chore(pkg): add kvlist validator (#498)

Signed-off-by: Michele Meloni <[email protected]>

Author: mmeloni

pkg/api/schema/kvlist.go

@@ -0,0 +1,38 @@
+/*
+Copyright 2019-2020 vChain, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package schema
+
+import (
+	"encoding/base64"
+	"errors"
+)
+
+// Validate checks for duplicated keys values that are not supported at the moment.
+func (l KVList) Validate() error {
+	if len(l.GetKVs()) == 0 {
+		return errors.New("empty set")
+	}
+	m := make(map[string]struct{}, len(l.GetKVs()))
+	for _, k := range l.GetKVs() {
+		b64k := base64.StdEncoding.EncodeToString(k.Key)
+		if _, ok := m[b64k]; ok {
+			return errors.New("duplicate keys are not supported in single batch transaction")
+		}
+		m[b64k] = struct{}{}
+	}
+	return nil
+}

pkg/api/schema/kvlist_test.go

@@ -0,0 +1,71 @@
+/*
+Copyright 2019-2020 vChain, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package schema
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestKVList_Validate(t *testing.T) {
+	kv := &KVList{
+		KVs: []*KeyValue{
+			{
+				Key:   []byte("key1"),
+				Value: []byte("val1"),
+			},
+			{
+				Key:   []byte("key2"),
+				Value: []byte("val2"),
+			},
+			{
+				Key:   []byte("key3"),
+				Value: []byte("val3"),
+			},
+		},
+	}
+	err := kv.Validate()
+	assert.NoError(t, err)
+}
+
+func TestKVList_ValidateDuplicateKeys(t *testing.T) {
+	kv := &KVList{
+		KVs: []*KeyValue{
+			{
+				Key:   []byte("key1"),
+				Value: []byte("val1"),
+			},
+			{
+				Key:   []byte("key1"),
+				Value: []byte("val2"),
+			},
+			{
+				Key:   []byte("key3"),
+				Value: []byte("val3"),
+			},
+		},
+	}
+	err := kv.Validate()
+	assert.Errorf(t, err, "duplicate keys are not supported in single batch transaction")
+}
+func TestKVList_ValidateEmptySet(t *testing.T) {
+	kv := &KVList{
+		KVs: []*KeyValue{},
+	}
+	err := kv.Validate()
+	assert.Errorf(t, err, "empty set")
+}

pkg/store/store.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"context"
 	"crypto/sha256"
-	"errors"
 	"math"
 	"sync"
 
@@ -130,8 +129,8 @@ func (t *Store) CurrentRoot() (root *schema.Root, err error) {
 
 // SetBatch adds many entries at once
 func (t *Store) SetBatch(list schema.KVList, options ...WriteOption) (index *schema.Index, err error) {
-	if len(list.GetKVs()) == 0 {
-		return nil, errors.New("Empty set")
+	if err = list.Validate(); err != nil {
+		return nil, err
 	}
 	opts := makeWriteOptions(options...)
 	txn := t.db.NewTransactionAt(math.MaxUint64, true)