22b |
409 | state.file = file; |
b24e7fce |
410 | |
411 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
412 | if (state.state->mode != GZ_READ || |
413 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
414 | return 0; |
415 | |
416 | /* compute bytes to read -- error on overflow */ |
417 | len = nitems * size; |
418 | if (size && len / size != nitems) { |
419 | gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t"); |
420 | return 0; |
421 | } |
422 | |
423 | /* read len or fewer bytes to buf, return the number of full items read */ |
424 | return len ? gz_read(state, buf, len) / size : 0; |
425 | } |
426 | |
427 | /* -- see zlib.h -- */ |
648db22b |
428 | #if ZLIB_VERNUM >= 0x1261 |
b24e7fce |
429 | #ifdef Z_PREFIX_SET |
430 | # undef z_gzgetc |
431 | #else |
432 | # undef gzgetc |
433 | #endif |
648db22b |
434 | #endif |
435 | |
436 | #if ZLIB_VERNUM == 0x1260 |
437 | # undef gzgetc |
438 | #endif |
439 | |
440 | #if ZLIB_VERNUM <= 0x1250 |
441 | ZEXTERN int ZEXPORT gzgetc _Z_OF((gzFile file)); |
442 | ZEXTERN int ZEXPORT gzgetc_ _Z_OF((gzFile file)); |
443 | #endif |
444 | |
f535537f |
445 | int ZEXPORT gzgetc(gzFile file) { |
648db22b |
446 | int ret; |
b24e7fce |
447 | unsigned char buf[1]; |
448 | gz_statep state; |
449 | |
450 | /* get internal structure */ |
451 | if (file == NULL) |
452 | return -1; |
648db22b |
453 | state.file = file; |
b24e7fce |
454 | |
455 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
456 | if (state.state->mode != GZ_READ || |
457 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
458 | return -1; |
459 | |
460 | /* try output buffer (no need to check for skip request) */ |
648db22b |
461 | if (state.state->x.have) { |
462 | state.state->x.have--; |
463 | state.state->x.pos++; |
464 | return *(state.state->x.next)++; |
b24e7fce |
465 | } |
466 | |
467 | /* nothing there -- try gz_read() */ |
648db22b |
468 | ret = (int)gz_read(state, buf, 1); |
469 | return ret < 1 ? -1 : buf[0]; |
b24e7fce |
470 | } |
471 | |
f535537f |
472 | int ZEXPORT gzgetc_(gzFile file) { |
b24e7fce |
473 | return gzgetc(file); |
474 | } |
475 | |
476 | /* -- see zlib.h -- */ |
f535537f |
477 | int ZEXPORT gzungetc(int c, gzFile file) { |
b24e7fce |
478 | gz_statep state; |
479 | |
480 | /* get internal structure */ |
481 | if (file == NULL) |
482 | return -1; |
648db22b |
483 | state.file = file; |
b24e7fce |
484 | |
485 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
486 | if (state.state->mode != GZ_READ || |
487 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
488 | return -1; |
489 | |
490 | /* process a skip request */ |
648db22b |
491 | if (state.state->seek) { |
492 | state.state->seek = 0; |
493 | if (gz_skip(state, state.state->skip) == -1) |
b24e7fce |
494 | return -1; |
495 | } |
496 | |
497 | /* can't push EOF */ |
498 | if (c < 0) |
499 | return -1; |
500 | |
501 | /* if output buffer empty, put byte at end (allows more pushing) */ |
648db22b |
502 | if (state.state->x.have == 0) { |
503 | state.state->x.have = 1; |
504 | state.state->x.next = state.state->out + (state.state->size << 1) - 1; |
505 | state.state->x.next[0] = (unsigned char)c; |
506 | state.state->x.pos--; |
507 | state.state->past = 0; |
b24e7fce |
508 | return c; |
509 | } |
510 | |
511 | /* if no room, give up (must have already done a gzungetc()) */ |
648db22b |
512 | if (state.state->x.have == (state.state->size << 1)) { |
b24e7fce |
513 | gz_error(state, Z_DATA_ERROR, "out of room to push characters"); |
514 | return -1; |
515 | } |
516 | |
517 | /* slide output data if needed and insert byte before existing data */ |
648db22b |
518 | if (state.state->x.next == state.state->out) { |
519 | unsigned char *src = state.state->out + state.state->x.have; |
520 | unsigned char *dest = state.state->out + (state.state->size << 1); |
521 | while (src > state.state->out) |
b24e7fce |
522 | *--dest = *--src; |
648db22b |
523 | state.state->x.next = dest; |
b24e7fce |
524 | } |
648db22b |
525 | state.state->x.have++; |
526 | state.state->x.next--; |
527 | state.state->x.next[0] = (unsigned char)c; |
528 | state.state->x.pos--; |
529 | state.state->past = 0; |
b24e7fce |
530 | return c; |
531 | } |
532 | |
533 | /* -- see zlib.h -- */ |
f535537f |
534 | char * ZEXPORT gzgets(gzFile file, char *buf, int len) { |
b24e7fce |
535 | unsigned left, n; |
536 | char *str; |
537 | unsigned char *eol; |
538 | gz_statep state; |
539 | |
540 | /* check parameters and get internal structure */ |
541 | if (file == NULL || buf == NULL || len < 1) |
542 | return NULL; |
648db22b |
543 | state.file = file; |
b24e7fce |
544 | |
545 | /* check that we're reading and that there's no (serious) error */ |
648db22b |
546 | if (state.state->mode != GZ_READ || |
547 | (state.state->err != Z_OK && state.state->err != Z_BUF_ERROR)) |
b24e7fce |
548 | return NULL; |
549 | |
550 | /* process a skip request */ |
648db22b |
551 | if (state.state->seek) { |
552 | state.state->seek = 0; |
553 | if (gz_skip(state, state.state->skip) == -1) |
b24e7fce |
554 | return NULL; |
555 | } |
556 | |
557 | /* copy output bytes up to new line or len - 1, whichever comes first -- |
558 | append a terminating zero to the string (we don't check for a zero in |
559 | the contents, let the user worry about that) */ |
560 | str = buf; |
561 | left = (unsigned)len - 1; |
562 | if (left) do { |
563 | /* assure that something is in the output buffer */ |
648db22b |
564 | if (state.state->x.have == 0 && gz_fetch(state) == -1) |
b24e7fce |
565 | return NULL; /* error */ |
648db22b |
566 | if (state.state->x.have == 0) { /* end of file */ |
567 | state.state->past = 1; /* read past end */ |
b24e7fce |
568 | break; /* return what we have */ |
569 | } |
570 | |
571 | /* look for end-of-line in current output buffer */ |
648db22b |
572 | n = state.state->x.have > left ? left : state.state->x.have; |
573 | eol = (unsigned char *)memchr(state.state->x.next, '\n', n); |
b24e7fce |
574 | if (eol != NULL) |
648db22b |
575 | n = (unsigned)(eol - state.state->x.next) + 1; |
b24e7fce |
576 | |
577 | /* copy through end-of-line, or remainder if not found */ |
648db22b |
578 | memcpy(buf, state.state->x.next, n); |
579 | state.state->x.have -= n; |
580 | state.state->x.next += n; |
581 | state.state->x.pos += n; |
b24e7fce |
582 | left -= n; |
583 | buf += n; |
584 | } while (left && eol == NULL); |
585 | |
586 | /* return terminated string, or if nothing, end of file */ |
587 | if (buf == str) |
588 | return NULL; |
589 | buf[0] = 0; |
590 | return str; |
591 | } |
592 | |
593 | /* -- see zlib.h -- */ |
f535537f |
594 | int ZEXPORT gzdirect(gzFile file) { |
b24e7fce |
595 | gz_statep state; |
596 | |
597 | /* get internal structure */ |
598 | if (file == NULL) |
599 | return 0; |
648db22b |
600 | state.file = file; |
b24e7fce |
601 | |
602 | /* if the state is not known, but we can find out, then do so (this is |
603 | mainly for right after a gzopen() or gzdopen()) */ |
648db22b |
604 | if (state.state->mode == GZ_READ && state.state->how == LOOK && state.state->x.have == 0) |
b24e7fce |
605 | (void)gz_look(state); |
606 | |
607 | /* return 1 if transparent, 0 if processing a gzip stream */ |
648db22b |
608 | return state.state->direct; |
b24e7fce |
609 | } |
610 | |
611 | /* -- see zlib.h -- */ |
f535537f |
612 | int ZEXPORT gzclose_r(gzFile file) { |
b24e7fce |
613 | int ret, err; |
614 | gz_statep state; |
615 | |
616 | /* get internal structure */ |
617 | if (file == NULL) |
618 | return Z_STREAM_ERROR; |
648db22b |
619 | state.file = file; |
b24e7fce |
620 | |
621 | /* check that we're reading */ |
648db22b |
622 | if (state.state->mode != GZ_READ) |
b24e7fce |
623 | return Z_STREAM_ERROR; |
624 | |
625 | /* free memory and close file */ |
648db22b |
626 | if (state.state->size) { |
627 | inflateEnd(&(state.state->strm)); |
628 | free(state.state->out); |
629 | free(state.state->in); |
b24e7fce |
630 | } |
648db22b |
631 | err = state.state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK; |
b24e7fce |
632 | gz_error(state, Z_OK, NULL); |
648db22b |
633 | free(state.state->path); |
634 | ret = close(state.state->fd); |
635 | free(state.state); |
b24e7fce |
636 | return ret ? Z_ERRNO : err; |
637 | } |