lockfile: replace random() by rand()
[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
112db553
LT
192/*
193 * xread() is the same a read(), but it automatically restarts read()
194 * operations with a recoverable error (EAGAIN and EINTR). xread()
195 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
196 */
197ssize_t xread(int fd, void *buf, size_t len)
198{
199 ssize_t nr;
0b6806b9
SP
200 if (len > MAX_IO_SIZE)
201 len = MAX_IO_SIZE;
112db553
LT
202 while (1) {
203 nr = read(fd, buf, len);
204 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
205 continue;
206 return nr;
207 }
208}
209
210/*
211 * xwrite() is the same a write(), but it automatically restarts write()
212 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
213 * GUARANTEE that "len" bytes is written even if the operation is successful.
214 */
215ssize_t xwrite(int fd, const void *buf, size_t len)
216{
217 ssize_t nr;
0b6806b9
SP
218 if (len > MAX_IO_SIZE)
219 len = MAX_IO_SIZE;
112db553
LT
220 while (1) {
221 nr = write(fd, buf, len);
222 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
9aa91af0
YM
223 continue;
224 return nr;
225 }
226}
227
228/*
229 * xpread() is the same as pread(), but it automatically restarts pread()
230 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
231 * NOT GUARANTEE that "len" bytes is read even if the data is available.
232 */
233ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
234{
235 ssize_t nr;
236 if (len > MAX_IO_SIZE)
237 len = MAX_IO_SIZE;
238 while (1) {
239 nr = pread(fd, buf, len, offset);
240 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
112db553
LT
241 continue;
242 return nr;
243 }
244}
245
559e840b
JH
246ssize_t read_in_full(int fd, void *buf, size_t count)
247{
248 char *p = buf;
249 ssize_t total = 0;
250
251 while (count > 0) {
252 ssize_t loaded = xread(fd, p, count);
56d7c27a
JK
253 if (loaded < 0)
254 return -1;
255 if (loaded == 0)
256 return total;
559e840b
JH
257 count -= loaded;
258 p += loaded;
259 total += loaded;
260 }
261
262 return total;
263}
264
265ssize_t write_in_full(int fd, const void *buf, size_t count)
266{
267 const char *p = buf;
268 ssize_t total = 0;
269
270 while (count > 0) {
271 ssize_t written = xwrite(fd, p, count);
272 if (written < 0)
273 return -1;
274 if (!written) {
275 errno = ENOSPC;
276 return -1;
277 }
278 count -= written;
279 p += written;
280 total += written;
281 }
282
283 return total;
284}
285
426ddeea
YM
286ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
287{
288 char *p = buf;
289 ssize_t total = 0;
290
291 while (count > 0) {
292 ssize_t loaded = xpread(fd, p, count, offset);
293 if (loaded < 0)
294 return -1;
295 if (loaded == 0)
296 return total;
297 count -= loaded;
298 p += loaded;
299 total += loaded;
300 offset += loaded;
301 }
302
303 return total;
304}
305
112db553
LT
306int xdup(int fd)
307{
308 int ret = dup(fd);
309 if (ret < 0)
d824cbba 310 die_errno("dup failed");
112db553
LT
311 return ret;
312}
313
314FILE *xfdopen(int fd, const char *mode)
315{
316 FILE *stream = fdopen(fd, mode);
317 if (stream == NULL)
d824cbba 318 die_errno("Out of memory? fdopen failed");
112db553
LT
319 return stream;
320}
321
322int xmkstemp(char *template)
323{
324 int fd;
6cf6bb3e
AE
325 char origtemplate[PATH_MAX];
326 strlcpy(origtemplate, template, sizeof(origtemplate));
112db553
LT
327
328 fd = mkstemp(template);
6cf6bb3e
AE
329 if (fd < 0) {
330 int saved_errno = errno;
331 const char *nonrelative_template;
332
f7be59b4 333 if (strlen(template) != strlen(origtemplate))
6cf6bb3e
AE
334 template = origtemplate;
335
e2a57aac 336 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
337 errno = saved_errno;
338 die_errno("Unable to create temporary file '%s'",
339 nonrelative_template);
340 }
112db553
LT
341 return fd;
342}
39c68542 343
33f23936
JN
344/* git_mkstemp() - create tmp file honoring TMPDIR variable */
345int git_mkstemp(char *path, size_t len, const char *template)
346{
347 const char *tmp;
348 size_t n;
349
350 tmp = getenv("TMPDIR");
351 if (!tmp)
352 tmp = "/tmp";
353 n = snprintf(path, len, "%s/%s", tmp, template);
354 if (len <= n) {
355 errno = ENAMETOOLONG;
356 return -1;
357 }
358 return mkstemp(path);
359}
360
361/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
362int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
363{
364 const char *tmp;
365 size_t n;
366
367 tmp = getenv("TMPDIR");
368 if (!tmp)
369 tmp = "/tmp";
370 n = snprintf(path, len, "%s/%s", tmp, template);
371 if (len <= n) {
372 errno = ENAMETOOLONG;
373 return -1;
374 }
375 return mkstemps(path, suffix_len);
376}
377
378/* Adapted from libiberty's mkstemp.c. */
379
380#undef TMP_MAX
381#define TMP_MAX 16384
382
383int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
384{
385 static const char letters[] =
386 "abcdefghijklmnopqrstuvwxyz"
387 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
388 "0123456789";
389 static const int num_letters = 62;
390 uint64_t value;
391 struct timeval tv;
392 char *template;
393 size_t len;
394 int fd, count;
395
396 len = strlen(pattern);
397
398 if (len < 6 + suffix_len) {
399 errno = EINVAL;
400 return -1;
401 }
402
403 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
404 errno = EINVAL;
405 return -1;
406 }
407
408 /*
409 * Replace pattern's XXXXXX characters with randomness.
410 * Try TMP_MAX different filenames.
411 */
412 gettimeofday(&tv, NULL);
413 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
414 template = &pattern[len - 6 - suffix_len];
415 for (count = 0; count < TMP_MAX; ++count) {
416 uint64_t v = value;
417 /* Fill in the random bits. */
418 template[0] = letters[v % num_letters]; v /= num_letters;
419 template[1] = letters[v % num_letters]; v /= num_letters;
420 template[2] = letters[v % num_letters]; v /= num_letters;
421 template[3] = letters[v % num_letters]; v /= num_letters;
422 template[4] = letters[v % num_letters]; v /= num_letters;
423 template[5] = letters[v % num_letters]; v /= num_letters;
424
425 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
a2cb86c1 426 if (fd >= 0)
33f23936
JN
427 return fd;
428 /*
429 * Fatal error (EPERM, ENOSPC etc).
430 * It doesn't make sense to loop.
431 */
432 if (errno != EEXIST)
433 break;
434 /*
435 * This is a random value. It is only necessary that
436 * the next TMP_MAX values generated by adding 7777 to
437 * VALUE are different with (module 2^32).
438 */
439 value += 7777;
440 }
441 /* We return the null string if we can't find a unique file name. */
442 pattern[0] = '\0';
443 return -1;
444}
445
446int git_mkstemp_mode(char *pattern, int mode)
447{
448 /* mkstemp is just mkstemps with no suffix */
449 return git_mkstemps_mode(pattern, 0, mode);
450}
451
ec145c9c 452#ifdef NO_MKSTEMPS
33f23936
JN
453int gitmkstemps(char *pattern, int suffix_len)
454{
455 return git_mkstemps_mode(pattern, suffix_len, 0600);
456}
ec145c9c 457#endif
33f23936 458
b862b61c
MM
459int xmkstemp_mode(char *template, int mode)
460{
461 int fd;
6cf6bb3e
AE
462 char origtemplate[PATH_MAX];
463 strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c
MM
464
465 fd = git_mkstemp_mode(template, mode);
6cf6bb3e
AE
466 if (fd < 0) {
467 int saved_errno = errno;
468 const char *nonrelative_template;
469
470 if (!template[0])
471 template = origtemplate;
472
e2a57aac 473 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
474 errno = saved_errno;
475 die_errno("Unable to create temporary file '%s'",
476 nonrelative_template);
477 }
b862b61c
MM
478 return fd;
479}
480
10e13ec8 481static int warn_if_unremovable(const char *op, const char *file, int rc)
fc71db39 482{
1054af7d
RS
483 int err;
484 if (!rc || errno == ENOENT)
485 return 0;
486 err = errno;
487 warning("unable to %s %s: %s", op, file, strerror(errno));
488 errno = err;
fc71db39
AR
489 return rc;
490}
491
9ccc0c08
RS
492int unlink_or_msg(const char *file, struct strbuf *err)
493{
494 int rc = unlink(file);
495
496 assert(err);
497
498 if (!rc || errno == ENOENT)
499 return 0;
500
501 strbuf_addf(err, "unable to unlink %s: %s",
502 file, strerror(errno));
503 return -1;
504}
505
10e13ec8
PC
506int unlink_or_warn(const char *file)
507{
508 return warn_if_unremovable("unlink", file, unlink(file));
509}
d1723296
PC
510
511int rmdir_or_warn(const char *file)
512{
513 return warn_if_unremovable("rmdir", file, rmdir(file));
514}
80d706af
PC
515
516int remove_or_warn(unsigned int mode, const char *file)
517{
518 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
519}
2f705875 520
55b38a48
JH
521void warn_on_inaccessible(const char *path)
522{
523 warning(_("unable to access '%s': %s"), path, strerror(errno));
524}
525
4698c8fe
JN
526static int access_error_is_ok(int err, unsigned flag)
527{
528 return err == ENOENT || err == ENOTDIR ||
529 ((flag & ACCESS_EACCES_OK) && err == EACCES);
530}
531
532int access_or_warn(const char *path, int mode, unsigned flag)
ba8bd830
JK
533{
534 int ret = access(path, mode);
4698c8fe 535 if (ret && !access_error_is_ok(errno, flag))
55b38a48 536 warn_on_inaccessible(path);
ba8bd830
JK
537 return ret;
538}
539
4698c8fe 540int access_or_die(const char *path, int mode, unsigned flag)
96b9e0e3
JN
541{
542 int ret = access(path, mode);
4698c8fe 543 if (ret && !access_error_is_ok(errno, flag))
96b9e0e3
JN
544 die_errno(_("unable to access '%s'"), path);
545 return ret;
546}
547
2f705875
JK
548struct passwd *xgetpwuid_self(void)
549{
550 struct passwd *pw;
551
552 errno = 0;
553 pw = getpwuid(getuid());
554 if (!pw)
555 die(_("unable to look up current user in the passwd file: %s"),
556 errno ? strerror(errno) : _("no such user"));
557 return pw;
558}
aa14e980
RS
559
560char *xgetcwd(void)
561{
562 struct strbuf sb = STRBUF_INIT;
563 if (strbuf_getcwd(&sb))
564 die_errno(_("unable to get current working directory"));
565 return strbuf_detach(&sb, NULL);
566}
316e53e6
NTND
567
568int write_file(const char *path, int fatal, const char *fmt, ...)
569{
570 struct strbuf sb = STRBUF_INIT;
571 va_list params;
572 int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
573 if (fd < 0) {
574 if (fatal)
575 die_errno(_("could not open %s for writing"), path);
576 return -1;
577 }
578 va_start(params, fmt);
579 strbuf_vaddf(&sb, fmt, params);
580 va_end(params);
581 if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
582 int err = errno;
583 close(fd);
584 strbuf_release(&sb);
585 errno = err;
586 if (fatal)
587 die_errno(_("could not write to %s"), path);
588 return -1;
589 }
590 strbuf_release(&sb);
591 if (close(fd)) {
592 if (fatal)
593 die_errno(_("could not close %s"), path);
594 return -1;
595 }
596 return 0;
597}