Refactor, introduce MailQ struct

main.go

@@ -42,7 +42,7 @@ func interactiveShell() {
 }
 
 func showQueue() {
-	entries, err := fetchQueueEntries()
+	queue, err := fetchQueue()
 	if err != nil {
 		fmt.Printf("Could not fetch queue entries: %s\n", err.Error())
 		os.Exit(1)
@@ -50,27 +50,25 @@ func showQueue() {
 	pagerReader, pagerWriter := io.Pipe()
 	pagerDone := make(chan bool)
 	go launchPager(pagerReader, pagerDone)
-	printQueueEntries(entries, pagerWriter)
+	printQueueEntries(queue, pagerWriter)
 	pagerWriter.Close()
 	// Wait for pager to be closed before continuing the main program
 	<-pagerDone
 }
 
-func fetchQueueEntries() ([]parser.QEntry, error) {
-	var entries []parser.QEntry
-	var err error
+func fetchQueue() (parser.MailQ, error) {
 	if settings["mailqCommandArgs"] == "" {
-		entries, err = readFromCmd(exec.Command(settings["mailqCommand"]))
+		return readFromCmd(exec.Command(settings["mailqCommand"]))
 	} else {
-		entries, err = readFromCmd(exec.Command(settings["mailqCommand"], settings["mailqCommandArgs"]))
+		return readFromCmd(exec.Command(settings["mailqCommand"], settings["mailqCommandArgs"]))
 	}
-	return entries, err
 }
 
-func printQueueEntries(entries []parser.QEntry, writer io.Writer) {
+func printQueueEntries(queue parser.MailQ, writer io.Writer) {
+	fmt.Fprintf(writer, "%d entries total (%d active, %d deferred, %d on hold)\n\n", len(queue.Entries), queue.NumActive, queue.NumDeferred, queue.NumHold)
 	tabWriter := tabwriter.NewWriter(writer, 2, 2, 1, ' ', tabwriter.TabIndent)
 	fmt.Fprintf(tabWriter, "| %s\t| %s\t| %s\t| %s\t| %s\t| %s\t| %s\t| %s\t| \n", "Date", "Id", "Status", "Size", "Sender", "#", "First Recipient", "Reason")
-	for _, entry := range entries {
+	for _, entry := range queue.Entries {
 		_, writeError := fmt.Fprintf(tabWriter, "| %s\t| %s\t| %s\t| %d\t| %s\t| {%d}\t| %s\t| %s\t \n", entry.Date.Format(parser.SortableDateFormat), entry.Id, entry.Status, entry.Size, entry.Sender, len(entry.Recipients), entry.Recipients[0], entry.Reason)
 		if writeError != nil {
 			// A writeError is expected once the reader was closed
@@ -96,17 +94,17 @@ func launchPager(reader *io.PipeReader, pagerDone chan<- bool) {
 	}
 }
 
-func readFromCmd(cmd *exec.Cmd) ([]parser.QEntry, error) {
+func readFromCmd(cmd *exec.Cmd) (parser.MailQ, error) {
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {
-		return nil, err
+		return parser.MailQ{}, err
 	}
 	if err := cmd.Start(); err != nil {
-		return nil, err
+		return parser.MailQ{}, err
 	}
 	result, resultError := parser.ParseMailQ(stdout)
 	if err := cmd.Wait(); err != nil {
-		return nil, err
+		return parser.MailQ{}, err
 	}
 	return result, resultError
 }

parser/parser.go

@@ -21,6 +21,14 @@ type QEntry struct {
 	Reason     string
 }
 
+type MailQ struct {
+	NumTotal    int
+	NumActive   int
+	NumHold     int
+	NumDeferred int
+	Entries     []QEntry
+}
+
 const SortableDateFormat = "2006-01-02 15:04:05"
 
 func (m QEntry) ShortString() string {
@@ -43,7 +51,7 @@ func (m QEntry) DetailedString() string {
 	return fmt.Sprintf("Id: %s\nDate: %s\nStatus: %s\nReason: %s\nSize: %d\nSender: %s\nRecipients: %s", m.Id, m.Date.Format(SortableDateFormat), m.Status, reasonStr, m.Size, m.Sender, strings.Join(m.Recipients, ", "))
 }
 
-func ParseMailQ(dataSource io.Reader) ([]QEntry, error) {
+func ParseMailQ(dataSource io.Reader) (MailQ, error) {
 	const dateFormat = "2006 Mon Jan _2 15:04:05"
 	var messageIdStart = regexp.MustCompile("^[0-9A-Za-z]+[*!]? ")
 	scanner := bufio.NewScanner(dataSource)
@@ -52,14 +60,13 @@ func ParseMailQ(dataSource io.Reader) ([]QEntry, error) {
 	line = scanner.Text()
 	if strings.HasPrefix(line, "Mail queue is empty") {
 		// If mail queue is empty, there is nothing to do
-		return []QEntry{}, nil
+		return MailQ{}, nil
 	} else if strings.HasPrefix(line, "-Queue ID-") == false {
 		// Abort if input does not look like output from mailq(1)
-		return nil, errors.New("Sorry, this does not look like output from mailq(1).")
+		return MailQ{}, errors.New("Sorry, this does not look like output from mailq(1).")
 	}
+	var queue MailQ
 	var currentMail QEntry
-	var queueEntries []QEntry
-
 	for scanner.Scan() {
 		// Read input line by line
 		line := scanner.Text()
@@ -70,12 +77,16 @@ func ParseMailQ(dataSource io.Reader) ([]QEntry, error) {
 		} else if messageIdStart.MatchString(line) {
 			// Handle line starting next mail in queue
 			messageId := fields[0]
+			queue.NumTotal += 1
 			if strings.HasSuffix(messageId, "*") {
+				queue.NumActive += 1
 				currentMail.Status = "active"
 			} else if strings.HasSuffix(messageId, "!") {
 				currentMail.Status = "hold"
+				queue.NumHold += 1
 			} else {
 				currentMail.Status = "deferred"
+				queue.NumDeferred += 1
 			}
 			dateString := strconv.Itoa(time.Now().Year()) + " " + strings.Join(fields[2:6], " ")
 			mailDate, _ := time.Parse(dateFormat, dateString)
@@ -95,13 +106,13 @@ func ParseMailQ(dataSource io.Reader) ([]QEntry, error) {
 		} else if len(fields) == 0 {
 			// If the next line is empty, make sure to push current mail to list
 			// and create a new struct for the next mail to process
-			queueEntries = append(queueEntries, currentMail)
+			queue.Entries = append(queue.Entries, currentMail)
 			currentMail = QEntry{}
 		}
 	}
 	if scanner.Err() != nil {
 		// If the scanner failed, let our caller know.
-		return nil, errors.New("Something went wrong with reading from stdin. Sorry!")
+		return MailQ{}, errors.New("Something went wrong with reading from stdin. Sorry!")
 	}
-	return queueEntries, nil
+	return queue, nil
 }