refs.c: spell NULL pointer as NULL
[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
136 * the absense of bugs, large chunks can result in bad latencies when
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))
172 continue;
173 return nr;
174 }
175}
176
559e840b
JH
177ssize_t read_in_full(int fd, void *buf, size_t count)
178{
179 char *p = buf;
180 ssize_t total = 0;
181
182 while (count > 0) {
183 ssize_t loaded = xread(fd, p, count);
56d7c27a
JK
184 if (loaded < 0)
185 return -1;
186 if (loaded == 0)
187 return total;
559e840b
JH
188 count -= loaded;
189 p += loaded;
190 total += loaded;
191 }
192
193 return total;
194}
195
196ssize_t write_in_full(int fd, const void *buf, size_t count)
197{
198 const char *p = buf;
199 ssize_t total = 0;
200
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;
208 }
209 count -= written;
210 p += written;
211 total += written;
212 }
213
214 return total;
215}
216
112db553
LT
217int xdup(int fd)
218{
219 int ret = dup(fd);
220 if (ret < 0)
d824cbba 221 die_errno("dup failed");
112db553
LT
222 return ret;
223}
224
225FILE *xfdopen(int fd, const char *mode)
226{
227 FILE *stream = fdopen(fd, mode);
228 if (stream == NULL)
d824cbba 229 die_errno("Out of memory? fdopen failed");
112db553
LT
230 return stream;
231}
232
233int xmkstemp(char *template)
234{
235 int fd;
6cf6bb3e
AE
236 char origtemplate[PATH_MAX];
237 strlcpy(origtemplate, template, sizeof(origtemplate));
112db553
LT
238
239 fd = mkstemp(template);
6cf6bb3e
AE
240 if (fd < 0) {
241 int saved_errno = errno;
242 const char *nonrelative_template;
243
f7be59b4 244 if (strlen(template) != strlen(origtemplate))
6cf6bb3e
AE
245 template = origtemplate;
246
e2a57aac 247 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
248 errno = saved_errno;
249 die_errno("Unable to create temporary file '%s'",
250 nonrelative_template);
251 }
112db553
LT
252 return fd;
253}
39c68542 254
33f23936
JN
255/* git_mkstemp() - create tmp file honoring TMPDIR variable */
256int git_mkstemp(char *path, size_t len, const char *template)
257{
258 const char *tmp;
259 size_t n;
260
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;
268 }
269 return mkstemp(path);
270}
271
272/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
273int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
274{
275 const char *tmp;
276 size_t n;
277
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;
285 }
286 return mkstemps(path, suffix_len);
287}
288
289/* Adapted from libiberty's mkstemp.c. */
290
291#undef TMP_MAX
292#define TMP_MAX 16384
293
294int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
295{
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;
306
307 len = strlen(pattern);
308
309 if (len < 6 + suffix_len) {
310 errno = EINVAL;
311 return -1;
312 }
313
314 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
315 errno = EINVAL;
316 return -1;
317 }
318
319 /*
320 * Replace pattern's XXXXXX characters with randomness.
321 * Try TMP_MAX different filenames.
322 */
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;
335
336 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
a2cb86c1 337 if (fd >= 0)
33f23936
JN
338 return fd;
339 /*
340 * Fatal error (EPERM, ENOSPC etc).
341 * It doesn't make sense to loop.
342 */
343 if (errno != EEXIST)
344 break;
345 /*
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).
349 */
350 value += 7777;
351 }
352 /* We return the null string if we can't find a unique file name. */
353 pattern[0] = '\0';
354 return -1;
355}
356
357int git_mkstemp_mode(char *pattern, int mode)
358{
359 /* mkstemp is just mkstemps with no suffix */
360 return git_mkstemps_mode(pattern, 0, mode);
361}
362
363int gitmkstemps(char *pattern, int suffix_len)
364{
365 return git_mkstemps_mode(pattern, suffix_len, 0600);
366}
367
b862b61c
MM
368int xmkstemp_mode(char *template, int mode)
369{
370 int fd;
6cf6bb3e
AE
371 char origtemplate[PATH_MAX];
372 strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c
MM
373
374 fd = git_mkstemp_mode(template, mode);
6cf6bb3e
AE
375 if (fd < 0) {
376 int saved_errno = errno;
377 const char *nonrelative_template;
378
379 if (!template[0])
380 template = origtemplate;
381
e2a57aac 382 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
383 errno = saved_errno;
384 die_errno("Unable to create temporary file '%s'",
385 nonrelative_template);
386 }
b862b61c
MM
387 return fd;
388}
389
10e13ec8 390static int warn_if_unremovable(const char *op, const char *file, int rc)
fc71db39 391{
fc71db39
AR
392 if (rc < 0) {
393 int err = errno;
394 if (ENOENT != err) {
10e13ec8
PC
395 warning("unable to %s %s: %s",
396 op, file, strerror(errno));
fc71db39
AR
397 errno = err;
398 }
399 }
400 return rc;
401}
402
10e13ec8
PC
403int unlink_or_warn(const char *file)
404{
405 return warn_if_unremovable("unlink", file, unlink(file));
406}
d1723296
PC
407
408int rmdir_or_warn(const char *file)
409{
410 return warn_if_unremovable("rmdir", file, rmdir(file));
411}
80d706af
PC
412
413int remove_or_warn(unsigned int mode, const char *file)
414{
415 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
416}
2f705875 417
55b38a48
JH
418void warn_on_inaccessible(const char *path)
419{
420 warning(_("unable to access '%s': %s"), path, strerror(errno));
421}
422
4698c8fe
JN
423static int access_error_is_ok(int err, unsigned flag)
424{
425 return err == ENOENT || err == ENOTDIR ||
426 ((flag & ACCESS_EACCES_OK) && err == EACCES);
427}
428
429int access_or_warn(const char *path, int mode, unsigned flag)
ba8bd830
JK
430{
431 int ret = access(path, mode);
4698c8fe 432 if (ret && !access_error_is_ok(errno, flag))
55b38a48 433 warn_on_inaccessible(path);
ba8bd830
JK
434 return ret;
435}
436
4698c8fe 437int access_or_die(const char *path, int mode, unsigned flag)
96b9e0e3
JN
438{
439 int ret = access(path, mode);
4698c8fe 440 if (ret && !access_error_is_ok(errno, flag))
96b9e0e3
JN
441 die_errno(_("unable to access '%s'"), path);
442 return ret;
443}
444
2f705875
JK
445struct passwd *xgetpwuid_self(void)
446{
447 struct passwd *pw;
448
449 errno = 0;
450 pw = getpwuid(getuid());
451 if (!pw)
452 die(_("unable to look up current user in the passwd file: %s"),
453 errno ? strerror(errno) : _("no such user"));
454 return pw;
455}