Fix queue

queue.go

@@ -1,9 +1,5 @@
 package main
 
-import (
-	"github.com/stvp/rollbar"
-)
-
 type (
 	Queue struct {
 		Name    string
@@ -16,26 +12,35 @@ var (
 )
 
 func (q *Queue) Push(msg Message) {
-	saver <- Payload{Queue: q, Message: msg}
+	saver <- Payload{
+		Queue:   q,
+		Message: msg,
+	}
 }
 
-func (q *Queue) Fetch() (Message, error) {
-	i := q.Counter.Next()
+func (q *Queue) TryFetch() (Message, bool) {
+	if q.Counter.Distance() > 0 {
+		return q.Fetch()
+	} else {
+		return Message{}, false
+	}
+}
+
+func (q *Queue) Fetch() (Message, bool) {
+	i := q.Counter.Read()
 	key := NewKey(q.Name, i)
 
 	msg, err := storage.Get(key)
 	if err != nil {
-		rollbar.Error("error", err)
-		return msg, err
+		Error(err, "Failed to read record '%s'", key)
 	}
 
-	defer func() {
-		if err := storage.Remove(key); err != nil {
-			rollbar.Error("error", err)
-		}
-	}()
+	err = storage.Remove(key)
+	if err != nil {
+		Error(err, "Failed to delete record '%s'", key)
+	}
 
-	return msg, nil
+	return msg, (err == nil)
 }
 
 func GetQueue(name string) *Queue {
@@ -46,5 +51,8 @@ func GetQueue(name string) *Queue {
 }
 
 func RegisterQueue(name string, wi, ri uint) {
-	queues[name] = &Queue{Name: name, Counter: NewCounter(wi, ri)}
+	queues[name] = &Queue{
+		Name:    name,
+		Counter: NewCounter(wi, ri),
+	}
 }

state.go

@@ -20,8 +20,8 @@ func SaveState() {
 	state := make(ServerState)
 	for _, q := range queues {
 		state[q.Name] = QueueState{
-			"wi": q.Counter.Write,
-			"ri": q.Counter.Read,
+			"wi": q.Counter.WriteIndex,
+			"ri": q.Counter.ReadIndex,
 		}
 	}