Add cron method to gc LFS MetaObjects (#22385)

This PR adds a task to the cron service to allow garbage collection of
LFS meta objects. As repositories may have a large number of
LFSMetaObjects, an updated column is added to this table and it is used
to perform a generational GC to attempt to reduce the amount of work.
(There may need to be a bit more work here but this is probably enough
for the moment.)

Fix #7045

Signed-off-by: Andrew Thornton <art27@cantab.net>

1 files changed, 15 insertions, 1 deletions

diff --git a/modules/doctor/lfs.go b/modules/doctor/lfs.go
index 410ed5a9a5..64ee4c40bf 100644
--- a/modules/doctor/lfs.go
+++ b/modules/doctor/lfs.go
@@ -6,6 +6,7 @@ package doctor
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -29,7 +30,20 @@ func garbageCollectLFSCheck(ctx context.Context, logger log.Logger, autofix bool
 		return fmt.Errorf("LFS support is disabled")
 	}
 
-	if err := repository.GarbageCollectLFSMetaObjects(ctx, logger, autofix); err != nil {
+	if err := repository.GarbageCollectLFSMetaObjects(ctx, repository.GarbageCollectLFSMetaObjectsOptions{
+		Logger:  logger,
+		AutoFix: autofix,
+		// Only attempt to garbage collect lfs meta objects older than a week as the order of git lfs upload
+		// and git object upload is not necessarily guaranteed. It's possible to imagine a situation whereby
+		// an LFS object is uploaded but the git branch is not uploaded immediately, or there are some rapid
+		// changes in new branches that might lead to lfs objects becoming temporarily unassociated with git
+		// objects.
+		//
+		// It is likely that a week is potentially excessive but it should definitely be enough that any
+		// unassociated LFS object is genuinely unassociated.
+		OlderThan: time.Now().Add(-24 * time.Hour * 7),
+		// We don't set the UpdatedLessRecentlyThan because we want to do a full GC
+	}); err != nil {
 		return err
 	}