repack: introduce repack.writeBitmaps config option
[git.git] / wrapper.c
blob9a6aaafaf35bbd6d2a7a97589edfd9b0b12102c7
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 void memory_limit_check(size_t size)
14 static int limit = -1;
15 if (limit == -1) {
16 const char *env = getenv("GIT_ALLOC_LIMIT");
17 limit = env ? atoi(env) * 1024 : 0;
19 if (limit && size > limit)
20 die("attempting to allocate %"PRIuMAX" over limit %d",
21 (intmax_t)size, limit);
24 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
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;
33 char *xstrdup(const char *str)
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");
42 return ret;
45 void *xmalloc(size_t size)
47 void *ret;
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);
62 #ifdef XMALLOC_POISON
63 memset(ret, 0xA5, size);
64 #endif
65 return ret;
68 void *xmallocz(size_t size)
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;
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.
84 void *xmemdupz(const void *data, size_t len)
86 return memcpy(xmallocz(len), data, len);
89 char *xstrndup(const char *str, size_t len)
91 char *p = memchr(str, '\0', len);
92 return xmemdupz(str, p ? p - str : len);
95 void *xrealloc(void *ptr, size_t size)
97 void *ret;
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");
111 return ret;
114 void *xcalloc(size_t nmemb, size_t size)
116 void *ret;
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");
130 return ret;
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
136 * the absense of bugs, large chunks can result in bad latencies when
137 * you decide to kill the process.
139 #define MAX_IO_SIZE (8*1024*1024)
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.
146 ssize_t xread(int fd, void *buf, size_t len)
148 ssize_t nr;
149 if (len > MAX_IO_SIZE)
150 len = MAX_IO_SIZE;
151 while (1) {
152 nr = read(fd, buf, len);
153 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
154 continue;
155 return nr;
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.
164 ssize_t xwrite(int fd, const void *buf, size_t len)
166 ssize_t nr;
167 if (len > MAX_IO_SIZE)
168 len = MAX_IO_SIZE;
169 while (1) {
170 nr = write(fd, buf, len);
171 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
172 continue;
173 return nr;
177 ssize_t read_in_full(int fd, void *buf, size_t count)
179 char *p = buf;
180 ssize_t total = 0;
182 while (count > 0) {
183 ssize_t loaded = xread(fd, p, count);
184 if (loaded < 0)
185 return -1;
186 if (loaded == 0)
187 return total;
188 count -= loaded;
189 p += loaded;
190 total += loaded;
193 return total;
196 ssize_t write_in_full(int fd, const void *buf, size_t count)
198 const char *p = buf;
199 ssize_t total = 0;
201 while (count > 0) {
202 ssize_t written = xwrite(fd, p, count);
203 if (written < 0)
204 return -1;
205 if (!written) {
206 errno = ENOSPC;
207 return -1;
209 count -= written;
210 p += written;
211 total += written;
214 return total;
217 int xdup(int fd)
219 int ret = dup(fd);
220 if (ret < 0)
221 die_errno("dup failed");
222 return ret;
225 FILE *xfdopen(int fd, const char *mode)
227 FILE *stream = fdopen(fd, mode);
228 if (stream == NULL)
229 die_errno("Out of memory? fdopen failed");
230 return stream;
233 int xmkstemp(char *template)
235 int fd;
236 char origtemplate[PATH_MAX];
237 strlcpy(origtemplate, template, sizeof(origtemplate));
239 fd = mkstemp(template);
240 if (fd < 0) {
241 int saved_errno = errno;
242 const char *nonrelative_template;
244 if (strlen(template) != strlen(origtemplate))
245 template = origtemplate;
247 nonrelative_template = absolute_path(template);
248 errno = saved_errno;
249 die_errno("Unable to create temporary file '%s'",
250 nonrelative_template);
252 return fd;
255 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
256 int git_mkstemp(char *path, size_t len, const char *template)
258 const char *tmp;
259 size_t n;
261 tmp = getenv("TMPDIR");
262 if (!tmp)
263 tmp = "/tmp";
264 n = snprintf(path, len, "%s/%s", tmp, template);
265 if (len <= n) {
266 errno = ENAMETOOLONG;
267 return -1;
269 return mkstemp(path);
272 /* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
273 int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
275 const char *tmp;
276 size_t n;
278 tmp = getenv("TMPDIR");
279 if (!tmp)
280 tmp = "/tmp";
281 n = snprintf(path, len, "%s/%s", tmp, template);
282 if (len <= n) {
283 errno = ENAMETOOLONG;
284 return -1;
286 return mkstemps(path, suffix_len);
289 /* Adapted from libiberty's mkstemp.c. */
291 #undef TMP_MAX
292 #define TMP_MAX 16384
294 int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
296 static const char letters[] =
297 "abcdefghijklmnopqrstuvwxyz"
298 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
299 "0123456789";
300 static const int num_letters = 62;
301 uint64_t value;
302 struct timeval tv;
303 char *template;
304 size_t len;
305 int fd, count;
307 len = strlen(pattern);
309 if (len < 6 + suffix_len) {
310 errno = EINVAL;
311 return -1;
314 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
315 errno = EINVAL;
316 return -1;
320 * Replace pattern's XXXXXX characters with randomness.
321 * Try TMP_MAX different filenames.
323 gettimeofday(&tv, NULL);
324 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
325 template = &pattern[len - 6 - suffix_len];
326 for (count = 0; count < TMP_MAX; ++count) {
327 uint64_t v = value;
328 /* Fill in the random bits. */
329 template[0] = letters[v % num_letters]; v /= num_letters;
330 template[1] = letters[v % num_letters]; v /= num_letters;
331 template[2] = letters[v % num_letters]; v /= num_letters;
332 template[3] = letters[v % num_letters]; v /= num_letters;
333 template[4] = letters[v % num_letters]; v /= num_letters;
334 template[5] = letters[v % num_letters]; v /= num_letters;
336 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
337 if (fd >= 0)
338 return fd;
340 * Fatal error (EPERM, ENOSPC etc).
341 * It doesn't make sense to loop.
343 if (errno != EEXIST)
344 break;
346 * This is a random value. It is only necessary that
347 * the next TMP_MAX values generated by adding 7777 to
348 * VALUE are different with (module 2^32).
350 value += 7777;
352 /* We return the null string if we can't find a unique file name. */
353 pattern[0] = '\0';
354 return -1;
357 int git_mkstemp_mode(char *pattern, int mode)
359 /* mkstemp is just mkstemps with no suffix */
360 return git_mkstemps_mode(pattern, 0, mode);
363 #ifdef NO_MKSTEMPS
364 int gitmkstemps(char *pattern, int suffix_len)
366 return git_mkstemps_mode(pattern, suffix_len, 0600);
368 #endif
370 int xmkstemp_mode(char *template, int mode)
372 int fd;
373 char origtemplate[PATH_MAX];
374 strlcpy(origtemplate, template, sizeof(origtemplate));
376 fd = git_mkstemp_mode(template, mode);
377 if (fd < 0) {
378 int saved_errno = errno;
379 const char *nonrelative_template;
381 if (!template[0])
382 template = origtemplate;
384 nonrelative_template = absolute_path(template);
385 errno = saved_errno;
386 die_errno("Unable to create temporary file '%s'",
387 nonrelative_template);
389 return fd;
392 static int warn_if_unremovable(const char *op, const char *file, int rc)
394 if (rc < 0) {
395 int err = errno;
396 if (ENOENT != err) {
397 warning("unable to %s %s: %s",
398 op, file, strerror(errno));
399 errno = err;
402 return rc;
405 int unlink_or_warn(const char *file)
407 return warn_if_unremovable("unlink", file, unlink(file));
410 int rmdir_or_warn(const char *file)
412 return warn_if_unremovable("rmdir", file, rmdir(file));
415 int remove_or_warn(unsigned int mode, const char *file)
417 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
420 void warn_on_inaccessible(const char *path)
422 warning(_("unable to access '%s': %s"), path, strerror(errno));
425 static int access_error_is_ok(int err, unsigned flag)
427 return err == ENOENT || err == ENOTDIR ||
428 ((flag & ACCESS_EACCES_OK) && err == EACCES);
431 int access_or_warn(const char *path, int mode, unsigned flag)
433 int ret = access(path, mode);
434 if (ret && !access_error_is_ok(errno, flag))
435 warn_on_inaccessible(path);
436 return ret;
439 int access_or_die(const char *path, int mode, unsigned flag)
441 int ret = access(path, mode);
442 if (ret && !access_error_is_ok(errno, flag))
443 die_errno(_("unable to access '%s'"), path);
444 return ret;
447 struct passwd *xgetpwuid_self(void)
449 struct passwd *pw;
451 errno = 0;
452 pw = getpwuid(getuid());
453 if (!pw)
454 die(_("unable to look up current user in the passwd file: %s"),
455 errno ? strerror(errno) : _("no such user"));
456 return pw;