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authorMichael Haggerty <mhagger@alum.mit.edu>2014-10-01 12:28:32 +0200
committerJunio C Hamano <gitster@pobox.com>2014-10-01 13:50:01 -0700
commitcf6950d3bfe1447ac04867b1f5654a2fc9c5db96 (patch)
tree2c99e3011a6e6f27286091a7066fe8c91683bcd1 /lockfile.c
parent3e88e8fc085bbfad142d51a07ef918b9b5ca1d72 (diff)
downloadgit-cf6950d3bfe1447ac04867b1f5654a2fc9c5db96.tar.gz
lockfile: change lock_file::filename into a strbuf
For now, we still make sure to allocate at least PATH_MAX characters for the strbuf because resolve_symlink() doesn't know how to expand the space for its return value. (That will be fixed in a moment.) Another alternative would be to just use a strbuf as scratch space in lock_file() but then store a pointer to the naked string in struct lock_file. But lock_file objects are often reused. By reusing the same strbuf, we can avoid having to reallocate the string most times when a lock_file object is reused. Helped-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'lockfile.c')
-rw-r--r--lockfile.c53
1 files changed, 24 insertions, 29 deletions
diff --git a/lockfile.c b/lockfile.c
index 1dd118f556..85c8648c51 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -47,9 +47,9 @@
* failed attempt to lock, or a failed close_lock_file()). In this
* state:
* - active is unset
- * - filename[0] == '\0' (usually, though there are transitory states
- * in which this condition doesn't hold). Client code should *not*
- * rely on this fact!
+ * - filename is empty (usually, though there are transitory
+ * states in which this condition doesn't hold). Client code should
+ * *not* rely on the filename being empty in this state.
* - fd is -1
* - the object is left registered in the lock_file_list, and
* on_list is set.
@@ -170,13 +170,6 @@ static char *resolve_symlink(char *p, size_t s)
/* Make sure errno contains a meaningful value on error */
static int lock_file(struct lock_file *lk, const char *path, int flags)
{
- /*
- * subtract LOCK_SUFFIX_LEN from size to make sure there's
- * room for adding ".lock" for the lock file name:
- */
- static const size_t max_path_len = sizeof(lk->filename) -
- LOCK_SUFFIX_LEN;
-
if (!lock_file_list) {
/* One-time initialization */
sigchain_push_common(remove_lock_file_on_signal);
@@ -191,30 +184,32 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
lk->fd = -1;
lk->active = 0;
lk->owner = 0;
- lk->filename[0] = 0;
+ strbuf_init(&lk->filename, PATH_MAX);
lk->next = lock_file_list;
lock_file_list = lk;
lk->on_list = 1;
+ } else if (lk->filename.len) {
+ /* This shouldn't happen, but better safe than sorry. */
+ die("BUG: lock_file(\"%s\") called with improperly-reset lock_file object",
+ path);
}
- if (strlen(path) >= max_path_len) {
- errno = ENAMETOOLONG;
- return -1;
+ strbuf_addstr(&lk->filename, path);
+ if (!(flags & LOCK_NODEREF)) {
+ resolve_symlink(lk->filename.buf, lk->filename.alloc);
+ strbuf_setlen(&lk->filename, strlen(lk->filename.buf));
}
- strcpy(lk->filename, path);
- if (!(flags & LOCK_NODEREF))
- resolve_symlink(lk->filename, max_path_len);
- strcat(lk->filename, LOCK_SUFFIX);
- lk->fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
+ strbuf_addstr(&lk->filename, LOCK_SUFFIX);
+ lk->fd = open(lk->filename.buf, O_RDWR | O_CREAT | O_EXCL, 0666);
if (lk->fd < 0) {
- lk->filename[0] = 0;
+ strbuf_reset(&lk->filename);
return -1;
}
lk->owner = getpid();
lk->active = 1;
- if (adjust_shared_perm(lk->filename)) {
+ if (adjust_shared_perm(lk->filename.buf)) {
int save_errno = errno;
- error("cannot fix permission bits on %s", lk->filename);
+ error("cannot fix permission bits on %s", lk->filename.buf);
rollback_lock_file(lk);
errno = save_errno;
return -1;
@@ -313,7 +308,7 @@ int reopen_lock_file(struct lock_file *lk)
die(_("BUG: reopen a lockfile that is still open"));
if (!lk->active)
die(_("BUG: reopen a lockfile that has been committed"));
- lk->fd = open(lk->filename, O_WRONLY);
+ lk->fd = open(lk->filename.buf, O_WRONLY);
return lk->fd;
}
@@ -329,9 +324,9 @@ int commit_lock_file(struct lock_file *lk)
return -1;
/* remove ".lock": */
- strbuf_add(&result_file, lk->filename,
- strlen(lk->filename) - LOCK_SUFFIX_LEN);
- err = rename(lk->filename, result_file.buf);
+ strbuf_add(&result_file, lk->filename.buf,
+ lk->filename.len - LOCK_SUFFIX_LEN);
+ err = rename(lk->filename.buf, result_file.buf);
strbuf_reset(&result_file);
if (err) {
int save_errno = errno;
@@ -341,7 +336,7 @@ int commit_lock_file(struct lock_file *lk)
}
lk->active = 0;
- lk->filename[0] = 0;
+ strbuf_reset(&lk->filename);
return 0;
}
@@ -359,8 +354,8 @@ void rollback_lock_file(struct lock_file *lk)
return;
if (!close_lock_file(lk)) {
- unlink_or_warn(lk->filename);
+ unlink_or_warn(lk->filename.buf);
lk->active = 0;
- lk->filename[0] = 0;
+ strbuf_reset(&lk->filename);
}
}