abspath: convert real_path_internal() to strbuf
[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
d41489a6
NTND
12static void memory_limit_check(size_t size)
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 die("attempting to allocate %"PRIuMAX" over limit %d",
21 (intmax_t)size, limit);
22}
23
851c34b0 24try_to_free_t set_try_to_free_routine(try_to_free_t routine)
a9a74636 25{
851c34b0 26 try_to_free_t old = try_to_free_routine;
00b0d7f7
JH
27 if (!routine)
28 routine = do_nothing;
851c34b0
JS
29 try_to_free_routine = routine;
30 return old;
a9a74636
NP
31}
32
112db553
LT
33char *xstrdup(const char *str)
34{
35 char *ret = strdup(str);
36 if (!ret) {
a9a74636 37 try_to_free_routine(strlen(str) + 1);
112db553
LT
38 ret = strdup(str);
39 if (!ret)
40 die("Out of memory, strdup failed");
41 }
42 return ret;
43}
44
45void *xmalloc(size_t size)
46{
d41489a6
NTND
47 void *ret;
48
49 memory_limit_check(size);
50 ret = malloc(size);
112db553
LT
51 if (!ret && !size)
52 ret = malloc(1);
53 if (!ret) {
a9a74636 54 try_to_free_routine(size);
112db553
LT
55 ret = malloc(size);
56 if (!ret && !size)
57 ret = malloc(1);
58 if (!ret)
8bd9fd50
MM
59 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
60 (unsigned long)size);
112db553
LT
61 }
62#ifdef XMALLOC_POISON
63 memset(ret, 0xA5, size);
64#endif
65 return ret;
66}
67
5bf9219d
IL
68void *xmallocz(size_t size)
69{
70 void *ret;
1368f650 71 if (unsigned_add_overflows(size, 1))
5bf9219d
IL
72 die("Data too large to fit into virtual memory space.");
73 ret = xmalloc(size + 1);
74 ((char*)ret)[size] = 0;
75 return ret;
76}
77
112db553
LT
78/*
79 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
80 * "data" to the allocated memory, zero terminates the allocated memory,
81 * and returns a pointer to the allocated memory. If the allocation fails,
82 * the program dies.
83 */
84void *xmemdupz(const void *data, size_t len)
85{
5bf9219d 86 return memcpy(xmallocz(len), data, len);
112db553
LT
87}
88
89char *xstrndup(const char *str, size_t len)
90{
91 char *p = memchr(str, '\0', len);
92 return xmemdupz(str, p ? p - str : len);
93}
94
95void *xrealloc(void *ptr, size_t size)
96{
d41489a6
NTND
97 void *ret;
98
99 memory_limit_check(size);
100 ret = realloc(ptr, size);
112db553
LT
101 if (!ret && !size)
102 ret = realloc(ptr, 1);
103 if (!ret) {
a9a74636 104 try_to_free_routine(size);
112db553
LT
105 ret = realloc(ptr, size);
106 if (!ret && !size)
107 ret = realloc(ptr, 1);
108 if (!ret)
109 die("Out of memory, realloc failed");
110 }
111 return ret;
112}
113
114void *xcalloc(size_t nmemb, size_t size)
115{
d41489a6
NTND
116 void *ret;
117
118 memory_limit_check(size * nmemb);
119 ret = calloc(nmemb, size);
112db553
LT
120 if (!ret && (!nmemb || !size))
121 ret = calloc(1, 1);
122 if (!ret) {
a9a74636 123 try_to_free_routine(nmemb * size);
112db553
LT
124 ret = calloc(nmemb, size);
125 if (!ret && (!nmemb || !size))
126 ret = calloc(1, 1);
127 if (!ret)
128 die("Out of memory, calloc failed");
129 }
130 return ret;
131}
132
0b6806b9
SP
133/*
134 * Limit size of IO chunks, because huge chunks only cause pain. OS X
135 * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
382d20e3 136 * the absence of bugs, large chunks can result in bad latencies when
0b6806b9
SP
137 * you decide to kill the process.
138 */
139#define MAX_IO_SIZE (8*1024*1024)
140
112db553
LT
141/*
142 * xread() is the same a read(), but it automatically restarts read()
143 * operations with a recoverable error (EAGAIN and EINTR). xread()
144 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
145 */
146ssize_t xread(int fd, void *buf, size_t len)
147{
148 ssize_t nr;
0b6806b9
SP
149 if (len > MAX_IO_SIZE)
150 len = MAX_IO_SIZE;
112db553
LT
151 while (1) {
152 nr = read(fd, buf, len);
153 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
154 continue;
155 return nr;
156 }
157}
158
159/*
160 * xwrite() is the same a write(), but it automatically restarts write()
161 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
162 * GUARANTEE that "len" bytes is written even if the operation is successful.
163 */
164ssize_t xwrite(int fd, const void *buf, size_t len)
165{
166 ssize_t nr;
0b6806b9
SP
167 if (len > MAX_IO_SIZE)
168 len = MAX_IO_SIZE;
112db553
LT
169 while (1) {
170 nr = write(fd, buf, len);
171 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
9aa91af0
YM
172 continue;
173 return nr;
174 }
175}
176
177/*
178 * xpread() is the same as pread(), but it automatically restarts pread()
179 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
180 * NOT GUARANTEE that "len" bytes is read even if the data is available.
181 */
182ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
183{
184 ssize_t nr;
185 if (len > MAX_IO_SIZE)
186 len = MAX_IO_SIZE;
187 while (1) {
188 nr = pread(fd, buf, len, offset);
189 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
112db553
LT
190 continue;
191 return nr;
192 }
193}
194
559e840b
JH
195ssize_t read_in_full(int fd, void *buf, size_t count)
196{
197 char *p = buf;
198 ssize_t total = 0;
199
200 while (count > 0) {
201 ssize_t loaded = xread(fd, p, count);
56d7c27a
JK
202 if (loaded < 0)
203 return -1;
204 if (loaded == 0)
205 return total;
559e840b
JH
206 count -= loaded;
207 p += loaded;
208 total += loaded;
209 }
210
211 return total;
212}
213
214ssize_t write_in_full(int fd, const void *buf, size_t count)
215{
216 const char *p = buf;
217 ssize_t total = 0;
218
219 while (count > 0) {
220 ssize_t written = xwrite(fd, p, count);
221 if (written < 0)
222 return -1;
223 if (!written) {
224 errno = ENOSPC;
225 return -1;
226 }
227 count -= written;
228 p += written;
229 total += written;
230 }
231
232 return total;
233}
234
426ddeea
YM
235ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
236{
237 char *p = buf;
238 ssize_t total = 0;
239
240 while (count > 0) {
241 ssize_t loaded = xpread(fd, p, count, offset);
242 if (loaded < 0)
243 return -1;
244 if (loaded == 0)
245 return total;
246 count -= loaded;
247 p += loaded;
248 total += loaded;
249 offset += loaded;
250 }
251
252 return total;
253}
254
112db553
LT
255int xdup(int fd)
256{
257 int ret = dup(fd);
258 if (ret < 0)
d824cbba 259 die_errno("dup failed");
112db553
LT
260 return ret;
261}
262
263FILE *xfdopen(int fd, const char *mode)
264{
265 FILE *stream = fdopen(fd, mode);
266 if (stream == NULL)
d824cbba 267 die_errno("Out of memory? fdopen failed");
112db553
LT
268 return stream;
269}
270
271int xmkstemp(char *template)
272{
273 int fd;
6cf6bb3e
AE
274 char origtemplate[PATH_MAX];
275 strlcpy(origtemplate, template, sizeof(origtemplate));
112db553
LT
276
277 fd = mkstemp(template);
6cf6bb3e
AE
278 if (fd < 0) {
279 int saved_errno = errno;
280 const char *nonrelative_template;
281
f7be59b4 282 if (strlen(template) != strlen(origtemplate))
6cf6bb3e
AE
283 template = origtemplate;
284
e2a57aac 285 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
286 errno = saved_errno;
287 die_errno("Unable to create temporary file '%s'",
288 nonrelative_template);
289 }
112db553
LT
290 return fd;
291}
39c68542 292
33f23936
JN
293/* git_mkstemp() - create tmp file honoring TMPDIR variable */
294int git_mkstemp(char *path, size_t len, const char *template)
295{
296 const char *tmp;
297 size_t n;
298
299 tmp = getenv("TMPDIR");
300 if (!tmp)
301 tmp = "/tmp";
302 n = snprintf(path, len, "%s/%s", tmp, template);
303 if (len <= n) {
304 errno = ENAMETOOLONG;
305 return -1;
306 }
307 return mkstemp(path);
308}
309
310/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
311int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
312{
313 const char *tmp;
314 size_t n;
315
316 tmp = getenv("TMPDIR");
317 if (!tmp)
318 tmp = "/tmp";
319 n = snprintf(path, len, "%s/%s", tmp, template);
320 if (len <= n) {
321 errno = ENAMETOOLONG;
322 return -1;
323 }
324 return mkstemps(path, suffix_len);
325}
326
327/* Adapted from libiberty's mkstemp.c. */
328
329#undef TMP_MAX
330#define TMP_MAX 16384
331
332int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
333{
334 static const char letters[] =
335 "abcdefghijklmnopqrstuvwxyz"
336 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
337 "0123456789";
338 static const int num_letters = 62;
339 uint64_t value;
340 struct timeval tv;
341 char *template;
342 size_t len;
343 int fd, count;
344
345 len = strlen(pattern);
346
347 if (len < 6 + suffix_len) {
348 errno = EINVAL;
349 return -1;
350 }
351
352 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
353 errno = EINVAL;
354 return -1;
355 }
356
357 /*
358 * Replace pattern's XXXXXX characters with randomness.
359 * Try TMP_MAX different filenames.
360 */
361 gettimeofday(&tv, NULL);
362 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
363 template = &pattern[len - 6 - suffix_len];
364 for (count = 0; count < TMP_MAX; ++count) {
365 uint64_t v = value;
366 /* Fill in the random bits. */
367 template[0] = letters[v % num_letters]; v /= num_letters;
368 template[1] = letters[v % num_letters]; v /= num_letters;
369 template[2] = letters[v % num_letters]; v /= num_letters;
370 template[3] = letters[v % num_letters]; v /= num_letters;
371 template[4] = letters[v % num_letters]; v /= num_letters;
372 template[5] = letters[v % num_letters]; v /= num_letters;
373
374 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
a2cb86c1 375 if (fd >= 0)
33f23936
JN
376 return fd;
377 /*
378 * Fatal error (EPERM, ENOSPC etc).
379 * It doesn't make sense to loop.
380 */
381 if (errno != EEXIST)
382 break;
383 /*
384 * This is a random value. It is only necessary that
385 * the next TMP_MAX values generated by adding 7777 to
386 * VALUE are different with (module 2^32).
387 */
388 value += 7777;
389 }
390 /* We return the null string if we can't find a unique file name. */
391 pattern[0] = '\0';
392 return -1;
393}
394
395int git_mkstemp_mode(char *pattern, int mode)
396{
397 /* mkstemp is just mkstemps with no suffix */
398 return git_mkstemps_mode(pattern, 0, mode);
399}
400
ec145c9c 401#ifdef NO_MKSTEMPS
33f23936
JN
402int gitmkstemps(char *pattern, int suffix_len)
403{
404 return git_mkstemps_mode(pattern, suffix_len, 0600);
405}
ec145c9c 406#endif
33f23936 407
b862b61c
MM
408int xmkstemp_mode(char *template, int mode)
409{
410 int fd;
6cf6bb3e
AE
411 char origtemplate[PATH_MAX];
412 strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c
MM
413
414 fd = git_mkstemp_mode(template, mode);
6cf6bb3e
AE
415 if (fd < 0) {
416 int saved_errno = errno;
417 const char *nonrelative_template;
418
419 if (!template[0])
420 template = origtemplate;
421
e2a57aac 422 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
423 errno = saved_errno;
424 die_errno("Unable to create temporary file '%s'",
425 nonrelative_template);
426 }
b862b61c
MM
427 return fd;
428}
429
10e13ec8 430static int warn_if_unremovable(const char *op, const char *file, int rc)
fc71db39 431{
fc71db39
AR
432 if (rc < 0) {
433 int err = errno;
434 if (ENOENT != err) {
10e13ec8
PC
435 warning("unable to %s %s: %s",
436 op, file, strerror(errno));
fc71db39
AR
437 errno = err;
438 }
439 }
440 return rc;
441}
442
10e13ec8
PC
443int unlink_or_warn(const char *file)
444{
445 return warn_if_unremovable("unlink", file, unlink(file));
446}
d1723296
PC
447
448int rmdir_or_warn(const char *file)
449{
450 return warn_if_unremovable("rmdir", file, rmdir(file));
451}
80d706af
PC
452
453int remove_or_warn(unsigned int mode, const char *file)
454{
455 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
456}
2f705875 457
55b38a48
JH
458void warn_on_inaccessible(const char *path)
459{
460 warning(_("unable to access '%s': %s"), path, strerror(errno));
461}
462
4698c8fe
JN
463static int access_error_is_ok(int err, unsigned flag)
464{
465 return err == ENOENT || err == ENOTDIR ||
466 ((flag & ACCESS_EACCES_OK) && err == EACCES);
467}
468
469int access_or_warn(const char *path, int mode, unsigned flag)
ba8bd830
JK
470{
471 int ret = access(path, mode);
4698c8fe 472 if (ret && !access_error_is_ok(errno, flag))
55b38a48 473 warn_on_inaccessible(path);
ba8bd830
JK
474 return ret;
475}
476
4698c8fe 477int access_or_die(const char *path, int mode, unsigned flag)
96b9e0e3
JN
478{
479 int ret = access(path, mode);
4698c8fe 480 if (ret && !access_error_is_ok(errno, flag))
96b9e0e3
JN
481 die_errno(_("unable to access '%s'"), path);
482 return ret;
483}
484
2f705875
JK
485struct passwd *xgetpwuid_self(void)
486{
487 struct passwd *pw;
488
489 errno = 0;
490 pw = getpwuid(getuid());
491 if (!pw)
492 die(_("unable to look up current user in the passwd file: %s"),
493 errno ? strerror(errno) : _("no such user"));
494 return pw;
495}