mirrors/git
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge branch 'mh/tempfile'

Browse Source 
The "lockfile" API has been rebuilt on top of a new "tempfile" API.

* mh/tempfile:
  credential-cache--daemon: use tempfile module
  credential-cache--daemon: delete socket from main()
  gc: use tempfile module to handle gc.pid file
  lock_repo_for_gc(): compute the path to "gc.pid" only once
  diff: use tempfile module
  setup_temporary_shallow(): use tempfile module
  write_shared_index(): use tempfile module
  register_tempfile(): new function to handle an existing temporary file
  tempfile: add several functions for creating temporary files
  prepare_tempfile_object(): new function, extracted from create_tempfile()
  tempfile: a new module for handling temporary files
  commit_lock_file(): use get_locked_file_path()
  lockfile: add accessor get_lock_file_path()
  lockfile: add accessors get_lock_file_fd() and get_lock_file_fp()
  create_bundle(): duplicate file descriptor to avoid closing it twice
  lockfile: move documentation to lockfile.h and lockfile.c
This commit is contained in:
Junio C Hamano
2015-08-25 14:57:09 -07:00
parent 424f89f098 9e9033166b
commit db86e61cbb
18 changed files with 964 additions and 625 deletions
Download Patch File Download Diff File Expand all files Collapse all files

211
lockfile.c
View File

@ -1,38 +1,9 @@
/*
* Copyright (c) 2005, Junio C Hamano
*/
#include "cache.h"
#include "lockfile.h"
#include "sigchain.h"
static struct lock_file *volatile lock_file_list;
static void remove_lock_files(int skip_fclose)
{
pid_t me = getpid();
while (lock_file_list) {
if (lock_file_list->owner == me) {
/* fclose() is not safe to call in a signal handler */
if (skip_fclose)
lock_file_list->fp = NULL;
rollback_lock_file(lock_file_list);
}
lock_file_list = lock_file_list->next;
}
}
static void remove_lock_files_on_exit(void)
{
remove_lock_files(0);
}
static void remove_lock_files_on_signal(int signo)
{
remove_lock_files(1);
sigchain_pop(signo);
raise(signo);
}
/*
* path = absolute or relative path name
@ -101,60 +72,17 @@ static void resolve_symlink(struct strbuf *path)
/* Make sure errno contains a meaningful value on error */
static int lock_file(struct lock_file *lk, const char *path, int flags)
{
size_t pathlen = strlen(path);
int fd;
struct strbuf filename = STRBUF_INIT;
if (!lock_file_list) {
/* One-time initialization */
sigchain_push_common(remove_lock_files_on_signal);
atexit(remove_lock_files_on_exit);
}
strbuf_addstr(&filename, path);
if (!(flags & LOCK_NO_DEREF))
resolve_symlink(&filename);
if (lk->active)
die("BUG: cannot lock_file(\"%s\") using active struct lock_file",
path);
if (!lk->on_list) {
/* Initialize *lk and add it to lock_file_list: */
lk->fd = -1;
lk->fp = NULL;
lk->active = 0;
lk->owner = 0;
strbuf_init(&lk->filename, pathlen + LOCK_SUFFIX_LEN);
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 (flags & LOCK_NO_DEREF) {
strbuf_add_absolute_path(&lk->filename, path);
} else {
struct strbuf resolved_path = STRBUF_INIT;
strbuf_add(&resolved_path, path, pathlen);
resolve_symlink(&resolved_path);
strbuf_add_absolute_path(&lk->filename, resolved_path.buf);
strbuf_release(&resolved_path);
}
strbuf_addstr(&lk->filename, LOCK_SUFFIX);
lk->fd = open(lk->filename.buf, O_RDWR | O_CREAT | O_EXCL, 0666);
if (lk->fd < 0) {
strbuf_reset(&lk->filename);
return -1;
}
lk->owner = getpid();
lk->active = 1;
if (adjust_shared_perm(lk->filename.buf)) {
int save_errno = errno;
error("cannot fix permission bits on %s", lk->filename.buf);
rollback_lock_file(lk);
errno = save_errno;
return -1;
}
return lk->fd;
strbuf_addstr(&filename, LOCK_SUFFIX);
fd = create_tempfile(&lk->tempfile, filename.buf);
strbuf_release(&filename);
return fd;
}
/*
@ -287,116 +215,29 @@ int hold_lock_file_for_append(struct lock_file *lk, const char *path, int flags)
return fd;
}
FILE *fdopen_lock_file(struct lock_file *lk, const char *mode)
{
if (!lk->active)
die("BUG: fdopen_lock_file() called for unlocked object");
if (lk->fp)
die("BUG: fdopen_lock_file() called twice for file '%s'", lk->filename.buf);
lk->fp = fdopen(lk->fd, mode);
return lk->fp;
}
char *get_locked_file_path(struct lock_file *lk)
{
if (!lk->active)
die("BUG: get_locked_file_path() called for unlocked object");
if (lk->filename.len <= LOCK_SUFFIX_LEN)
struct strbuf ret = STRBUF_INIT;
strbuf_addstr(&ret, get_tempfile_path(&lk->tempfile));
if (ret.len <= LOCK_SUFFIX_LEN ||
strcmp(ret.buf + ret.len - LOCK_SUFFIX_LEN, LOCK_SUFFIX))
die("BUG: get_locked_file_path() called for malformed lock object");
return xmemdupz(lk->filename.buf, lk->filename.len - LOCK_SUFFIX_LEN);
}
int close_lock_file(struct lock_file *lk)
{
int fd = lk->fd;
FILE *fp = lk->fp;
int err;
if (fd < 0)
return 0;
lk->fd = -1;
if (fp) {
lk->fp = NULL;
/*
* Note: no short-circuiting here; we want to fclose()
* in any case!
*/
err = ferror(fp) | fclose(fp);
} else {
err = close(fd);
}
if (err) {
int save_errno = errno;
rollback_lock_file(lk);
errno = save_errno;
return -1;
}
return 0;
}
int reopen_lock_file(struct lock_file *lk)
{
if (0 <= lk->fd)
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.buf, O_WRONLY);
return lk->fd;
}
int commit_lock_file_to(struct lock_file *lk, const char *path)
{
if (!lk->active)
die("BUG: attempt to commit unlocked object to \"%s\"", path);
if (close_lock_file(lk))
return -1;
if (rename(lk->filename.buf, path)) {
int save_errno = errno;
rollback_lock_file(lk);
errno = save_errno;
return -1;
}
lk->active = 0;
strbuf_reset(&lk->filename);
return 0;
/* remove ".lock": */
strbuf_setlen(&ret, ret.len - LOCK_SUFFIX_LEN);
return strbuf_detach(&ret, NULL);
}
int commit_lock_file(struct lock_file *lk)
{
static struct strbuf result_file = STRBUF_INIT;
int err;
char *result_path = get_locked_file_path(lk);
if (!lk->active)
die("BUG: attempt to commit unlocked object");
if (lk->filename.len <= LOCK_SUFFIX_LEN ||
strcmp(lk->filename.buf + lk->filename.len - LOCK_SUFFIX_LEN, LOCK_SUFFIX))
die("BUG: lockfile filename corrupt");
/* remove ".lock": */
strbuf_add(&result_file, lk->filename.buf,
lk->filename.len - LOCK_SUFFIX_LEN);
err = commit_lock_file_to(lk, result_file.buf);
strbuf_reset(&result_file);
return err;
}
void rollback_lock_file(struct lock_file *lk)
{
if (!lk->active)
return;
if (!close_lock_file(lk)) {
unlink_or_warn(lk->filename.buf);
lk->active = 0;
strbuf_reset(&lk->filename);
if (commit_lock_file_to(lk, result_path)) {
int save_errno = errno;
free(result_path);
errno = save_errno;
return -1;
}
free(result_path);
return 0;
}