2006-06-06 19:51:49 +00:00
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/*
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* Copyright (c) 2005, Junio C Hamano
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*/
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#include "cache.h"
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static struct lock_file *lock_file_list;
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2007-04-01 06:27:41 +00:00
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static const char *alternate_index_output;
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2006-06-06 19:51:49 +00:00
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static void remove_lock_file(void)
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{
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2007-04-21 10:11:10 +00:00
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pid_t me = getpid();
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2006-06-06 19:51:49 +00:00
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while (lock_file_list) {
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2007-04-21 10:11:10 +00:00
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if (lock_file_list->owner == me &&
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lock_file_list->filename[0])
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2006-06-06 19:51:49 +00:00
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unlink(lock_file_list->filename);
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lock_file_list = lock_file_list->next;
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}
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}
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static void remove_lock_file_on_signal(int signo)
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{
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remove_lock_file();
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signal(SIGINT, SIG_DFL);
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raise(signo);
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}
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2006-08-12 08:03:47 +00:00
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static int lock_file(struct lock_file *lk, const char *path)
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2006-06-06 19:51:49 +00:00
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{
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int fd;
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sprintf(lk->filename, "%s.lock", path);
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fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
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2006-06-10 05:07:23 +00:00
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if (0 <= fd) {
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2007-07-13 14:14:50 +00:00
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if (!lock_file_list) {
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signal(SIGINT, remove_lock_file_on_signal);
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atexit(remove_lock_file);
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}
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2007-04-21 10:11:10 +00:00
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lk->owner = getpid();
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2007-01-02 19:19:05 +00:00
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if (!lk->on_list) {
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2006-06-10 05:07:23 +00:00
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lk->next = lock_file_list;
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lock_file_list = lk;
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2007-01-02 19:19:05 +00:00
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lk->on_list = 1;
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}
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2006-06-10 05:07:23 +00:00
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if (adjust_shared_perm(lk->filename))
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return error("cannot fix permission bits on %s",
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lk->filename);
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2006-06-06 19:51:49 +00:00
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}
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2007-01-02 19:19:05 +00:00
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else
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lk->filename[0] = 0;
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2006-06-06 19:51:49 +00:00
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return fd;
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}
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2006-08-12 08:03:47 +00:00
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int hold_lock_file_for_update(struct lock_file *lk, const char *path, int die_on_error)
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{
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int fd = lock_file(lk, path);
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if (fd < 0 && die_on_error)
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2007-01-06 03:14:04 +00:00
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die("unable to create '%s.lock': %s", path, strerror(errno));
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2006-08-12 08:03:47 +00:00
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return fd;
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}
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2006-06-06 19:51:49 +00:00
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int commit_lock_file(struct lock_file *lk)
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{
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char result_file[PATH_MAX];
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int i;
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strcpy(result_file, lk->filename);
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i = strlen(result_file) - 5; /* .lock */
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result_file[i] = 0;
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i = rename(lk->filename, result_file);
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lk->filename[0] = 0;
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return i;
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}
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_GIT_INDEX_OUTPUT: allow plumbing to output to an alternative index file.
When defined, this allows plumbing commands that update the
index (add, apply, checkout-index, merge-recursive, mv,
read-tree, rm, update-index, and write-tree) to write their
resulting index to an alternative index file while holding a
lock to the original index file. With this, git-commit that
jumps the index does not have to make an extra copy of the index
file, and more importantly, it can do the update while holding
the lock on the index.
However, I think the interface to let an environment variable
specify the output is a mistake, as shown in the documentation.
If a curious user has the environment variable set to something
other than the file GIT_INDEX_FILE points at, almost everything
will break. This should instead be a command line parameter to
tell these plumbing commands to write the result in the named
file, to prevent stupid mistakes.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-01 06:09:02 +00:00
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int hold_locked_index(struct lock_file *lk, int die_on_error)
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{
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return hold_lock_file_for_update(lk, get_index_file(), die_on_error);
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}
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2007-04-01 06:27:41 +00:00
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void set_alternate_index_output(const char *name)
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{
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alternate_index_output = name;
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}
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_GIT_INDEX_OUTPUT: allow plumbing to output to an alternative index file.
When defined, this allows plumbing commands that update the
index (add, apply, checkout-index, merge-recursive, mv,
read-tree, rm, update-index, and write-tree) to write their
resulting index to an alternative index file while holding a
lock to the original index file. With this, git-commit that
jumps the index does not have to make an extra copy of the index
file, and more importantly, it can do the update while holding
the lock on the index.
However, I think the interface to let an environment variable
specify the output is a mistake, as shown in the documentation.
If a curious user has the environment variable set to something
other than the file GIT_INDEX_FILE points at, almost everything
will break. This should instead be a command line parameter to
tell these plumbing commands to write the result in the named
file, to prevent stupid mistakes.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-01 06:09:02 +00:00
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int commit_locked_index(struct lock_file *lk)
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{
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2007-04-01 06:27:41 +00:00
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if (alternate_index_output) {
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int result = rename(lk->filename, alternate_index_output);
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_GIT_INDEX_OUTPUT: allow plumbing to output to an alternative index file.
When defined, this allows plumbing commands that update the
index (add, apply, checkout-index, merge-recursive, mv,
read-tree, rm, update-index, and write-tree) to write their
resulting index to an alternative index file while holding a
lock to the original index file. With this, git-commit that
jumps the index does not have to make an extra copy of the index
file, and more importantly, it can do the update while holding
the lock on the index.
However, I think the interface to let an environment variable
specify the output is a mistake, as shown in the documentation.
If a curious user has the environment variable set to something
other than the file GIT_INDEX_FILE points at, almost everything
will break. This should instead be a command line parameter to
tell these plumbing commands to write the result in the named
file, to prevent stupid mistakes.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-01 06:09:02 +00:00
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lk->filename[0] = 0;
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return result;
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}
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else
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return commit_lock_file(lk);
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}
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2006-06-06 19:51:49 +00:00
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void rollback_lock_file(struct lock_file *lk)
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{
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if (lk->filename[0])
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unlink(lk->filename);
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lk->filename[0] = 0;
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}
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