Function TestOpen_Size

db_test.go:282–327

Ensure that opening a database does not increase its size. https://github.com/boltdb/bolt/issues/291

(t *testing.T)

// Ensure that opening a database does not increase its size.
// https://github.com/boltdb/bolt/issues/291
func TestOpen_Size(t *testing.T) {
	// Open a data file.
	db := btesting.MustCreateDB(t)

	pagesize := db.Info().PageSize

	// Insert until we get above the minimum 4MB size.
	err := db.Fill([]byte("data"), 1, 10000,
		func(tx int, k int) []byte { return []byte(fmt.Sprintf("%04d", k)) },
		func(tx int, k int) []byte { return make([]byte, 1000) },
	)
	if err != nil {
		t.Fatal(err)
	}

	path := db.Path()
	db.MustClose()

	sz := fileSize(path)
	if sz == 0 {
		t.Fatalf("unexpected new file size: %d", sz)
	}

	db.MustReopen()
	if err := db.Update(func(tx *bolt.Tx) error {
		if err := tx.Bucket([]byte("data")).Put([]byte{0}, []byte{0}); err != nil {
			t.Fatal(err)
		}
		return nil
	}); err != nil {
		t.Fatal(err)
	}
	if err := db.Close(); err != nil {
		t.Fatal(err)
	}
	newSz := fileSize(path)
	if newSz == 0 {
		t.Fatalf("unexpected new file size: %d", newSz)
	}

	// Compare the original size with the new size.
	// db size might increase by a few page sizes due to the new small update.
	if sz < newSz-5*int64(pagesize) {
		t.Fatalf("unexpected file growth: %d => %d", sz, newSz)
	}
}

// Ensure that opening a database beyond the max step size does not increase its size.
// https://github.com/boltdb/bolt/issues/303