refactor: make db iterate context aware (#27710)

the iteration will run until finished atm.

this changes it by checking if if the context got canceled before each
run of a loop sequence is executed

[View this pull with now
whitespace](https://github.com/go-gitea/gitea/pull/27710/files?diff=unified&w=1)

models/db/iterate.go

@@ -17,6 +17,10 @@ func Iterate[Bean any](ctx context.Context, cond builder.Cond, f func(ctx contex
 	batchSize := setting.Database.IterateBufferSize
 	sess := GetEngine(ctx)
 	for {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
 			beans := make([]*Bean, 0, batchSize)
 			if cond != nil {
 				sess = sess.Where(cond)
@@ -35,4 +39,5 @@ func Iterate[Bean any](ctx context.Context, cond builder.Cond, f func(ctx contex
 				}
 			}
 		}
+	}
 }

modules/doctor/repository.go

@@ -37,6 +37,10 @@ func deleteOrphanedRepos(ctx context.Context) (int64, error) {
 	adminUser := &user_model.User{IsAdmin: true}
 
 	for {
+		select {
+		case <-ctx.Done():
+			return deleted, ctx.Err()
+		default:
 			var ids []int64
 			if err := e.Table("`repository`").
 				Join("LEFT", "`user`", "repository.owner_id=user.id").
@@ -57,6 +61,7 @@ func deleteOrphanedRepos(ctx context.Context) (int64, error) {
 				deleted++
 			}
 		}
+	}
 }
 
 func init() {