config.mak.uname: set FREAD_READS_DIRECTORIES for Darwin, too
[git/git.git] / wrapper.c
CommitLineData
112db553
LT
1/*
2 * Various trivial helper wrappers around standard functions
3 */
4#include "cache.h"
5
e0500293 6static void do_nothing(size_t size)
a9a74636 7{
a9a74636
NP
8}
9
e0500293 10static void (*try_to_free_routine)(size_t size) = do_nothing;
a9a74636 11
f8bb1d94 12static int memory_limit_check(size_t size, int gentle)
d41489a6 13{
9927d962
SP
14 static size_t limit = 0;
15 if (!limit) {
16 limit = git_env_ulong("GIT_ALLOC_LIMIT", 0);
17 if (!limit)
18 limit = SIZE_MAX;
d41489a6 19 }
f0d89001 20 if (size > limit) {
f8bb1d94 21 if (gentle) {
f0d89001
JH
22 error("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
23 (uintmax_t)size, (uintmax_t)limit);
f8bb1d94
NTND
24 return -1;
25 } else
f0d89001
JH
26 die("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
27 (uintmax_t)size, (uintmax_t)limit);
f8bb1d94
NTND
28 }
29 return 0;
d41489a6
NTND
30}
31
851c34b0 32try_to_free_t set_try_to_free_routine(try_to_free_t routine)
a9a74636 33{
851c34b0 34 try_to_free_t old = try_to_free_routine;
00b0d7f7
JH
35 if (!routine)
36 routine = do_nothing;
851c34b0
JS
37 try_to_free_routine = routine;
38 return old;
a9a74636
NP
39}
40
112db553
LT
41char *xstrdup(const char *str)
42{
43 char *ret = strdup(str);
44 if (!ret) {
a9a74636 45 try_to_free_routine(strlen(str) + 1);
112db553
LT
46 ret = strdup(str);
47 if (!ret)
48 die("Out of memory, strdup failed");
49 }
50 return ret;
51}
52
f8bb1d94 53static void *do_xmalloc(size_t size, int gentle)
112db553 54{
d41489a6
NTND
55 void *ret;
56
f8bb1d94
NTND
57 if (memory_limit_check(size, gentle))
58 return NULL;
d41489a6 59 ret = malloc(size);
112db553
LT
60 if (!ret && !size)
61 ret = malloc(1);
62 if (!ret) {
a9a74636 63 try_to_free_routine(size);
112db553
LT
64 ret = malloc(size);
65 if (!ret && !size)
66 ret = malloc(1);
f8bb1d94
NTND
67 if (!ret) {
68 if (!gentle)
69 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
70 (unsigned long)size);
71 else {
72 error("Out of memory, malloc failed (tried to allocate %lu bytes)",
73 (unsigned long)size);
74 return NULL;
75 }
76 }
112db553
LT
77 }
78#ifdef XMALLOC_POISON
79 memset(ret, 0xA5, size);
80#endif
81 return ret;
82}
83
f8bb1d94
NTND
84void *xmalloc(size_t size)
85{
86 return do_xmalloc(size, 0);
87}
88
89static void *do_xmallocz(size_t size, int gentle)
5bf9219d
IL
90{
91 void *ret;
f8bb1d94
NTND
92 if (unsigned_add_overflows(size, 1)) {
93 if (gentle) {
94 error("Data too large to fit into virtual memory space.");
95 return NULL;
96 } else
97 die("Data too large to fit into virtual memory space.");
98 }
99 ret = do_xmalloc(size + 1, gentle);
100 if (ret)
101 ((char*)ret)[size] = 0;
5bf9219d
IL
102 return ret;
103}
104
f8bb1d94
NTND
105void *xmallocz(size_t size)
106{
107 return do_xmallocz(size, 0);
108}
109
110void *xmallocz_gently(size_t size)
111{
112 return do_xmallocz(size, 1);
113}
114
112db553
LT
115/*
116 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
117 * "data" to the allocated memory, zero terminates the allocated memory,
118 * and returns a pointer to the allocated memory. If the allocation fails,
119 * the program dies.
120 */
121void *xmemdupz(const void *data, size_t len)
122{
5bf9219d 123 return memcpy(xmallocz(len), data, len);
112db553
LT
124}
125
126char *xstrndup(const char *str, size_t len)
127{
128 char *p = memchr(str, '\0', len);
129 return xmemdupz(str, p ? p - str : len);
130}
131
132void *xrealloc(void *ptr, size_t size)
133{
d41489a6
NTND
134 void *ret;
135
f8bb1d94 136 memory_limit_check(size, 0);
d41489a6 137 ret = realloc(ptr, size);
112db553
LT
138 if (!ret && !size)
139 ret = realloc(ptr, 1);
140 if (!ret) {
a9a74636 141 try_to_free_routine(size);
112db553
LT
142 ret = realloc(ptr, size);
143 if (!ret && !size)
144 ret = realloc(ptr, 1);
145 if (!ret)
146 die("Out of memory, realloc failed");
147 }
148 return ret;
149}
150
151void *xcalloc(size_t nmemb, size_t size)
152{
d41489a6
NTND
153 void *ret;
154
e7792a74
JK
155 if (unsigned_mult_overflows(nmemb, size))
156 die("data too large to fit into virtual memory space");
157
f8bb1d94 158 memory_limit_check(size * nmemb, 0);
d41489a6 159 ret = calloc(nmemb, size);
112db553
LT
160 if (!ret && (!nmemb || !size))
161 ret = calloc(1, 1);
162 if (!ret) {
a9a74636 163 try_to_free_routine(nmemb * size);
112db553
LT
164 ret = calloc(nmemb, size);
165 if (!ret && (!nmemb || !size))
166 ret = calloc(1, 1);
167 if (!ret)
168 die("Out of memory, calloc failed");
169 }
170 return ret;
171}
172
0b6806b9
SP
173/*
174 * Limit size of IO chunks, because huge chunks only cause pain. OS X
175 * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
382d20e3 176 * the absence of bugs, large chunks can result in bad latencies when
0b6806b9 177 * you decide to kill the process.
a983e6ac
JH
178 *
179 * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
180 * that is smaller than that, clip it to SSIZE_MAX, as a call to
181 * read(2) or write(2) larger than that is allowed to fail. As the last
182 * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
183 * to override this, if the definition of SSIZE_MAX given by the platform
184 * is broken.
0b6806b9 185 */
a983e6ac
JH
186#ifndef MAX_IO_SIZE
187# define MAX_IO_SIZE_DEFAULT (8*1024*1024)
188# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT)
189# define MAX_IO_SIZE SSIZE_MAX
190# else
191# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT
192# endif
193#endif
0b6806b9 194
3ff53df7
PT
195/**
196 * xopen() is the same as open(), but it die()s if the open() fails.
197 */
198int xopen(const char *path, int oflag, ...)
199{
200 mode_t mode = 0;
201 va_list ap;
202
203 /*
204 * va_arg() will have undefined behavior if the specified type is not
205 * compatible with the argument type. Since integers are promoted to
206 * ints, we fetch the next argument as an int, and then cast it to a
207 * mode_t to avoid undefined behavior.
208 */
209 va_start(ap, oflag);
210 if (oflag & O_CREAT)
211 mode = va_arg(ap, int);
212 va_end(ap);
213
214 for (;;) {
215 int fd = open(path, oflag, mode);
216 if (fd >= 0)
217 return fd;
218 if (errno == EINTR)
219 continue;
220
221 if ((oflag & O_RDWR) == O_RDWR)
222 die_errno(_("could not open '%s' for reading and writing"), path);
223 else if ((oflag & O_WRONLY) == O_WRONLY)
224 die_errno(_("could not open '%s' for writing"), path);
225 else
226 die_errno(_("could not open '%s' for reading"), path);
227 }
228}
229
d751dd11
EW
230static int handle_nonblock(int fd, short poll_events, int err)
231{
232 struct pollfd pfd;
233
234 if (err != EAGAIN && err != EWOULDBLOCK)
235 return 0;
236
237 pfd.fd = fd;
238 pfd.events = poll_events;
239
240 /*
241 * no need to check for errors, here;
242 * a subsequent read/write will detect unrecoverable errors
243 */
244 poll(&pfd, 1, -1);
245 return 1;
246}
247
112db553
LT
248/*
249 * xread() is the same a read(), but it automatically restarts read()
250 * operations with a recoverable error (EAGAIN and EINTR). xread()
251 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
252 */
253ssize_t xread(int fd, void *buf, size_t len)
254{
255 ssize_t nr;
0b6806b9
SP
256 if (len > MAX_IO_SIZE)
257 len = MAX_IO_SIZE;
112db553
LT
258 while (1) {
259 nr = read(fd, buf, len);
1079c4be
SB
260 if (nr < 0) {
261 if (errno == EINTR)
262 continue;
d751dd11 263 if (handle_nonblock(fd, POLLIN, errno))
c22f6202 264 continue;
1079c4be 265 }
112db553
LT
266 return nr;
267 }
268}
269
270/*
271 * xwrite() is the same a write(), but it automatically restarts write()
272 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
273 * GUARANTEE that "len" bytes is written even if the operation is successful.
274 */
275ssize_t xwrite(int fd, const void *buf, size_t len)
276{
277 ssize_t nr;
0b6806b9
SP
278 if (len > MAX_IO_SIZE)
279 len = MAX_IO_SIZE;
112db553
LT
280 while (1) {
281 nr = write(fd, buf, len);
ef1cf016
EW
282 if (nr < 0) {
283 if (errno == EINTR)
284 continue;
d751dd11 285 if (handle_nonblock(fd, POLLOUT, errno))
ef1cf016 286 continue;
ef1cf016
EW
287 }
288
9aa91af0
YM
289 return nr;
290 }
291}
292
293/*
294 * xpread() is the same as pread(), but it automatically restarts pread()
295 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
296 * NOT GUARANTEE that "len" bytes is read even if the data is available.
297 */
298ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
299{
300 ssize_t nr;
301 if (len > MAX_IO_SIZE)
302 len = MAX_IO_SIZE;
303 while (1) {
304 nr = pread(fd, buf, len, offset);
305 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
112db553
LT
306 continue;
307 return nr;
308 }
309}
310
559e840b
JH
311ssize_t read_in_full(int fd, void *buf, size_t count)
312{
313 char *p = buf;
314 ssize_t total = 0;
315
316 while (count > 0) {
317 ssize_t loaded = xread(fd, p, count);
56d7c27a
JK
318 if (loaded < 0)
319 return -1;
320 if (loaded == 0)
321 return total;
559e840b
JH
322 count -= loaded;
323 p += loaded;
324 total += loaded;
325 }
326
327 return total;
328}
329
330ssize_t write_in_full(int fd, const void *buf, size_t count)
331{
332 const char *p = buf;
333 ssize_t total = 0;
334
335 while (count > 0) {
336 ssize_t written = xwrite(fd, p, count);
337 if (written < 0)
338 return -1;
339 if (!written) {
340 errno = ENOSPC;
341 return -1;
342 }
343 count -= written;
344 p += written;
345 total += written;
346 }
347
348 return total;
349}
350
426ddeea
YM
351ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
352{
353 char *p = buf;
354 ssize_t total = 0;
355
356 while (count > 0) {
357 ssize_t loaded = xpread(fd, p, count, offset);
358 if (loaded < 0)
359 return -1;
360 if (loaded == 0)
361 return total;
362 count -= loaded;
363 p += loaded;
364 total += loaded;
365 offset += loaded;
366 }
367
368 return total;
369}
370
112db553
LT
371int xdup(int fd)
372{
373 int ret = dup(fd);
374 if (ret < 0)
d824cbba 375 die_errno("dup failed");
112db553
LT
376 return ret;
377}
378
260eec29
PT
379/**
380 * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
381 */
382FILE *xfopen(const char *path, const char *mode)
383{
384 for (;;) {
385 FILE *fp = fopen(path, mode);
386 if (fp)
387 return fp;
388 if (errno == EINTR)
389 continue;
390
391 if (*mode && mode[1] == '+')
392 die_errno(_("could not open '%s' for reading and writing"), path);
393 else if (*mode == 'w' || *mode == 'a')
394 die_errno(_("could not open '%s' for writing"), path);
395 else
396 die_errno(_("could not open '%s' for reading"), path);
397 }
398}
399
112db553
LT
400FILE *xfdopen(int fd, const char *mode)
401{
402 FILE *stream = fdopen(fd, mode);
403 if (stream == NULL)
d824cbba 404 die_errno("Out of memory? fdopen failed");
112db553
LT
405 return stream;
406}
407
79d7582e
JS
408FILE *fopen_for_writing(const char *path)
409{
410 FILE *ret = fopen(path, "w");
411
412 if (!ret && errno == EPERM) {
413 if (!unlink(path))
414 ret = fopen(path, "w");
415 else
416 errno = EPERM;
417 }
418 return ret;
419}
420
112db553
LT
421int xmkstemp(char *template)
422{
423 int fd;
6cf6bb3e
AE
424 char origtemplate[PATH_MAX];
425 strlcpy(origtemplate, template, sizeof(origtemplate));
112db553
LT
426
427 fd = mkstemp(template);
6cf6bb3e
AE
428 if (fd < 0) {
429 int saved_errno = errno;
430 const char *nonrelative_template;
431
f7be59b4 432 if (strlen(template) != strlen(origtemplate))
6cf6bb3e
AE
433 template = origtemplate;
434
e2a57aac 435 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
436 errno = saved_errno;
437 die_errno("Unable to create temporary file '%s'",
438 nonrelative_template);
439 }
112db553
LT
440 return fd;
441}
39c68542 442
33f23936
JN
443/* Adapted from libiberty's mkstemp.c. */
444
445#undef TMP_MAX
446#define TMP_MAX 16384
447
448int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
449{
450 static const char letters[] =
451 "abcdefghijklmnopqrstuvwxyz"
452 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
453 "0123456789";
454 static const int num_letters = 62;
455 uint64_t value;
456 struct timeval tv;
457 char *template;
458 size_t len;
459 int fd, count;
460
461 len = strlen(pattern);
462
463 if (len < 6 + suffix_len) {
464 errno = EINVAL;
465 return -1;
466 }
467
468 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
469 errno = EINVAL;
470 return -1;
471 }
472
473 /*
474 * Replace pattern's XXXXXX characters with randomness.
475 * Try TMP_MAX different filenames.
476 */
477 gettimeofday(&tv, NULL);
478 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
479 template = &pattern[len - 6 - suffix_len];
480 for (count = 0; count < TMP_MAX; ++count) {
481 uint64_t v = value;
482 /* Fill in the random bits. */
483 template[0] = letters[v % num_letters]; v /= num_letters;
484 template[1] = letters[v % num_letters]; v /= num_letters;
485 template[2] = letters[v % num_letters]; v /= num_letters;
486 template[3] = letters[v % num_letters]; v /= num_letters;
487 template[4] = letters[v % num_letters]; v /= num_letters;
488 template[5] = letters[v % num_letters]; v /= num_letters;
489
490 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
a2cb86c1 491 if (fd >= 0)
33f23936
JN
492 return fd;
493 /*
494 * Fatal error (EPERM, ENOSPC etc).
495 * It doesn't make sense to loop.
496 */
497 if (errno != EEXIST)
498 break;
499 /*
500 * This is a random value. It is only necessary that
501 * the next TMP_MAX values generated by adding 7777 to
502 * VALUE are different with (module 2^32).
503 */
504 value += 7777;
505 }
506 /* We return the null string if we can't find a unique file name. */
507 pattern[0] = '\0';
508 return -1;
509}
510
511int git_mkstemp_mode(char *pattern, int mode)
512{
513 /* mkstemp is just mkstemps with no suffix */
514 return git_mkstemps_mode(pattern, 0, mode);
515}
516
b862b61c
MM
517int xmkstemp_mode(char *template, int mode)
518{
519 int fd;
6cf6bb3e
AE
520 char origtemplate[PATH_MAX];
521 strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c
MM
522
523 fd = git_mkstemp_mode(template, mode);
6cf6bb3e
AE
524 if (fd < 0) {
525 int saved_errno = errno;
526 const char *nonrelative_template;
527
528 if (!template[0])
529 template = origtemplate;
530
e2a57aac 531 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
532 errno = saved_errno;
533 die_errno("Unable to create temporary file '%s'",
534 nonrelative_template);
535 }
b862b61c
MM
536 return fd;
537}
538
10e13ec8 539static int warn_if_unremovable(const char *op, const char *file, int rc)
fc71db39 540{
1054af7d
RS
541 int err;
542 if (!rc || errno == ENOENT)
543 return 0;
544 err = errno;
1da045fb 545 warning_errno("unable to %s %s", op, file);
1054af7d 546 errno = err;
fc71db39
AR
547 return rc;
548}
549
9ccc0c08
RS
550int unlink_or_msg(const char *file, struct strbuf *err)
551{
552 int rc = unlink(file);
553
554 assert(err);
555
556 if (!rc || errno == ENOENT)
557 return 0;
558
559 strbuf_addf(err, "unable to unlink %s: %s",
560 file, strerror(errno));
561 return -1;
562}
563
10e13ec8
PC
564int unlink_or_warn(const char *file)
565{
566 return warn_if_unremovable("unlink", file, unlink(file));
567}
d1723296
PC
568
569int rmdir_or_warn(const char *file)
570{
571 return warn_if_unremovable("rmdir", file, rmdir(file));
572}
80d706af
PC
573
574int remove_or_warn(unsigned int mode, const char *file)
575{
576 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
577}
2f705875 578
55b38a48
JH
579void warn_on_inaccessible(const char *path)
580{
1da045fb 581 warning_errno(_("unable to access '%s'"), path);
55b38a48
JH
582}
583
4698c8fe
JN
584static int access_error_is_ok(int err, unsigned flag)
585{
586 return err == ENOENT || err == ENOTDIR ||
587 ((flag & ACCESS_EACCES_OK) && err == EACCES);
588}
589
590int access_or_warn(const char *path, int mode, unsigned flag)
ba8bd830
JK
591{
592 int ret = access(path, mode);
4698c8fe 593 if (ret && !access_error_is_ok(errno, flag))
55b38a48 594 warn_on_inaccessible(path);
ba8bd830
JK
595 return ret;
596}
597
4698c8fe 598int access_or_die(const char *path, int mode, unsigned flag)
96b9e0e3
JN
599{
600 int ret = access(path, mode);
4698c8fe 601 if (ret && !access_error_is_ok(errno, flag))
96b9e0e3
JN
602 die_errno(_("unable to access '%s'"), path);
603 return ret;
604}
605
aa14e980
RS
606char *xgetcwd(void)
607{
608 struct strbuf sb = STRBUF_INIT;
609 if (strbuf_getcwd(&sb))
610 die_errno(_("unable to get current working directory"));
611 return strbuf_detach(&sb, NULL);
612}
316e53e6 613
7b03c89e
JK
614int xsnprintf(char *dst, size_t max, const char *fmt, ...)
615{
616 va_list ap;
617 int len;
618
619 va_start(ap, fmt);
620 len = vsnprintf(dst, max, fmt, ap);
621 va_end(ap);
622
623 if (len < 0)
624 die("BUG: your snprintf is broken");
625 if (len >= max)
626 die("BUG: attempt to snprintf into too-small buffer");
627 return len;
628}
629
52563d7e 630void write_file_buf(const char *path, const char *buf, size_t len)
316e53e6 631{
52563d7e
JK
632 int fd = xopen(path, O_WRONLY | O_CREAT | O_TRUNC, 0666);
633 if (write_in_full(fd, buf, len) != len)
634 die_errno(_("could not write to %s"), path);
635 if (close(fd))
636 die_errno(_("could not close %s"), path);
316e53e6 637}
2024d317 638
ef22318c 639void write_file(const char *path, const char *fmt, ...)
12d6ce1d 640{
12d6ce1d 641 va_list params;
316e53e6 642 struct strbuf sb = STRBUF_INIT;
12d6ce1d
JH
643
644 va_start(params, fmt);
ef22318c 645 strbuf_vaddf(&sb, fmt, params);
12d6ce1d 646 va_end(params);
12d6ce1d 647
ef22318c 648 strbuf_complete_line(&sb);
12d6ce1d 649
52563d7e 650 write_file_buf(path, sb.buf, sb.len);
ef22318c 651 strbuf_release(&sb);
12d6ce1d
JH
652}
653
2024d317
JS
654void sleep_millisec(int millisec)
655{
656 poll(NULL, 0, millisec);
657}
5781a9a2
DT
658
659int xgethostname(char *buf, size_t len)
660{
661 /*
662 * If the full hostname doesn't fit in buf, POSIX does not
663 * specify whether the buffer will be null-terminated, so to
664 * be safe, do it ourselves.
665 */
666 int ret = gethostname(buf, len);
667 if (!ret)
668 buf[len - 1] = 0;
669 return ret;
670}