Add Support for TOPK.INFO

Author: dengliming

client.go

@@ -2,6 +2,7 @@ package redis_bloom_go
 
 import (
 	"errors"
+	"fmt"
 	"github.com/gomodule/redigo/redis"
 	"strconv"
 	"strings"
@@ -174,3 +175,32 @@ func (client *Client) TopkList(key string) ([]string, error) {
 	result, err := conn.Do("TOPK.LIST", key)
 	return redis.Strings(result, err)
 }
+
+// Returns number of required items (k), width, depth and decay values.
+func (client *Client) TopkInfo(key string) (map[string]string, error) {
+	conn := client.Pool.Get()
+	defer conn.Close()
+	reply, err := conn.Do("TOPK.INFO", key)
+	values, err := redis.Values(reply, err)
+	if err != nil {
+		return nil, err
+	}
+	if len(values)%2 != 0 {
+		return nil, errors.New("expects even number of values result")
+	}
+
+	m := make(map[string]string, len(values)/2)
+	for i := 0; i < len(values); i += 2 {
+		k := values[i].(string)
+		switch v := values[i+1].(type) {
+		case []byte:
+			m[k] = string(values[i+1].([]byte))
+			break
+		case int64:
+			m[k] = strconv.FormatInt(values[i+1].(int64), 10)
+		default:
+			return nil, fmt.Errorf("unexpected element type for (Ints,String), got type %T", v)
+		}
+	}
+	return m, err
+}

client_test.go

@@ -174,3 +174,19 @@ func TestClient_TopkQuery(t *testing.T) {
 	assert.Equal(t, 3, len(keys))
 	assert.Equal(t, []string{"D", "A", "B"}, keys)
 }
+
+func TestClient_TopkInfo(t *testing.T) {
+	client.FlushAll()
+	key := "test_topk_info"
+	ret, err := client.TopkReserve(key, 10, 2000, 7, 0.925)
+	assert.Nil(t, err)
+	assert.Equal(t, "OK", ret)
+
+	info, err := client.TopkInfo(key)
+	assert.Equal(t, "10", info["k"])
+	assert.Equal(t, "2000", info["width"])
+	assert.Equal(t, "7", info["depth"])
+
+	info, err = client.TopkInfo("notexists")
+	assert.NotNil(t, err)
+}