Make WrappedQueues and PersistableChannelUniqueQueues Pausable (#18393)

Implements the Pausable interface on WrappedQueues and PersistableChannelUniqueQueues

Reference #15928

Signed-off-by: Andrew Thornton art27@cantab.net

9 files changed, 72 insertions, 14 deletions

diff --git a/modules/queue/queue.go b/modules/queue/queue.go
index 3a51965143..a166a935a6 100644
--- a/modules/queue/queue.go
+++ b/modules/queue/queue.go
@@ -196,7 +196,7 @@ func RegisteredTypesAsString() []string {
 func NewQueue(queueType Type, handlerFunc HandlerFunc, opts, exemplar interface{}) (Queue, error) {
 	newFn, ok := queuesMap[queueType]
 	if !ok {
-		return nil, fmt.Errorf("Unsupported queue type: %v", queueType)
+		return nil, fmt.Errorf("unsupported queue type: %v", queueType)
 	}
 	return newFn(handlerFunc, opts, exemplar)
 }
diff --git a/modules/queue/queue_bytefifo.go b/modules/queue/queue_bytefifo.go
index 0380497ea6..7f2acf3deb 100644
--- a/modules/queue/queue_bytefifo.go
+++ b/modules/queue/queue_bytefifo.go
@@ -92,7 +92,7 @@ func (q *ByteFIFOQueue) Push(data Data) error {
 // PushBack pushes data to the fifo
 func (q *ByteFIFOQueue) PushBack(data Data) error {
 	if !assignableTo(data, q.exemplar) {
-		return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
+		return fmt.Errorf("unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
 	}
 	bs, err := json.Marshal(data)
 	if err != nil {
@@ -110,7 +110,7 @@ func (q *ByteFIFOQueue) PushBack(data Data) error {
 // PushFunc pushes data to the fifo
 func (q *ByteFIFOQueue) PushFunc(data Data, fn func() error) error {
 	if !assignableTo(data, q.exemplar) {
-		return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
+		return fmt.Errorf("unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
 	}
 	bs, err := json.Marshal(data)
 	if err != nil {
@@ -398,7 +398,7 @@ func NewByteFIFOUniqueQueue(typ Type, byteFIFO UniqueByteFIFO, handle HandlerFun
 // Has checks if the provided data is in the queue
 func (q *ByteFIFOUniqueQueue) Has(data Data) (bool, error) {
 	if !assignableTo(data, q.exemplar) {
-		return false, fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
+		return false, fmt.Errorf("unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
 	}
 	bs, err := json.Marshal(data)
 	if err != nil {
diff --git a/modules/queue/queue_channel.go b/modules/queue/queue_channel.go
index 7de9c17c86..105388f421 100644
--- a/modules/queue/queue_channel.go
+++ b/modules/queue/queue_channel.go
@@ -93,7 +93,7 @@ func (q *ChannelQueue) Run(atShutdown, atTerminate func(func())) {
 // Push will push data into the queue
 func (q *ChannelQueue) Push(data Data) error {
 	if !assignableTo(data, q.exemplar) {
-		return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in queue: %s", data, q.exemplar, q.name)
+		return fmt.Errorf("unable to assign data: %v to same type as exemplar: %v in queue: %s", data, q.exemplar, q.name)
 	}
 	q.WorkerPool.Push(data)
 	return nil
diff --git a/modules/queue/queue_wrapped.go b/modules/queue/queue_wrapped.go
index edb589338a..02f7818aa8 100644
--- a/modules/queue/queue_wrapped.go
+++ b/modules/queue/queue_wrapped.go
@@ -59,7 +59,7 @@ func (q *delayedStarter) setInternal(atShutdown func(func()), handle HandlerFunc
 			if s, ok := cfg.([]byte); ok {
 				cfg = string(s)
 			}
-			return fmt.Errorf("Timedout creating queue %v with cfg %#v in %s", q.underlying, cfg, q.name)
+			return fmt.Errorf("timedout creating queue %v with cfg %#v in %s", q.underlying, cfg, q.name)
 		default:
 			queue, err := NewQueue(q.underlying, handle, q.cfg, exemplar)
 			if err == nil {
@@ -76,9 +76,9 @@ func (q *delayedStarter) setInternal(atShutdown func(func()), handle HandlerFunc
 			i++
 			if q.maxAttempts > 0 && i > q.maxAttempts {
 				if bs, ok := q.cfg.([]byte); ok {
-					return fmt.Errorf("Unable to create queue %v for %s with cfg %s by max attempts: error: %v", q.underlying, q.name, string(bs), err)
+					return fmt.Errorf("unable to create queue %v for %s with cfg %s by max attempts: error: %v", q.underlying, q.name, string(bs), err)
 				}
-				return fmt.Errorf("Unable to create queue %v for %s with cfg %#v by max attempts: error: %v", q.underlying, q.name, q.cfg, err)
+				return fmt.Errorf("unable to create queue %v for %s with cfg %#v by max attempts: error: %v", q.underlying, q.name, q.cfg, err)
 			}
 			sleepTime := 100 * time.Millisecond
 			if q.timeout > 0 && q.maxAttempts > 0 {
@@ -271,6 +271,46 @@ func (q *WrappedQueue) Terminate() {
 	log.Debug("WrappedQueue: %s Terminated", q.name)
 }
 
+// IsPaused will return if the pool or queue is paused
+func (q *WrappedQueue) IsPaused() bool {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+	pausable, ok := q.internal.(Pausable)
+	return ok && pausable.IsPaused()
+}
+
+// Pause will pause the pool or queue
+func (q *WrappedQueue) Pause() {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+	if pausable, ok := q.internal.(Pausable); ok {
+		pausable.Pause()
+	}
+}
+
+// Resume will resume the pool or queue
+func (q *WrappedQueue) Resume() {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+	if pausable, ok := q.internal.(Pausable); ok {
+		pausable.Resume()
+	}
+}
+
+// IsPausedIsResumed will return a bool indicating if the pool or queue is paused and a channel that will be closed when it is resumed
+func (q *WrappedQueue) IsPausedIsResumed() (paused, resumed <-chan struct{}) {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+	if pausable, ok := q.internal.(Pausable); ok {
+		return pausable.IsPausedIsResumed()
+	}
+	return context.Background().Done(), closedChan
+}
+
+var closedChan chan struct{}
+
 func init() {
 	queuesMap[WrappedQueueType] = NewWrappedQueue
+	closedChan = make(chan struct{})
+	close(closedChan)
 }
diff --git a/modules/queue/setting.go b/modules/queue/setting.go
index 61f156c377..880770f073 100644
--- a/modules/queue/setting.go
+++ b/modules/queue/setting.go
@@ -22,7 +22,7 @@ func validType(t string) (Type, error) {
 			return typ, nil
 		}
 	}
-	return PersistableChannelQueueType, fmt.Errorf("Unknown queue type: %s defaulting to %s", t, string(PersistableChannelQueueType))
+	return PersistableChannelQueueType, fmt.Errorf("unknown queue type: %s defaulting to %s", t, string(PersistableChannelQueueType))
 }
 
 func getQueueSettings(name string) (setting.QueueSettings, []byte) {
diff --git a/modules/queue/unique_queue_channel.go b/modules/queue/unique_queue_channel.go
index b6d2e770fc..59210855a1 100644
--- a/modules/queue/unique_queue_channel.go
+++ b/modules/queue/unique_queue_channel.go
@@ -111,7 +111,7 @@ func (q *ChannelUniqueQueue) Push(data Data) error {
 // PushFunc will push data into the queue
 func (q *ChannelUniqueQueue) PushFunc(data Data, fn func() error) error {
 	if !assignableTo(data, q.exemplar) {
-		return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in queue: %s", data, q.exemplar, q.name)
+		return fmt.Errorf("unable to assign data: %v to same type as exemplar: %v in queue: %s", data, q.exemplar, q.name)
 	}
 
 	bs, err := json.Marshal(data)
diff --git a/modules/queue/unique_queue_disk_channel.go b/modules/queue/unique_queue_disk_channel.go
index 7fc304b17e..ac7919926f 100644
--- a/modules/queue/unique_queue_disk_channel.go
+++ b/modules/queue/unique_queue_disk_channel.go
@@ -239,6 +239,26 @@ func (q *PersistableChannelUniqueQueue) IsEmpty() bool {
 	return q.channelQueue.IsEmpty()
 }
 
+// IsPaused will return if the pool or queue is paused
+func (q *PersistableChannelUniqueQueue) IsPaused() bool {
+	return q.channelQueue.IsPaused()
+}
+
+// Pause will pause the pool or queue
+func (q *PersistableChannelUniqueQueue) Pause() {
+	q.channelQueue.Pause()
+}
+
+// Resume will resume the pool or queue
+func (q *PersistableChannelUniqueQueue) Resume() {
+	q.channelQueue.Resume()
+}
+
+// IsPausedIsResumed will return a bool indicating if the pool or queue is paused and a channel that will be closed when it is resumed
+func (q *PersistableChannelUniqueQueue) IsPausedIsResumed() (paused, resumed <-chan struct{}) {
+	return q.channelQueue.IsPausedIsResumed()
+}
+
 // Shutdown processing this queue
 func (q *PersistableChannelUniqueQueue) Shutdown() {
 	log.Trace("PersistableChannelUniqueQueue: %s Shutting down", q.delayedStarter.name)
diff --git a/modules/queue/unique_queue_wrapped.go b/modules/queue/unique_queue_wrapped.go
index 32fa9ed970..5245a35f77 100644
--- a/modules/queue/unique_queue_wrapped.go
+++ b/modules/queue/unique_queue_wrapped.go
@@ -105,7 +105,7 @@ func (q *WrappedUniqueQueue) Push(data Data) error {
 // PushFunc will push the data to the internal channel checking it against the exemplar
 func (q *WrappedUniqueQueue) PushFunc(data Data, fn func() error) error {
 	if !assignableTo(data, q.exemplar) {
-		return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
+		return fmt.Errorf("unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
 	}
 
 	q.tlock.Lock()
diff --git a/modules/queue/workerpool.go b/modules/queue/workerpool.go
index da56216dcb..30dc8073c9 100644
--- a/modules/queue/workerpool.go
+++ b/modules/queue/workerpool.go
@@ -57,14 +57,12 @@ func NewWorkerPool(handle HandlerFunc, config WorkerPoolConfiguration) *WorkerPo
 	ctx, cancel := context.WithCancel(context.Background())
 
 	dataChan := make(chan Data, config.QueueLength)
-	resumed := make(chan struct{})
-	close(resumed)
 	pool := &WorkerPool{
 		baseCtx:            ctx,
 		baseCtxCancel:      cancel,
 		batchLength:        config.BatchLength,
 		dataChan:           dataChan,
-		resumed:            resumed,
+		resumed:            closedChan,
 		paused:             make(chan struct{}),
 		handle:             handle,
 		blockTimeout:       config.BlockTimeout,