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>
diff --git a/cgit.h b/cgit.h
index ea90833..c99d337 100644
--- a/cgit.h
+++ b/cgit.h
@@ -61,6 +61,7 @@
int snapshots;
int enable_log_filecount;
int enable_log_linecount;
+ time_t mtime;
};
struct cgit_repolist {
diff --git a/shared.c b/shared.c
index f5875e4..89d1bab 100644
--- a/shared.c
+++ b/shared.c
@@ -60,6 +60,7 @@
ret->enable_log_linecount = ctx.cfg.enable_log_linecount;
ret->module_link = ctx.cfg.module_link;
ret->readme = NULL;
+ ret->mtime = -1;
return ret;
}
diff --git a/ui-repolist.c b/ui-repolist.c
index cf27cb3..aa743bf 100644
--- a/ui-repolist.c
+++ b/ui-repolist.c
@@ -32,19 +32,27 @@
{
char *path;
struct stat s;
+ struct cgit_repo *r = (struct cgit_repo *)repo;
+ if (repo->mtime != -1) {
+ *mtime = repo->mtime;
+ return 1;
+ }
path = fmt("%s/%s", repo->path, ctx.cfg.agefile);
if (stat(path, &s) == 0) {
*mtime = read_agefile(path);
+ r->mtime = *mtime;
return 1;
}
path = fmt("%s/refs/heads/%s", repo->path, repo->defbranch);
- if (stat(path, &s) == 0) {
+ if (stat(path, &s) == 0)
*mtime = s.st_mtime;
- return 1;
- }
- return 0;
+ else
+ *mtime = 0;
+
+ r->mtime = *mtime;
+ return (r->mtime != 0);
}
static void print_modtime(struct cgit_repo *repo)