示例#1
0
// Idle setup the processes to wait for notifications from the IMAP source connection.
// If an EXISTS or EXPUNGE command comes across the pipe, the appropriate actions will be
// taken to update the destinations. If the process decides the inboxes are out of sync,
// it will pass a bool to the requestPurge channel. It is expected that the requestPurge
// channel is setup to initiate a purge process when it receives the notificaiton.
func Idle(src *imap.Client, appendRequests []chan WorkRequest, requestPurge chan bool) (err error) {
	var nextUID uint32
	if nextUID, err = getNextUID(src); err != nil {
		log.Printf("Unable to get UIDNext: %s", err.Error())
		return err
	}

	// hold the size so we can determine how to react to commands
	startSize := src.Mailbox.Messages

	// setup interrupt signal channel to terminate the idle
	interrupt := make(chan os.Signal, 1)
	signal.Notify(interrupt, os.Interrupt, os.Kill)

	// setup ticker to reset the idle every 20 minutes (RFC-2177 recommends 29 mins max)
	timeout := time.NewTicker(idleTimeoutMinutes * time.Minute)

	// setup poller signal for checking for data on the idle command
	poll := make(chan bool, 1)
	poll <- true

	log.Print("beginning idle...")
	_, idleErr := src.Idle()
	if (idleErr != nil) && (idleErr != imap.ErrTimeout) {
		log.Printf("Idle error: %s", idleErr.Error())
		return
	}

	for {

		select {
		// if we receive a 'poll' we should check the pipe for new messages
		case <-poll:

			err = src.Recv(0)
			if (idleErr != nil) && (idleErr != imap.ErrTimeout) {
				log.Printf("Idle error: %s", idleErr.Error())
				go sleep(poll)
				continue
			}

			// cache the data so we dont mess it up while start/stopping idle
			var tempData []*imap.Response
			tempData = append(tempData, src.Data...)
			src.Data = nil
			for _, data := range tempData {
				switch data.Type {
				case imap.Data:
					// len of 2 likely means its an EXPUNGE or EXISTS command...
					if len(data.Fields) == 2 {
						msgNum := imap.AsNumber(data.Fields[0])

						switch data.Fields[1] {
						case "EXPUNGE":
							log.Printf("Received an EXPUNGE notification requesting purge - %d", msgNum)
							startSize = msgNum
							requestPurge <- true

						case "EXISTS":
							log.Printf("Received an EXISTS notification - %d", msgNum)
							if startSize > msgNum {
								log.Printf("Mailbox decreased in size %d --> %d. Requesting a purge. MAILBOX MAY NEED TO SYNC", startSize, msgNum)
								requestPurge <- true
								startSize = msgNum
								continue
							}

							// temporarily term the idle so we can fetch the message
							if _, err = src.IdleTerm(); err != nil {
								log.Printf("error while temporarily terminating idle: %s", err.Error())
								return
							}
							log.Printf("terminated idle. appending message.")

							newMessages := msgNum - startSize
							log.Printf("attempting to find/append %d new messages", newMessages)
							for i := uint32(0); i < newMessages; i++ {
								var request WorkRequest
								if request, err = getMessageInfo(src, nextUID); err == nil {

									log.Printf("creating %d append requests for %d", len(appendRequests), nextUID)
									for _, requests := range appendRequests {
										requests <- request
									}
									log.Printf("done creating append requests for %d", nextUID)
									nextUID++
									startSize++
								} else {
									log.Printf("Unable to find message for UID (%d): %s", nextUID, err.Error())
								}
							}

							log.Printf("continuing idle...")
							// turn idle back on
							if _, err = src.Idle(); err != nil {
								log.Printf("Unable to restart idle: %s", err.Error())
								return
							}
						}
					}
				}
			}

			go sleep(poll)

		case <-interrupt:
			log.Printf("Received interrupt. Terminating idle...")
			_, err = src.IdleTerm()
			if err != nil {
				log.Printf("error while terminating idle: %s", err.Error())
			}
			return
		case <-timeout.C:
			log.Printf("resetting idle...")
			_, err = src.IdleTerm()
			if err != nil {
				log.Printf("error while temporarily terminating idle: %s", err.Error())
				return
			}
			log.Printf("terminated idle.")

			// turn idle back on
			_, err = src.Idle()
			if err != nil {
				log.Printf("Unable to restart idle: %s", err.Error())
				return
			}
			log.Printf("idle restarted.")
		}
	}

	return
}
示例#2
0
func ExampleClient() {
	//
	// Note: most of error handling code is omitted for brevity
	//
	var (
		c   *imap.Client
		cmd *imap.Command
		rsp *imap.Response
	)

	// Connect to the server
	c, _ = imap.Dial("imap.example.com")

	// Remember to log out and close the connection when finished
	defer c.Logout(30 * time.Second)

	// Print server greeting (first response in the unilateral server data queue)
	fmt.Println("Server says hello:", c.Data[0].Info)
	c.Data = nil

	// Enable encryption, if supported by the server
	if c.Caps["STARTTLS"] {
		c.StartTLS(nil)
	}

	// Authenticate
	if c.State() == imap.Login {
		c.Login("*****@*****.**", "mysupersecretpassword")
	}

	// List all top-level mailboxes, wait for the command to finish
	cmd, _ = imap.Wait(c.List("", "%"))

	// Print mailbox information
	fmt.Println("\nTop-level mailboxes:")
	for _, rsp = range cmd.Data {
		fmt.Println("|--", rsp.MailboxInfo())
	}

	// Check for new unilateral server data responses
	for _, rsp = range c.Data {
		fmt.Println("Server data:", rsp)
	}
	c.Data = nil

	// Open a mailbox (synchronous command - no need for imap.Wait)
	c.Select("INBOX", true)
	fmt.Print("\nMailbox status:\n", c.Mailbox)

	// Fetch the headers of the 10 most recent messages
	set, _ := imap.NewSeqSet("")
	if c.Mailbox.Messages >= 10 {
		set.AddRange(c.Mailbox.Messages-9, c.Mailbox.Messages)
	} else {
		set.Add("1:*")
	}
	cmd, _ = c.Fetch(set, "RFC822.HEADER")

	// Process responses while the command is running
	fmt.Println("\nMost recent messages:")
	for cmd.InProgress() {
		// Wait for the next response (no timeout)
		c.Recv(-1)

		// Process command data
		for _, rsp = range cmd.Data {
			header := imap.AsBytes(rsp.MessageInfo().Attrs["RFC822.HEADER"])
			if msg, _ := mail.ReadMessage(bytes.NewReader(header)); msg != nil {
				fmt.Println("|--", msg.Header.Get("Subject"))
			}
		}
		cmd.Data = nil

		// Process unilateral server data
		for _, rsp = range c.Data {
			fmt.Println("Server data:", rsp)
		}
		c.Data = nil
	}

	// Check command completion status
	if rsp, err := cmd.Result(imap.OK); err != nil {
		if err == imap.ErrAborted {
			fmt.Println("Fetch command aborted")
		} else {
			fmt.Println("Fetch error:", rsp.Info)
		}
	}
}