1 files changed, 457 insertions, 0 deletions
diff --git a/wrapper.c b/wrapper.c
new file mode 100644
index 0000000000..9a6aaafaf3
--- /dev/null
+++ b/wrapper.c
@@ -0,0 +1,457 @@
+/*
+ * 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;
+
+static void memory_limit_check(size_t size)
+{
+	static int limit = -1;
+	if (limit == -1) {
+		const char *env = getenv("GIT_ALLOC_LIMIT");
+		limit = env ? atoi(env) * 1024 : 0;
+	}
+	if (limit && size > limit)
+		die("attempting to allocate %"PRIuMAX" over limit %d",
+		    (intmax_t)size, limit);
+}
+
+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;
+
+	memory_limit_check(size);
+	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;
+
+	memory_limit_check(size);
+	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;
+
+	memory_limit_check(size * nmemb);
+	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;
+}
+
+/*
+ * Limit size of IO chunks, because huge chunks only cause pain.  OS X
+ * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
+ * the absense of bugs, large chunks can result in bad latencies when
+ * you decide to kill the process.
+ */
+#define MAX_IO_SIZE (8*1024*1024)
+
+/*
+ * 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;
+	if (len > MAX_IO_SIZE)
+	    len = MAX_IO_SIZE;
+	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;
+	if (len > MAX_IO_SIZE)
+	    len = MAX_IO_SIZE;
+	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 -1;
+		if (loaded == 0)
+			return total;
+		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 (strlen(template) != strlen(origtemplate))
+			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);
+}
+
+#ifdef NO_MKSTEMPS
+int gitmkstemps(char *pattern, int suffix_len)
+{
+	return git_mkstemps_mode(pattern, suffix_len, 0600);
+}
+#endif
+
+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);
+}
+
+void warn_on_inaccessible(const char *path)
+{
+	warning(_("unable to access '%s': %s"), path, strerror(errno));
+}
+
+static int access_error_is_ok(int err, unsigned flag)
+{
+	return err == ENOENT || err == ENOTDIR ||
+		((flag & ACCESS_EACCES_OK) && err == EACCES);
+}
+
+int access_or_warn(const char *path, int mode, unsigned flag)
+{
+	int ret = access(path, mode);
+	if (ret && !access_error_is_ok(errno, flag))
+		warn_on_inaccessible(path);
+	return ret;
+}
+
+int access_or_die(const char *path, int mode, unsigned flag)
+{
+	int ret = access(path, mode);
+	if (ret && !access_error_is_ok(errno, flag))
+		die_errno(_("unable to access '%s'"), path);
+	return ret;
+}
+
+struct passwd *xgetpwuid_self(void)
+{
+	struct passwd *pw;
+
+	errno = 0;
+	pw = getpwuid(getuid());
+	if (!pw)
+		die(_("unable to look up current user in the passwd file: %s"),
+		    errno ? strerror(errno) : _("no such user"));
+	return pw;
+}