alps/conn_pool.go
2019-12-02 17:40:53 +01:00

74 lines
1.2 KiB
Go

package koushin
import (
"crypto/rand"
"encoding/base64"
"errors"
"sync"
imapclient "github.com/emersion/go-imap/client"
)
func generateToken() (string, error) {
b := make([]byte, 32)
_, err := rand.Read(b)
if err != nil {
return "", err
}
return base64.URLEncoding.EncodeToString(b), nil
}
var ErrSessionExpired = errors.New("session expired")
// TODO: expiration timer
type ConnPool struct {
locker sync.Mutex
conns map[string]*imapclient.Client
}
func NewConnPool() *ConnPool {
return &ConnPool{
conns: make(map[string]*imapclient.Client),
}
}
func (pool *ConnPool) Get(token string) (*imapclient.Client, error) {
pool.locker.Lock()
defer pool.locker.Unlock()
conn, ok := pool.conns[token]
if !ok {
return nil, ErrSessionExpired
}
return conn, nil
}
func (pool *ConnPool) Put(conn *imapclient.Client) (token string, err error) {
pool.locker.Lock()
defer pool.locker.Unlock()
for {
var err error
token, err = generateToken()
if err != nil {
conn.Logout()
return "", err
}
if _, ok := pool.conns[token]; !ok {
break
}
}
pool.conns[token] = conn
go func() {
<-conn.LoggedOut()
pool.locker.Lock()
delete(pool.conns, token)
pool.locker.Unlock()
}()
return token, nil
}