wrapper: implement xopen()
[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
f8bb1d94 155 memory_limit_check(size * nmemb, 0);
d41489a6 156 ret = calloc(nmemb, size);
112db553
LT
157 if (!ret && (!nmemb || !size))
158 ret = calloc(1, 1);
159 if (!ret) {
a9a74636 160 try_to_free_routine(nmemb * size);
112db553
LT
161 ret = calloc(nmemb, size);
162 if (!ret && (!nmemb || !size))
163 ret = calloc(1, 1);
164 if (!ret)
165 die("Out of memory, calloc failed");
166 }
167 return ret;
168}
169
0b6806b9
SP
170/*
171 * Limit size of IO chunks, because huge chunks only cause pain. OS X
172 * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
382d20e3 173 * the absence of bugs, large chunks can result in bad latencies when
0b6806b9 174 * you decide to kill the process.
a983e6ac
JH
175 *
176 * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
177 * that is smaller than that, clip it to SSIZE_MAX, as a call to
178 * read(2) or write(2) larger than that is allowed to fail. As the last
179 * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
180 * to override this, if the definition of SSIZE_MAX given by the platform
181 * is broken.
0b6806b9 182 */
a983e6ac
JH
183#ifndef MAX_IO_SIZE
184# define MAX_IO_SIZE_DEFAULT (8*1024*1024)
185# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT)
186# define MAX_IO_SIZE SSIZE_MAX
187# else
188# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT
189# endif
190#endif
0b6806b9 191
3ff53df7
PT
192/**
193 * xopen() is the same as open(), but it die()s if the open() fails.
194 */
195int xopen(const char *path, int oflag, ...)
196{
197 mode_t mode = 0;
198 va_list ap;
199
200 /*
201 * va_arg() will have undefined behavior if the specified type is not
202 * compatible with the argument type. Since integers are promoted to
203 * ints, we fetch the next argument as an int, and then cast it to a
204 * mode_t to avoid undefined behavior.
205 */
206 va_start(ap, oflag);
207 if (oflag & O_CREAT)
208 mode = va_arg(ap, int);
209 va_end(ap);
210
211 for (;;) {
212 int fd = open(path, oflag, mode);
213 if (fd >= 0)
214 return fd;
215 if (errno == EINTR)
216 continue;
217
218 if ((oflag & O_RDWR) == O_RDWR)
219 die_errno(_("could not open '%s' for reading and writing"), path);
220 else if ((oflag & O_WRONLY) == O_WRONLY)
221 die_errno(_("could not open '%s' for writing"), path);
222 else
223 die_errno(_("could not open '%s' for reading"), path);
224 }
225}
226
112db553
LT
227/*
228 * xread() is the same a read(), but it automatically restarts read()
229 * operations with a recoverable error (EAGAIN and EINTR). xread()
230 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
231 */
232ssize_t xread(int fd, void *buf, size_t len)
233{
234 ssize_t nr;
0b6806b9
SP
235 if (len > MAX_IO_SIZE)
236 len = MAX_IO_SIZE;
112db553
LT
237 while (1) {
238 nr = read(fd, buf, len);
239 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
240 continue;
241 return nr;
242 }
243}
244
245/*
246 * xwrite() is the same a write(), but it automatically restarts write()
247 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
248 * GUARANTEE that "len" bytes is written even if the operation is successful.
249 */
250ssize_t xwrite(int fd, const void *buf, size_t len)
251{
252 ssize_t nr;
0b6806b9
SP
253 if (len > MAX_IO_SIZE)
254 len = MAX_IO_SIZE;
112db553
LT
255 while (1) {
256 nr = write(fd, buf, len);
257 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
9aa91af0
YM
258 continue;
259 return nr;
260 }
261}
262
263/*
264 * xpread() is the same as pread(), but it automatically restarts pread()
265 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
266 * NOT GUARANTEE that "len" bytes is read even if the data is available.
267 */
268ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
269{
270 ssize_t nr;
271 if (len > MAX_IO_SIZE)
272 len = MAX_IO_SIZE;
273 while (1) {
274 nr = pread(fd, buf, len, offset);
275 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
112db553
LT
276 continue;
277 return nr;
278 }
279}
280
559e840b
JH
281ssize_t read_in_full(int fd, void *buf, size_t count)
282{
283 char *p = buf;
284 ssize_t total = 0;
285
286 while (count > 0) {
287 ssize_t loaded = xread(fd, p, count);
56d7c27a
JK
288 if (loaded < 0)
289 return -1;
290 if (loaded == 0)
291 return total;
559e840b
JH
292 count -= loaded;
293 p += loaded;
294 total += loaded;
295 }
296
297 return total;
298}
299
300ssize_t write_in_full(int fd, const void *buf, size_t count)
301{
302 const char *p = buf;
303 ssize_t total = 0;
304
305 while (count > 0) {
306 ssize_t written = xwrite(fd, p, count);
307 if (written < 0)
308 return -1;
309 if (!written) {
310 errno = ENOSPC;
311 return -1;
312 }
313 count -= written;
314 p += written;
315 total += written;
316 }
317
318 return total;
319}
320
426ddeea
YM
321ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
322{
323 char *p = buf;
324 ssize_t total = 0;
325
326 while (count > 0) {
327 ssize_t loaded = xpread(fd, p, count, offset);
328 if (loaded < 0)
329 return -1;
330 if (loaded == 0)
331 return total;
332 count -= loaded;
333 p += loaded;
334 total += loaded;
335 offset += loaded;
336 }
337
338 return total;
339}
340
112db553
LT
341int xdup(int fd)
342{
343 int ret = dup(fd);
344 if (ret < 0)
d824cbba 345 die_errno("dup failed");
112db553
LT
346 return ret;
347}
348
349FILE *xfdopen(int fd, const char *mode)
350{
351 FILE *stream = fdopen(fd, mode);
352 if (stream == NULL)
d824cbba 353 die_errno("Out of memory? fdopen failed");
112db553
LT
354 return stream;
355}
356
357int xmkstemp(char *template)
358{
359 int fd;
6cf6bb3e
AE
360 char origtemplate[PATH_MAX];
361 strlcpy(origtemplate, template, sizeof(origtemplate));
112db553
LT
362
363 fd = mkstemp(template);
6cf6bb3e
AE
364 if (fd < 0) {
365 int saved_errno = errno;
366 const char *nonrelative_template;
367
f7be59b4 368 if (strlen(template) != strlen(origtemplate))
6cf6bb3e
AE
369 template = origtemplate;
370
e2a57aac 371 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
372 errno = saved_errno;
373 die_errno("Unable to create temporary file '%s'",
374 nonrelative_template);
375 }
112db553
LT
376 return fd;
377}
39c68542 378
33f23936
JN
379/* git_mkstemp() - create tmp file honoring TMPDIR variable */
380int git_mkstemp(char *path, size_t len, const char *template)
381{
382 const char *tmp;
383 size_t n;
384
385 tmp = getenv("TMPDIR");
386 if (!tmp)
387 tmp = "/tmp";
388 n = snprintf(path, len, "%s/%s", tmp, template);
389 if (len <= n) {
390 errno = ENAMETOOLONG;
391 return -1;
392 }
393 return mkstemp(path);
394}
395
396/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
397int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
398{
399 const char *tmp;
400 size_t n;
401
402 tmp = getenv("TMPDIR");
403 if (!tmp)
404 tmp = "/tmp";
405 n = snprintf(path, len, "%s/%s", tmp, template);
406 if (len <= n) {
407 errno = ENAMETOOLONG;
408 return -1;
409 }
410 return mkstemps(path, suffix_len);
411}
412
413/* Adapted from libiberty's mkstemp.c. */
414
415#undef TMP_MAX
416#define TMP_MAX 16384
417
418int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
419{
420 static const char letters[] =
421 "abcdefghijklmnopqrstuvwxyz"
422 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
423 "0123456789";
424 static const int num_letters = 62;
425 uint64_t value;
426 struct timeval tv;
427 char *template;
428 size_t len;
429 int fd, count;
430
431 len = strlen(pattern);
432
433 if (len < 6 + suffix_len) {
434 errno = EINVAL;
435 return -1;
436 }
437
438 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
439 errno = EINVAL;
440 return -1;
441 }
442
443 /*
444 * Replace pattern's XXXXXX characters with randomness.
445 * Try TMP_MAX different filenames.
446 */
447 gettimeofday(&tv, NULL);
448 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
449 template = &pattern[len - 6 - suffix_len];
450 for (count = 0; count < TMP_MAX; ++count) {
451 uint64_t v = value;
452 /* Fill in the random bits. */
453 template[0] = letters[v % num_letters]; v /= num_letters;
454 template[1] = letters[v % num_letters]; v /= num_letters;
455 template[2] = letters[v % num_letters]; v /= num_letters;
456 template[3] = letters[v % num_letters]; v /= num_letters;
457 template[4] = letters[v % num_letters]; v /= num_letters;
458 template[5] = letters[v % num_letters]; v /= num_letters;
459
460 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
a2cb86c1 461 if (fd >= 0)
33f23936
JN
462 return fd;
463 /*
464 * Fatal error (EPERM, ENOSPC etc).
465 * It doesn't make sense to loop.
466 */
467 if (errno != EEXIST)
468 break;
469 /*
470 * This is a random value. It is only necessary that
471 * the next TMP_MAX values generated by adding 7777 to
472 * VALUE are different with (module 2^32).
473 */
474 value += 7777;
475 }
476 /* We return the null string if we can't find a unique file name. */
477 pattern[0] = '\0';
478 return -1;
479}
480
481int git_mkstemp_mode(char *pattern, int mode)
482{
483 /* mkstemp is just mkstemps with no suffix */
484 return git_mkstemps_mode(pattern, 0, mode);
485}
486
ec145c9c 487#ifdef NO_MKSTEMPS
33f23936
JN
488int gitmkstemps(char *pattern, int suffix_len)
489{
490 return git_mkstemps_mode(pattern, suffix_len, 0600);
491}
ec145c9c 492#endif
33f23936 493
b862b61c
MM
494int xmkstemp_mode(char *template, int mode)
495{
496 int fd;
6cf6bb3e
AE
497 char origtemplate[PATH_MAX];
498 strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c
MM
499
500 fd = git_mkstemp_mode(template, mode);
6cf6bb3e
AE
501 if (fd < 0) {
502 int saved_errno = errno;
503 const char *nonrelative_template;
504
505 if (!template[0])
506 template = origtemplate;
507
e2a57aac 508 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
509 errno = saved_errno;
510 die_errno("Unable to create temporary file '%s'",
511 nonrelative_template);
512 }
b862b61c
MM
513 return fd;
514}
515
10e13ec8 516static int warn_if_unremovable(const char *op, const char *file, int rc)
fc71db39 517{
1054af7d
RS
518 int err;
519 if (!rc || errno == ENOENT)
520 return 0;
521 err = errno;
522 warning("unable to %s %s: %s", op, file, strerror(errno));
523 errno = err;
fc71db39
AR
524 return rc;
525}
526
9ccc0c08
RS
527int unlink_or_msg(const char *file, struct strbuf *err)
528{
529 int rc = unlink(file);
530
531 assert(err);
532
533 if (!rc || errno == ENOENT)
534 return 0;
535
536 strbuf_addf(err, "unable to unlink %s: %s",
537 file, strerror(errno));
538 return -1;
539}
540
10e13ec8
PC
541int unlink_or_warn(const char *file)
542{
543 return warn_if_unremovable("unlink", file, unlink(file));
544}
d1723296
PC
545
546int rmdir_or_warn(const char *file)
547{
548 return warn_if_unremovable("rmdir", file, rmdir(file));
549}
80d706af
PC
550
551int remove_or_warn(unsigned int mode, const char *file)
552{
553 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
554}
2f705875 555
55b38a48
JH
556void warn_on_inaccessible(const char *path)
557{
558 warning(_("unable to access '%s': %s"), path, strerror(errno));
559}
560
4698c8fe
JN
561static int access_error_is_ok(int err, unsigned flag)
562{
563 return err == ENOENT || err == ENOTDIR ||
564 ((flag & ACCESS_EACCES_OK) && err == EACCES);
565}
566
567int access_or_warn(const char *path, int mode, unsigned flag)
ba8bd830
JK
568{
569 int ret = access(path, mode);
4698c8fe 570 if (ret && !access_error_is_ok(errno, flag))
55b38a48 571 warn_on_inaccessible(path);
ba8bd830
JK
572 return ret;
573}
574
4698c8fe 575int access_or_die(const char *path, int mode, unsigned flag)
96b9e0e3
JN
576{
577 int ret = access(path, mode);
4698c8fe 578 if (ret && !access_error_is_ok(errno, flag))
96b9e0e3
JN
579 die_errno(_("unable to access '%s'"), path);
580 return ret;
581}
582
2f705875
JK
583struct passwd *xgetpwuid_self(void)
584{
585 struct passwd *pw;
586
587 errno = 0;
588 pw = getpwuid(getuid());
589 if (!pw)
590 die(_("unable to look up current user in the passwd file: %s"),
591 errno ? strerror(errno) : _("no such user"));
592 return pw;
593}
aa14e980
RS
594
595char *xgetcwd(void)
596{
597 struct strbuf sb = STRBUF_INIT;
598 if (strbuf_getcwd(&sb))
599 die_errno(_("unable to get current working directory"));
600 return strbuf_detach(&sb, NULL);
601}
316e53e6
NTND
602
603int write_file(const char *path, int fatal, const char *fmt, ...)
604{
605 struct strbuf sb = STRBUF_INIT;
606 va_list params;
607 int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
608 if (fd < 0) {
609 if (fatal)
610 die_errno(_("could not open %s for writing"), path);
611 return -1;
612 }
613 va_start(params, fmt);
614 strbuf_vaddf(&sb, fmt, params);
615 va_end(params);
616 if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
617 int err = errno;
618 close(fd);
619 strbuf_release(&sb);
620 errno = err;
621 if (fatal)
622 die_errno(_("could not write to %s"), path);
623 return -1;
624 }
625 strbuf_release(&sb);
626 if (close(fd)) {
627 if (fatal)
628 die_errno(_("could not close %s"), path);
629 return -1;
630 }
631 return 0;
632}
2024d317
JS
633
634void sleep_millisec(int millisec)
635{
636 poll(NULL, 0, millisec);
637}