Files
crockery/vendor/github.com/emersion/go-imap/backend/updates.go
2018-03-05 12:19:04 +00:00

110 lines
2.7 KiB
Go

package backend
import (
"github.com/emersion/go-imap"
)
// Update contains user and mailbox information about an unilateral backend
// update.
type Update struct {
// The user targeted by this update. If empty, all connected users will
// be notified.
Username string
// The mailbox targeted by this update. If empty, the update targets all
// mailboxes.
Mailbox string
// A channel that will be closed once the update has been processed.
done chan struct{}
}
// Done returns a channel that is closed when the update has been broadcast to
// all clients.
func (u *Update) Done() <-chan struct{} {
if u.done == nil {
u.done = make(chan struct{})
}
return u.done
}
// DoneUpdate marks an update as done.
// TODO: remove this function
func DoneUpdate(u *Update) {
if u.done != nil {
close(u.done)
}
}
// StatusUpdate is a status update. See RFC 3501 section 7.1 for a list of
// status responses.
type StatusUpdate struct {
Update
*imap.StatusResp
}
// MailboxUpdate is a mailbox update.
type MailboxUpdate struct {
Update
*imap.MailboxStatus
}
// MessageUpdate is a message update.
type MessageUpdate struct {
Update
*imap.Message
}
// ExpungeUpdate is an expunge update.
type ExpungeUpdate struct {
Update
SeqNum uint32
}
// Updater is a Backend that implements Updater is able to send unilateral
// backend updates. Backends not implementing this interface don't correctly
// send unilateral updates, for instance if a user logs in from two connections
// and deletes a message from one of them, the over is not aware that such a
// mesage has been deleted. More importantly, backends implementing Updater can
// notify the user for external updates such as new message notifications.
type Updater interface {
// Updates returns a set of channels where updates are sent to.
Updates() <-chan interface{}
}
// UpdaterMailbox is a Mailbox that implements UpdaterMailbox is able to poll
// updates for new messages or message status updates during a period of
// inactivity.
type UpdaterMailbox interface {
// Poll requests mailbox updates.
Poll() error
}
// WaitUpdates returns a channel that's closed when all provided updates have
// been dispatched to all clients. It panics if one of the provided value is
// not an update.
func WaitUpdates(updates ...interface{}) <-chan struct{} {
done := make(chan struct{})
var chs []<-chan struct{}
for _, u := range updates {
uu, ok := u.(interface {
Done() <-chan struct{}
})
if !ok {
panic("imap: cannot wait for update: provided value is not a valid update")
}
chs = append(chs, uu.Done())
}
go func() {
// Wait for all updates to be sent
for _, ch := range chs {
<-ch
}
close(done)
}()
return done
}