/*
 * Copyright (c) 2005, Junio C Hamano
 */
#include <signal.h>
#include "cache.h"

static struct cache_file *cache_file_list;

static void remove_lock_file(void)
{
        while (cache_file_list) {
                if (cache_file_list->lockfile[0])
                        unlink(cache_file_list->lockfile);
                cache_file_list = cache_file_list->next;
        }
}

static void remove_lock_file_on_signal(int signo)
{
        remove_lock_file();
        signal(SIGINT, SIG_DFL);
        raise(signo);
}

int hold_index_file_for_update(struct cache_file *cf, const char *path)
{
        int fd;
        sprintf(cf->lockfile, "%s.lock", path);
        fd = open(cf->lockfile, O_RDWR | O_CREAT | O_EXCL, 0666);
        if (fd >=0 && !cf->next) {
                cf->next = cache_file_list;
                cache_file_list = cf;
                signal(SIGINT, remove_lock_file_on_signal);
                atexit(remove_lock_file);
        }
        return fd;
}

int commit_index_file(struct cache_file *cf)
{
        char indexfile[PATH_MAX];
        int i;
        strcpy(indexfile, cf->lockfile);
        i = strlen(indexfile) - 5; /* .lock */
        indexfile[i] = 0;
        i = rename(cf->lockfile, indexfile);
        cf->lockfile[0] = 0;
        return i;
}

void rollback_index_file(struct cache_file *cf)
{
        if (cf->lockfile[0])
                unlink(cf->lockfile);
        cf->lockfile[0] = 0;
}