Git 2.7.4
[git/gitweb.git] / wrapper.c
blob32c6c609da0fbc3a40d17b34de61bffa7c43700c
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) && (errno == EAGAIN || errno == EINTR))
243 continue;
244 return nr;
249 * xwrite() is the same a write(), but it automatically restarts write()
250 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
251 * GUARANTEE that "len" bytes is written even if the operation is successful.
253 ssize_t xwrite(int fd, const void *buf, size_t len)
255 ssize_t nr;
256 if (len > MAX_IO_SIZE)
257 len = MAX_IO_SIZE;
258 while (1) {
259 nr = write(fd, buf, len);
260 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
261 continue;
262 return nr;
267 * xpread() is the same as pread(), but it automatically restarts pread()
268 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
269 * NOT GUARANTEE that "len" bytes is read even if the data is available.
271 ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
273 ssize_t nr;
274 if (len > MAX_IO_SIZE)
275 len = MAX_IO_SIZE;
276 while (1) {
277 nr = pread(fd, buf, len, offset);
278 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
279 continue;
280 return nr;
284 ssize_t read_in_full(int fd, void *buf, size_t count)
286 char *p = buf;
287 ssize_t total = 0;
289 while (count > 0) {
290 ssize_t loaded = xread(fd, p, count);
291 if (loaded < 0)
292 return -1;
293 if (loaded == 0)
294 return total;
295 count -= loaded;
296 p += loaded;
297 total += loaded;
300 return total;
303 ssize_t write_in_full(int fd, const void *buf, size_t count)
305 const char *p = buf;
306 ssize_t total = 0;
308 while (count > 0) {
309 ssize_t written = xwrite(fd, p, count);
310 if (written < 0)
311 return -1;
312 if (!written) {
313 errno = ENOSPC;
314 return -1;
316 count -= written;
317 p += written;
318 total += written;
321 return total;
324 ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
326 char *p = buf;
327 ssize_t total = 0;
329 while (count > 0) {
330 ssize_t loaded = xpread(fd, p, count, offset);
331 if (loaded < 0)
332 return -1;
333 if (loaded == 0)
334 return total;
335 count -= loaded;
336 p += loaded;
337 total += loaded;
338 offset += loaded;
341 return total;
344 int xdup(int fd)
346 int ret = dup(fd);
347 if (ret < 0)
348 die_errno("dup failed");
349 return ret;
353 * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
355 FILE *xfopen(const char *path, const char *mode)
357 for (;;) {
358 FILE *fp = fopen(path, mode);
359 if (fp)
360 return fp;
361 if (errno == EINTR)
362 continue;
364 if (*mode && mode[1] == '+')
365 die_errno(_("could not open '%s' for reading and writing"), path);
366 else if (*mode == 'w' || *mode == 'a')
367 die_errno(_("could not open '%s' for writing"), path);
368 else
369 die_errno(_("could not open '%s' for reading"), path);
373 FILE *xfdopen(int fd, const char *mode)
375 FILE *stream = fdopen(fd, mode);
376 if (stream == NULL)
377 die_errno("Out of memory? fdopen failed");
378 return stream;
381 FILE *fopen_for_writing(const char *path)
383 FILE *ret = fopen(path, "w");
385 if (!ret && errno == EPERM) {
386 if (!unlink(path))
387 ret = fopen(path, "w");
388 else
389 errno = EPERM;
391 return ret;
394 int xmkstemp(char *template)
396 int fd;
397 char origtemplate[PATH_MAX];
398 strlcpy(origtemplate, template, sizeof(origtemplate));
400 fd = mkstemp(template);
401 if (fd < 0) {
402 int saved_errno = errno;
403 const char *nonrelative_template;
405 if (strlen(template) != strlen(origtemplate))
406 template = origtemplate;
408 nonrelative_template = absolute_path(template);
409 errno = saved_errno;
410 die_errno("Unable to create temporary file '%s'",
411 nonrelative_template);
413 return fd;
416 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
417 int git_mkstemp(char *path, size_t len, const char *template)
419 const char *tmp;
420 size_t n;
422 tmp = getenv("TMPDIR");
423 if (!tmp)
424 tmp = "/tmp";
425 n = snprintf(path, len, "%s/%s", tmp, template);
426 if (len <= n) {
427 errno = ENAMETOOLONG;
428 return -1;
430 return mkstemp(path);
433 /* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
434 int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
436 const char *tmp;
437 size_t n;
439 tmp = getenv("TMPDIR");
440 if (!tmp)
441 tmp = "/tmp";
442 n = snprintf(path, len, "%s/%s", tmp, template);
443 if (len <= n) {
444 errno = ENAMETOOLONG;
445 return -1;
447 return mkstemps(path, suffix_len);
450 /* Adapted from libiberty's mkstemp.c. */
452 #undef TMP_MAX
453 #define TMP_MAX 16384
455 int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
457 static const char letters[] =
458 "abcdefghijklmnopqrstuvwxyz"
459 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
460 "0123456789";
461 static const int num_letters = 62;
462 uint64_t value;
463 struct timeval tv;
464 char *template;
465 size_t len;
466 int fd, count;
468 len = strlen(pattern);
470 if (len < 6 + suffix_len) {
471 errno = EINVAL;
472 return -1;
475 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
476 errno = EINVAL;
477 return -1;
481 * Replace pattern's XXXXXX characters with randomness.
482 * Try TMP_MAX different filenames.
484 gettimeofday(&tv, NULL);
485 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
486 template = &pattern[len - 6 - suffix_len];
487 for (count = 0; count < TMP_MAX; ++count) {
488 uint64_t v = value;
489 /* Fill in the random bits. */
490 template[0] = letters[v % num_letters]; v /= num_letters;
491 template[1] = letters[v % num_letters]; v /= num_letters;
492 template[2] = letters[v % num_letters]; v /= num_letters;
493 template[3] = letters[v % num_letters]; v /= num_letters;
494 template[4] = letters[v % num_letters]; v /= num_letters;
495 template[5] = letters[v % num_letters]; v /= num_letters;
497 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
498 if (fd >= 0)
499 return fd;
501 * Fatal error (EPERM, ENOSPC etc).
502 * It doesn't make sense to loop.
504 if (errno != EEXIST)
505 break;
507 * This is a random value. It is only necessary that
508 * the next TMP_MAX values generated by adding 7777 to
509 * VALUE are different with (module 2^32).
511 value += 7777;
513 /* We return the null string if we can't find a unique file name. */
514 pattern[0] = '\0';
515 return -1;
518 int git_mkstemp_mode(char *pattern, int mode)
520 /* mkstemp is just mkstemps with no suffix */
521 return git_mkstemps_mode(pattern, 0, mode);
524 #ifdef NO_MKSTEMPS
525 int gitmkstemps(char *pattern, int suffix_len)
527 return git_mkstemps_mode(pattern, suffix_len, 0600);
529 #endif
531 int xmkstemp_mode(char *template, int mode)
533 int fd;
534 char origtemplate[PATH_MAX];
535 strlcpy(origtemplate, template, sizeof(origtemplate));
537 fd = git_mkstemp_mode(template, mode);
538 if (fd < 0) {
539 int saved_errno = errno;
540 const char *nonrelative_template;
542 if (!template[0])
543 template = origtemplate;
545 nonrelative_template = absolute_path(template);
546 errno = saved_errno;
547 die_errno("Unable to create temporary file '%s'",
548 nonrelative_template);
550 return fd;
553 static int warn_if_unremovable(const char *op, const char *file, int rc)
555 int err;
556 if (!rc || errno == ENOENT)
557 return 0;
558 err = errno;
559 warning("unable to %s %s: %s", op, file, strerror(errno));
560 errno = err;
561 return rc;
564 int unlink_or_msg(const char *file, struct strbuf *err)
566 int rc = unlink(file);
568 assert(err);
570 if (!rc || errno == ENOENT)
571 return 0;
573 strbuf_addf(err, "unable to unlink %s: %s",
574 file, strerror(errno));
575 return -1;
578 int unlink_or_warn(const char *file)
580 return warn_if_unremovable("unlink", file, unlink(file));
583 int rmdir_or_warn(const char *file)
585 return warn_if_unremovable("rmdir", file, rmdir(file));
588 int remove_or_warn(unsigned int mode, const char *file)
590 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
593 void warn_on_inaccessible(const char *path)
595 warning(_("unable to access '%s': %s"), path, strerror(errno));
598 static int access_error_is_ok(int err, unsigned flag)
600 return err == ENOENT || err == ENOTDIR ||
601 ((flag & ACCESS_EACCES_OK) && err == EACCES);
604 int access_or_warn(const char *path, int mode, unsigned flag)
606 int ret = access(path, mode);
607 if (ret && !access_error_is_ok(errno, flag))
608 warn_on_inaccessible(path);
609 return ret;
612 int access_or_die(const char *path, int mode, unsigned flag)
614 int ret = access(path, mode);
615 if (ret && !access_error_is_ok(errno, flag))
616 die_errno(_("unable to access '%s'"), path);
617 return ret;
620 char *xgetcwd(void)
622 struct strbuf sb = STRBUF_INIT;
623 if (strbuf_getcwd(&sb))
624 die_errno(_("unable to get current working directory"));
625 return strbuf_detach(&sb, NULL);
628 int xsnprintf(char *dst, size_t max, const char *fmt, ...)
630 va_list ap;
631 int len;
633 va_start(ap, fmt);
634 len = vsnprintf(dst, max, fmt, ap);
635 va_end(ap);
637 if (len < 0)
638 die("BUG: your snprintf is broken");
639 if (len >= max)
640 die("BUG: attempt to snprintf into too-small buffer");
641 return len;
644 static int write_file_v(const char *path, int fatal,
645 const char *fmt, va_list params)
647 struct strbuf sb = STRBUF_INIT;
648 int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
649 if (fd < 0) {
650 if (fatal)
651 die_errno(_("could not open %s for writing"), path);
652 return -1;
654 strbuf_vaddf(&sb, fmt, params);
655 strbuf_complete_line(&sb);
656 if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
657 int err = errno;
658 close(fd);
659 strbuf_release(&sb);
660 errno = err;
661 if (fatal)
662 die_errno(_("could not write to %s"), path);
663 return -1;
665 strbuf_release(&sb);
666 if (close(fd)) {
667 if (fatal)
668 die_errno(_("could not close %s"), path);
669 return -1;
671 return 0;
674 int write_file(const char *path, const char *fmt, ...)
676 int status;
677 va_list params;
679 va_start(params, fmt);
680 status = write_file_v(path, 1, fmt, params);
681 va_end(params);
682 return status;
685 int write_file_gently(const char *path, const char *fmt, ...)
687 int status;
688 va_list params;
690 va_start(params, fmt);
691 status = write_file_v(path, 0, fmt, params);
692 va_end(params);
693 return status;
696 void sleep_millisec(int millisec)
698 poll(NULL, 0, millisec);