Change rdb Dequeue signature

internal/rdb/rdb.go

@@ -1,3 +1,4 @@
+// Package rdb encapsulates the interactions with redis.
 package rdb
 
 import (
@@ -22,9 +23,10 @@ const (
 	InProgress   = "asynq:in_progress"     // SET
 )
 
+// ErrDequeueTimeout indicates that the blocking dequeue operation timed out.
 var ErrDequeueTimeout = errors.New("blocking dequeue operation timed out")
 
-// RDB encapsulates the interactions with redis server.
+// RDB is a client interface to query and mutate task queues.
 type RDB struct {
 	client *redis.Client
 }
@@ -34,29 +36,25 @@ func NewRDB(client *redis.Client) *RDB {
 	return &RDB{client}
 }
 
-// TaskMessage is an internal representation of a task with additional metadata fields.
+// TaskMessage is the internal representation of a task with additional metadata fields.
-// This data gets written in redis.
+// Serialized data of this type gets written in redis.
 type TaskMessage struct {
 	//-------- Task fields --------
-
+	// Type represents the kind of task.
 	Type string
+	// Payload holds data needed to process the task.
 	Payload map[string]interface{}
 
-	//-------- metadata fields --------
+	//-------- Metadata fields --------
-
+	// ID is a unique identifier for each task
-	// unique identifier for each task
 	ID uuid.UUID
-
+	// Queue is a name this message should be enqueued to
-	// queue name this message should be enqueued to
 	Queue string
-
+	// Retry is the max number of retry for this task.
-	// max number of retry for this task.
 	Retry int
-
+	// Retried is the number of times we've retried this task so far
-	// number of times we've retried so far
 	Retried int
-
+	// ErrorMsg holds the error message from the last failure
-	// error message from the last failure
 	ErrorMsg string
 }
 
@@ -71,7 +69,7 @@ type Stats struct {
 }
 
 // EnqueuedTask is a task in a queue and is ready to be processed.
-// This is read only and used for inspection purpose.
+// Note: This is read only and used for monitoring purpose.
 type EnqueuedTask struct {
 	ID      uuid.UUID
 	Type    string
@@ -79,7 +77,7 @@ type EnqueuedTask struct {
 }
 
 // InProgressTask is a task that's currently being processed.
-// This is read only and used for inspection purpose.
+// Note: This is read only and used for monitoring purpose.
 type InProgressTask struct {
 	ID      uuid.UUID
 	Type    string
@@ -87,7 +85,7 @@ type InProgressTask struct {
 }
 
 // ScheduledTask is a task that's scheduled to be processed in the future.
-// This is read only and used for inspection purpose.
+// Note: This is read only and used for monitoring purpose.
 type ScheduledTask struct {
 	ID        uuid.UUID
 	Type      string
@@ -96,7 +94,7 @@ type ScheduledTask struct {
 }
 
 // RetryTask is a task that's in retry queue because worker failed to process the task.
-// This is read only and used for inspection purpose.
+// Note: This is read only and used for monitoring purpose.
 type RetryTask struct {
 	ID      uuid.UUID
 	Type    string
@@ -109,7 +107,7 @@ type RetryTask struct {
 }
 
 // DeadTask is a task in that has exhausted all retries.
-// This is read only and used for inspection purpose.
+// Note: This is read only and used for monitoring purpose.
 type DeadTask struct {
 	ID           uuid.UUID
 	Type         string
@@ -144,20 +142,20 @@ func (r *RDB) Enqueue(msg *TaskMessage) error {
 // Dequeue blocks until there is a task available to be processed,
 // once a task is available, it adds the task to "in progress" list
 // and returns the task.
-func (r *RDB) Dequeue(qname string, timeout time.Duration) (*TaskMessage, error) {
+func (r *RDB) Dequeue(timeout time.Duration) (*TaskMessage, error) {
-	data, err := r.client.BRPopLPush(qname, InProgress, timeout).Result()
+	data, err := r.client.BRPopLPush(DefaultQueue, InProgress, timeout).Result()
 	if err == redis.Nil {
 		return nil, ErrDequeueTimeout
 	}
 	if err != nil {
-		return nil, fmt.Errorf("command `BRPOPLPUSH %q %q %v` failed: %v", qname, InProgress, timeout, err)
+		return nil, fmt.Errorf("command `BRPOPLPUSH %q %q %v` failed: %v", DefaultQueue, InProgress, timeout, err)
 	}
 	var msg TaskMessage
 	err = json.Unmarshal([]byte(data), &msg)
 	if err != nil {
 		return nil, fmt.Errorf("could not unmarshal %v to json: %v", data, err)
 	}
-	fmt.Printf("[DEBUG] perform task %+v from %s\n", msg, qname)
+	fmt.Printf("[DEBUG] perform task %+v from %s\n", msg, DefaultQueue)
 	return &msg, nil
 }
 

internal/rdb/rdb_test.go

@@ -142,7 +142,7 @@ func TestDequeue(t *testing.T) {
 		for _, m := range tc.queued {
 			r.Enqueue(m)
 		}
-		got, err := r.Dequeue(DefaultQueue, time.Second)
+		got, err := r.Dequeue(time.Second)
 		if !cmp.Equal(got, tc.want) || err != tc.err {
 			t.Errorf("(*rdb).dequeue(%q, time.Second) = %v, %v; want %v, %v",
 				DefaultQueue, got, err, tc.want, tc.err)

processor.go

@@ -70,7 +70,7 @@ func (p *processor) start() {
 // exec pulls a task out of the queue and starts a worker goroutine to
 // process the task.
 func (p *processor) exec() {
-	msg, err := p.rdb.Dequeue(rdb.DefaultQueue, p.dequeueTimeout)
+	msg, err := p.rdb.Dequeue(p.dequeueTimeout)
 	if err == rdb.ErrDequeueTimeout {
 		// timed out, this is a normal behavior.
 		return