Function TestIteratePrefix

iterator_test.go:127–237

(t *testing.T)

}

func TestIteratePrefix(t *testing.T) {
	testIteratorPrefix := func(t *testing.T, db *DB) {
		bkey := func(i int) []byte {
			return []byte(fmt.Sprintf("%04d", i))
		}
		val := []byte("OK")
		n := 10000

		batch := db.NewWriteBatch()
		for i := 0; i < n; i++ {
			if (i % 1000) == 0 {
				t.Logf("Put i=%d\n", i)
			}
			require.NoError(t, batch.Set(bkey(i), val))
		}
		require.NoError(t, batch.Flush())

		countKeys := func(prefix string) int {
			t.Logf("Testing with prefix: %s", prefix)
			var count int
			opt := DefaultIteratorOptions
			opt.Prefix = []byte(prefix)
			err := db.View(func(txn *Txn) error {
				itr := txn.NewIterator(opt)
				defer itr.Close()
				for itr.Rewind(); itr.Valid(); itr.Next() {
					item := itr.Item()
					err := item.Value(func(v []byte) error {
						require.Equal(t, val, v)
						return nil
					})
					require.NoError(t, err)
					require.True(t, bytes.HasPrefix(item.Key(), opt.Prefix))
					count++
				}
				return nil
			})
			require.NoError(t, err)
			return count
		}

		countOneKey := func(key []byte) int {
			var count int
			err := db.View(func(txn *Txn) error {
				itr := txn.NewKeyIterator(key, DefaultIteratorOptions)
				defer itr.Close()
				for itr.Rewind(); itr.Valid(); itr.Next() {
					item := itr.Item()
					err := item.Value(func(v []byte) error {
						require.Equal(t, val, v)
						return nil
					})
					require.NoError(t, err)
					require.Equal(t, key, item.Key())
					count++
				}
				return nil
			})