refactor: #1899 redis cache module refactor

redis cache module refactor, to view the discussion:

  https://github.com/astaxie/beego/issues/1899

cache/redis/redis.go

@@ -32,6 +32,7 @@ package redis
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"strconv"
 	"time"
 
@@ -59,14 +60,23 @@ func NewRedisCache() cache.Cache {
 	return &Cache{key: DefaultKey}
 }
 
-// actually do the redis cmds
+// actually do the redis cmds, args[0] must be the key name.
 func (rc *Cache) do(commandName string, args ...interface{}) (reply interface{}, err error) {
+	if len(args) < 1 {
+		return nil, errors.New("missing required arguments")
+	}
+	args[0] = rc.associate(args[0])
 	c := rc.p.Get()
 	defer c.Close()
 
 	return c.Do(commandName, args...)
 }
 
+// associate with config key.
+func (rc *Cache) associate(originKey interface{}) string {
+	return fmt.Sprintf("%s:%s", rc.key, originKey)
+}
+
 // Get cache from redis.
 func (rc *Cache) Get(key string) interface{} {
 	if v, err := rc.do("GET", key); err == nil {
@@ -77,57 +87,28 @@ func (rc *Cache) Get(key string) interface{} {
 
 // GetMulti get cache from redis.
 func (rc *Cache) GetMulti(keys []string) []interface{} {
-	size := len(keys)
-	var rv []interface{}
 	c := rc.p.Get()
 	defer c.Close()
-	var err error
+	var args []interface{}
 	for _, key := range keys {
-		err = c.Send("GET", key)
-		if err != nil {
-			goto ERROR
-		}
+		args = append(args, rc.associate(key))
 	}
-	if err = c.Flush(); err != nil {
-		goto ERROR
+	values, err := redis.Values(c.Do("MGET", args...))
+	if err != nil {
+		return nil
 	}
-	for i := 0; i < size; i++ {
-		if v, err := c.Receive(); err == nil {
-			rv = append(rv, v.([]byte))
-		} else {
-			rv = append(rv, err)
-		}
-	}
-	return rv
-ERROR:
-	rv = rv[0:0]
-	for i := 0; i < size; i++ {
-		rv = append(rv, nil)
-	}
-
-	return rv
+	return values
 }
 
 // Put put cache to redis.
 func (rc *Cache) Put(key string, val interface{}, timeout time.Duration) error {
-	var err error
-	if _, err = rc.do("SETEX", key, int64(timeout/time.Second), val); err != nil {
-		return err
-	}
-
-	if _, err = rc.do("HSET", rc.key, key, true); err != nil {
-		return err
-	}
+	_, err := rc.do("SETEX", key, int64(timeout/time.Second), val)
 	return err
 }
 
 // Delete delete cache in redis.
 func (rc *Cache) Delete(key string) error {
-	var err error
-	if _, err = rc.do("DEL", key); err != nil {
-		return err
-	}
-	_, err = rc.do("HDEL", rc.key, key)
+	_, err := rc.do("DEL", key)
 	return err
 }
 
@@ -137,11 +118,6 @@ func (rc *Cache) IsExist(key string) bool {
 	if err != nil {
 		return false
 	}
-	if !v {
-		if _, err = rc.do("HDEL", rc.key, key); err != nil {
-			return false
-		}
-	}
 	return v
 }
 
@@ -159,16 +135,17 @@ func (rc *Cache) Decr(key string) error {
 
 // ClearAll clean all cache in redis. delete this redis collection.
 func (rc *Cache) ClearAll() error {
-	cachedKeys, err := redis.Strings(rc.do("HKEYS", rc.key))
+	c := rc.p.Get()
+	defer c.Close()
+	cachedKeys, err := redis.Strings(c.Do("KEYS", rc.key+":*"))
 	if err != nil {
 		return err
 	}
 	for _, str := range cachedKeys {
-		if _, err = rc.do("DEL", str); err != nil {
+		if _, err = c.Do("DEL", str); err != nil {
 			return err
 		}
 	}
-	_, err = rc.do("DEL", rc.key)
 	return err
 }