xref: /dragonfly/contrib/zlib-1.2/gzwrite.c (revision e041647a)
1 /* gzwrite.c -- zlib functions for writing gzip files
2  * Copyright (C) 2004-2017 Mark Adler
3  * For conditions of distribution and use, see copyright notice in zlib.h
4  */
5 
6 #include "gzguts.h"
7 
8 /* Local functions */
9 local int gz_init OF((gz_statep));
10 local int gz_comp OF((gz_statep, int));
11 local int gz_zero OF((gz_statep, z_off64_t));
12 local z_size_t gz_write OF((gz_statep, voidpc, z_size_t));
13 
14 /* Initialize state for writing a gzip file.  Mark initialization by setting
15    state->size to non-zero.  Return -1 on a memory allocation failure, or 0 on
16    success. */
gz_init(state)17 local int gz_init(state)
18     gz_statep state;
19 {
20     int ret;
21     z_streamp strm = &(state->strm);
22 
23     /* allocate input buffer (double size for gzprintf) */
24     state->in = (unsigned char *)malloc(state->want << 1);
25     if (state->in == NULL) {
26         gz_error(state, Z_MEM_ERROR, "out of memory");
27         return -1;
28     }
29 
30     /* only need output buffer and deflate state if compressing */
31     if (!state->direct) {
32         /* allocate output buffer */
33         state->out = (unsigned char *)malloc(state->want);
34         if (state->out == NULL) {
35             free(state->in);
36             gz_error(state, Z_MEM_ERROR, "out of memory");
37             return -1;
38         }
39 
40         /* allocate deflate memory, set up for gzip compression */
41         strm->zalloc = Z_NULL;
42         strm->zfree = Z_NULL;
43         strm->opaque = Z_NULL;
44         ret = deflateInit2(strm, state->level, Z_DEFLATED,
45                            MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
46         if (ret != Z_OK) {
47             free(state->out);
48             free(state->in);
49             gz_error(state, Z_MEM_ERROR, "out of memory");
50             return -1;
51         }
52         strm->next_in = NULL;
53     }
54 
55     /* mark state as initialized */
56     state->size = state->want;
57 
58     /* initialize write buffer if compressing */
59     if (!state->direct) {
60         strm->avail_out = state->size;
61         strm->next_out = state->out;
62         state->x.next = strm->next_out;
63     }
64     return 0;
65 }
66 
67 /* Compress whatever is at avail_in and next_in and write to the output file.
68    Return -1 if there is an error writing to the output file or if gz_init()
69    fails to allocate memory, otherwise 0.  flush is assumed to be a valid
70    deflate() flush value.  If flush is Z_FINISH, then the deflate() state is
71    reset to start a new gzip stream.  If gz->direct is true, then simply write
72    to the output file without compressing, and ignore flush. */
gz_comp(state,flush)73 local int gz_comp(state, flush)
74     gz_statep state;
75     int flush;
76 {
77     int ret, writ;
78     unsigned have, put, max = ((unsigned)-1 >> 2) + 1;
79     z_streamp strm = &(state->strm);
80 
81     /* allocate memory if this is the first time through */
82     if (state->size == 0 && gz_init(state) == -1)
83         return -1;
84 
85     /* write directly if requested */
86     if (state->direct) {
87         while (strm->avail_in) {
88             put = strm->avail_in > max ? max : strm->avail_in;
89             writ = write(state->fd, strm->next_in, put);
90             if (writ < 0) {
91                 gz_error(state, Z_ERRNO, zstrerror());
92                 return -1;
93             }
94             strm->avail_in -= (unsigned)writ;
95             strm->next_in += writ;
96         }
97         return 0;
98     }
99 
100     /* run deflate() on provided input until it produces no more output */
101     ret = Z_OK;
102     do {
103         /* write out current buffer contents if full, or if flushing, but if
104            doing Z_FINISH then don't write until we get to Z_STREAM_END */
105         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
106             (flush != Z_FINISH || ret == Z_STREAM_END))) {
107             while (strm->next_out > state->x.next) {
108                 put = strm->next_out - state->x.next > (int)max ? max :
109                       (unsigned)(strm->next_out - state->x.next);
110                 writ = write(state->fd, state->x.next, put);
111                 if (writ < 0) {
112                     gz_error(state, Z_ERRNO, zstrerror());
113                     return -1;
114                 }
115                 state->x.next += writ;
116             }
117             if (strm->avail_out == 0) {
118                 strm->avail_out = state->size;
119                 strm->next_out = state->out;
120                 state->x.next = state->out;
121             }
122         }
123 
124         /* compress */
125         have = strm->avail_out;
126         ret = deflate(strm, flush);
127         if (ret == Z_STREAM_ERROR) {
128             gz_error(state, Z_STREAM_ERROR,
129                       "internal error: deflate stream corrupt");
130             return -1;
131         }
132         have -= strm->avail_out;
133     } while (have);
134 
135     /* if that completed a deflate stream, allow another to start */
136     if (flush == Z_FINISH)
137         deflateReset(strm);
138 
139     /* all done, no errors */
140     return 0;
141 }
142 
143 /* Compress len zeros to output.  Return -1 on a write error or memory
144    allocation failure by gz_comp(), or 0 on success. */
gz_zero(state,len)145 local int gz_zero(state, len)
146     gz_statep state;
147     z_off64_t len;
148 {
149     int first;
150     unsigned n;
151     z_streamp strm = &(state->strm);
152 
153     /* consume whatever's left in the input buffer */
154     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
155         return -1;
156 
157     /* compress len zeros (len guaranteed > 0) */
158     first = 1;
159     while (len) {
160         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
161             (unsigned)len : state->size;
162         if (first) {
163             memset(state->in, 0, n);
164             first = 0;
165         }
166         strm->avail_in = n;
167         strm->next_in = state->in;
168         state->x.pos += n;
169         if (gz_comp(state, Z_NO_FLUSH) == -1)
170             return -1;
171         len -= n;
172     }
173     return 0;
174 }
175 
176 /* Write len bytes from buf to file.  Return the number of bytes written.  If
177    the returned value is less than len, then there was an error. */
gz_write(state,buf,len)178 local z_size_t gz_write(state, buf, len)
179     gz_statep state;
180     voidpc buf;
181     z_size_t len;
182 {
183     z_size_t put = len;
184 
185     /* if len is zero, avoid unnecessary operations */
186     if (len == 0)
187         return 0;
188 
189     /* allocate memory if this is the first time through */
190     if (state->size == 0 && gz_init(state) == -1)
191         return 0;
192 
193     /* check for seek request */
194     if (state->seek) {
195         state->seek = 0;
196         if (gz_zero(state, state->skip) == -1)
197             return 0;
198     }
199 
200     /* for small len, copy to input buffer, otherwise compress directly */
201     if (len < state->size) {
202         /* copy to input buffer, compress when full */
203         do {
204             unsigned have, copy;
205 
206             if (state->strm.avail_in == 0)
207                 state->strm.next_in = state->in;
208             have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
209                               state->in);
210             copy = state->size - have;
211             if (copy > len)
212                 copy = len;
213             memcpy(state->in + have, buf, copy);
214             state->strm.avail_in += copy;
215             state->x.pos += copy;
216             buf = (const char *)buf + copy;
217             len -= copy;
218             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
219                 return 0;
220         } while (len);
221     }
222     else {
223         /* consume whatever's left in the input buffer */
224         if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
225             return 0;
226 
227         /* directly compress user buffer to file */
228         state->strm.next_in = (z_const Bytef *)buf;
229         do {
230             unsigned n = (unsigned)-1;
231             if (n > len)
232                 n = len;
233             state->strm.avail_in = n;
234             state->x.pos += n;
235             if (gz_comp(state, Z_NO_FLUSH) == -1)
236                 return 0;
237             len -= n;
238         } while (len);
239     }
240 
241     /* input was all buffered or compressed */
242     return put;
243 }
244 
245 /* -- see zlib.h -- */
gzwrite(file,buf,len)246 int ZEXPORT gzwrite(file, buf, len)
247     gzFile file;
248     voidpc buf;
249     unsigned len;
250 {
251     gz_statep state;
252 
253     /* get internal structure */
254     if (file == NULL)
255         return 0;
256     state = (gz_statep)file;
257 
258     /* check that we're writing and that there's no error */
259     if (state->mode != GZ_WRITE || state->err != Z_OK)
260         return 0;
261 
262     /* since an int is returned, make sure len fits in one, otherwise return
263        with an error (this avoids a flaw in the interface) */
264     if ((int)len < 0) {
265         gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
266         return 0;
267     }
268 
269     /* write len bytes from buf (the return value will fit in an int) */
270     return (int)gz_write(state, buf, len);
271 }
272 
273 /* -- see zlib.h -- */
gzfwrite(buf,size,nitems,file)274 z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
275     voidpc buf;
276     z_size_t size;
277     z_size_t nitems;
278     gzFile file;
279 {
280     z_size_t len;
281     gz_statep state;
282 
283     /* get internal structure */
284     if (file == NULL)
285         return 0;
286     state = (gz_statep)file;
287 
288     /* check that we're writing and that there's no error */
289     if (state->mode != GZ_WRITE || state->err != Z_OK)
290         return 0;
291 
292     /* compute bytes to read -- error on overflow */
293     len = nitems * size;
294     if (size && len / size != nitems) {
295         gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
296         return 0;
297     }
298 
299     /* write len bytes to buf, return the number of full items written */
300     return len ? gz_write(state, buf, len) / size : 0;
301 }
302 
303 /* -- see zlib.h -- */
gzputc(file,c)304 int ZEXPORT gzputc(file, c)
305     gzFile file;
306     int c;
307 {
308     unsigned have;
309     unsigned char buf[1];
310     gz_statep state;
311     z_streamp strm;
312 
313     /* get internal structure */
314     if (file == NULL)
315         return -1;
316     state = (gz_statep)file;
317     strm = &(state->strm);
318 
319     /* check that we're writing and that there's no error */
320     if (state->mode != GZ_WRITE || state->err != Z_OK)
321         return -1;
322 
323     /* check for seek request */
324     if (state->seek) {
325         state->seek = 0;
326         if (gz_zero(state, state->skip) == -1)
327             return -1;
328     }
329 
330     /* try writing to input buffer for speed (state->size == 0 if buffer not
331        initialized) */
332     if (state->size) {
333         if (strm->avail_in == 0)
334             strm->next_in = state->in;
335         have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
336         if (have < state->size) {
337             state->in[have] = (unsigned char)c;
338             strm->avail_in++;
339             state->x.pos++;
340             return c & 0xff;
341         }
342     }
343 
344     /* no room in buffer or not initialized, use gz_write() */
345     buf[0] = (unsigned char)c;
346     if (gz_write(state, buf, 1) != 1)
347         return -1;
348     return c & 0xff;
349 }
350 
351 /* -- see zlib.h -- */
gzputs(file,str)352 int ZEXPORT gzputs(file, str)
353     gzFile file;
354     const char *str;
355 {
356     int ret;
357     z_size_t len;
358     gz_statep state;
359 
360     /* get internal structure */
361     if (file == NULL)
362         return -1;
363     state = (gz_statep)file;
364 
365     /* check that we're writing and that there's no error */
366     if (state->mode != GZ_WRITE || state->err != Z_OK)
367         return -1;
368 
369     /* write string */
370     len = strlen(str);
371     ret = gz_write(state, str, len);
372     return ret == 0 && len != 0 ? -1 : ret;
373 }
374 
375 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
376 #include <stdarg.h>
377 
378 /* -- see zlib.h -- */
gzvprintf(gzFile file,const char * format,va_list va)379 int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
380 {
381     int len;
382     unsigned left;
383     char *next;
384     gz_statep state;
385     z_streamp strm;
386 
387     /* get internal structure */
388     if (file == NULL)
389         return Z_STREAM_ERROR;
390     state = (gz_statep)file;
391     strm = &(state->strm);
392 
393     /* check that we're writing and that there's no error */
394     if (state->mode != GZ_WRITE || state->err != Z_OK)
395         return Z_STREAM_ERROR;
396 
397     /* make sure we have some buffer space */
398     if (state->size == 0 && gz_init(state) == -1)
399         return state->err;
400 
401     /* check for seek request */
402     if (state->seek) {
403         state->seek = 0;
404         if (gz_zero(state, state->skip) == -1)
405             return state->err;
406     }
407 
408     /* do the printf() into the input buffer, put length in len -- the input
409        buffer is double-sized just for this function, so there is guaranteed to
410        be state->size bytes available after the current contents */
411     if (strm->avail_in == 0)
412         strm->next_in = state->in;
413     next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
414     next[state->size - 1] = 0;
415 #ifdef NO_vsnprintf
416 #  ifdef HAS_vsprintf_void
417     (void)vsprintf(next, format, va);
418     for (len = 0; len < state->size; len++)
419         if (next[len] == 0) break;
420 #  else
421     len = vsprintf(next, format, va);
422 #  endif
423 #else
424 #  ifdef HAS_vsnprintf_void
425     (void)vsnprintf(next, state->size, format, va);
426     len = strlen(next);
427 #  else
428     len = vsnprintf(next, state->size, format, va);
429 #  endif
430 #endif
431 
432     /* check that printf() results fit in buffer */
433     if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
434         return 0;
435 
436     /* update buffer and position, compress first half if past that */
437     strm->avail_in += (unsigned)len;
438     state->x.pos += len;
439     if (strm->avail_in >= state->size) {
440         left = strm->avail_in - state->size;
441         strm->avail_in = state->size;
442         if (gz_comp(state, Z_NO_FLUSH) == -1)
443             return state->err;
444         memcpy(state->in, state->in + state->size, left);
445         strm->next_in = state->in;
446         strm->avail_in = left;
447     }
448     return len;
449 }
450 
gzprintf(gzFile file,const char * format,...)451 int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
452 {
453     va_list va;
454     int ret;
455 
456     va_start(va, format);
457     ret = gzvprintf(file, format, va);
458     va_end(va);
459     return ret;
460 }
461 
462 #else /* !STDC && !Z_HAVE_STDARG_H */
463 
464 /* -- see zlib.h -- */
gzprintf(file,format,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,a16,a17,a18,a19,a20)465 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
466                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
467     gzFile file;
468     const char *format;
469     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
470         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
471 {
472     unsigned len, left;
473     char *next;
474     gz_statep state;
475     z_streamp strm;
476 
477     /* get internal structure */
478     if (file == NULL)
479         return Z_STREAM_ERROR;
480     state = (gz_statep)file;
481     strm = &(state->strm);
482 
483     /* check that can really pass pointer in ints */
484     if (sizeof(int) != sizeof(void *))
485         return Z_STREAM_ERROR;
486 
487     /* check that we're writing and that there's no error */
488     if (state->mode != GZ_WRITE || state->err != Z_OK)
489         return Z_STREAM_ERROR;
490 
491     /* make sure we have some buffer space */
492     if (state->size == 0 && gz_init(state) == -1)
493         return state->error;
494 
495     /* check for seek request */
496     if (state->seek) {
497         state->seek = 0;
498         if (gz_zero(state, state->skip) == -1)
499             return state->error;
500     }
501 
502     /* do the printf() into the input buffer, put length in len -- the input
503        buffer is double-sized just for this function, so there is guaranteed to
504        be state->size bytes available after the current contents */
505     if (strm->avail_in == 0)
506         strm->next_in = state->in;
507     next = (char *)(strm->next_in + strm->avail_in);
508     next[state->size - 1] = 0;
509 #ifdef NO_snprintf
510 #  ifdef HAS_sprintf_void
511     sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
512             a13, a14, a15, a16, a17, a18, a19, a20);
513     for (len = 0; len < size; len++)
514         if (next[len] == 0)
515             break;
516 #  else
517     len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
518                   a12, a13, a14, a15, a16, a17, a18, a19, a20);
519 #  endif
520 #else
521 #  ifdef HAS_snprintf_void
522     snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
523              a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
524     len = strlen(next);
525 #  else
526     len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
527                    a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
528 #  endif
529 #endif
530 
531     /* check that printf() results fit in buffer */
532     if (len == 0 || len >= state->size || next[state->size - 1] != 0)
533         return 0;
534 
535     /* update buffer and position, compress first half if past that */
536     strm->avail_in += len;
537     state->x.pos += len;
538     if (strm->avail_in >= state->size) {
539         left = strm->avail_in - state->size;
540         strm->avail_in = state->size;
541         if (gz_comp(state, Z_NO_FLUSH) == -1)
542             return state->err;
543         memcpy(state->in, state->in + state->size, left);
544         strm->next_in = state->in;
545         strm->avail_in = left;
546     }
547     return (int)len;
548 }
549 
550 #endif
551 
552 /* -- see zlib.h -- */
gzflush(file,flush)553 int ZEXPORT gzflush(file, flush)
554     gzFile file;
555     int flush;
556 {
557     gz_statep state;
558 
559     /* get internal structure */
560     if (file == NULL)
561         return Z_STREAM_ERROR;
562     state = (gz_statep)file;
563 
564     /* check that we're writing and that there's no error */
565     if (state->mode != GZ_WRITE || state->err != Z_OK)
566         return Z_STREAM_ERROR;
567 
568     /* check flush parameter */
569     if (flush < 0 || flush > Z_FINISH)
570         return Z_STREAM_ERROR;
571 
572     /* check for seek request */
573     if (state->seek) {
574         state->seek = 0;
575         if (gz_zero(state, state->skip) == -1)
576             return state->err;
577     }
578 
579     /* compress remaining data with requested flush */
580     (void)gz_comp(state, flush);
581     return state->err;
582 }
583 
584 /* -- see zlib.h -- */
gzsetparams(file,level,strategy)585 int ZEXPORT gzsetparams(file, level, strategy)
586     gzFile file;
587     int level;
588     int strategy;
589 {
590     gz_statep state;
591     z_streamp strm;
592 
593     /* get internal structure */
594     if (file == NULL)
595         return Z_STREAM_ERROR;
596     state = (gz_statep)file;
597     strm = &(state->strm);
598 
599     /* check that we're writing and that there's no error */
600     if (state->mode != GZ_WRITE || state->err != Z_OK)
601         return Z_STREAM_ERROR;
602 
603     /* if no change is requested, then do nothing */
604     if (level == state->level && strategy == state->strategy)
605         return Z_OK;
606 
607     /* check for seek request */
608     if (state->seek) {
609         state->seek = 0;
610         if (gz_zero(state, state->skip) == -1)
611             return state->err;
612     }
613 
614     /* change compression parameters for subsequent input */
615     if (state->size) {
616         /* flush previous input with previous parameters before changing */
617         if (strm->avail_in && gz_comp(state, Z_BLOCK) == -1)
618             return state->err;
619         deflateParams(strm, level, strategy);
620     }
621     state->level = level;
622     state->strategy = strategy;
623     return Z_OK;
624 }
625 
626 /* -- see zlib.h -- */
gzclose_w(file)627 int ZEXPORT gzclose_w(file)
628     gzFile file;
629 {
630     int ret = Z_OK;
631     gz_statep state;
632 
633     /* get internal structure */
634     if (file == NULL)
635         return Z_STREAM_ERROR;
636     state = (gz_statep)file;
637 
638     /* check that we're writing */
639     if (state->mode != GZ_WRITE)
640         return Z_STREAM_ERROR;
641 
642     /* check for seek request */
643     if (state->seek) {
644         state->seek = 0;
645         if (gz_zero(state, state->skip) == -1)
646             ret = state->err;
647     }
648 
649     /* flush, free memory, and close file */
650     if (gz_comp(state, Z_FINISH) == -1)
651         ret = state->err;
652     if (state->size) {
653         if (!state->direct) {
654             (void)deflateEnd(&(state->strm));
655             free(state->out);
656         }
657         free(state->in);
658     }
659     gz_error(state, Z_OK, NULL);
660     free(state->path);
661     if (close(state->fd) == -1)
662         ret = Z_ERRNO;
663     free(state);
664     return ret;
665 }
666