Fix cache algorithm loophole

This closes the door for unneccessary calls to cgit_fill_cache().

Noticed by Linus.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/cache.c b/cache.c
index b034c48..0ffa502 100644
--- a/cache.c
+++ b/cache.c
@@ -1,80 +1,84 @@
 /* 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;
 
-int cache_lookup(struct cacheitem *item)
+void cache_prepare(struct cacheitem *item)
 {
 	if (!cgit_query_repo) {
 		item->name = xstrdup(fmt("%s/index.html", cgit_cache_root));
 		item->ttl = cgit_cache_root_ttl;
 	} else if (!cgit_query_page) {
 		item->name = xstrdup(fmt("%s/%s/index.html", cgit_cache_root, 
 			   cgit_query_repo));
 		item->ttl = cgit_cache_repo_ttl;
 	} else {
 		item->name = xstrdup(fmt("%s/%s/%s/%s.html", cgit_cache_root, 
 			   cgit_query_repo, cgit_query_page, 
 			   cgit_querystring));
 		if (cgit_query_has_symref)
 			item->ttl = cgit_cache_dynamic_ttl;
 		else if (cgit_query_has_sha1)
 			item->ttl = cgit_cache_static_ttl;
 		else
 			item->ttl = cgit_cache_repo_ttl;
 	}
+}
+
+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;
 
 	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_lock(struct cacheitem *item)
 {
 	int ret;
 	char *lockfile = fmt("%s.lock", item->name);
 
  top:  
        	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) {
 		struct stat st;
 		time_t t;
 		if (stat(lockfile, &st))
 			return ret;
 		t = time(NULL);
 		if (t-st.st_mtime > cgit_cache_max_create_time && 
 		    !unlink(lockfile))
 			goto top;
 		return 0;
 	}
 	return (item->fd > 0);