Merge pull request #29 from lovoo/iterator-fix

iterator offset key skipping

storage/storage.go

@@ -84,6 +84,11 @@ func (i *iter) Next() bool {
 
 	// find the next non deleted snapshot value
 	for !i.snapExhausted() {
+		if string(i.Key()) == offsetKey {
+			i.current++
+			continue
+		}
+
 		if val, err := i.Value(); err != nil {
 			// TODO (franz): sure we want a panic? Not returning the error?
 			i.storage.log.Panicf("error getting snapshot value in next: %v", err)
@@ -96,6 +101,10 @@ func (i *iter) Next() bool {
 
 	// find next value in db that was not in snapshot
 	for i.iter.Next() {
+		if string(i.Key()) == offsetKey {
+			continue
+		}
+
 		if !i.snapshot.Has(string(i.Key())) {
 			return true
 		}
@@ -114,7 +123,11 @@ func (i *iter) Key() []byte {
 
 func (i *iter) Value() (interface{}, error) {
 	if i.snapExhausted() {
-		return i.storage.codec.Decode(i.iter.Value())
+		dec, err := i.storage.codec.Decode(i.iter.Value())
+		if err != nil {
+			return nil, fmt.Errorf("error decoding value (key: %s): %v", string(i.Key()), err)
+		}
+		return dec, nil
 	}
 
 	val, enc, err := i.snapshot.Get(string(i.Key()), i.storage.stateCloner(i.storage.codec))

storage/storage_mock.go

@@ -28,6 +28,9 @@ func (i *memiter) exhausted() bool {
 
 func (i *memiter) Next() bool {
 	i.current++
+	if string(i.Key()) == offsetKey {
+		i.current++
+	}
 	return !i.exhausted()
 }
 

storage/storage_test.go

@@ -46,11 +46,12 @@ func TestMemIter(t *testing.T) {
 
 	found := map[string]string{}
 
+	storage.Set(offsetKey, "not-returned")
 	for k, v := range kv {
 		storage.Set(k, v)
 	}
 
-	// released iterator should be immidiately exhausted
+	// released iterator should be immediately exhausted
 	iter := storage.Iterator()
 	iter.Release()
 	ensure.False(t, iter.Next(), "released iterator had a next")