Merge branch 'maint'
[git/mjg.git] / wrapper.c
blob28290002b9f6434d716a39612f3afc9958c292af
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 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
14 try_to_free_t old = try_to_free_routine;
15 if (!routine)
16 routine = do_nothing;
17 try_to_free_routine = routine;
18 return old;
21 char *xstrdup(const char *str)
23 char *ret = strdup(str);
24 if (!ret) {
25 try_to_free_routine(strlen(str) + 1);
26 ret = strdup(str);
27 if (!ret)
28 die("Out of memory, strdup failed");
30 return ret;
33 void *xmalloc(size_t size)
35 void *ret = malloc(size);
36 if (!ret && !size)
37 ret = malloc(1);
38 if (!ret) {
39 try_to_free_routine(size);
40 ret = malloc(size);
41 if (!ret && !size)
42 ret = malloc(1);
43 if (!ret)
44 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
45 (unsigned long)size);
47 #ifdef XMALLOC_POISON
48 memset(ret, 0xA5, size);
49 #endif
50 return ret;
53 void *xmallocz(size_t size)
55 void *ret;
56 if (unsigned_add_overflows(size, 1))
57 die("Data too large to fit into virtual memory space.");
58 ret = xmalloc(size + 1);
59 ((char*)ret)[size] = 0;
60 return ret;
64 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
65 * "data" to the allocated memory, zero terminates the allocated memory,
66 * and returns a pointer to the allocated memory. If the allocation fails,
67 * the program dies.
69 void *xmemdupz(const void *data, size_t len)
71 return memcpy(xmallocz(len), data, len);
74 char *xstrndup(const char *str, size_t len)
76 char *p = memchr(str, '\0', len);
77 return xmemdupz(str, p ? p - str : len);
80 void *xrealloc(void *ptr, size_t size)
82 void *ret = realloc(ptr, size);
83 if (!ret && !size)
84 ret = realloc(ptr, 1);
85 if (!ret) {
86 try_to_free_routine(size);
87 ret = realloc(ptr, size);
88 if (!ret && !size)
89 ret = realloc(ptr, 1);
90 if (!ret)
91 die("Out of memory, realloc failed");
93 return ret;
96 void *xcalloc(size_t nmemb, size_t size)
98 void *ret = calloc(nmemb, size);
99 if (!ret && (!nmemb || !size))
100 ret = calloc(1, 1);
101 if (!ret) {
102 try_to_free_routine(nmemb * size);
103 ret = calloc(nmemb, size);
104 if (!ret && (!nmemb || !size))
105 ret = calloc(1, 1);
106 if (!ret)
107 die("Out of memory, calloc failed");
109 return ret;
113 * xread() is the same a read(), but it automatically restarts read()
114 * operations with a recoverable error (EAGAIN and EINTR). xread()
115 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
117 ssize_t xread(int fd, void *buf, size_t len)
119 ssize_t nr;
120 while (1) {
121 nr = read(fd, buf, len);
122 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
123 continue;
124 return nr;
129 * xwrite() is the same a write(), but it automatically restarts write()
130 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
131 * GUARANTEE that "len" bytes is written even if the operation is successful.
133 ssize_t xwrite(int fd, const void *buf, size_t len)
135 ssize_t nr;
136 while (1) {
137 nr = write(fd, buf, len);
138 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
139 continue;
140 return nr;
144 ssize_t read_in_full(int fd, void *buf, size_t count)
146 char *p = buf;
147 ssize_t total = 0;
149 while (count > 0) {
150 ssize_t loaded = xread(fd, p, count);
151 if (loaded <= 0)
152 return total ? total : loaded;
153 count -= loaded;
154 p += loaded;
155 total += loaded;
158 return total;
161 ssize_t write_in_full(int fd, const void *buf, size_t count)
163 const char *p = buf;
164 ssize_t total = 0;
166 while (count > 0) {
167 ssize_t written = xwrite(fd, p, count);
168 if (written < 0)
169 return -1;
170 if (!written) {
171 errno = ENOSPC;
172 return -1;
174 count -= written;
175 p += written;
176 total += written;
179 return total;
182 int xdup(int fd)
184 int ret = dup(fd);
185 if (ret < 0)
186 die_errno("dup failed");
187 return ret;
190 FILE *xfdopen(int fd, const char *mode)
192 FILE *stream = fdopen(fd, mode);
193 if (stream == NULL)
194 die_errno("Out of memory? fdopen failed");
195 return stream;
198 int xmkstemp(char *template)
200 int fd;
201 char origtemplate[PATH_MAX];
202 strlcpy(origtemplate, template, sizeof(origtemplate));
204 fd = mkstemp(template);
205 if (fd < 0) {
206 int saved_errno = errno;
207 const char *nonrelative_template;
209 if (!template[0])
210 template = origtemplate;
212 nonrelative_template = absolute_path(template);
213 errno = saved_errno;
214 die_errno("Unable to create temporary file '%s'",
215 nonrelative_template);
217 return fd;
220 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
221 int git_mkstemp(char *path, size_t len, const char *template)
223 const char *tmp;
224 size_t n;
226 tmp = getenv("TMPDIR");
227 if (!tmp)
228 tmp = "/tmp";
229 n = snprintf(path, len, "%s/%s", tmp, template);
230 if (len <= n) {
231 errno = ENAMETOOLONG;
232 return -1;
234 return mkstemp(path);
237 /* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
238 int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
240 const char *tmp;
241 size_t n;
243 tmp = getenv("TMPDIR");
244 if (!tmp)
245 tmp = "/tmp";
246 n = snprintf(path, len, "%s/%s", tmp, template);
247 if (len <= n) {
248 errno = ENAMETOOLONG;
249 return -1;
251 return mkstemps(path, suffix_len);
254 /* Adapted from libiberty's mkstemp.c. */
256 #undef TMP_MAX
257 #define TMP_MAX 16384
259 int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
261 static const char letters[] =
262 "abcdefghijklmnopqrstuvwxyz"
263 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
264 "0123456789";
265 static const int num_letters = 62;
266 uint64_t value;
267 struct timeval tv;
268 char *template;
269 size_t len;
270 int fd, count;
272 len = strlen(pattern);
274 if (len < 6 + suffix_len) {
275 errno = EINVAL;
276 return -1;
279 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
280 errno = EINVAL;
281 return -1;
285 * Replace pattern's XXXXXX characters with randomness.
286 * Try TMP_MAX different filenames.
288 gettimeofday(&tv, NULL);
289 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
290 template = &pattern[len - 6 - suffix_len];
291 for (count = 0; count < TMP_MAX; ++count) {
292 uint64_t v = value;
293 /* Fill in the random bits. */
294 template[0] = letters[v % num_letters]; v /= num_letters;
295 template[1] = letters[v % num_letters]; v /= num_letters;
296 template[2] = letters[v % num_letters]; v /= num_letters;
297 template[3] = letters[v % num_letters]; v /= num_letters;
298 template[4] = letters[v % num_letters]; v /= num_letters;
299 template[5] = letters[v % num_letters]; v /= num_letters;
301 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
302 if (fd > 0)
303 return fd;
305 * Fatal error (EPERM, ENOSPC etc).
306 * It doesn't make sense to loop.
308 if (errno != EEXIST)
309 break;
311 * This is a random value. It is only necessary that
312 * the next TMP_MAX values generated by adding 7777 to
313 * VALUE are different with (module 2^32).
315 value += 7777;
317 /* We return the null string if we can't find a unique file name. */
318 pattern[0] = '\0';
319 return -1;
322 int git_mkstemp_mode(char *pattern, int mode)
324 /* mkstemp is just mkstemps with no suffix */
325 return git_mkstemps_mode(pattern, 0, mode);
328 int gitmkstemps(char *pattern, int suffix_len)
330 return git_mkstemps_mode(pattern, suffix_len, 0600);
333 int xmkstemp_mode(char *template, int mode)
335 int fd;
336 char origtemplate[PATH_MAX];
337 strlcpy(origtemplate, template, sizeof(origtemplate));
339 fd = git_mkstemp_mode(template, mode);
340 if (fd < 0) {
341 int saved_errno = errno;
342 const char *nonrelative_template;
344 if (!template[0])
345 template = origtemplate;
347 nonrelative_template = absolute_path(template);
348 errno = saved_errno;
349 die_errno("Unable to create temporary file '%s'",
350 nonrelative_template);
352 return fd;
355 static int warn_if_unremovable(const char *op, const char *file, int rc)
357 if (rc < 0) {
358 int err = errno;
359 if (ENOENT != err) {
360 warning("unable to %s %s: %s",
361 op, file, strerror(errno));
362 errno = err;
365 return rc;
368 int unlink_or_warn(const char *file)
370 return warn_if_unremovable("unlink", file, unlink(file));
373 int rmdir_or_warn(const char *file)
375 return warn_if_unremovable("rmdir", file, rmdir(file));
378 int remove_or_warn(unsigned int mode, const char *file)
380 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);