git-svn: delay term initialization
[git.git] / wrapper.c
1 /*
2 * Various trivial helper wrappers around standard functions
3 */
4 #include "cache.h"
5
6 static void do_nothing(size_t size)
7 {
8 }
9
10 static void (*try_to_free_routine)(size_t size) = do_nothing;
11
12 static int memory_limit_check(size_t size, int gentle)
13 {
14 static int limit = -1;
15 if (limit == -1) {
16 const char *env = getenv("GIT_ALLOC_LIMIT");
17 limit = env ? atoi(env) * 1024 : 0;
18 }
19 if (limit && size > limit) {
20 if (gentle) {
21 error("attempting to allocate %"PRIuMAX" over limit %d",
22 (intmax_t)size, limit);
23 return -1;
24 } else
25 die("attempting to allocate %"PRIuMAX" over limit %d",
26 (intmax_t)size, limit);
27 }
28 return 0;
29 }
30
31 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
32 {
33 try_to_free_t old = try_to_free_routine;
34 if (!routine)
35 routine = do_nothing;
36 try_to_free_routine = routine;
37 return old;
38 }
39
40 char *xstrdup(const char *str)
41 {
42 char *ret = strdup(str);
43 if (!ret) {
44 try_to_free_routine(strlen(str) + 1);
45 ret = strdup(str);
46 if (!ret)
47 die("Out of memory, strdup failed");
48 }
49 return ret;
50 }
51
52 static void *do_xmalloc(size_t size, int gentle)
53 {
54 void *ret;
55
56 if (memory_limit_check(size, gentle))
57 return NULL;
58 ret = malloc(size);
59 if (!ret && !size)
60 ret = malloc(1);
61 if (!ret) {
62 try_to_free_routine(size);
63 ret = malloc(size);
64 if (!ret && !size)
65 ret = malloc(1);
66 if (!ret) {
67 if (!gentle)
68 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
69 (unsigned long)size);
70 else {
71 error("Out of memory, malloc failed (tried to allocate %lu bytes)",
72 (unsigned long)size);
73 return NULL;
74 }
75 }
76 }
77 #ifdef XMALLOC_POISON
78 memset(ret, 0xA5, size);
79 #endif
80 return ret;
81 }
82
83 void *xmalloc(size_t size)
84 {
85 return do_xmalloc(size, 0);
86 }
87
88 static void *do_xmallocz(size_t size, int gentle)
89 {
90 void *ret;
91 if (unsigned_add_overflows(size, 1)) {
92 if (gentle) {
93 error("Data too large to fit into virtual memory space.");
94 return NULL;
95 } else
96 die("Data too large to fit into virtual memory space.");
97 }
98 ret = do_xmalloc(size + 1, gentle);
99 if (ret)
100 ((char*)ret)[size] = 0;
101 return ret;
102 }
103
104 void *xmallocz(size_t size)
105 {
106 return do_xmallocz(size, 0);
107 }
108
109 void *xmallocz_gently(size_t size)
110 {
111 return do_xmallocz(size, 1);
112 }
113
114 /*
115 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
116 * "data" to the allocated memory, zero terminates the allocated memory,
117 * and returns a pointer to the allocated memory. If the allocation fails,
118 * the program dies.
119 */
120 void *xmemdupz(const void *data, size_t len)
121 {
122 return memcpy(xmallocz(len), data, len);
123 }
124
125 char *xstrndup(const char *str, size_t len)
126 {
127 char *p = memchr(str, '\0', len);
128 return xmemdupz(str, p ? p - str : len);
129 }
130
131 void *xrealloc(void *ptr, size_t size)
132 {
133 void *ret;
134
135 memory_limit_check(size, 0);
136 ret = realloc(ptr, size);
137 if (!ret && !size)
138 ret = realloc(ptr, 1);
139 if (!ret) {
140 try_to_free_routine(size);
141 ret = realloc(ptr, size);
142 if (!ret && !size)
143 ret = realloc(ptr, 1);
144 if (!ret)
145 die("Out of memory, realloc failed");
146 }
147 return ret;
148 }
149
150 void *xcalloc(size_t nmemb, size_t size)
151 {
152 void *ret;
153
154 memory_limit_check(size * nmemb, 0);
155 ret = calloc(nmemb, size);
156 if (!ret && (!nmemb || !size))
157 ret = calloc(1, 1);
158 if (!ret) {
159 try_to_free_routine(nmemb * size);
160 ret = calloc(nmemb, size);
161 if (!ret && (!nmemb || !size))
162 ret = calloc(1, 1);
163 if (!ret)
164 die("Out of memory, calloc failed");
165 }
166 return ret;
167 }
168
169 /*
170 * Limit size of IO chunks, because huge chunks only cause pain. OS X
171 * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
172 * the absence of bugs, large chunks can result in bad latencies when
173 * you decide to kill the process.
174 */
175 #define MAX_IO_SIZE (8*1024*1024)
176
177 /*
178 * xread() is the same a read(), but it automatically restarts read()
179 * operations with a recoverable error (EAGAIN and EINTR). xread()
180 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
181 */
182 ssize_t xread(int fd, void *buf, size_t len)
183 {
184 ssize_t nr;
185 if (len > MAX_IO_SIZE)
186 len = MAX_IO_SIZE;
187 while (1) {
188 nr = read(fd, buf, len);
189 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
190 continue;
191 return nr;
192 }
193 }
194
195 /*
196 * xwrite() is the same a write(), but it automatically restarts write()
197 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
198 * GUARANTEE that "len" bytes is written even if the operation is successful.
199 */
200 ssize_t xwrite(int fd, const void *buf, size_t len)
201 {
202 ssize_t nr;
203 if (len > MAX_IO_SIZE)
204 len = MAX_IO_SIZE;
205 while (1) {
206 nr = write(fd, buf, len);
207 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
208 continue;
209 return nr;
210 }
211 }
212
213 /*
214 * xpread() is the same as pread(), but it automatically restarts pread()
215 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
216 * NOT GUARANTEE that "len" bytes is read even if the data is available.
217 */
218 ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
219 {
220 ssize_t nr;
221 if (len > MAX_IO_SIZE)
222 len = MAX_IO_SIZE;
223 while (1) {
224 nr = pread(fd, buf, len, offset);
225 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
226 continue;
227 return nr;
228 }
229 }
230
231 ssize_t read_in_full(int fd, void *buf, size_t count)
232 {
233 char *p = buf;
234 ssize_t total = 0;
235
236 while (count > 0) {
237 ssize_t loaded = xread(fd, p, count);
238 if (loaded < 0)
239 return -1;
240 if (loaded == 0)
241 return total;
242 count -= loaded;
243 p += loaded;
244 total += loaded;
245 }
246
247 return total;
248 }
249
250 ssize_t write_in_full(int fd, const void *buf, size_t count)
251 {
252 const char *p = buf;
253 ssize_t total = 0;
254
255 while (count > 0) {
256 ssize_t written = xwrite(fd, p, count);
257 if (written < 0)
258 return -1;
259 if (!written) {
260 errno = ENOSPC;
261 return -1;
262 }
263 count -= written;
264 p += written;
265 total += written;
266 }
267
268 return total;
269 }
270
271 ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
272 {
273 char *p = buf;
274 ssize_t total = 0;
275
276 while (count > 0) {
277 ssize_t loaded = xpread(fd, p, count, offset);
278 if (loaded < 0)
279 return -1;
280 if (loaded == 0)
281 return total;
282 count -= loaded;
283 p += loaded;
284 total += loaded;
285 offset += loaded;
286 }
287
288 return total;
289 }
290
291 int xdup(int fd)
292 {
293 int ret = dup(fd);
294 if (ret < 0)
295 die_errno("dup failed");
296 return ret;
297 }
298
299 FILE *xfdopen(int fd, const char *mode)
300 {
301 FILE *stream = fdopen(fd, mode);
302 if (stream == NULL)
303 die_errno("Out of memory? fdopen failed");
304 return stream;
305 }
306
307 int xmkstemp(char *template)
308 {
309 int fd;
310 char origtemplate[PATH_MAX];
311 strlcpy(origtemplate, template, sizeof(origtemplate));
312
313 fd = mkstemp(template);
314 if (fd < 0) {
315 int saved_errno = errno;
316 const char *nonrelative_template;
317
318 if (strlen(template) != strlen(origtemplate))
319 template = origtemplate;
320
321 nonrelative_template = absolute_path(template);
322 errno = saved_errno;
323 die_errno("Unable to create temporary file '%s'",
324 nonrelative_template);
325 }
326 return fd;
327 }
328
329 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
330 int git_mkstemp(char *path, size_t len, const char *template)
331 {
332 const char *tmp;
333 size_t n;
334
335 tmp = getenv("TMPDIR");
336 if (!tmp)
337 tmp = "/tmp";
338 n = snprintf(path, len, "%s/%s", tmp, template);
339 if (len <= n) {
340 errno = ENAMETOOLONG;
341 return -1;
342 }
343 return mkstemp(path);
344 }
345
346 /* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
347 int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
348 {
349 const char *tmp;
350 size_t n;
351
352 tmp = getenv("TMPDIR");
353 if (!tmp)
354 tmp = "/tmp";
355 n = snprintf(path, len, "%s/%s", tmp, template);
356 if (len <= n) {
357 errno = ENAMETOOLONG;
358 return -1;
359 }
360 return mkstemps(path, suffix_len);
361 }
362
363 /* Adapted from libiberty's mkstemp.c. */
364
365 #undef TMP_MAX
366 #define TMP_MAX 16384
367
368 int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
369 {
370 static const char letters[] =
371 "abcdefghijklmnopqrstuvwxyz"
372 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
373 "0123456789";
374 static const int num_letters = 62;
375 uint64_t value;
376 struct timeval tv;
377 char *template;
378 size_t len;
379 int fd, count;
380
381 len = strlen(pattern);
382
383 if (len < 6 + suffix_len) {
384 errno = EINVAL;
385 return -1;
386 }
387
388 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
389 errno = EINVAL;
390 return -1;
391 }
392
393 /*
394 * Replace pattern's XXXXXX characters with randomness.
395 * Try TMP_MAX different filenames.
396 */
397 gettimeofday(&tv, NULL);
398 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
399 template = &pattern[len - 6 - suffix_len];
400 for (count = 0; count < TMP_MAX; ++count) {
401 uint64_t v = value;
402 /* Fill in the random bits. */
403 template[0] = letters[v % num_letters]; v /= num_letters;
404 template[1] = letters[v % num_letters]; v /= num_letters;
405 template[2] = letters[v % num_letters]; v /= num_letters;
406 template[3] = letters[v % num_letters]; v /= num_letters;
407 template[4] = letters[v % num_letters]; v /= num_letters;
408 template[5] = letters[v % num_letters]; v /= num_letters;
409
410 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
411 if (fd >= 0)
412 return fd;
413 /*
414 * Fatal error (EPERM, ENOSPC etc).
415 * It doesn't make sense to loop.
416 */
417 if (errno != EEXIST)
418 break;
419 /*
420 * This is a random value. It is only necessary that
421 * the next TMP_MAX values generated by adding 7777 to
422 * VALUE are different with (module 2^32).
423 */
424 value += 7777;
425 }
426 /* We return the null string if we can't find a unique file name. */
427 pattern[0] = '\0';
428 return -1;
429 }
430
431 int git_mkstemp_mode(char *pattern, int mode)
432 {
433 /* mkstemp is just mkstemps with no suffix */
434 return git_mkstemps_mode(pattern, 0, mode);
435 }
436
437 #ifdef NO_MKSTEMPS
438 int gitmkstemps(char *pattern, int suffix_len)
439 {
440 return git_mkstemps_mode(pattern, suffix_len, 0600);
441 }
442 #endif
443
444 int xmkstemp_mode(char *template, int mode)
445 {
446 int fd;
447 char origtemplate[PATH_MAX];
448 strlcpy(origtemplate, template, sizeof(origtemplate));
449
450 fd = git_mkstemp_mode(template, mode);
451 if (fd < 0) {
452 int saved_errno = errno;
453 const char *nonrelative_template;
454
455 if (!template[0])
456 template = origtemplate;
457
458 nonrelative_template = absolute_path(template);
459 errno = saved_errno;
460 die_errno("Unable to create temporary file '%s'",
461 nonrelative_template);
462 }
463 return fd;
464 }
465
466 static int warn_if_unremovable(const char *op, const char *file, int rc)
467 {
468 if (rc < 0) {
469 int err = errno;
470 if (ENOENT != err) {
471 warning("unable to %s %s: %s",
472 op, file, strerror(errno));
473 errno = err;
474 }
475 }
476 return rc;
477 }
478
479 int unlink_or_warn(const char *file)
480 {
481 return warn_if_unremovable("unlink", file, unlink(file));
482 }
483
484 int rmdir_or_warn(const char *file)
485 {
486 return warn_if_unremovable("rmdir", file, rmdir(file));
487 }
488
489 int remove_or_warn(unsigned int mode, const char *file)
490 {
491 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
492 }
493
494 void warn_on_inaccessible(const char *path)
495 {
496 warning(_("unable to access '%s': %s"), path, strerror(errno));
497 }
498
499 static int access_error_is_ok(int err, unsigned flag)
500 {
501 return err == ENOENT || err == ENOTDIR ||
502 ((flag & ACCESS_EACCES_OK) && err == EACCES);
503 }
504
505 int access_or_warn(const char *path, int mode, unsigned flag)
506 {
507 int ret = access(path, mode);
508 if (ret && !access_error_is_ok(errno, flag))
509 warn_on_inaccessible(path);
510 return ret;
511 }
512
513 int access_or_die(const char *path, int mode, unsigned flag)
514 {
515 int ret = access(path, mode);
516 if (ret && !access_error_is_ok(errno, flag))
517 die_errno(_("unable to access '%s'"), path);
518 return ret;
519 }
520
521 struct passwd *xgetpwuid_self(void)
522 {
523 struct passwd *pw;
524
525 errno = 0;
526 pw = getpwuid(getuid());
527 if (!pw)
528 die(_("unable to look up current user in the passwd file: %s"),
529 errno ? strerror(errno) : _("no such user"));
530 return pw;
531 }
532
533 char *xgetcwd(void)
534 {
535 struct strbuf sb = STRBUF_INIT;
536 if (strbuf_getcwd(&sb))
537 die_errno(_("unable to get current working directory"));
538 return strbuf_detach(&sb, NULL);
539 }