/* cache.c: cache management * * Copyright (C) 2006 Lars Hjemli * * Licensed under GNU General Public License v2 *   (see COPYING for full license text) */ #include "cgit.h" const int NOLOCK = -1; char *cache_safe_filename(const char *unsafe){	static char buf[PATH_MAX];	char *s = buf;	char c; 	while(unsafe && (c = *unsafe++) != 0) {		if (c == '/' || c == ' ' || c == '&' || c == '|' || 		    c == '>' || c == '<' || c == '.')			c = '_';		*s++ = c;	}	*s = '\0';	return buf;} int cache_exist(struct cacheitem *item){	if (stat(item->name, &item->st)) {		item->st.st_mtime = 0;		return 0;	}	return 1;} int cache_create_dirs(){	char *path; 	path = fmt("%s", cgit_cache_root);	if (mkdir(path, S_IRWXU) && errno!=EEXIST)		return 0; 	if (!cgit_query_repo)		return 0; 	path = fmt("%s/%s", cgit_cache_root, cgit_query_repo);	if (mkdir(path, S_IRWXU) && errno!=EEXIST)		return 0; 	if (cgit_query_page) {		path = fmt("%s/%s/%s", cgit_cache_root, cgit_query_repo, 			   cgit_query_page);		if (mkdir(path, S_IRWXU) && errno!=EEXIST)			return 0;	}	return 1;} int cache_refill_overdue(const char *lockfile){	struct stat st; 	if (stat(lockfile, &st))		return 0;	else		return (time(NULL) - st.st_mtime > cgit_cache_max_create_time);} int cache_lock(struct cacheitem *item){	int i = 0;	char *lockfile = xstrdup(fmt("%s.lock", item->name));  top:	if (++i > cgit_max_lock_attempts)		die("cache_lock: unable to lock %s: %s",		    item->name, strerror(errno));        	item->fd = open(lockfile, O_WRONLY|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR); 	if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs())		goto top; 	if (item->fd == NOLOCK && errno == EEXIST &&	    cache_refill_overdue(lockfile) && !unlink(lockfile))			goto top; 	free(lockfile);	return (item->fd > 0);} int cache_unlock(struct cacheitem *item){	close(item->fd);	return (rename(fmt("%s.lock", item->name), item->name) == 0);} int cache_cancel_lock(struct cacheitem *item){	return (unlink(fmt("%s.lock", item->name)) == 0);} int cache_expired(struct cacheitem *item){	if (item->ttl < 0)		return 0;	return item->st.st_mtime + item->ttl * 60 < time(NULL);}