git-svn: skip mergeinfo handling with --no-follow-parent
[git.git] / wrapper.c
blob5dc4e15aa9bf73bb2ce0a7af1837e092e0cab585
1 /*
2 * Various trivial helper wrappers around standard functions
3 */
4 #include "cache.h"
6 static void do_nothing(size_t size)
10 static void (*try_to_free_routine)(size_t size) = do_nothing;
12 static int memory_limit_check(size_t size, int gentle)
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;
20 if (size > limit) {
21 if (gentle) {
22 error("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
23 (uintmax_t)size, (uintmax_t)limit);
24 return -1;
25 } else
26 die("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
27 (uintmax_t)size, (uintmax_t)limit);
29 return 0;
32 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
34 try_to_free_t old = try_to_free_routine;
35 if (!routine)
36 routine = do_nothing;
37 try_to_free_routine = routine;
38 return old;
41 char *xstrdup(const char *str)
43 char *ret = strdup(str);
44 if (!ret) {
45 try_to_free_routine(strlen(str) + 1);
46 ret = strdup(str);
47 if (!ret)
48 die("Out of memory, strdup failed");
50 return ret;
53 static void *do_xmalloc(size_t size, int gentle)
55 void *ret;
57 if (memory_limit_check(size, gentle))
58 return NULL;
59 ret = malloc(size);
60 if (!ret && !size)
61 ret = malloc(1);
62 if (!ret) {
63 try_to_free_routine(size);
64 ret = malloc(size);
65 if (!ret && !size)
66 ret = malloc(1);
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;
78 #ifdef XMALLOC_POISON
79 memset(ret, 0xA5, size);
80 #endif
81 return ret;
84 void *xmalloc(size_t size)
86 return do_xmalloc(size, 0);
89 static void *do_xmallocz(size_t size, int gentle)
91 void *ret;
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.");
99 ret = do_xmalloc(size + 1, gentle);
100 if (ret)
101 ((char*)ret)[size] = 0;
102 return ret;
105 void *xmallocz(size_t size)
107 return do_xmallocz(size, 0);
110 void *xmallocz_gently(size_t size)
112 return do_xmallocz(size, 1);
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.
121 void *xmemdupz(const void *data, size_t len)
123 return memcpy(xmallocz(len), data, len);
126 char *xstrndup(const char *str, size_t len)
128 char *p = memchr(str, '\0', len);
129 return xmemdupz(str, p ? p - str : len);
132 void *xrealloc(void *ptr, size_t size)
134 void *ret;
136 memory_limit_check(size, 0);
137 ret = realloc(ptr, size);
138 if (!ret && !size)
139 ret = realloc(ptr, 1);
140 if (!ret) {
141 try_to_free_routine(size);
142 ret = realloc(ptr, size);
143 if (!ret && !size)
144 ret = realloc(ptr, 1);
145 if (!ret)
146 die("Out of memory, realloc failed");
148 return ret;
151 void *xcalloc(size_t nmemb, size_t size)
153 void *ret;
155 if (unsigned_mult_overflows(nmemb, size))
156 die("data too large to fit into virtual memory space");
158 memory_limit_check(size * nmemb, 0);
159 ret = calloc(nmemb, size);
160 if (!ret && (!nmemb || !size))
161 ret = calloc(1, 1);
162 if (!ret) {
163 try_to_free_routine(nmemb * size);
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");
170 return ret;
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
176 * the absence of bugs, large chunks can result in bad latencies when
177 * you decide to kill the process.
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.
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
196 * xopen() is the same as open(), but it die()s if the open() fails.
198 int xopen(const char *path, int oflag, ...)
200 mode_t mode = 0;
201 va_list ap;
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.
209 va_start(ap, oflag);
210 if (oflag & O_CREAT)
211 mode = va_arg(ap, int);
212 va_end(ap);
214 for (;;) {
215 int fd = open(path, oflag, mode);
216 if (fd >= 0)
217 return fd;
218 if (errno == EINTR)
219 continue;
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);
231 * xread() is the same a read(), but it automatically restarts read()
232 * operations with a recoverable error (EAGAIN and EINTR). xread()
233 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
235 ssize_t xread(int fd, void *buf, size_t len)
237 ssize_t nr;
238 if (len > MAX_IO_SIZE)
239 len = MAX_IO_SIZE;
240 while (1) {
241 nr = read(fd, buf, len);
242 if (nr < 0) {
243 if (errno == EINTR)
244 continue;
245 if (errno == EAGAIN || errno == EWOULDBLOCK) {
246 struct pollfd pfd;
247 pfd.events = POLLIN;
248 pfd.fd = fd;
250 * it is OK if this poll() failed; we
251 * want to leave this infinite loop
252 * only when read() returns with
253 * success, or an expected failure,
254 * which would be checked by the next
255 * call to read(2).
257 poll(&pfd, 1, -1);
260 return nr;
265 * xwrite() is the same a write(), but it automatically restarts write()
266 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
267 * GUARANTEE that "len" bytes is written even if the operation is successful.
269 ssize_t xwrite(int fd, const void *buf, size_t len)
271 ssize_t nr;
272 if (len > MAX_IO_SIZE)
273 len = MAX_IO_SIZE;
274 while (1) {
275 nr = write(fd, buf, len);
276 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
277 continue;
278 return nr;
283 * xpread() is the same as pread(), but it automatically restarts pread()
284 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
285 * NOT GUARANTEE that "len" bytes is read even if the data is available.
287 ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
289 ssize_t nr;
290 if (len > MAX_IO_SIZE)
291 len = MAX_IO_SIZE;
292 while (1) {
293 nr = pread(fd, buf, len, offset);
294 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
295 continue;
296 return nr;
300 ssize_t read_in_full(int fd, void *buf, size_t count)
302 char *p = buf;
303 ssize_t total = 0;
305 while (count > 0) {
306 ssize_t loaded = xread(fd, p, count);
307 if (loaded < 0)
308 return -1;
309 if (loaded == 0)
310 return total;
311 count -= loaded;
312 p += loaded;
313 total += loaded;
316 return total;
319 ssize_t write_in_full(int fd, const void *buf, size_t count)
321 const char *p = buf;
322 ssize_t total = 0;
324 while (count > 0) {
325 ssize_t written = xwrite(fd, p, count);
326 if (written < 0)
327 return -1;
328 if (!written) {
329 errno = ENOSPC;
330 return -1;
332 count -= written;
333 p += written;
334 total += written;
337 return total;
340 ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
342 char *p = buf;
343 ssize_t total = 0;
345 while (count > 0) {
346 ssize_t loaded = xpread(fd, p, count, offset);
347 if (loaded < 0)
348 return -1;
349 if (loaded == 0)
350 return total;
351 count -= loaded;
352 p += loaded;
353 total += loaded;
354 offset += loaded;
357 return total;
360 int xdup(int fd)
362 int ret = dup(fd);
363 if (ret < 0)
364 die_errno("dup failed");
365 return ret;
369 * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
371 FILE *xfopen(const char *path, const char *mode)
373 for (;;) {
374 FILE *fp = fopen(path, mode);
375 if (fp)
376 return fp;
377 if (errno == EINTR)
378 continue;
380 if (*mode && mode[1] == '+')
381 die_errno(_("could not open '%s' for reading and writing"), path);
382 else if (*mode == 'w' || *mode == 'a')
383 die_errno(_("could not open '%s' for writing"), path);
384 else
385 die_errno(_("could not open '%s' for reading"), path);
389 FILE *xfdopen(int fd, const char *mode)
391 FILE *stream = fdopen(fd, mode);
392 if (stream == NULL)
393 die_errno("Out of memory? fdopen failed");
394 return stream;
397 FILE *fopen_for_writing(const char *path)
399 FILE *ret = fopen(path, "w");
401 if (!ret && errno == EPERM) {
402 if (!unlink(path))
403 ret = fopen(path, "w");
404 else
405 errno = EPERM;
407 return ret;
410 int xmkstemp(char *template)
412 int fd;
413 char origtemplate[PATH_MAX];
414 strlcpy(origtemplate, template, sizeof(origtemplate));
416 fd = mkstemp(template);
417 if (fd < 0) {
418 int saved_errno = errno;
419 const char *nonrelative_template;
421 if (strlen(template) != strlen(origtemplate))
422 template = origtemplate;
424 nonrelative_template = absolute_path(template);
425 errno = saved_errno;
426 die_errno("Unable to create temporary file '%s'",
427 nonrelative_template);
429 return fd;
432 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
433 int git_mkstemp(char *path, size_t len, const char *template)
435 const char *tmp;
436 size_t n;
438 tmp = getenv("TMPDIR");
439 if (!tmp)
440 tmp = "/tmp";
441 n = snprintf(path, len, "%s/%s", tmp, template);
442 if (len <= n) {
443 errno = ENAMETOOLONG;
444 return -1;
446 return mkstemp(path);
449 /* Adapted from libiberty's mkstemp.c. */
451 #undef TMP_MAX
452 #define TMP_MAX 16384
454 int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
456 static const char letters[] =
457 "abcdefghijklmnopqrstuvwxyz"
458 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
459 "0123456789";
460 static const int num_letters = 62;
461 uint64_t value;
462 struct timeval tv;
463 char *template;
464 size_t len;
465 int fd, count;
467 len = strlen(pattern);
469 if (len < 6 + suffix_len) {
470 errno = EINVAL;
471 return -1;
474 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
475 errno = EINVAL;
476 return -1;
480 * Replace pattern's XXXXXX characters with randomness.
481 * Try TMP_MAX different filenames.
483 gettimeofday(&tv, NULL);
484 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
485 template = &pattern[len - 6 - suffix_len];
486 for (count = 0; count < TMP_MAX; ++count) {
487 uint64_t v = value;
488 /* Fill in the random bits. */
489 template[0] = letters[v % num_letters]; v /= num_letters;
490 template[1] = letters[v % num_letters]; v /= num_letters;
491 template[2] = letters[v % num_letters]; v /= num_letters;
492 template[3] = letters[v % num_letters]; v /= num_letters;
493 template[4] = letters[v % num_letters]; v /= num_letters;
494 template[5] = letters[v % num_letters]; v /= num_letters;
496 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
497 if (fd >= 0)
498 return fd;
500 * Fatal error (EPERM, ENOSPC etc).
501 * It doesn't make sense to loop.
503 if (errno != EEXIST)
504 break;
506 * This is a random value. It is only necessary that
507 * the next TMP_MAX values generated by adding 7777 to
508 * VALUE are different with (module 2^32).
510 value += 7777;
512 /* We return the null string if we can't find a unique file name. */
513 pattern[0] = '\0';
514 return -1;
517 int git_mkstemp_mode(char *pattern, int mode)
519 /* mkstemp is just mkstemps with no suffix */
520 return git_mkstemps_mode(pattern, 0, mode);
523 #ifdef NO_MKSTEMPS
524 int gitmkstemps(char *pattern, int suffix_len)
526 return git_mkstemps_mode(pattern, suffix_len, 0600);
528 #endif
530 int xmkstemp_mode(char *template, int mode)
532 int fd;
533 char origtemplate[PATH_MAX];
534 strlcpy(origtemplate, template, sizeof(origtemplate));
536 fd = git_mkstemp_mode(template, mode);
537 if (fd < 0) {
538 int saved_errno = errno;
539 const char *nonrelative_template;
541 if (!template[0])
542 template = origtemplate;
544 nonrelative_template = absolute_path(template);
545 errno = saved_errno;
546 die_errno("Unable to create temporary file '%s'",
547 nonrelative_template);
549 return fd;
552 static int warn_if_unremovable(const char *op, const char *file, int rc)
554 int err;
555 if (!rc || errno == ENOENT)
556 return 0;
557 err = errno;
558 warning_errno("unable to %s %s", op, file);
559 errno = err;
560 return rc;
563 int unlink_or_msg(const char *file, struct strbuf *err)
565 int rc = unlink(file);
567 assert(err);
569 if (!rc || errno == ENOENT)
570 return 0;
572 strbuf_addf(err, "unable to unlink %s: %s",
573 file, strerror(errno));
574 return -1;
577 int unlink_or_warn(const char *file)
579 return warn_if_unremovable("unlink", file, unlink(file));
582 int rmdir_or_warn(const char *file)
584 return warn_if_unremovable("rmdir", file, rmdir(file));
587 int remove_or_warn(unsigned int mode, const char *file)
589 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
592 void warn_on_inaccessible(const char *path)
594 warning_errno(_("unable to access '%s'"), path);
597 static int access_error_is_ok(int err, unsigned flag)
599 return err == ENOENT || err == ENOTDIR ||
600 ((flag & ACCESS_EACCES_OK) && err == EACCES);
603 int access_or_warn(const char *path, int mode, unsigned flag)
605 int ret = access(path, mode);
606 if (ret && !access_error_is_ok(errno, flag))
607 warn_on_inaccessible(path);
608 return ret;
611 int access_or_die(const char *path, int mode, unsigned flag)
613 int ret = access(path, mode);
614 if (ret && !access_error_is_ok(errno, flag))
615 die_errno(_("unable to access '%s'"), path);
616 return ret;
619 char *xgetcwd(void)
621 struct strbuf sb = STRBUF_INIT;
622 if (strbuf_getcwd(&sb))
623 die_errno(_("unable to get current working directory"));
624 return strbuf_detach(&sb, NULL);
627 int xsnprintf(char *dst, size_t max, const char *fmt, ...)
629 va_list ap;
630 int len;
632 va_start(ap, fmt);
633 len = vsnprintf(dst, max, fmt, ap);
634 va_end(ap);
636 if (len < 0)
637 die("BUG: your snprintf is broken");
638 if (len >= max)
639 die("BUG: attempt to snprintf into too-small buffer");
640 return len;
643 static int write_file_v(const char *path, int fatal,
644 const char *fmt, va_list params)
646 struct strbuf sb = STRBUF_INIT;
647 int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
648 if (fd < 0) {
649 if (fatal)
650 die_errno(_("could not open %s for writing"), path);
651 return -1;
653 strbuf_vaddf(&sb, fmt, params);
654 strbuf_complete_line(&sb);
655 if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
656 int err = errno;
657 close(fd);
658 strbuf_release(&sb);
659 errno = err;
660 if (fatal)
661 die_errno(_("could not write to %s"), path);
662 return -1;
664 strbuf_release(&sb);
665 if (close(fd)) {
666 if (fatal)
667 die_errno(_("could not close %s"), path);
668 return -1;
670 return 0;
673 int write_file(const char *path, const char *fmt, ...)
675 int status;
676 va_list params;
678 va_start(params, fmt);
679 status = write_file_v(path, 1, fmt, params);
680 va_end(params);
681 return status;
684 int write_file_gently(const char *path, const char *fmt, ...)
686 int status;
687 va_list params;
689 va_start(params, fmt);
690 status = write_file_v(path, 0, fmt, params);
691 va_end(params);
692 return status;
695 void sleep_millisec(int millisec)
697 poll(NULL, 0, millisec);