Git 2.5
[git.git] / wrapper.c
blobff49807948f3c406fe73511cec4ef4e2b2df186a
1 /*
2 * Various trivial helper wrappers around standard functions
3 */
4 #include "cache.h"
6 static void do_nothing(size_t size)
7 {
8 }
10 static void (*try_to_free_routine)(size_t size) = do_nothing;
12 static int memory_limit_check(size_t size, int gentle)
13 {
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;
19 }
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);
28 }
29 return 0;
30 }
32 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
33 {
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;
39 }
41 char *xstrdup(const char *str)
42 {
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");
49 }
50 return ret;
51 }
53 static void *do_xmalloc(size_t size, int gentle)
54 {
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;
75 }
76 }
77 }
78 #ifdef XMALLOC_POISON
79 memset(ret, 0xA5, size);
80 #endif
81 return ret;
82 }
84 void *xmalloc(size_t size)
85 {
86 return do_xmalloc(size, 0);
87 }
89 static void *do_xmallocz(size_t size, int gentle)
90 {
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.");
98 }
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);
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 */
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 memory_limit_check(size * nmemb, 0);
156 ret = calloc(nmemb, size);
157 if (!ret && (!nmemb || !size))
158 ret = calloc(1, 1);
159 if (!ret) {
160 try_to_free_routine(nmemb * size);
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");
167 return ret;
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
173 * the absence of bugs, large chunks can result in bad latencies when
174 * you decide to kill the process.
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.
182 */
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
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 */
197 ssize_t xread(int fd, void *buf, size_t len)
199 ssize_t nr;
200 if (len > MAX_IO_SIZE)
201 len = MAX_IO_SIZE;
202 while (1) {
203 nr = read(fd, buf, len);
204 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
205 continue;
206 return nr;
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 */
215 ssize_t xwrite(int fd, const void *buf, size_t len)
217 ssize_t nr;
218 if (len > MAX_IO_SIZE)
219 len = MAX_IO_SIZE;
220 while (1) {
221 nr = write(fd, buf, len);
222 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
223 continue;
224 return nr;
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 */
233 ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
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))
241 continue;
242 return nr;
246 ssize_t read_in_full(int fd, void *buf, size_t count)
248 char *p = buf;
249 ssize_t total = 0;
251 while (count > 0) {
252 ssize_t loaded = xread(fd, p, count);
253 if (loaded < 0)
254 return -1;
255 if (loaded == 0)
256 return total;
257 count -= loaded;
258 p += loaded;
259 total += loaded;
262 return total;
265 ssize_t write_in_full(int fd, const void *buf, size_t count)
267 const char *p = buf;
268 ssize_t total = 0;
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;
278 count -= written;
279 p += written;
280 total += written;
283 return total;
286 ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
288 char *p = buf;
289 ssize_t total = 0;
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;
303 return total;
306 int xdup(int fd)
308 int ret = dup(fd);
309 if (ret < 0)
310 die_errno("dup failed");
311 return ret;
314 FILE *xfdopen(int fd, const char *mode)
316 FILE *stream = fdopen(fd, mode);
317 if (stream == NULL)
318 die_errno("Out of memory? fdopen failed");
319 return stream;
322 int xmkstemp(char *template)
324 int fd;
325 char origtemplate[PATH_MAX];
326 strlcpy(origtemplate, template, sizeof(origtemplate));
328 fd = mkstemp(template);
329 if (fd < 0) {
330 int saved_errno = errno;
331 const char *nonrelative_template;
333 if (strlen(template) != strlen(origtemplate))
334 template = origtemplate;
336 nonrelative_template = absolute_path(template);
337 errno = saved_errno;
338 die_errno("Unable to create temporary file '%s'",
339 nonrelative_template);
341 return fd;
344 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
345 int git_mkstemp(char *path, size_t len, const char *template)
347 const char *tmp;
348 size_t n;
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;
358 return mkstemp(path);
361 /* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
362 int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
364 const char *tmp;
365 size_t n;
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;
375 return mkstemps(path, suffix_len);
378 /* Adapted from libiberty's mkstemp.c. */
380 #undef TMP_MAX
381 #define TMP_MAX 16384
383 int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
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;
396 len = strlen(pattern);
398 if (len < 6 + suffix_len) {
399 errno = EINVAL;
400 return -1;
403 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
404 errno = EINVAL;
405 return -1;
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;
425 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
426 if (fd >= 0)
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;
441 /* We return the null string if we can't find a unique file name. */
442 pattern[0] = '\0';
443 return -1;
446 int git_mkstemp_mode(char *pattern, int mode)
448 /* mkstemp is just mkstemps with no suffix */
449 return git_mkstemps_mode(pattern, 0, mode);
452 #ifdef NO_MKSTEMPS
453 int gitmkstemps(char *pattern, int suffix_len)
455 return git_mkstemps_mode(pattern, suffix_len, 0600);
457 #endif
459 int xmkstemp_mode(char *template, int mode)
461 int fd;
462 char origtemplate[PATH_MAX];
463 strlcpy(origtemplate, template, sizeof(origtemplate));
465 fd = git_mkstemp_mode(template, mode);
466 if (fd < 0) {
467 int saved_errno = errno;
468 const char *nonrelative_template;
470 if (!template[0])
471 template = origtemplate;
473 nonrelative_template = absolute_path(template);
474 errno = saved_errno;
475 die_errno("Unable to create temporary file '%s'",
476 nonrelative_template);
478 return fd;
481 static int warn_if_unremovable(const char *op, const char *file, int rc)
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;
489 return rc;
492 int unlink_or_msg(const char *file, struct strbuf *err)
494 int rc = unlink(file);
496 assert(err);
498 if (!rc || errno == ENOENT)
499 return 0;
501 strbuf_addf(err, "unable to unlink %s: %s",
502 file, strerror(errno));
503 return -1;
506 int unlink_or_warn(const char *file)
508 return warn_if_unremovable("unlink", file, unlink(file));
511 int rmdir_or_warn(const char *file)
513 return warn_if_unremovable("rmdir", file, rmdir(file));
516 int remove_or_warn(unsigned int mode, const char *file)
518 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
521 void warn_on_inaccessible(const char *path)
523 warning(_("unable to access '%s': %s"), path, strerror(errno));
526 static int access_error_is_ok(int err, unsigned flag)
528 return err == ENOENT || err == ENOTDIR ||
529 ((flag & ACCESS_EACCES_OK) && err == EACCES);
532 int access_or_warn(const char *path, int mode, unsigned flag)
534 int ret = access(path, mode);
535 if (ret && !access_error_is_ok(errno, flag))
536 warn_on_inaccessible(path);
537 return ret;
540 int access_or_die(const char *path, int mode, unsigned flag)
542 int ret = access(path, mode);
543 if (ret && !access_error_is_ok(errno, flag))
544 die_errno(_("unable to access '%s'"), path);
545 return ret;
548 struct passwd *xgetpwuid_self(void)
550 struct passwd *pw;
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;
560 char *xgetcwd(void)
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);
568 int write_file(const char *path, int fatal, const char *fmt, ...)
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;
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;
590 strbuf_release(&sb);
591 if (close(fd)) {
592 if (fatal)
593 die_errno(_("could not close %s"), path);
594 return -1;
596 return 0;
599 void sleep_millisec(int millisec)
601 poll(NULL, 0, millisec);