alps/conn_pool.go
Simon Ser 48d6d5d227
Add session lock
HTTP requests can be processed in parallel, but we only have one IMAP
connection per session.

Closes: https://todo.sr.ht/~sircmpwn/koushin/12
2019-12-03 17:18:17 +01:00

91 lines
1.6 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")
type Session struct {
locker sync.Mutex
imapConn *imapclient.Client
username, password string
}
func (s *Session) Do(f func(*imapclient.Client) error) error {
s.locker.Lock()
defer s.locker.Unlock()
return f(s.imapConn)
}
// TODO: expiration timer
type ConnPool struct {
locker sync.Mutex
sessions map[string]*Session
}
func NewConnPool() *ConnPool {
return &ConnPool{
sessions: make(map[string]*Session),
}
}
func (pool *ConnPool) Get(token string) (*Session, error) {
pool.locker.Lock()
defer pool.locker.Unlock()
session, ok := pool.sessions[token]
if !ok {
return nil, ErrSessionExpired
}
return session, nil
}
func (pool *ConnPool) Put(imapConn *imapclient.Client, username, password string) (token string, err error) {
pool.locker.Lock()
defer pool.locker.Unlock()
for {
var err error
token, err = generateToken()
if err != nil {
imapConn.Logout()
return "", err
}
if _, ok := pool.sessions[token]; !ok {
break
}
}
pool.sessions[token] = &Session{
imapConn: imapConn,
username: username,
password: password,
}
go func() {
<-imapConn.LoggedOut()
pool.locker.Lock()
delete(pool.sessions, token)
pool.locker.Unlock()
}()
return token, nil
}