Merge branch 'mm/color-auto-default'
[git/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 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
24 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
25 {
26 try_to_free_t old = try_to_free_routine;
27 if (!routine)
28 routine = do_nothing;
29 try_to_free_routine = routine;
30 return old;
31 }
32
33 char *xstrdup(const char *str)
34 {
35 char *ret = strdup(str);
36 if (!ret) {
37 try_to_free_routine(strlen(str) + 1);
38 ret = strdup(str);
39 if (!ret)
40 die("Out of memory, strdup failed");
41 }
42 return ret;
43 }
44
45 void *xmalloc(size_t size)
46 {
47 void *ret;
48
49 memory_limit_check(size);
50 ret = malloc(size);
51 if (!ret && !size)
52 ret = malloc(1);
53 if (!ret) {
54 try_to_free_routine(size);
55 ret = malloc(size);
56 if (!ret && !size)
57 ret = malloc(1);
58 if (!ret)
59 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
60 (unsigned long)size);
61 }
62 #ifdef XMALLOC_POISON
63 memset(ret, 0xA5, size);
64 #endif
65 return ret;
66 }
67
68 void *xmallocz(size_t size)
69 {
70 void *ret;
71 if (unsigned_add_overflows(size, 1))
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
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 */
84 void *xmemdupz(const void *data, size_t len)
85 {
86 return memcpy(xmallocz(len), data, len);
87 }
88
89 char *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
95 void *xrealloc(void *ptr, size_t size)
96 {
97 void *ret;
98
99 memory_limit_check(size);
100 ret = realloc(ptr, size);
101 if (!ret && !size)
102 ret = realloc(ptr, 1);
103 if (!ret) {
104 try_to_free_routine(size);
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
114 void *xcalloc(size_t nmemb, size_t size)
115 {
116 void *ret;
117
118 memory_limit_check(size * nmemb);
119 ret = calloc(nmemb, size);
120 if (!ret && (!nmemb || !size))
121 ret = calloc(1, 1);
122 if (!ret) {
123 try_to_free_routine(nmemb * size);
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
133 /*
134 * xread() is the same a read(), but it automatically restarts read()
135 * operations with a recoverable error (EAGAIN and EINTR). xread()
136 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
137 */
138 ssize_t xread(int fd, void *buf, size_t len)
139 {
140 ssize_t nr;
141 while (1) {
142 nr = read(fd, buf, len);
143 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
144 continue;
145 return nr;
146 }
147 }
148
149 /*
150 * xwrite() is the same a write(), but it automatically restarts write()
151 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
152 * GUARANTEE that "len" bytes is written even if the operation is successful.
153 */
154 ssize_t xwrite(int fd, const void *buf, size_t len)
155 {
156 ssize_t nr;
157 while (1) {
158 nr = write(fd, buf, len);
159 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
160 continue;
161 return nr;
162 }
163 }
164
165 ssize_t read_in_full(int fd, void *buf, size_t count)
166 {
167 char *p = buf;
168 ssize_t total = 0;
169
170 while (count > 0) {
171 ssize_t loaded = xread(fd, p, count);
172 if (loaded < 0)
173 return -1;
174 if (loaded == 0)
175 return total;
176 count -= loaded;
177 p += loaded;
178 total += loaded;
179 }
180
181 return total;
182 }
183
184 ssize_t write_in_full(int fd, const void *buf, size_t count)
185 {
186 const char *p = buf;
187 ssize_t total = 0;
188
189 while (count > 0) {
190 ssize_t written = xwrite(fd, p, count);
191 if (written < 0)
192 return -1;
193 if (!written) {
194 errno = ENOSPC;
195 return -1;
196 }
197 count -= written;
198 p += written;
199 total += written;
200 }
201
202 return total;
203 }
204
205 int xdup(int fd)
206 {
207 int ret = dup(fd);
208 if (ret < 0)
209 die_errno("dup failed");
210 return ret;
211 }
212
213 FILE *xfdopen(int fd, const char *mode)
214 {
215 FILE *stream = fdopen(fd, mode);
216 if (stream == NULL)
217 die_errno("Out of memory? fdopen failed");
218 return stream;
219 }
220
221 int xmkstemp(char *template)
222 {
223 int fd;
224 char origtemplate[PATH_MAX];
225 strlcpy(origtemplate, template, sizeof(origtemplate));
226
227 fd = mkstemp(template);
228 if (fd < 0) {
229 int saved_errno = errno;
230 const char *nonrelative_template;
231
232 if (strlen(template) != strlen(origtemplate))
233 template = origtemplate;
234
235 nonrelative_template = absolute_path(template);
236 errno = saved_errno;
237 die_errno("Unable to create temporary file '%s'",
238 nonrelative_template);
239 }
240 return fd;
241 }
242
243 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
244 int git_mkstemp(char *path, size_t len, const char *template)
245 {
246 const char *tmp;
247 size_t n;
248
249 tmp = getenv("TMPDIR");
250 if (!tmp)
251 tmp = "/tmp";
252 n = snprintf(path, len, "%s/%s", tmp, template);
253 if (len <= n) {
254 errno = ENAMETOOLONG;
255 return -1;
256 }
257 return mkstemp(path);
258 }
259
260 /* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
261 int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
262 {
263 const char *tmp;
264 size_t n;
265
266 tmp = getenv("TMPDIR");
267 if (!tmp)
268 tmp = "/tmp";
269 n = snprintf(path, len, "%s/%s", tmp, template);
270 if (len <= n) {
271 errno = ENAMETOOLONG;
272 return -1;
273 }
274 return mkstemps(path, suffix_len);
275 }
276
277 /* Adapted from libiberty's mkstemp.c. */
278
279 #undef TMP_MAX
280 #define TMP_MAX 16384
281
282 int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
283 {
284 static const char letters[] =
285 "abcdefghijklmnopqrstuvwxyz"
286 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
287 "0123456789";
288 static const int num_letters = 62;
289 uint64_t value;
290 struct timeval tv;
291 char *template;
292 size_t len;
293 int fd, count;
294
295 len = strlen(pattern);
296
297 if (len < 6 + suffix_len) {
298 errno = EINVAL;
299 return -1;
300 }
301
302 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
303 errno = EINVAL;
304 return -1;
305 }
306
307 /*
308 * Replace pattern's XXXXXX characters with randomness.
309 * Try TMP_MAX different filenames.
310 */
311 gettimeofday(&tv, NULL);
312 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
313 template = &pattern[len - 6 - suffix_len];
314 for (count = 0; count < TMP_MAX; ++count) {
315 uint64_t v = value;
316 /* Fill in the random bits. */
317 template[0] = letters[v % num_letters]; v /= num_letters;
318 template[1] = letters[v % num_letters]; v /= num_letters;
319 template[2] = letters[v % num_letters]; v /= num_letters;
320 template[3] = letters[v % num_letters]; v /= num_letters;
321 template[4] = letters[v % num_letters]; v /= num_letters;
322 template[5] = letters[v % num_letters]; v /= num_letters;
323
324 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
325 if (fd > 0)
326 return fd;
327 /*
328 * Fatal error (EPERM, ENOSPC etc).
329 * It doesn't make sense to loop.
330 */
331 if (errno != EEXIST)
332 break;
333 /*
334 * This is a random value. It is only necessary that
335 * the next TMP_MAX values generated by adding 7777 to
336 * VALUE are different with (module 2^32).
337 */
338 value += 7777;
339 }
340 /* We return the null string if we can't find a unique file name. */
341 pattern[0] = '\0';
342 return -1;
343 }
344
345 int git_mkstemp_mode(char *pattern, int mode)
346 {
347 /* mkstemp is just mkstemps with no suffix */
348 return git_mkstemps_mode(pattern, 0, mode);
349 }
350
351 int gitmkstemps(char *pattern, int suffix_len)
352 {
353 return git_mkstemps_mode(pattern, suffix_len, 0600);
354 }
355
356 int xmkstemp_mode(char *template, int mode)
357 {
358 int fd;
359 char origtemplate[PATH_MAX];
360 strlcpy(origtemplate, template, sizeof(origtemplate));
361
362 fd = git_mkstemp_mode(template, mode);
363 if (fd < 0) {
364 int saved_errno = errno;
365 const char *nonrelative_template;
366
367 if (!template[0])
368 template = origtemplate;
369
370 nonrelative_template = absolute_path(template);
371 errno = saved_errno;
372 die_errno("Unable to create temporary file '%s'",
373 nonrelative_template);
374 }
375 return fd;
376 }
377
378 static int warn_if_unremovable(const char *op, const char *file, int rc)
379 {
380 if (rc < 0) {
381 int err = errno;
382 if (ENOENT != err) {
383 warning("unable to %s %s: %s",
384 op, file, strerror(errno));
385 errno = err;
386 }
387 }
388 return rc;
389 }
390
391 int unlink_or_warn(const char *file)
392 {
393 return warn_if_unremovable("unlink", file, unlink(file));
394 }
395
396 int rmdir_or_warn(const char *file)
397 {
398 return warn_if_unremovable("rmdir", file, rmdir(file));
399 }
400
401 int remove_or_warn(unsigned int mode, const char *file)
402 {
403 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
404 }
405
406 void warn_on_inaccessible(const char *path)
407 {
408 warning(_("unable to access '%s': %s"), path, strerror(errno));
409 }
410
411 static int access_error_is_ok(int err, unsigned flag)
412 {
413 return err == ENOENT || err == ENOTDIR ||
414 ((flag & ACCESS_EACCES_OK) && err == EACCES);
415 }
416
417 int access_or_warn(const char *path, int mode, unsigned flag)
418 {
419 int ret = access(path, mode);
420 if (ret && !access_error_is_ok(errno, flag))
421 warn_on_inaccessible(path);
422 return ret;
423 }
424
425 int access_or_die(const char *path, int mode, unsigned flag)
426 {
427 int ret = access(path, mode);
428 if (ret && !access_error_is_ok(errno, flag))
429 die_errno(_("unable to access '%s'"), path);
430 return ret;
431 }
432
433 struct passwd *xgetpwuid_self(void)
434 {
435 struct passwd *pw;
436
437 errno = 0;
438 pw = getpwuid(getuid());
439 if (!pw)
440 die(_("unable to look up current user in the passwd file: %s"),
441 errno ? strerror(errno) : _("no such user"));
442 return pw;
443 }