1 files changed, 57 insertions, 0 deletions
diff --git a/index.c b/index.c
new file mode 100644
index 0000000..f92b960
--- /dev/null
+++ b/index.c
@@ -0,0 +1,57 @@
+/*
+ * 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;
+}
+