Function TestPartialAppendToValueLog

value_test.go:586–658

(t *testing.T)

}

func TestPartialAppendToValueLog(t *testing.T) {
	dir, err := ioutil.TempDir("", "badger-test")
	require.NoError(t, err)
	defer removeDir(dir)

	// Create skeleton files.
	opts := getTestOptions(dir)
	opts.Truncate = true
	opts.ValueLogFileSize = 100 * 1024 * 1024 // 100Mb
	opts.ValueThreshold = 32
	kv, err := Open(opts)
	require.NoError(t, err)
	require.NoError(t, kv.Close())

	var (
		k0 = []byte("k0")
		k1 = []byte("k1")
		k2 = []byte("k2")
		k3 = []byte("k3")
		v0 = []byte("value0-01234567890123456789012012345678901234567890123")
		v1 = []byte("value1-01234567890123456789012012345678901234567890123")
		v2 = []byte("value2-01234567890123456789012012345678901234567890123")
		v3 = []byte("value3-01234567890123456789012012345678901234567890123")
	)
	// Values need to be long enough to actually get written to value log.
	require.True(t, len(v3) >= kv.opt.ValueThreshold)

	// Create truncated vlog to simulate a partial append.
	// k0 - single transaction, k1 and k2 in another transaction
	buf := createVlog(t, []*Entry{
		{Key: k0, Value: v0},
		{Key: k1, Value: v1},
		{Key: k2, Value: v2},
	})
	buf = buf[:len(buf)-6]
	require.NoError(t, ioutil.WriteFile(vlogFilePath(dir, 0), buf, 0777))

	// Badger should now start up
	kv, err = Open(opts)
	require.NoError(t, err)

	require.NoError(t, kv.View(func(txn *Txn) error {
		item, err := txn.Get(k0)
		require.NoError(t, err)
		require.Equal(t, v0, getItemValue(t, item))

		_, err = txn.Get(k1)
		require.Equal(t, ErrKeyNotFound, err)
		_, err = txn.Get(k2)
		require.Equal(t, ErrKeyNotFound, err)
		return nil
	}))

	// When K3 is set, it should be persisted after a restart.
	txnSet(t, kv, k3, v3, 0)
	require.NoError(t, kv.Close())
	kv, err = Open(opts)
	require.NoError(t, err)