Merge pull request #664 from cosmos/sunny/IAVLsubspace

added Subspace Iterator to IAVLTree

store/iavlstore.go

@@ -119,6 +119,13 @@ func (st *iavlStore) Iterator(start, end []byte) Iterator {
 	return newIAVLIterator(st.tree.Tree(), start, end, true)
 }
 
+func (st *iavlStore) Subspace(prefix []byte) Iterator {
+	end := make([]byte, len(prefix))
+	copy(end, prefix)
+	end[len(end)-1]++
+	return st.Iterator(prefix, end)
+}
+
 // Implements IterKVStore.
 func (st *iavlStore) ReverseIterator(start, end []byte) Iterator {
 	return newIAVLIterator(st.tree.Tree(), start, end, false)

store/iavlstore_test.go

@@ -82,6 +82,26 @@ func TestIAVLIterator(t *testing.T) {
 	}
 }
 
+func TestIAVLSubspace(t *testing.T) {
+	db := dbm.NewMemDB()
+	tree, _ := newTree(t, db)
+	iavlStore := newIAVLStore(tree, numHistory)
+
+	iavlStore.Set([]byte("test1"), []byte("test1"))
+	iavlStore.Set([]byte("test2"), []byte("test2"))
+	iavlStore.Set([]byte("test3"), []byte("test3"))
+
+	iter := iavlStore.Subspace([]byte("test"))
+	expected := []string{"test1", "test2", "test3"}
+	for i := 0; iter.Valid(); iter.Next() {
+		expectedKey := expected[i]
+		key, value := iter.Key(), iter.Value()
+		assert.EqualValues(t, key, expectedKey)
+		assert.EqualValues(t, value, expectedKey)
+		i += 1
+	}
+}
+
 func TestIAVLStoreQuery(t *testing.T) {
 	db := dbm.NewMemDB()
 	tree := iavl.NewVersionedTree(db, cacheSize)