feat: add custom unique key option

client.go

@@ -55,6 +55,7 @@ const (
 	TimeoutOpt
 	DeadlineOpt
 	UniqueOpt
+	UniqueKeyOpt
 	ProcessAtOpt
 	ProcessInOpt
 	TaskIDOpt
@@ -82,6 +83,7 @@ type (
 	timeoutOption   time.Duration
 	deadlineOption  time.Time
 	uniqueOption    time.Duration
+	uniqueKeyOption string
 	processAtOption time.Time
 	processInOption time.Duration
 	retentionOption time.Duration
@@ -160,10 +162,11 @@ func (t deadlineOption) Value() interface{} { return time.Time(t) }
 // ErrDuplicateTask error is returned when enqueueing a duplicate task.
 // TTL duration must be greater than or equal to 1 second.
 //
-// Uniqueness of a task is based on the following properties:
+// By default, the uniqueness of a task is based on the following properties:
 //   - Task Type
 //   - Task Payload
 //   - Queue Name
+// UniqueKey can be used to specify a custom string for calculating uniqueness, instead of task payload.
 func Unique(ttl time.Duration) Option {
 	return uniqueOption(ttl)
 }
@@ -172,6 +175,24 @@ func (ttl uniqueOption) String() string     { return fmt.Sprintf("Unique(%v)", t
 func (ttl uniqueOption) Type() OptionType   { return UniqueOpt }
 func (ttl uniqueOption) Value() interface{} { return time.Duration(ttl) }
 
+// UniqueKey returns an option to define the custom uniqueness of a task.
+// If uniqueKey is not empty, the uniqueness of a task is based on the following properties:
+//   - Task Type
+//   - UniqueKey
+//   - Queue Name
+// Otherwise, task payload will be used, see Unique.
+//
+// UniqueKey should be used together with Unique.
+func UniqueKey(uniqueKey string) Option {
+	return uniqueKeyOption(uniqueKey)
+}
+
+func (uniqueKey uniqueKeyOption) String() string {
+	return fmt.Sprintf("UniqueKey(%q)", string(uniqueKey))
+}
+func (uniqueKey uniqueKeyOption) Type() OptionType   { return UniqueKeyOpt }
+func (uniqueKey uniqueKeyOption) Value() interface{} { return string(uniqueKey) }
+
 // ProcessAt returns an option to specify when to process the given task.
 //
 // If there's a conflicting ProcessIn option, the last option passed to Enqueue overrides the others.
@@ -234,6 +255,7 @@ type option struct {
 	timeout   time.Duration
 	deadline  time.Time
 	uniqueTTL time.Duration
+	uniqueKey string
 	processAt time.Time
 	retention time.Duration
 	group     string
@@ -278,6 +300,8 @@ func composeOptions(opts ...Option) (option, error) {
 				return option{}, errors.New("Unique TTL cannot be less than 1s")
 			}
 			res.uniqueTTL = ttl
+		case uniqueKeyOption:
+			res.uniqueKey = string(opt)
 		case processAtOption:
 			res.processAt = time.Time(opt)
 		case processInOption:
@@ -379,7 +403,11 @@ func (c *Client) EnqueueContext(ctx context.Context, task *Task, opts ...Option)
 	}
 	var uniqueKey string
 	if opt.uniqueTTL > 0 {
-		uniqueKey = base.UniqueKey(opt.queue, task.Type(), task.Payload())
+		if opt.uniqueKey != "" {
+			uniqueKey = base.CustomUniqueKey(opt.queue, task.Type(), opt.uniqueKey)
+		} else {
+			uniqueKey = base.UniqueKey(opt.queue, task.Type(), task.Payload())
+		}
 	}
 	msg := &base.TaskMessage{
 		ID:        opt.taskID,

client_test.go

@@ -1191,3 +1191,46 @@ func TestClientEnqueueUniqueWithProcessAtOption(t *testing.T) {
 		}
 	}
 }
+
+func TestClientEnqueueUniqueWithUniqueKeyOption(t *testing.T) {
+	r := setup(t)
+	c := NewClient(getRedisConnOpt(t))
+	defer c.Close()
+
+	tests := []struct {
+		task *Task
+		ttl  time.Duration
+	}{
+		{
+			NewTask("email", h.JSON(map[string]interface{}{"user_id": 123})),
+			time.Hour,
+		},
+	}
+
+	for _, tc := range tests {
+		h.FlushDB(t, r) // clean up db before each test case.
+
+		// Enqueue the task first. It should succeed.
+		_, err := c.Enqueue(tc.task, Unique(tc.ttl), UniqueKey("custom_unique_key"))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		gotTTL := r.TTL(context.Background(), base.CustomUniqueKey(base.DefaultQueueName, tc.task.Type(), "custom_unique_key")).Val()
+		if !cmp.Equal(tc.ttl.Seconds(), gotTTL.Seconds(), cmpopts.EquateApprox(0, 1)) {
+			t.Errorf("TTL = %v, want %v", gotTTL, tc.ttl)
+			continue
+		}
+
+		// Enqueue the task again. It should fail.
+		_, err = c.Enqueue(tc.task, Unique(tc.ttl), UniqueKey("custom_unique_key"))
+		if err == nil {
+			t.Errorf("Enqueueing %+v did not return an error", tc.task)
+			continue
+		}
+		if !errors.Is(err, ErrDuplicateTask) {
+			t.Errorf("Enqueueing %+v returned an error that is not ErrDuplicateTask", tc.task)
+			continue
+		}
+	}
+}

inspector.go

@@ -960,6 +960,12 @@ func parseOption(s string) (Option, error) {
 			return nil, err
 		}
 		return Unique(d), nil
+	case "UniqueKey":
+		key, err := strconv.Unquote(arg)
+		if err != nil {
+			return nil, err
+		}
+		return UniqueKey(key), nil
 	case "ProcessAt":
 		t, err := time.Parse(time.UnixDate, arg)
 		if err != nil {

internal/base/base.go

@@ -205,6 +205,12 @@ func UniqueKey(qname, tasktype string, payload []byte) string {
 	return QueueKeyPrefix(qname) + "unique:" + tasktype + ":" + hex.EncodeToString(checksum[:])
 }
 
+// CustomUniqueKey returns a redis key with the given type, custom key, and queue name.
+func CustomUniqueKey(qname, tasktype string, customKey string) string {
+	checksum := md5.Sum([]byte(customKey))
+	return fmt.Sprintf("%sunique:%s:%s", QueueKeyPrefix(qname), tasktype, hex.EncodeToString(checksum[:]))
+}
+
 // GroupKeyPrefix returns a prefix for group key.
 func GroupKeyPrefix(qname string) string {
 	return QueueKeyPrefix(qname) + "g:"