feat: add publish and getpubsub for streaming

Signed-off-by: FogDong <fog@bentoml.com>

asynq.go

@@ -14,8 +14,8 @@ import (
 	"strings"
 	"time"
 
-	"github.com/redis/go-redis/v9"
 	"github.com/hibiken/asynq/internal/base"
+	"github.com/redis/go-redis/v9"
 )
 
 // Task represents a unit of work to be performed.
@@ -438,6 +438,7 @@ func (opt RedisClusterClientOpt) MakeRedisClient() interface{} {
 //
 // Three URI schemes are supported, which are redis:, rediss:, redis-socket:, and redis-sentinel:.
 // Supported formats are:
+//
 //	redis://[:password@]host[:port][/dbnumber]
 //	rediss://[:password@]host[:port][/dbnumber]
 //	redis-socket://[:password@]path[?db=dbnumber]
@@ -535,12 +536,22 @@ type ResultWriter struct {
 func (w *ResultWriter) Write(data []byte) (n int, err error) {
 	select {
 	case <-w.ctx.Done():
-		return 0, fmt.Errorf("failed to result task result: %v", w.ctx.Err())
+		return 0, fmt.Errorf("failed to write task result: %v", w.ctx.Err())
 	default:
 	}
 	return w.broker.WriteResult(w.qname, w.id, data)
 }
 
+// Publish publishes the given data to the task channel.
+func (w *ResultWriter) Publish(data []byte) (n int, err error) {
+	select {
+	case <-w.ctx.Done():
+		return 0, fmt.Errorf("failed to publish task result: %v", w.ctx.Err())
+	default:
+	}
+	return w.broker.Publish(w.qname, w.id, data)
+}
+
 // TaskID returns the ID of the task the ResultWriter is associated with.
 func (w *ResultWriter) TaskID() string {
 	return w.id

inspector.go

@@ -5,15 +5,16 @@
 package asynq
 
 import (
+	"context"
 	"fmt"
 	"strconv"
 	"strings"
 	"time"
 
-	"github.com/redis/go-redis/v9"
 	"github.com/hibiken/asynq/internal/base"
 	"github.com/hibiken/asynq/internal/errors"
 	"github.com/hibiken/asynq/internal/rdb"
+	"github.com/redis/go-redis/v9"
 )
 
 // Inspector is a client interface to inspect and mutate the state of
@@ -235,6 +236,13 @@ func (i *Inspector) GetTaskInfo(queue, id string) (*TaskInfo, error) {
 	return newTaskInfo(info.Message, info.State, info.NextProcessAt, info.Result), nil
 }
 
+// GetTaskPubSub returns a pubsub instance for the given task.
+func (i *Inspector) GetTaskPubSub(queue, id string) *redis.PubSub {
+	taskKey := base.TaskKey(queue, id)
+	ctx := context.Background()
+	return i.rdb.Client().Subscribe(ctx, taskKey)
+}
+
 // ListOption specifies behavior of list operation.
 type ListOption interface{}
 

internal/base/base.go

@@ -752,4 +752,6 @@ type Broker interface {
 	PublishCancelation(id string) error
 
 	WriteResult(qname, id string, data []byte) (n int, err error)
+
+	Publish(qname, id string, data []byte) (n int, err error)
 }

internal/rdb/rdb.go

@@ -1519,3 +1519,14 @@ func (r *RDB) WriteResult(qname, taskID string, data []byte) (int, error) {
 	}
 	return len(data), nil
 }
+
+// Publish publishes the given task message to the specified channel.
+func (r *RDB) Publish(qname, taskID string, data []byte) (int, error) {
+	var op errors.Op = "rdb.Publish"
+	ctx := context.Background()
+	taskKey := base.TaskKey(qname, taskID)
+	if err := r.client.Publish(ctx, taskKey, data).Err(); err != nil {
+		return 0, errors.E(op, errors.Unknown, &errors.RedisCommandError{Command: "publish", Err: err})
+	}
+	return len(data), nil
+}

internal/testbroker/testbroker.go

@@ -11,8 +11,8 @@ import (
 	"sync"
 	"time"
 
-	"github.com/redis/go-redis/v9"
 	"github.com/hibiken/asynq/internal/base"
+	"github.com/redis/go-redis/v9"
 )
 
 var errRedisDown = errors.New("testutil: redis is down")
@@ -217,6 +217,15 @@ func (tb *TestBroker) WriteResult(qname, id string, data []byte) (int, error) {
 	return tb.real.WriteResult(qname, id, data)
 }
 
+func (tb *TestBroker) Publish(qname, id string, data []byte) (int, error) {
+	tb.mu.Lock()
+	defer tb.mu.Unlock()
+	if tb.sleeping {
+		return 0, errRedisDown
+	}
+	return tb.real.Publish(qname, id, data)
+}
+
 func (tb *TestBroker) Ping() error {
 	tb.mu.Lock()
 	defer tb.mu.Unlock()