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authorMatthieu Moy <Matthieu.Moy@imag.fr>2010-02-22 23:32:12 +0100
committerJunio C Hamano <gitster@pobox.com>2010-02-22 15:24:45 -0800
commit00787ed55adbc2350efa911bf0bdebf6ca08c095 (patch)
treef54877ee15a2c2478fe1f2fa8c651644aaf21dce /path.c
parent7aba6185d55e06db3f3ef18daa63baf3821e5030 (diff)
downloadgit-00787ed55adbc2350efa911bf0bdebf6ca08c095.tar.gz
Move gitmkstemps to path.c
This function used to be only a compatibility function, but we're going to extend it and actually use it, so make it part of Git. Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'path.c')
-rw-r--r--path.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/path.c b/path.c
index 79aa104712..ab2e3687ab 100644
--- a/path.c
+++ b/path.c
@@ -157,6 +157,75 @@ int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
return mkstemps(path, suffix_len);
}
+/* Adapted from libiberty's mkstemp.c. */
+
+#undef TMP_MAX
+#define TMP_MAX 16384
+
+int gitmkstemps(char *pattern, int suffix_len)
+{
+ 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, 0600);
+ 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';
+ errno = EINVAL;
+ return -1;
+}
+
int validate_headref(const char *path)
{
struct stat st;