[git/git.git] / wrapper.c

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

static void try_to_free_builtin(size_t size)
{
	release_pack_memory(size, -1);
}

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

try_to_free_t set_try_to_free_routine(try_to_free_t routine)
{
	try_to_free_t old = try_to_free_routine;
	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 (size + 1 < size)
		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;

	fd = mkstemp(template);
	if (fd < 0)
		die_errno("Unable to create temporary file");
	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;

	fd = git_mkstemp_mode(template, mode);
	if (fd < 0)
		die_errno("Unable to create temporary file");
	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
a9a74636 NP	6	static void try_to_free_builtin(size_t size)
	7	{
	8	release_pack_memory(size, -1);
	9	}
	10
	11	static void (*try_to_free_routine)(size_t size) = try_to_free_builtin;
	12
851c34b0	13	try_to_free_t set_try_to_free_routine(try_to_free_t routine)
a9a74636	14	{
851c34b0 JS	15	try_to_free_t old = try_to_free_routine;
	16	try_to_free_routine = routine;
	17	return old;
a9a74636 NP	18	}
a9a74636 NP	19
112db553 LT	20	char xstrdup(const char str)
	21	{
	22	char *ret = strdup(str);
	23	if (!ret) {
a9a74636	24	try_to_free_routine(strlen(str) + 1);
112db553 LT	25	ret = strdup(str);
	26	if (!ret)
	27	die("Out of memory, strdup failed");
	28	}
	29	return ret;
	30	}
	31
	32	void *xmalloc(size_t size)
	33	{
	34	void *ret = malloc(size);
	35	if (!ret && !size)
	36	ret = malloc(1);
	37	if (!ret) {
a9a74636	38	try_to_free_routine(size);
112db553 LT	39	ret = malloc(size);
	40	if (!ret && !size)
	41	ret = malloc(1);
	42	if (!ret)
8bd9fd50 MM	43	die("Out of memory, malloc failed (tried to allocate %lu bytes)",
8bd9fd50 MM	44	(unsigned long)size);
112db553 LT	45	}
	46	#ifdef XMALLOC_POISON
	47	memset(ret, 0xA5, size);
	48	#endif
	49	return ret;
	50	}
	51
5bf9219d IL	52	void *xmallocz(size_t size)
	53	{
	54	void *ret;
	55	if (size + 1 < size)
	56	die("Data too large to fit into virtual memory space.");
	57	ret = xmalloc(size + 1);
	58	((char*)ret)[size] = 0;
	59	return ret;
	60	}
	61
112db553 LT	62	/*
	63	* xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
	64	* "data" to the allocated memory, zero terminates the allocated memory,
	65	* and returns a pointer to the allocated memory. If the allocation fails,
	66	* the program dies.
	67	*/
	68	void xmemdupz(const void data, size_t len)
	69	{
5bf9219d	70	return memcpy(xmallocz(len), data, len);
112db553 LT	71	}
	72
	73	char xstrndup(const char str, size_t len)
	74	{
	75	char *p = memchr(str, '\0', len);
	76	return xmemdupz(str, p ? p - str : len);
	77	}
	78
	79	void xrealloc(void ptr, size_t size)
	80	{
	81	void *ret = realloc(ptr, size);
	82	if (!ret && !size)
	83	ret = realloc(ptr, 1);
	84	if (!ret) {
a9a74636	85	try_to_free_routine(size);
112db553 LT	86	ret = realloc(ptr, size);
	87	if (!ret && !size)
	88	ret = realloc(ptr, 1);
	89	if (!ret)
	90	die("Out of memory, realloc failed");
	91	}
	92	return ret;
	93	}
	94
	95	void *xcalloc(size_t nmemb, size_t size)
	96	{
	97	void *ret = calloc(nmemb, size);
	98	if (!ret && (!nmemb \|\| !size))
	99	ret = calloc(1, 1);
	100	if (!ret) {
a9a74636	101	try_to_free_routine(nmemb * size);
112db553 LT	102	ret = calloc(nmemb, size);
	103	if (!ret && (!nmemb \|\| !size))
	104	ret = calloc(1, 1);
	105	if (!ret)
	106	die("Out of memory, calloc failed");
	107	}
	108	return ret;
	109	}
	110
112db553 LT	111	/*
	112	* xread() is the same a read(), but it automatically restarts read()
	113	* operations with a recoverable error (EAGAIN and EINTR). xread()
	114	* DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
	115	*/
	116	ssize_t xread(int fd, void *buf, size_t len)
	117	{
	118	ssize_t nr;
	119	while (1) {
	120	nr = read(fd, buf, len);
	121	if ((nr < 0) && (errno == EAGAIN \|\| errno == EINTR))
	122	continue;
	123	return nr;
	124	}
	125	}
	126
	127	/*
	128	* xwrite() is the same a write(), but it automatically restarts write()
	129	* operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
	130	* GUARANTEE that "len" bytes is written even if the operation is successful.
	131	*/
	132	ssize_t xwrite(int fd, const void *buf, size_t len)
	133	{
	134	ssize_t nr;
	135	while (1) {
	136	nr = write(fd, buf, len);
	137	if ((nr < 0) && (errno == EAGAIN \|\| errno == EINTR))
	138	continue;
	139	return nr;
	140	}
	141	}
	142
559e840b JH	143	ssize_t read_in_full(int fd, void *buf, size_t count)
	144	{
	145	char *p = buf;
	146	ssize_t total = 0;
	147
	148	while (count > 0) {
	149	ssize_t loaded = xread(fd, p, count);
	150	if (loaded <= 0)
	151	return total ? total : loaded;
	152	count -= loaded;
	153	p += loaded;
	154	total += loaded;
	155	}
	156
	157	return total;
	158	}
	159
	160	ssize_t write_in_full(int fd, const void *buf, size_t count)
	161	{
	162	const char *p = buf;
	163	ssize_t total = 0;
	164
	165	while (count > 0) {
	166	ssize_t written = xwrite(fd, p, count);
	167	if (written < 0)
	168	return -1;
	169	if (!written) {
	170	errno = ENOSPC;
	171	return -1;
	172	}
	173	count -= written;
	174	p += written;
	175	total += written;
	176	}
	177
	178	return total;
	179	}
	180
112db553 LT	181	int xdup(int fd)
	182	{
	183	int ret = dup(fd);
	184	if (ret < 0)
d824cbba	185	die_errno("dup failed");
112db553 LT	186	return ret;
	187	}
	188
	189	FILE xfdopen(int fd, const char mode)
	190	{
	191	FILE *stream = fdopen(fd, mode);
	192	if (stream == NULL)
d824cbba	193	die_errno("Out of memory? fdopen failed");
112db553 LT	194	return stream;
	195	}
	196
	197	int xmkstemp(char *template)
	198	{
	199	int fd;
	200
	201	fd = mkstemp(template);
	202	if (fd < 0)
d824cbba	203	die_errno("Unable to create temporary file");
112db553 LT	204	return fd;
112db553 LT	205	}
39c68542	206
33f23936 JN	207	/* git_mkstemp() - create tmp file honoring TMPDIR variable */
	208	int git_mkstemp(char path, size_t len, const char template)
	209	{
	210	const char *tmp;
	211	size_t n;
	212
	213	tmp = getenv("TMPDIR");
	214	if (!tmp)
	215	tmp = "/tmp";
	216	n = snprintf(path, len, "%s/%s", tmp, template);
	217	if (len <= n) {
	218	errno = ENAMETOOLONG;
	219	return -1;
	220	}
	221	return mkstemp(path);
	222	}
	223
	224	/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
	225	int git_mkstemps(char path, size_t len, const char template, int suffix_len)
	226	{
	227	const char *tmp;
	228	size_t n;
	229
	230	tmp = getenv("TMPDIR");
	231	if (!tmp)
	232	tmp = "/tmp";
	233	n = snprintf(path, len, "%s/%s", tmp, template);
	234	if (len <= n) {
	235	errno = ENAMETOOLONG;
	236	return -1;
	237	}
	238	return mkstemps(path, suffix_len);
	239	}
	240
	241	/* Adapted from libiberty's mkstemp.c. */
	242
	243	#undef TMP_MAX
	244	#define TMP_MAX 16384
	245
	246	int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
	247	{
	248	static const char letters[] =
	249	"abcdefghijklmnopqrstuvwxyz"
	250	"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	251	"0123456789";
	252	static const int num_letters = 62;
	253	uint64_t value;
	254	struct timeval tv;
	255	char *template;
	256	size_t len;
	257	int fd, count;
	258
	259	len = strlen(pattern);
	260
	261	if (len < 6 + suffix_len) {
	262	errno = EINVAL;
	263	return -1;
	264	}
	265
	266	if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
	267	errno = EINVAL;
	268	return -1;
	269	}
	270
271	/*
272	* Replace pattern's XXXXXX characters with randomness.
273	* Try TMP_MAX different filenames.
274	*/
275	gettimeofday(&tv, NULL);
276	value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
277	template = &pattern[len - 6 - suffix_len];
278	for (count = 0; count < TMP_MAX; ++count) {
279	uint64_t v = value;
280	/* Fill in the random bits. */
281	template[0] = letters[v % num_letters]; v /= num_letters;
282	template[1] = letters[v % num_letters]; v /= num_letters;
283	template[2] = letters[v % num_letters]; v /= num_letters;
284	template[3] = letters[v % num_letters]; v /= num_letters;
285	template[4] = letters[v % num_letters]; v /= num_letters;
286	template[5] = letters[v % num_letters]; v /= num_letters;
287
288	fd = open(pattern, O_CREAT \| O_EXCL \| O_RDWR, mode);
289	if (fd > 0)
290	return fd;
291	/*
292	* Fatal error (EPERM, ENOSPC etc).
293	* It doesn't make sense to loop.
294	*/
295	if (errno != EEXIST)
296	break;
297	/*
298	* This is a random value. It is only necessary that
299	* the next TMP_MAX values generated by adding 7777 to
300	* VALUE are different with (module 2^32).
301	*/
302	value += 7777;
303	}
304	/* We return the null string if we can't find a unique file name. */
305	pattern[0] = '\0';
306	return -1;
307	}
308
309	int git_mkstemp_mode(char *pattern, int mode)
310	{
311	/* mkstemp is just mkstemps with no suffix */
312	return git_mkstemps_mode(pattern, 0, mode);
313	}
314
315	int gitmkstemps(char *pattern, int suffix_len)
316	{
317	return git_mkstemps_mode(pattern, suffix_len, 0600);
318	}
319
b862b61c MM	320	int xmkstemp_mode(char *template, int mode)
	321	{
	322	int fd;
	323
	324	fd = git_mkstemp_mode(template, mode);
	325	if (fd < 0)
	326	die_errno("Unable to create temporary file");
	327	return fd;
	328	}
	329
10e13ec8	330	static int warn_if_unremovable(const char op, const char file, int rc)
fc71db39	331	{
fc71db39 AR	332	if (rc < 0) {
	333	int err = errno;
	334	if (ENOENT != err) {
10e13ec8 PC	335	warning("unable to %s %s: %s",
10e13ec8 PC	336	op, file, strerror(errno));
fc71db39 AR	337	errno = err;
	338	}
	339	}
	340	return rc;
	341	}
	342
10e13ec8 PC	343	int unlink_or_warn(const char *file)
	344	{
	345	return warn_if_unremovable("unlink", file, unlink(file));
	346	}
d1723296 PC	347
	348	int rmdir_or_warn(const char *file)
	349	{
	350	return warn_if_unremovable("rmdir", file, rmdir(file));
	351	}
80d706af PC	352
	353	int remove_or_warn(unsigned int mode, const char *file)
	354	{
	355	return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
	356	}