Support FT.ADDHASH command (#62)

* Support FT.ADDHASH command

Author: dengliming

README.md

@@ -78,7 +78,7 @@ func ExampleClient() {
 | :---          |  ----: |
 | [FT.CREATE](https://oss.redislabs.com/redisearch/Commands.html#ftcreate) |   [CreateIndex](https://godoc.org/github.com/RediSearch/redisearch-go/redisearch#Client.CreateIndex)          |
 | [FT.ADD](https://oss.redislabs.com/redisearch/Commands.html#ftadd) |   [IndexOptions](https://godoc.org/github.com/RediSearch/redisearch-go/redisearch#Client.IndexOptions)          |
-| [FT.ADDHASH](https://oss.redislabs.com/redisearch/Commands.html#ftaddhash) | N/A |
+| [FT.ADDHASH](https://oss.redislabs.com/redisearch/Commands.html#ftaddhash) | [AddHash](https://godoc.org/github.com/RediSearch/redisearch-go/redisearch#Client.AddHash) |
 | [FT.ALTER](https://oss.redislabs.com/redisearch/Commands.html#ftalter) |    N/A |
 | [FT.ALIASADD](https://oss.redislabs.com/redisearch/Commands.html#ftaliasadd) |  [AliasAdd](https://godoc.org/github.com/RediSearch/redisearch-go/redisearch#Client.AliasAdd)         |
 | [FT.ALIASUPDATE](https://oss.redislabs.com/redisearch/Commands.html#ftaliasupdate) |     [AliasUpdate](https://godoc.org/github.com/RediSearch/redisearch-go/redisearch#Client.AliasUpdate)          |

redisearch/client.go

@@ -585,3 +585,19 @@ func (i *Client) SynDump(indexName string) (map[string][]int64, error) {
 	}
 	return m, nil
 }
+
+// Adds a document to the index from an existing HASH key in Redis.
+func (i *Client) AddHash(docId string, score float32, language string, replace bool) (string, error) {
+	conn := i.pool.Get()
+	defer conn.Close()
+
+	args := redis.Args{i.name, docId, score}
+	if language != "" {
+		args = args.Add("LANGUAGE", language)
+	}
+
+	if replace {
+		args = args.Add("REPLACE")
+	}
+	return redis.String(conn.Do("FT.ADDHASH", args...))
+}

redisearch/client_test.go

@@ -512,3 +512,21 @@ func TestClient_SynDump(t *testing.T) {
 	assert.Equal(t, gid, m["baby"][0])
 	assert.Equal(t, gid2, m["child"][0])
 }
+
+func TestClient_AddHash(t *testing.T) {
+	c := createClient("testAddHash")
+
+	sc := NewSchema(DefaultOptions).
+		AddField(NewTextField("name")).
+		AddField(NewTextField("addr"))
+	c.Drop()
+	err := c.CreateIndex(sc)
+	assert.Nil(t, err)
+
+	// Add a hash key
+	c.pool.Get().Do("HMSET", "myhash", "field1", "Hello")
+
+	ret, err := c.AddHash("myhash", 1, "english", false)
+	assert.Nil(t, err)
+	assert.Equal(t, "OK", ret)
+}