Refactor LFS GC functions

- Remove options that currently aren't set
on `GarbageCollectLFSMetaObjectsOptions` and
`IterateLFSMetaObjectsForRepoOptions`.
- Simplify `IterateRepositoryIDsWithLFSMetaObjects` and
`IterateLFSMetaObjectsForRepo`.
- `IterateLFSMetaObjectsForRepo` was previously able to get in a
loop (`gc-lfs` doctor check was able to reproduce this) because the code
expected that the records would be updated to not match the SQL query,
but that wasn't the case. Simply enforce that only records higher than
the latest `id` from the previous iteration are allowed.
- For `gc-lfs` doctor check this was because `UpdatedLessRecentlyThan`
option was not set, which caused that records just marked as active in
the iteration weren't being filtered.
- Add unit tests
- Most likely a regression from 2cc3a6381c.
- The bug with `gc-lfs` was found on Codeberg.

(cherry picked from commit 7ffa7f5bce)

models/git/lfs_test.go

@@ -0,0 +1,101 @@
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package git
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/test"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIterateRepositoryIDsWithLFSMetaObjects(t *testing.T) {
+	defer unittest.OverrideFixtures(
+		unittest.FixturesOptions{
+			Dir:  filepath.Join(setting.AppWorkPath, "models/fixtures/"),
+			Base: setting.AppWorkPath,
+			Dirs: []string{"models/git/TestIterateRepositoryIDsWithLFSMetaObjects/"},
+		},
+	)()
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	type repocount struct {
+		repoid int64
+		count  int64
+	}
+	expected := []repocount{{1, 1}, {54, 4}}
+
+	t.Run("Normal batch size", func(t *testing.T) {
+		defer test.MockVariableValue(&setting.Database.IterateBufferSize, 20)()
+		cases := []repocount{}
+
+		err := IterateRepositoryIDsWithLFSMetaObjects(db.DefaultContext, func(ctx context.Context, repoID, count int64) error {
+			cases = append(cases, repocount{repoID, count})
+			return nil
+		})
+		assert.NoError(t, err)
+		assert.EqualValues(t, expected, cases)
+	})
+
+	t.Run("Low batch size", func(t *testing.T) {
+		defer test.MockVariableValue(&setting.Database.IterateBufferSize, 1)()
+		cases := []repocount{}
+
+		err := IterateRepositoryIDsWithLFSMetaObjects(db.DefaultContext, func(ctx context.Context, repoID, count int64) error {
+			cases = append(cases, repocount{repoID, count})
+			return nil
+		})
+		assert.NoError(t, err)
+		assert.EqualValues(t, expected, cases)
+	})
+}
+
+func TestIterateLFSMetaObjectsForRepo(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	expectedIDs := []int64{1, 2, 3, 4}
+
+	t.Run("Normal batch size", func(t *testing.T) {
+		defer test.MockVariableValue(&setting.Database.IterateBufferSize, 20)()
+		actualIDs := []int64{}
+
+		err := IterateLFSMetaObjectsForRepo(db.DefaultContext, 54, func(ctx context.Context, lo *LFSMetaObject) error {
+			actualIDs = append(actualIDs, lo.ID)
+			return nil
+		}, &IterateLFSMetaObjectsForRepoOptions{})
+		assert.NoError(t, err)
+		assert.EqualValues(t, expectedIDs, actualIDs)
+	})
+
+	t.Run("Low batch size", func(t *testing.T) {
+		defer test.MockVariableValue(&setting.Database.IterateBufferSize, 1)()
+		actualIDs := []int64{}
+
+		err := IterateLFSMetaObjectsForRepo(db.DefaultContext, 54, func(ctx context.Context, lo *LFSMetaObject) error {
+			actualIDs = append(actualIDs, lo.ID)
+			return nil
+		}, &IterateLFSMetaObjectsForRepoOptions{})
+		assert.NoError(t, err)
+		assert.EqualValues(t, expectedIDs, actualIDs)
+
+		t.Run("Batch handles updates", func(t *testing.T) {
+			actualIDs := []int64{}
+
+			err := IterateLFSMetaObjectsForRepo(db.DefaultContext, 54, func(ctx context.Context, lo *LFSMetaObject) error {
+				actualIDs = append(actualIDs, lo.ID)
+				_, err := db.DeleteByID[LFSMetaObject](ctx, lo.ID)
+				assert.NoError(t, err)
+				return nil
+			}, &IterateLFSMetaObjectsForRepoOptions{})
+			assert.NoError(t, err)
+			assert.EqualValues(t, expectedIDs, actualIDs)
+		})
+	})
+}