feat: add finished handler to server

processor.go

@@ -44,6 +44,8 @@ type processor struct {
 	errHandler      ErrorHandler
 	shutdownTimeout time.Duration
 
+	finishedHandler FinishedHandler
+
 	// channel via which to send sync requests to syncer.
 	syncRequestCh chan<- *syncRequest
 
@@ -85,6 +87,7 @@ type processorParams struct {
 	queues            map[string]int
 	strictPriority    bool
 	errHandler        ErrorHandler
+	finishedHandler   FinishedHandler
 	shutdownTimeout   time.Duration
 	starting          chan<- *workerInfo
 	finished          chan<- *base.TaskMessage
@@ -115,6 +118,7 @@ func newProcessor(params processorParams) *processor {
 		quit:              make(chan struct{}),
 		abort:             make(chan struct{}),
 		errHandler:        params.errHandler,
+		finishedHandler:   params.finishedHandler,
 		handler:           HandlerFunc(func(ctx context.Context, t *Task) error { return fmt.Errorf("handler not set") }),
 		shutdownTimeout:   params.shutdownTimeout,
 		starting:          params.starting,
@@ -291,12 +295,21 @@ func (p *processor) markAsComplete(l *base.Lease, msg *base.TaskMessage) {
 		p.logger.Warnf("%s; Will retry syncing", errMsg)
 		p.syncRequestCh <- &syncRequest{
 			fn: func() error {
-				return p.broker.MarkAsComplete(ctx, msg)
+				if err := p.broker.MarkAsComplete(ctx, msg); err != nil {
+					return err
+				}
+				if p.finishedHandler != nil {
+					p.finishedHandler.HandleFinished(newTaskInfo(msg, base.TaskStateArchived, time.Time{}, nil))
+				}
+				return nil
 			},
 			errMsg:   errMsg,
 			deadline: l.Deadline(),
 		}
 	}
+	if p.finishedHandler != nil {
+		p.finishedHandler.HandleFinished(newTaskInfo(msg, base.TaskStateArchived, time.Time{}, nil))
+	}
 }
 
 func (p *processor) markAsDone(l *base.Lease, msg *base.TaskMessage) {
@@ -311,12 +324,21 @@ func (p *processor) markAsDone(l *base.Lease, msg *base.TaskMessage) {
 		p.logger.Warnf("%s; Will retry syncing", errMsg)
 		p.syncRequestCh <- &syncRequest{
 			fn: func() error {
-				return p.broker.Done(ctx, msg)
+				if err := p.broker.Done(ctx, msg); err != nil {
+					return err
+				}
+				if p.finishedHandler != nil {
+					p.finishedHandler.HandleFinished(newTaskInfo(msg, base.TaskStateArchived, time.Time{}, nil))
+				}
+				return nil
 			},
 			errMsg:   errMsg,
 			deadline: l.Deadline(),
 		}
 	}
+	if p.finishedHandler != nil {
+		p.finishedHandler.HandleFinished(newTaskInfo(msg, base.TaskStateArchived, time.Time{}, nil))
+	}
 }
 
 // SkipRetry is used as a return value from Handler.ProcessTask to indicate that
@@ -374,12 +396,21 @@ func (p *processor) archive(l *base.Lease, msg *base.TaskMessage, e error) {
 		p.logger.Warnf("%s; Will retry syncing", errMsg)
 		p.syncRequestCh <- &syncRequest{
 			fn: func() error {
-				return p.broker.Archive(ctx, msg, e.Error())
+				if err := p.broker.Archive(ctx, msg, e.Error()); err != nil {
+					return err
+				}
+				if p.finishedHandler != nil {
+					p.finishedHandler.HandleFinished(newTaskInfo(msg, base.TaskStateArchived, time.Time{}, nil))
+				}
+				return nil
 			},
 			errMsg:   errMsg,
 			deadline: l.Deadline(),
 		}
 	}
+	if p.finishedHandler != nil {
+		p.finishedHandler.HandleFinished(newTaskInfo(msg, base.TaskStateArchived, time.Time{}, nil))
+	}
 }
 
 // queues returns a list of queues to query.

server.go

@@ -103,7 +103,7 @@ type Config struct {
 	// If BaseContext is nil, the default is context.Background().
 	// If this is defined, then it MUST return a non-nil context
 	BaseContext func() context.Context
-	
+
 	// TaskCheckInterval specifies the interval between checks for new tasks to process when all queues are empty.
 	//
 	// If unset, zero or a negative value, the interval is set to 1 second.
@@ -183,6 +183,11 @@ type Config struct {
 
 	ErrorHandler ErrorHandler
 
+	// FinishedHandler handles a task that has been processed.
+	//
+	// FinishedHandler is called when the task status becomes completed or archived.
+	FinishedHandler FinishedHandler
+
 	// Logger specifies the logger used by the server instance.
 	//
 	// If unset, default logger is used.
@@ -275,6 +280,20 @@ func (fn ErrorHandlerFunc) HandleError(ctx context.Context, task *Task, err erro
 	fn(ctx, task, err)
 }
 
+// An FinishedHandler handles a task that has been processed.
+type FinishedHandler interface {
+	HandleFinished(task *TaskInfo)
+}
+
+// The FinishedHandlerFunc type is an adapter to allow the use of  ordinary functions as a FinishedHandler.
+// If f is a function with the appropriate signature, FinishedHandlerFunc(f) is a FinishedHandler that calls f.
+type FinishedHandlerFunc func(task *TaskInfo)
+
+// HandleFinished calls fn(ctx, task, err)
+func (fn FinishedHandlerFunc) HandleFinished(task *TaskInfo) {
+	fn(task)
+}
+
 // RetryDelayFunc calculates the retry delay duration for a failed task given
 // the retry count, error, and the task.
 //
@@ -529,6 +548,7 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 		queues:            queues,
 		strictPriority:    cfg.StrictPriority,
 		errHandler:        cfg.ErrorHandler,
+		finishedHandler:   cfg.FinishedHandler,
 		shutdownTimeout:   shutdownTimeout,
 		starting:          starting,
 		finished:          finished,