Merge pull request #4173 from AllenX2018/fix-bug-queryRow

Fix issue 3866

pkg/client/cache/memcache/memcache.go

@@ -0,0 +1,189 @@
+// Copyright 2014 beego Author. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package memcache for cache provider
+//
+// depend on github.com/bradfitz/gomemcache/memcache
+//
+// go install github.com/bradfitz/gomemcache/memcache
+//
+// Usage:
+// import(
+//   _ "github.com/astaxie/beego/cache/memcache"
+//   "github.com/astaxie/beego/cache"
+// )
+//
+//  bm, err := cache.NewCache("memcache", `{"conn":"127.0.0.1:11211"}`)
+//
+//  more docs http://beego.me/docs/module/cache.md
+package memcache
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/bradfitz/gomemcache/memcache"
+
+	"github.com/astaxie/beego/pkg/client/cache"
+)
+
+// Cache Memcache adapter.
+type Cache struct {
+	conn     *memcache.Client
+	conninfo []string
+}
+
+// NewMemCache creates a new memcache adapter.
+func NewMemCache() cache.Cache {
+	return &Cache{}
+}
+
+// Get get value from memcache.
+func (rc *Cache) Get(key string) interface{} {
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return err
+		}
+	}
+	if item, err := rc.conn.Get(key); err == nil {
+		return item.Value
+	}
+	return nil
+}
+
+// GetMulti gets a value from a key in memcache.
+func (rc *Cache) GetMulti(keys []string) []interface{} {
+	size := len(keys)
+	var rv []interface{}
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			for i := 0; i < size; i++ {
+				rv = append(rv, err)
+			}
+			return rv
+		}
+	}
+	mv, err := rc.conn.GetMulti(keys)
+	if err == nil {
+		for _, v := range mv {
+			rv = append(rv, v.Value)
+		}
+		return rv
+	}
+	for i := 0; i < size; i++ {
+		rv = append(rv, err)
+	}
+	return rv
+}
+
+// Put puts a value into memcache.
+func (rc *Cache) Put(key string, val interface{}, timeout time.Duration) error {
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return err
+		}
+	}
+	item := memcache.Item{Key: key, Expiration: int32(timeout / time.Second)}
+	if v, ok := val.([]byte); ok {
+		item.Value = v
+	} else if str, ok := val.(string); ok {
+		item.Value = []byte(str)
+	} else {
+		return errors.New("val only support string and []byte")
+	}
+	return rc.conn.Set(&item)
+}
+
+// Delete deletes a value in memcache.
+func (rc *Cache) Delete(key string) error {
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return err
+		}
+	}
+	return rc.conn.Delete(key)
+}
+
+// Incr increases counter.
+func (rc *Cache) Incr(key string) error {
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return err
+		}
+	}
+	_, err := rc.conn.Increment(key, 1)
+	return err
+}
+
+// Decr decreases counter.
+func (rc *Cache) Decr(key string) error {
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return err
+		}
+	}
+	_, err := rc.conn.Decrement(key, 1)
+	return err
+}
+
+// IsExist checks if a value exists in memcache.
+func (rc *Cache) IsExist(key string) bool {
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return false
+		}
+	}
+	_, err := rc.conn.Get(key)
+	return err == nil
+}
+
+// ClearAll clears all cache in memcache.
+func (rc *Cache) ClearAll() error {
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return err
+		}
+	}
+	return rc.conn.FlushAll()
+}
+
+// StartAndGC starts the memcache adapter.
+// config: must be in the format {"conn":"connection info"}.
+// If an error occurs during connecting, an error is returned
+func (rc *Cache) StartAndGC(config string) error {
+	var cf map[string]string
+	json.Unmarshal([]byte(config), &cf)
+	if _, ok := cf["conn"]; !ok {
+		return errors.New("config has no conn key")
+	}
+	rc.conninfo = strings.Split(cf["conn"], ";")
+	if rc.conn == nil {
+		if err := rc.connectInit(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// connect to memcache and keep the connection.
+func (rc *Cache) connectInit() error {
+	rc.conn = memcache.New(rc.conninfo...)
+	return nil
+}
+
+func init() {
+	cache.Register("memcache", NewMemCache)
+}