add comments for session packages, part 2

@@ -9,6 +9,8 @@ import (
 
 var mempder = &MemProvider{list: list.New(), sessions: make(map[string]*list.Element)}
 
+// memory session store.
+// it saved sessions in a map in memory.
 type MemSessionStore struct {
 	sid          string                      //session id
 	timeAccessed time.Time                   //last access time
@@ -16,6 +18,7 @@ type MemSessionStore struct {
 	lock         sync.RWMutex
 }
 
+// set value to memory session
 func (st *MemSessionStore) Set(key, value interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -23,6 +26,7 @@ func (st *MemSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// get value from memory session by key
 func (st *MemSessionStore) Get(key interface{}) interface{} {
 	st.lock.RLock()
 	defer st.lock.RUnlock()
@@ -34,6 +38,7 @@ func (st *MemSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// delete in memory session by key
 func (st *MemSessionStore) Delete(key interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -41,6 +46,7 @@ func (st *MemSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// clear all values in memory session
 func (st *MemSessionStore) Flush() error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -48,27 +54,31 @@ func (st *MemSessionStore) Flush() error {
 	return nil
 }
 
+// get this id of memory session store
 func (st *MemSessionStore) SessionID() string {
 	return st.sid
 }
 
+// Implement method, no used.
 func (st *MemSessionStore) SessionRelease(w http.ResponseWriter) {
 }
 
 type MemProvider struct {
-	lock        sync.RWMutex             //用来锁
-	sessions    map[string]*list.Element //用来存储在内存
-	list        *list.List               //用来做gc
+	lock        sync.RWMutex             // locker
+	sessions    map[string]*list.Element // map in memory
+	list        *list.List               // for gc
 	maxlifetime int64
 	savePath    string
 }
 
+// init memory session
 func (pder *MemProvider) SessionInit(maxlifetime int64, savePath string) error {
 	pder.maxlifetime = maxlifetime
 	pder.savePath = savePath
 	return nil
 }
 
+// get memory session store by sid
 func (pder *MemProvider) SessionRead(sid string) (SessionStore, error) {
 	pder.lock.RLock()
 	if element, ok := pder.sessions[sid]; ok {
@@ -87,6 +97,7 @@ func (pder *MemProvider) SessionRead(sid string) (SessionStore, error) {
 	return nil, nil
 }
 
+// check session store exist in memory session by sid
 func (pder *MemProvider) SessionExist(sid string) bool {
 	pder.lock.RLock()
 	defer pder.lock.RUnlock()
@@ -97,6 +108,7 @@ func (pder *MemProvider) SessionExist(sid string) bool {
 	}
 }
 
+// generate new sid for session store in memory session
 func (pder *MemProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	pder.lock.RLock()
 	if element, ok := pder.sessions[oldsid]; ok {
@@ -120,6 +132,7 @@ func (pder *MemProvider) SessionRegenerate(oldsid, sid string) (SessionStore, er
 	return nil, nil
 }
 
+// delete session store in memory session by id
 func (pder *MemProvider) SessionDestroy(sid string) error {
 	pder.lock.Lock()
 	defer pder.lock.Unlock()
@@ -131,6 +144,7 @@ func (pder *MemProvider) SessionDestroy(sid string) error {
 	return nil
 }
 
+// clean expired session stores in memory session
 func (pder *MemProvider) SessionGC() {
 	pder.lock.RLock()
 	for {
@@ -152,10 +166,12 @@ func (pder *MemProvider) SessionGC() {
 	pder.lock.RUnlock()
 }
 
+// get count number of memory session
 func (pder *MemProvider) SessionAll() int {
 	return pder.list.Len()
 }
 
+// expand time of session store by id in memory session
 func (pder *MemProvider) SessionUpdate(sid string) error {
 	pder.lock.Lock()
 	defer pder.lock.Unlock()

 package session
 
-//CREATE TABLE `session` (
+// mysql session support need create table as sql:
+//	CREATE TABLE `session` (
 //	`session_key` char(64) NOT NULL,
-//  `session_data` blob,
+//	session_data` blob,
 //	`session_expiry` int(11) unsigned NOT NULL,
 //	PRIMARY KEY (`session_key`)
-//) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+//	) ENGINE=MyISAM DEFAULT CHARSET=utf8;
 
 import (
 	"database/sql"
@@ -18,6 +19,7 @@ import (
 
 var mysqlpder = &MysqlProvider{}
 
+// mysql session store
 type MysqlSessionStore struct {
 	c      *sql.DB
 	sid    string
@@ -25,6 +27,8 @@ type MysqlSessionStore struct {
 	values map[interface{}]interface{}
 }
 
+// set value in mysql session.
+// it is temp value in map.
 func (st *MysqlSessionStore) Set(key, value interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -32,6 +36,7 @@ func (st *MysqlSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// get value from mysql session
 func (st *MysqlSessionStore) Get(key interface{}) interface{} {
 	st.lock.RLock()
 	defer st.lock.RUnlock()
@@ -43,6 +48,7 @@ func (st *MysqlSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// delete value in mysql session
 func (st *MysqlSessionStore) Delete(key interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -50,6 +56,7 @@ func (st *MysqlSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// clear all values in mysql session
 func (st *MysqlSessionStore) Flush() error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -57,10 +64,13 @@ func (st *MysqlSessionStore) Flush() error {
 	return nil
 }
 
+// get session id of this mysql session store
 func (st *MysqlSessionStore) SessionID() string {
 	return st.sid
 }
 
+// save mysql session values to database.
+// must call this method to save values to database.
 func (st *MysqlSessionStore) SessionRelease(w http.ResponseWriter) {
 	defer st.c.Close()
 	b, err := encodeGob(st.values)
@@ -72,11 +82,13 @@ func (st *MysqlSessionStore) SessionRelease(w http.ResponseWriter) {
 
 }
 
+// mysql session provider
 type MysqlProvider struct {
 	maxlifetime int64
 	savePath    string
 }
 
+// connect to mysql
 func (mp *MysqlProvider) connectInit() *sql.DB {
 	db, e := sql.Open("mysql", mp.savePath)
 	if e != nil {
@@ -85,12 +97,15 @@ func (mp *MysqlProvider) connectInit() *sql.DB {
 	return db
 }
 
+// init mysql session.
+// savepath is the connection string of mysql.
 func (mp *MysqlProvider) SessionInit(maxlifetime int64, savePath string) error {
 	mp.maxlifetime = maxlifetime
 	mp.savePath = savePath
 	return nil
 }
 
+// get mysql session by sid
 func (mp *MysqlProvider) SessionRead(sid string) (SessionStore, error) {
 	c := mp.connectInit()
 	row := c.QueryRow("select session_data from session where session_key=?", sid)
@@ -113,6 +128,7 @@ func (mp *MysqlProvider) SessionRead(sid string) (SessionStore, error) {
 	return rs, nil
 }
 
+// check mysql session exist
 func (mp *MysqlProvider) SessionExist(sid string) bool {
 	c := mp.connectInit()
 	defer c.Close()
@@ -126,6 +142,7 @@ func (mp *MysqlProvider) SessionExist(sid string) bool {
 	}
 }
 
+// generate new sid for mysql session
 func (mp *MysqlProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	c := mp.connectInit()
 	row := c.QueryRow("select session_data from session where session_key=?", oldsid)
@@ -148,6 +165,7 @@ func (mp *MysqlProvider) SessionRegenerate(oldsid, sid string) (SessionStore, er
 	return rs, nil
 }
 
+// delete mysql session by sid
 func (mp *MysqlProvider) SessionDestroy(sid string) error {
 	c := mp.connectInit()
 	c.Exec("DELETE FROM session where session_key=?", sid)
@@ -155,6 +173,7 @@ func (mp *MysqlProvider) SessionDestroy(sid string) error {
 	return nil
 }
 
+// delete expired values in mysql session
 func (mp *MysqlProvider) SessionGC() {
 	c := mp.connectInit()
 	c.Exec("DELETE from session where session_expiry < ?", time.Now().Unix()-mp.maxlifetime)
@@ -162,6 +181,7 @@ func (mp *MysqlProvider) SessionGC() {
 	return
 }
 
+// count values in mysql session
 func (mp *MysqlProvider) SessionAll() int {
 	c := mp.connectInit()
 	defer c.Close()

@@ -11,10 +11,12 @@ import (
 
 var redispder = &RedisProvider{}
 
+// redis max pool size
 var MAX_POOL_SIZE = 100
 
 var redisPool chan redis.Conn
 
+// redis session store
 type RedisSessionStore struct {
 	p           *redis.Pool
 	sid         string
@@ -23,6 +25,7 @@ type RedisSessionStore struct {
 	maxlifetime int64
 }
 
+// set value in redis session
 func (rs *RedisSessionStore) Set(key, value interface{}) error {
 	rs.lock.Lock()
 	defer rs.lock.Unlock()
@@ -30,6 +33,7 @@ func (rs *RedisSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// get value in redis session
 func (rs *RedisSessionStore) Get(key interface{}) interface{} {
 	rs.lock.RLock()
 	defer rs.lock.RUnlock()
@@ -41,6 +45,7 @@ func (rs *RedisSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// delete value in redis session
 func (rs *RedisSessionStore) Delete(key interface{}) error {
 	rs.lock.Lock()
 	defer rs.lock.Unlock()
@@ -48,6 +53,7 @@ func (rs *RedisSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// clear all values in redis session
 func (rs *RedisSessionStore) Flush() error {
 	rs.lock.Lock()
 	defer rs.lock.Unlock()
@@ -55,10 +61,12 @@ func (rs *RedisSessionStore) Flush() error {
 	return nil
 }
 
+// get redis session id
 func (rs *RedisSessionStore) SessionID() string {
 	return rs.sid
 }
 
+// save session values to redis
 func (rs *RedisSessionStore) SessionRelease(w http.ResponseWriter) {
 	c := rs.p.Get()
 	defer c.Close()
@@ -77,6 +85,7 @@ func (rs *RedisSessionStore) SessionRelease(w http.ResponseWriter) {
 	c.Do("SET", rs.sid, string(b), "EX", rs.maxlifetime)
 }
 
+// redis session provider
 type RedisProvider struct {
 	maxlifetime int64
 	savePath    string
@@ -85,8 +94,9 @@ type RedisProvider struct {
 	poollist    *redis.Pool
 }
 
-//savepath like redisserveraddr,poolsize,password
-//127.0.0.1:6379,100,astaxie
+// init redis session
+// savepath like redis server addr,pool size,password
+// e.g. 127.0.0.1:6379,100,astaxie
 func (rp *RedisProvider) SessionInit(maxlifetime int64, savePath string) error {
 	rp.maxlifetime = maxlifetime
 	configs := strings.Split(savePath, ",")
@@ -122,6 +132,7 @@ func (rp *RedisProvider) SessionInit(maxlifetime int64, savePath string) error {
 	return nil
 }
 
+// read redis session by sid
 func (rp *RedisProvider) SessionRead(sid string) (SessionStore, error) {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -141,6 +152,7 @@ func (rp *RedisProvider) SessionRead(sid string) (SessionStore, error) {
 	return rs, nil
 }
 
+// check redis session exist by sid
 func (rp *RedisProvider) SessionExist(sid string) bool {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -152,6 +164,7 @@ func (rp *RedisProvider) SessionExist(sid string) bool {
 	}
 }
 
+// generate new sid for redis session
 func (rp *RedisProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -181,6 +194,7 @@ func (rp *RedisProvider) SessionRegenerate(oldsid, sid string) (SessionStore, er
 	return rs, nil
 }
 
+// delete redis session by id
 func (rp *RedisProvider) SessionDestroy(sid string) error {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -189,11 +203,12 @@ func (rp *RedisProvider) SessionDestroy(sid string) error {
 	return nil
 }
 
+// Impelment method, no used.
 func (rp *RedisProvider) SessionGC() {
 	return
 }
 
-//@todo
+// @todo
 func (rp *RedisProvider) SessionAll() int {
 	return 0
 }