[PATCH 1/2] rerere: represent time duration in timestamp_t internally

[Junio C Hamano]

The two configuration variables, gc.rerereResolved and
gc.rerereUnresolved, are measured in days and are passed as such
into the prune_one() helper function, which worked in time_t to see
if an entry in the rerere database is past its expiry.

Instead, have the caller turn the number of days into the expiry
timestamp.  Further, use timestamp_t instead of time_t.  This will
make it possible to extend the way the configuration variable is
spelled by using date.c::parse_expiry_date() that gives the expiry
timestamp in timestamp_t.

Signed-off-by: Junio C Hamano <gits...@pobox.com>
---
 rerere.c | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/rerere.c b/rerere.c
index 70634d456c..f0b4bce881 100644
--- a/rerere.c
+++ b/rerere.c
@@ -1133,14 +1133,14 @@ int rerere_forget(struct pathspec *pathspec)
  * Garbage collection support
  */
 
-static time_t rerere_created_at(struct rerere_id *id)
+static timestamp_t rerere_created_at(struct rerere_id *id)
 {
        struct stat st;
 
        return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : 
st.st_mtime;
 }
 
-static time_t rerere_last_used_at(struct rerere_id *id)
+static timestamp_t rerere_last_used_at(struct rerere_id *id)
 {
        struct stat st;
 
@@ -1157,11 +1157,11 @@ static void unlink_rr_item(struct rerere_id *id)
        id->collection->status[id->variant] = 0;
 }
 
-static void prune_one(struct rerere_id *id, time_t now,
-                     int cutoff_resolve, int cutoff_noresolve)
+static void prune_one(struct rerere_id *id,
+                     timestamp_t cutoff_resolve, timestamp_t cutoff_noresolve)
 {
-       time_t then;
-       int cutoff;
+       timestamp_t then;
+       timestamp_t cutoff;
 
        then = rerere_last_used_at(id);
        if (then)
@@ -1172,25 +1172,35 @@ static void prune_one(struct rerere_id *id, time_t now,
                        return;
                cutoff = cutoff_noresolve;
        }
-       if (then < now - cutoff * 86400)
+       if (then < cutoff)
                unlink_rr_item(id);
 }
 
+static void config_get_expiry(const char *key, timestamp_t *cutoff, 
timestamp_t now)
+{
+       int days;
+
+       if (!git_config_get_int(key, &days)) {
+               const int scale = 86400;
+               *cutoff = now - days * scale;
+       }
+}
+
 void rerere_gc(struct string_list *rr)
 {
        struct string_list to_remove = STRING_LIST_INIT_DUP;
        DIR *dir;
        struct dirent *e;
        int i;
-       time_t now = time(NULL);
-       int cutoff_noresolve = 15;
-       int cutoff_resolve = 60;
+       timestamp_t now = time(NULL);
+       timestamp_t cutoff_noresolve = now - 15 * 86400;
+       timestamp_t cutoff_resolve = now - 60 * 86400;
 
        if (setup_rerere(rr, 0) < 0)
                return;
 
-       git_config_get_int("gc.rerereresolved", &cutoff_resolve);
-       git_config_get_int("gc.rerereunresolved", &cutoff_noresolve);
+       config_get_expiry("gc.rerereresolved", &cutoff_resolve, now);
+       config_get_expiry("gc.rerereunresolved", &cutoff_noresolve, now);
        git_config(git_default_config, NULL);
        dir = opendir(git_path("rr-cache"));
        if (!dir)
@@ -1211,7 +1221,7 @@ void rerere_gc(struct string_list *rr)
                for (id.variant = 0, id.collection = rr_dir;
                     id.variant < id.collection->status_nr;
                     id.variant++) {
-                       prune_one(&id, now, cutoff_resolve, cutoff_noresolve);
+                       prune_one(&id, cutoff_resolve, cutoff_noresolve);
                        if (id.collection->status[id.variant])
                                now_empty = 0;
                }
-- 
2.14.1-405-g52c75fc716