ui-repolist: implement lazy caching of repo->mtime

When sorting the list of repositories by their last modification time,
cgit would (in the worst case) invoke fstat(3) four times and open(3)
twice for each callback from qsort(3). This obviously scales very badly.

Now, the calculated modtime for each repo is saved in repo->mtime, thus
keeping the number of stat/open invocations identical for sorted and
unsorted repo-listings.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/shared.c b/shared.c
index f5875e4..89d1bab 100644
--- a/shared.c
+++ b/shared.c
@@ -15,96 +15,97 @@ int cgit_cmd;
 int chk_zero(int result, char *msg)
 {
 	if (result != 0)
 		die("%s: %s", msg, strerror(errno));
 	return result;
 }
 
 int chk_positive(int result, char *msg)
 {
 	if (result <= 0)
 		die("%s: %s", msg, strerror(errno));
 	return result;
 }
 
 int chk_non_negative(int result, char *msg)
 {
     	if (result < 0)
 	    	die("%s: %s",msg, strerror(errno));
 	return result;
 }
 
 struct cgit_repo *cgit_add_repo(const char *url)
 {
 	struct cgit_repo *ret;
 
 	if (++cgit_repolist.count > cgit_repolist.length) {
 		if (cgit_repolist.length == 0)
 			cgit_repolist.length = 8;
 		else
 			cgit_repolist.length *= 2;
 		cgit_repolist.repos = xrealloc(cgit_repolist.repos,
 					       cgit_repolist.length *
 					       sizeof(struct cgit_repo));
 	}
 
 	ret = &cgit_repolist.repos[cgit_repolist.count-1];
 	ret->url = trim_end(url, '/');
 	ret->name = ret->url;
 	ret->path = NULL;
 	ret->desc = "[no description]";
 	ret->owner = NULL;
 	ret->group = ctx.cfg.repo_group;
 	ret->defbranch = "master";
 	ret->snapshots = ctx.cfg.snapshots;
 	ret->enable_log_filecount = ctx.cfg.enable_log_filecount;
 	ret->enable_log_linecount = ctx.cfg.enable_log_linecount;
 	ret->module_link = ctx.cfg.module_link;
 	ret->readme = NULL;
+	ret->mtime = -1;
 	return ret;
 }
 
 struct cgit_repo *cgit_get_repoinfo(const char *url)
 {
 	int i;
 	struct cgit_repo *repo;
 
 	for (i=0; i<cgit_repolist.count; i++) {
 		repo = &cgit_repolist.repos[i];
 		if (!strcmp(repo->url, url))
 			return repo;
 	}
 	return NULL;
 }
 
 void *cgit_free_commitinfo(struct commitinfo *info)
 {
 	free(info->author);
 	free(info->author_email);
 	free(info->committer);
 	free(info->committer_email);
 	free(info->subject);
 	free(info->msg);
 	free(info->msg_encoding);
 	free(info);
 	return NULL;
 }
 
 char *trim_end(const char *str, char c)
 {
 	int len;
 	char *s, *t;
 
 	if (str == NULL)
 		return NULL;
 	t = (char *)str;
 	len = strlen(t);
 	while(len > 0 && t[len - 1] == c)
 		len--;
 
 	if (len == 0)
 		return NULL;
 
 	c = t[len];
 	t[len] = '\0';
 	s = xstrdup(t);
 	t[len] = c;