[thirdparty/git.git] / wrapper.c

/*
 * Various trivial helper wrappers around standard functions
 */
#include "cache.h"

static void do_nothing(size_t size)
{
}

static void (*try_to_free_routine)(size_t size) = do_nothing;

try_to_free_t set_try_to_free_routine(try_to_free_t routine)
{
	try_to_free_t old = try_to_free_routine;
	if (!routine)
		routine = do_nothing;
	try_to_free_routine = routine;
	return old;
}

char *xstrdup(const char *str)
{
	char *ret = strdup(str);
	if (!ret) {
		try_to_free_routine(strlen(str) + 1);
		ret = strdup(str);
		if (!ret)
			die("Out of memory, strdup failed");
	}
	return ret;
}

void *xmalloc(size_t size)
{
	void *ret = malloc(size);
	if (!ret && !size)
		ret = malloc(1);
	if (!ret) {
		try_to_free_routine(size);
		ret = malloc(size);
		if (!ret && !size)
			ret = malloc(1);
		if (!ret)
			die("Out of memory, malloc failed (tried to allocate %lu bytes)",
			    (unsigned long)size);
	}
#ifdef XMALLOC_POISON
	memset(ret, 0xA5, size);
#endif
	return ret;
}

void *xmallocz(size_t size)
{
	void *ret;
	if (unsigned_add_overflows(size, 1))
		die("Data too large to fit into virtual memory space.");
	ret = xmalloc(size + 1);
	((char*)ret)[size] = 0;
	return ret;
}

/*
 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
 * "data" to the allocated memory, zero terminates the allocated memory,
 * and returns a pointer to the allocated memory. If the allocation fails,
 * the program dies.
 */
void *xmemdupz(const void *data, size_t len)
{
	return memcpy(xmallocz(len), data, len);
}

char *xstrndup(const char *str, size_t len)
{
	char *p = memchr(str, '\0', len);
	return xmemdupz(str, p ? p - str : len);
}

void *xrealloc(void *ptr, size_t size)
{
	void *ret = realloc(ptr, size);
	if (!ret && !size)
		ret = realloc(ptr, 1);
	if (!ret) {
		try_to_free_routine(size);
		ret = realloc(ptr, size);
		if (!ret && !size)
			ret = realloc(ptr, 1);
		if (!ret)
			die("Out of memory, realloc failed");
	}
	return ret;
}

void *xcalloc(size_t nmemb, size_t size)
{
	void *ret = calloc(nmemb, size);
	if (!ret && (!nmemb || !size))
		ret = calloc(1, 1);
	if (!ret) {
		try_to_free_routine(nmemb * size);
		ret = calloc(nmemb, size);
		if (!ret && (!nmemb || !size))
			ret = calloc(1, 1);
		if (!ret)
			die("Out of memory, calloc failed");
	}
	return ret;
}

/*
 * xread() is the same a read(), but it automatically restarts read()
 * operations with a recoverable error (EAGAIN and EINTR). xread()
 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
 */
ssize_t xread(int fd, void *buf, size_t len)
{
	ssize_t nr;
	while (1) {
		nr = read(fd, buf, len);
		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
			continue;
		return nr;
	}
}

/*
 * xwrite() is the same a write(), but it automatically restarts write()
 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
 * GUARANTEE that "len" bytes is written even if the operation is successful.
 */
ssize_t xwrite(int fd, const void *buf, size_t len)
{
	ssize_t nr;
	while (1) {
		nr = write(fd, buf, len);
		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
			continue;
		return nr;
	}
}

ssize_t read_in_full(int fd, void *buf, size_t count)
{
	char *p = buf;
	ssize_t total = 0;

	while (count > 0) {
		ssize_t loaded = xread(fd, p, count);
		if (loaded <= 0)
			return total ? total : loaded;
		count -= loaded;
		p += loaded;
		total += loaded;
	}

	return total;
}

ssize_t write_in_full(int fd, const void *buf, size_t count)
{
	const char *p = buf;
	ssize_t total = 0;

	while (count > 0) {
		ssize_t written = xwrite(fd, p, count);
		if (written < 0)
			return -1;
		if (!written) {
			errno = ENOSPC;
			return -1;
		}
		count -= written;
		p += written;
		total += written;
	}

	return total;
}

int xdup(int fd)
{
	int ret = dup(fd);
	if (ret < 0)
		die_errno("dup failed");
	return ret;
}

FILE *xfdopen(int fd, const char *mode)
{
	FILE *stream = fdopen(fd, mode);
	if (stream == NULL)
		die_errno("Out of memory? fdopen failed");
	return stream;
}

int xmkstemp(char *template)
{
	int fd;
	char origtemplate[PATH_MAX];
	strlcpy(origtemplate, template, sizeof(origtemplate));

	fd = mkstemp(template);
	if (fd < 0) {
		int saved_errno = errno;
		const char *nonrelative_template;

		if (!template[0])
			template = origtemplate;

		nonrelative_template = absolute_path(template);
		errno = saved_errno;
		die_errno("Unable to create temporary file '%s'",
			nonrelative_template);
	}
	return fd;
}

/* git_mkstemp() - create tmp file honoring TMPDIR variable */
int git_mkstemp(char *path, size_t len, const char *template)
{
	const char *tmp;
	size_t n;

	tmp = getenv("TMPDIR");
	if (!tmp)
		tmp = "/tmp";
	n = snprintf(path, len, "%s/%s", tmp, template);
	if (len <= n) {
		errno = ENAMETOOLONG;
		return -1;
	}
	return mkstemp(path);
}

/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
{
	const char *tmp;
	size_t n;

	tmp = getenv("TMPDIR");
	if (!tmp)
		tmp = "/tmp";
	n = snprintf(path, len, "%s/%s", tmp, template);
	if (len <= n) {
		errno = ENAMETOOLONG;
		return -1;
	}
	return mkstemps(path, suffix_len);
}

/* Adapted from libiberty's mkstemp.c. */

#undef TMP_MAX
#define TMP_MAX 16384

int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
{
	static const char letters[] =
		"abcdefghijklmnopqrstuvwxyz"
		"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
		"0123456789";
	static const int num_letters = 62;
	uint64_t value;
	struct timeval tv;
	char *template;
	size_t len;
	int fd, count;

	len = strlen(pattern);

	if (len < 6 + suffix_len) {
		errno = EINVAL;
		return -1;
	}

	if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
		errno = EINVAL;
		return -1;
	}

	/*
	 * Replace pattern's XXXXXX characters with randomness.
	 * Try TMP_MAX different filenames.
	 */
	gettimeofday(&tv, NULL);
	value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
	template = &pattern[len - 6 - suffix_len];
	for (count = 0; count < TMP_MAX; ++count) {
		uint64_t v = value;
		/* Fill in the random bits. */
		template[0] = letters[v % num_letters]; v /= num_letters;
		template[1] = letters[v % num_letters]; v /= num_letters;
		template[2] = letters[v % num_letters]; v /= num_letters;
		template[3] = letters[v % num_letters]; v /= num_letters;
		template[4] = letters[v % num_letters]; v /= num_letters;
		template[5] = letters[v % num_letters]; v /= num_letters;

		fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
		if (fd > 0)
			return fd;
		/*
		 * Fatal error (EPERM, ENOSPC etc).
		 * It doesn't make sense to loop.
		 */
		if (errno != EEXIST)
			break;
		/*
		 * This is a random value.  It is only necessary that
		 * the next TMP_MAX values generated by adding 7777 to
		 * VALUE are different with (module 2^32).
		 */
		value += 7777;
	}
	/* We return the null string if we can't find a unique file name.  */
	pattern[0] = '\0';
	return -1;
}

int git_mkstemp_mode(char *pattern, int mode)
{
	/* mkstemp is just mkstemps with no suffix */
	return git_mkstemps_mode(pattern, 0, mode);
}

int gitmkstemps(char *pattern, int suffix_len)
{
	return git_mkstemps_mode(pattern, suffix_len, 0600);
}

int xmkstemp_mode(char *template, int mode)
{
	int fd;
	char origtemplate[PATH_MAX];
	strlcpy(origtemplate, template, sizeof(origtemplate));

	fd = git_mkstemp_mode(template, mode);
	if (fd < 0) {
		int saved_errno = errno;
		const char *nonrelative_template;

		if (!template[0])
			template = origtemplate;

		nonrelative_template = absolute_path(template);
		errno = saved_errno;
		die_errno("Unable to create temporary file '%s'",
			nonrelative_template);
	}
	return fd;
}

static int warn_if_unremovable(const char *op, const char *file, int rc)
{
	if (rc < 0) {
		int err = errno;
		if (ENOENT != err) {
			warning("unable to %s %s: %s",
				op, file, strerror(errno));
			errno = err;
		}
	}
	return rc;
}

int unlink_or_warn(const char *file)
{
	return warn_if_unremovable("unlink", file, unlink(file));
}

int rmdir_or_warn(const char *file)
{
	return warn_if_unremovable("rmdir", file, rmdir(file));
}

int remove_or_warn(unsigned int mode, const char *file)
{
	return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
}
Commit	Line	Data
112db553 LT	1	/*
	2	* Various trivial helper wrappers around standard functions
	3	*/
	4	#include "cache.h"
	5
e0500293	6	static void do_nothing(size_t size)
a9a74636	7	{
a9a74636 NP	8	}
a9a74636 NP	9
e0500293	10	static void (*try_to_free_routine)(size_t size) = do_nothing;
a9a74636	11
851c34b0	12	try_to_free_t set_try_to_free_routine(try_to_free_t routine)
a9a74636	13	{
851c34b0	14	try_to_free_t old = try_to_free_routine;
00b0d7f7 JH	15	if (!routine)
00b0d7f7 JH	16	routine = do_nothing;
851c34b0 JS	17	try_to_free_routine = routine;
851c34b0 JS	18	return old;
a9a74636 NP	19	}
a9a74636 NP	20
112db553 LT	21	char xstrdup(const char str)
	22	{
	23	char *ret = strdup(str);
	24	if (!ret) {
a9a74636	25	try_to_free_routine(strlen(str) + 1);
112db553 LT	26	ret = strdup(str);
	27	if (!ret)
	28	die("Out of memory, strdup failed");
	29	}
	30	return ret;
	31	}
	32
	33	void *xmalloc(size_t size)
	34	{
	35	void *ret = malloc(size);
	36	if (!ret && !size)
	37	ret = malloc(1);
	38	if (!ret) {
a9a74636	39	try_to_free_routine(size);
112db553 LT	40	ret = malloc(size);
	41	if (!ret && !size)
	42	ret = malloc(1);
	43	if (!ret)
8bd9fd50 MM	44	die("Out of memory, malloc failed (tried to allocate %lu bytes)",
8bd9fd50 MM	45	(unsigned long)size);
112db553 LT	46	}
	47	#ifdef XMALLOC_POISON
	48	memset(ret, 0xA5, size);
	49	#endif
	50	return ret;
	51	}
	52
5bf9219d IL	53	void *xmallocz(size_t size)
	54	{
	55	void *ret;
1368f650	56	if (unsigned_add_overflows(size, 1))
5bf9219d IL	57	die("Data too large to fit into virtual memory space.");
	58	ret = xmalloc(size + 1);
	59	((char*)ret)[size] = 0;
	60	return ret;
	61	}
	62
112db553 LT	63	/*
	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.
	68	*/
	69	void xmemdupz(const void data, size_t len)
	70	{
5bf9219d	71	return memcpy(xmallocz(len), data, len);
112db553 LT	72	}
	73
	74	char xstrndup(const char str, size_t len)
	75	{
	76	char *p = memchr(str, '\0', len);
	77	return xmemdupz(str, p ? p - str : len);
	78	}
	79
	80	void xrealloc(void ptr, size_t size)
	81	{
	82	void *ret = realloc(ptr, size);
	83	if (!ret && !size)
	84	ret = realloc(ptr, 1);
	85	if (!ret) {
a9a74636	86	try_to_free_routine(size);
112db553 LT	87	ret = realloc(ptr, size);
	88	if (!ret && !size)
	89	ret = realloc(ptr, 1);
	90	if (!ret)
	91	die("Out of memory, realloc failed");
	92	}
	93	return ret;
	94	}
	95
	96	void *xcalloc(size_t nmemb, size_t size)
	97	{
	98	void *ret = calloc(nmemb, size);
	99	if (!ret && (!nmemb \|\| !size))
	100	ret = calloc(1, 1);
	101	if (!ret) {
a9a74636	102	try_to_free_routine(nmemb * size);
112db553 LT	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");
	108	}
	109	return ret;
	110	}
	111
112db553 LT	112	/*
	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.
	116	*/
	117	ssize_t xread(int fd, void *buf, size_t len)
	118	{
	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;
	125	}
	126	}
	127
	128	/*
	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.
	132	*/
	133	ssize_t xwrite(int fd, const void *buf, size_t len)
	134	{
	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;
	141	}
	142	}
	143
559e840b JH	144	ssize_t read_in_full(int fd, void *buf, size_t count)
	145	{
	146	char *p = buf;
	147	ssize_t total = 0;
	148
	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;
	156	}
	157
	158	return total;
	159	}
	160
	161	ssize_t write_in_full(int fd, const void *buf, size_t count)
	162	{
	163	const char *p = buf;
	164	ssize_t total = 0;
	165
	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;
	173	}
	174	count -= written;
	175	p += written;
	176	total += written;
	177	}
	178
	179	return total;
	180	}
	181
112db553 LT	182	int xdup(int fd)
	183	{
	184	int ret = dup(fd);
	185	if (ret < 0)
d824cbba	186	die_errno("dup failed");
112db553 LT	187	return ret;
	188	}
	189
	190	FILE xfdopen(int fd, const char mode)
	191	{
	192	FILE *stream = fdopen(fd, mode);
	193	if (stream == NULL)
d824cbba	194	die_errno("Out of memory? fdopen failed");
112db553 LT	195	return stream;
	196	}
	197
	198	int xmkstemp(char *template)
	199	{
	200	int fd;
6cf6bb3e AE	201	char origtemplate[PATH_MAX];
6cf6bb3e AE	202	strlcpy(origtemplate, template, sizeof(origtemplate));
112db553 LT	203
112db553 LT	204	fd = mkstemp(template);
6cf6bb3e AE	205	if (fd < 0) {
	206	int saved_errno = errno;
	207	const char *nonrelative_template;
	208
	209	if (!template[0])
	210	template = origtemplate;
	211
e2a57aac	212	nonrelative_template = absolute_path(template);
6cf6bb3e AE	213	errno = saved_errno;
	214	die_errno("Unable to create temporary file '%s'",
	215	nonrelative_template);
	216	}
112db553 LT	217	return fd;
112db553 LT	218	}
39c68542	219
33f23936 JN	220	/* git_mkstemp() - create tmp file honoring TMPDIR variable */
	221	int git_mkstemp(char path, size_t len, const char template)
	222	{
	223	const char *tmp;
	224	size_t n;
	225
	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;
	233	}
	234	return mkstemp(path);
	235	}
	236
	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)
	239	{
	240	const char *tmp;
	241	size_t n;
	242
	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;
	250	}
	251	return mkstemps(path, suffix_len);
	252	}
	253
	254	/* Adapted from libiberty's mkstemp.c. */
	255
	256	#undef TMP_MAX
	257	#define TMP_MAX 16384
	258
	259	int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
	260	{
	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;
	271
	272	len = strlen(pattern);
	273
	274	if (len < 6 + suffix_len) {
	275	errno = EINVAL;
	276	return -1;
	277	}
	278
	279	if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
	280	errno = EINVAL;
	281	return -1;
	282	}
	283
284	/*
285	* Replace pattern's XXXXXX characters with randomness.
286	* Try TMP_MAX different filenames.
287	*/
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;
300
301	fd = open(pattern, O_CREAT \| O_EXCL \| O_RDWR, mode);
302	if (fd > 0)
303	return fd;
304	/*
305	* Fatal error (EPERM, ENOSPC etc).
306	* It doesn't make sense to loop.
307	*/
308	if (errno != EEXIST)
309	break;
310	/*
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).
314	*/
315	value += 7777;
316	}
317	/* We return the null string if we can't find a unique file name. */
318	pattern[0] = '\0';
319	return -1;
320	}
321
322	int git_mkstemp_mode(char *pattern, int mode)
323	{
324	/* mkstemp is just mkstemps with no suffix */
325	return git_mkstemps_mode(pattern, 0, mode);
326	}
327
328	int gitmkstemps(char *pattern, int suffix_len)
329	{
330	return git_mkstemps_mode(pattern, suffix_len, 0600);
331	}
332
b862b61c MM	333	int xmkstemp_mode(char *template, int mode)
	334	{
	335	int fd;
6cf6bb3e AE	336	char origtemplate[PATH_MAX];
6cf6bb3e AE	337	strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c MM	338
b862b61c MM	339	fd = git_mkstemp_mode(template, mode);
6cf6bb3e AE	340	if (fd < 0) {
	341	int saved_errno = errno;
	342	const char *nonrelative_template;
	343
	344	if (!template[0])
	345	template = origtemplate;
	346
e2a57aac	347	nonrelative_template = absolute_path(template);
6cf6bb3e AE	348	errno = saved_errno;
	349	die_errno("Unable to create temporary file '%s'",
	350	nonrelative_template);
	351	}
b862b61c MM	352	return fd;
	353	}
	354
10e13ec8	355	static int warn_if_unremovable(const char op, const char file, int rc)
fc71db39	356	{
fc71db39 AR	357	if (rc < 0) {
	358	int err = errno;
	359	if (ENOENT != err) {
10e13ec8 PC	360	warning("unable to %s %s: %s",
10e13ec8 PC	361	op, file, strerror(errno));
fc71db39 AR	362	errno = err;
	363	}
	364	}
	365	return rc;
	366	}
	367
10e13ec8 PC	368	int unlink_or_warn(const char *file)
	369	{
	370	return warn_if_unremovable("unlink", file, unlink(file));
	371	}
d1723296 PC	372
	373	int rmdir_or_warn(const char *file)
	374	{
	375	return warn_if_unremovable("rmdir", file, rmdir(file));
	376	}
80d706af PC	377
	378	int remove_or_warn(unsigned int mode, const char *file)
	379	{
	380	return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
	381	}