// Returns Mailer if one is available or if new connection is allowed.
// For newly created mailers dialing the connection may still be
// in progress.
// If the pool is exhausted, the method blocks until a connection
// becomes available.
func (this *Pool) GetMailer(auth smtp.Auth) (res *Mailer, err error) {
slog.Trace(1).Printe("Getting mailer", "auth", auth)
this.cc.L.Lock()
for {
if this.clsd {
err = errors.New("cannot check out from closed pool")
break
}
slog.Trace(2).Printe("Trying pool", "auth", auth, "cnt", this.ccnt)
if conn, ok := this.popMailer(auth); ok {
res, err = this.newMailer(conn, auth)
break
}
slog.Trace(2).Printe("Trying new", "auth", auth, "cnt", this.ccnt)
if this.MaxConns == 0 || this.ccnt < this.MaxConns {
res, err = this.newMailer(nil, auth)
break
}
slog.Trace(2).Printe("Trying any", "auth", auth, "cnt", this.ccnt)
if conn, ok := this.popMailer(nil); ok {
res, err = this.newMailer(conn, auth)
break
}
slog.Trace(2).Printe("Waiting", "auth", auth, "cnt", this.ccnt)
this.cc.Wait()
}
this.cc.L.Unlock()
if err != nil {
slog.On(err).Trace(1).Prints("Getting mailer", "auth", auth)
} else {
slog.Success().Trace(1).Prints("Getting mailer", "auth", auth)
}
return
}
// Puts Mailer back in the pool.
func (this *Pool) putMailer(mailer *Mailer) {
slog.Trace(1).Printe("Putting mailer", "mailer", mailer)
this.cc.L.Lock()
defer this.cc.L.Unlock()
conn := mailer.conn
if conn != nil {
conn = this.closeConnIfExp(conn)
}
if !this.clsd && conn != nil {
// return to idle pool
overflow := this.cpool.Push(conn)
// this should be empty or only have one item,
// unless pool resizing took place for some reason
for _, v := range overflow {
// TODO implement connection wait queue
// and return a connection instead of closing it
// if there are waiters
this.closeConn(v)
}
if len(overflow) == 0 {
this.cc.Signal()
}
}
slog.Success().Trace(1).Prints("Putting mailer", "mailer", mailer)
}
func (this *Pool) closeConnIfExp(conn *psmtpConn) *psmtpConn {
slog.Trace(3).Printe("Checking connection", "conn", conn)
now := time.Now()
if !conn.ok || conn.etime.Before(now) {
slog.With(errors.New("expired")).Trace(3).Prints("Checking connection", "conn", conn)
this.closeConn(conn)
return nil
}
slog.Success().Trace(3).Prints("Checking connection", "conn", conn)
return conn
}
func (this *Pool) closeConn(conn *psmtpConn) {
if conn.ok {
conn.ok = false
if conn.client != nil {
go func(c *psmtpConn, p *Pool) {
c.client.Quit()
p.cc.L.Lock()
slog.Trace(3).Printe("Async closing connection", "conn", conn, "cnt", p.ccnt)
p.ccnt--
slog.Success().Trace(3).Prints("Async closing connection", "conn", conn, "cnt", p.ccnt)
p.cc.L.Unlock()
p.cc.Signal()
}(conn, this)
return
}
}
slog.Trace(3).Printe("Closing connection", "conn", conn, "cnt", this.ccnt)
this.ccnt--
slog.Success().Trace(3).Prints("Closing connection", "conn", conn, "cnt", this.ccnt)
this.cc.Signal()
}
func (this *Pool) newMailer(conn *psmtpConn, auth smtp.Auth) (*Mailer, error) {
if conn != nil && conn.auth == auth {
return &Mailer{conn: conn, ctl: nil, pool: this}, nil
}
now := time.Now()
if now.Sub(this.ftime) < this.MinWaitTime {
return nil, errors.New("connect blackout period")
}
if conn == nil {
slog.Trace(3).Printe("Incrementing for new", "cnt", this.ccnt)
this.ccnt++
slog.Success().Trace(3).Prints("Incrementing for new", "cnt", this.ccnt)
}
ctl := make(chan *connResp, 1)
go func(ctl chan<- *connResp) {
defer close(ctl)
ok := false
defer func() {
if !ok {
this.cc.L.Lock()
slog.Trace(3).Printe("Decrementing on failure", "cnt", this.ccnt)
this.ccnt--
slog.Success().Trace(3).Prints("Decrementing on failure", "cnt", this.ccnt)
this.cc.L.Unlock()
this.cc.Signal()
}
}()
if conn != nil && conn.client != nil {
// TODO Convert to glog
//log.Printf("Closing old connection")
conn.client.Quit()
}
server := fmt.Sprintf("%s:%d", this.Host, this.Port)
// TODO Convert to glog
//log.Printf("Dialing %s...", server)
if this.net_DialTimeout == nil {
this.net_DialTimeout = net.DialTimeout
}
if this.tls_DialTimeout == nil {
this.tls_DialTimeout = func(network string, addr string, timeout time.Duration, tlsc *tls.Config) (net.Conn, error) {
dialer := &net.Dialer{Timeout: timeout}
return tls.DialWithDialer(dialer, network, addr, tlsc)
}
}
var l net.Conn
var err error
if this.Smtps {
var tlsc tls.Config
if this.TLSClientConfig != nil {
tlsc = *this.TLSClientConfig
}
l, err = this.tls_DialTimeout("tcp", server, this.Timeout, &tlsc)
} else {
l, err = this.net_DialTimeout("tcp", server, this.Timeout)
}
if err != nil {
// TODO Convert to glog
//log.Printf("Error dialing %s: %v", server, err)
this.ftime = now
ctl <- &connResp{nil, err}
return
}
if this.net_smtp_NewClient == nil {
this.net_smtp_NewClient = func(conn net.Conn, server string) (smtpClient, error) {
return smtp.NewClient(conn, server)
}
}
c, err := this.net_smtp_NewClient(l, this.Host)
if err != nil {
this.ftime = now
ctl <- &connResp{nil, err}
return
}
hostname, _ := os.Hostname()
if err = c.Hello(hostname); err != nil {
c.Quit()
ctl <- &connResp{nil, err}
return
}
if this.TLSClientConfig != nil && !this.Smtps {
tlsc := *this.TLSClientConfig
// TODO Convert to glog
//log.Printf("Starting TLS on %s...", server)
if err = c.StartTLS(&tlsc); err != nil {
this.ftime = now
c.Quit()
ctl <- &connResp{nil, err}
return
}
}
if auth != nil {
// TODO Convert to glog
//log.Printf("Authenticating with %s...", server)
if err = c.Auth(auth); err != nil {
c.Quit()
ctl <- &connResp{nil, err}
return
}
}
ok = true
ctl <- &connResp{
conn: &psmtpConn{
client: c,
ok: true,
auth: auth,
ctime: now,
etime: now.Add(this.MaxLiveTime),
atime: now,
},
err: nil,
}
}(ctl)
return &Mailer{
conn: nil,
ctl: ctl,
pool: this,
}, nil
}