maintenance: use random minute in launchctl scheduler

The get_random_minute() method was created to allow maintenance
schedules to be fixed to a random minute of the hour. This randomness is
only intended to spread out the load from a number of clients, but each
client should have an hour between each maintenance cycle.

Use get_random_minute() when constructing the schedules for launchctl.

The format already includes a 'Minute' key which is modified from 0 to
the random minute.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/gc.c b/builtin/gc.c
index 2ebae7bc17c568e89ff48dc952864625213d7890..286ce131a5c04d4c6106e6ed6aa7a61a66fe2165 100644 (file)
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -1708,7 +1708,6 @@ static int get_schedule_cmd(const char **cmd, int *is_available)
        return 1;
 }
 
-MAYBE_UNUSED
 static int get_random_minute(void)
 {
        /* Use a static value when under tests. */
@@ -1830,6 +1829,7 @@ static int launchctl_schedule_plist(const char *exec_path, enum schedule_priorit
        struct strbuf plist = STRBUF_INIT, plist2 = STRBUF_INIT;
        struct stat st;
        const char *cmd = "launchctl";
+       int minute = get_random_minute();
 
        get_schedule_cmd(&cmd, NULL);
        preamble = "<?xml version=\"1.0\"?>\n"
@@ -1855,29 +1855,30 @@ static int launchctl_schedule_plist(const char *exec_path, enum schedule_priorit
        case SCHEDULE_HOURLY:
                repeat = "<dict>\n"
                         "<key>Hour</key><integer>%d</integer>\n"
-                        "<key>Minute</key><integer>0</integer>\n"
+                        "<key>Minute</key><integer>%d</integer>\n"
                         "</dict>\n";
                for (i = 1; i <= 23; i++)
-                       strbuf_addf(&plist, repeat, i);
+                       strbuf_addf(&plist, repeat, i, minute);
                break;
 
        case SCHEDULE_DAILY:
                repeat = "<dict>\n"
                         "<key>Day</key><integer>%d</integer>\n"
                         "<key>Hour</key><integer>0</integer>\n"
-                        "<key>Minute</key><integer>0</integer>\n"
+                        "<key>Minute</key><integer>%d</integer>\n"
                         "</dict>\n";
                for (i = 1; i <= 6; i++)
-                       strbuf_addf(&plist, repeat, i);
+                       strbuf_addf(&plist, repeat, i, minute);
                break;
 
        case SCHEDULE_WEEKLY:
-               strbuf_addstr(&plist,
-                             "<dict>\n"
-                             "<key>Day</key><integer>0</integer>\n"
-                             "<key>Hour</key><integer>0</integer>\n"
-                             "<key>Minute</key><integer>0</integer>\n"
-                             "</dict>\n");
+               strbuf_addf(&plist,
+                           "<dict>\n"
+                           "<key>Day</key><integer>0</integer>\n"
+                           "<key>Hour</key><integer>0</integer>\n"
+                           "<key>Minute</key><integer>%d</integer>\n"
+                           "</dict>\n",
+                           minute);
                break;
 
        default: