add other session providers (#5963)

vendor/github.com/go-macaron/session/memcache/memcache.go

@@ -0,0 +1,204 @@
+// Copyright 2013 Beego Authors
+// Copyright 2014 The Macaron Authors
+//
+// 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 session
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+
+	"github.com/bradfitz/gomemcache/memcache"
+
+	"github.com/go-macaron/session"
+)
+
+// MemcacheStore represents a memcache session store implementation.
+type MemcacheStore struct {
+	c      *memcache.Client
+	sid    string
+	expire int32
+	lock   sync.RWMutex
+	data   map[interface{}]interface{}
+}
+
+// NewMemcacheStore creates and returns a memcache session store.
+func NewMemcacheStore(c *memcache.Client, sid string, expire int32, kv map[interface{}]interface{}) *MemcacheStore {
+	return &MemcacheStore{
+		c:      c,
+		sid:    sid,
+		expire: expire,
+		data:   kv,
+	}
+}
+
+func NewItem(sid string, data []byte, expire int32) *memcache.Item {
+	return &memcache.Item{
+		Key:        sid,
+		Value:      data,
+		Expiration: expire,
+	}
+}
+
+// Set sets value to given key in session.
+func (s *MemcacheStore) Set(key, val interface{}) error {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	s.data[key] = val
+	return nil
+}
+
+// Get gets value by given key in session.
+func (s *MemcacheStore) Get(key interface{}) interface{} {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+
+	return s.data[key]
+}
+
+// Delete delete a key from session.
+func (s *MemcacheStore) Delete(key interface{}) error {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	delete(s.data, key)
+	return nil
+}
+
+// ID returns current session ID.
+func (s *MemcacheStore) ID() string {
+	return s.sid
+}
+
+// Release releases resource and save data to provider.
+func (s *MemcacheStore) Release() error {
+	// Skip encoding if the data is empty
+	if len(s.data) == 0 {
+		return nil
+	}
+
+	data, err := session.EncodeGob(s.data)
+	if err != nil {
+		return err
+	}
+
+	return s.c.Set(NewItem(s.sid, data, s.expire))
+}
+
+// Flush deletes all session data.
+func (s *MemcacheStore) Flush() error {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	s.data = make(map[interface{}]interface{})
+	return nil
+}
+
+// MemcacheProvider represents a memcache session provider implementation.
+type MemcacheProvider struct {
+	c      *memcache.Client
+	expire int32
+}
+
+// Init initializes memcache session provider.
+// connStrs: 127.0.0.1:9090;127.0.0.1:9091
+func (p *MemcacheProvider) Init(expire int64, connStrs string) error {
+	p.expire = int32(expire)
+	p.c = memcache.New(strings.Split(connStrs, ";")...)
+	return nil
+}
+
+// Read returns raw session store by session ID.
+func (p *MemcacheProvider) Read(sid string) (session.RawStore, error) {
+	if !p.Exist(sid) {
+		if err := p.c.Set(NewItem(sid, []byte(""), p.expire)); err != nil {
+			return nil, err
+		}
+	}
+
+	var kv map[interface{}]interface{}
+	item, err := p.c.Get(sid)
+	if err != nil {
+		return nil, err
+	}
+	if len(item.Value) == 0 {
+		kv = make(map[interface{}]interface{})
+	} else {
+		kv, err = session.DecodeGob(item.Value)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return NewMemcacheStore(p.c, sid, p.expire, kv), nil
+}
+
+// Exist returns true if session with given ID exists.
+func (p *MemcacheProvider) Exist(sid string) bool {
+	_, err := p.c.Get(sid)
+	return err == nil
+}
+
+// Destory deletes a session by session ID.
+func (p *MemcacheProvider) Destory(sid string) error {
+	return p.c.Delete(sid)
+}
+
+// Regenerate regenerates a session store from old session ID to new one.
+func (p *MemcacheProvider) Regenerate(oldsid, sid string) (_ session.RawStore, err error) {
+	if p.Exist(sid) {
+		return nil, fmt.Errorf("new sid '%s' already exists", sid)
+	}
+
+	item := NewItem(sid, []byte(""), p.expire)
+	if p.Exist(oldsid) {
+		item, err = p.c.Get(oldsid)
+		if err != nil {
+			return nil, err
+		} else if err = p.c.Delete(oldsid); err != nil {
+			return nil, err
+		}
+		item.Key = sid
+	}
+	if err = p.c.Set(item); err != nil {
+		return nil, err
+	}
+
+	var kv map[interface{}]interface{}
+	if len(item.Value) == 0 {
+		kv = make(map[interface{}]interface{})
+	} else {
+		kv, err = session.DecodeGob(item.Value)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return NewMemcacheStore(p.c, sid, p.expire, kv), nil
+}
+
+// Count counts and returns number of sessions.
+func (p *MemcacheProvider) Count() int {
+	// FIXME: how come this library does not have Stats method?
+	return -1
+}
+
+// GC calls GC to clean expired sessions.
+func (p *MemcacheProvider) GC() {}
+
+func init() {
+	session.Register("memcache", &MemcacheProvider{})
+}