[libbeat] rename queue.Eventer -> queue.ACKListener

CHANGELOG-developer.next.asciidoc

@@ -30,6 +30,7 @@ The list below covers the major changes between 7.0.0-rc2 and master only.
 - Deprecate test flags, `generate` and `update_expected`, in favor of `data`. {pull}15292[15292]
 - Python 3 is required now to run python tests and tools. {pull}14798[14798]
 - The type `memqueue.Broker` is no longer exported; instead of `memqueue.NewBroker`, call `memqueue.NewQueue` (which provides the same public interface). {pull}16667[16667]
+- `queue.Eventer` has been renamed to `queue.ACKListener` {pull}16691[16691]
 
 ==== Bugfixes
 

libbeat/monitoring/report/elasticsearch/elasticsearch.go

@@ -171,11 +171,11 @@ func makeReporter(beat beat.Info, settings report.Settings, cfg *common.Config)
 		clients = append(clients, client)
 	}
 
-	queueFactory := func(e queue.Eventer) (queue.Queue, error) {
+	queueFactory := func(ackListener queue.ACKListener) (queue.Queue, error) {
 		return memqueue.NewQueue(log,
 			memqueue.Settings{
-				Eventer: e,
-				Events:  20,
+				ACKListener: ackListener,
+				Events:      20,
 			}), nil
 	}
 

libbeat/publisher/pipeline/client_test.go

@@ -33,7 +33,7 @@ func TestClient(t *testing.T) {
 	makePipeline := func(settings Settings, qu queue.Queue) *Pipeline {
 		p, err := New(beat.Info{},
 			Monitors{},
-			func(_ queue.Eventer) (queue.Queue, error) {
+			func(_ queue.ACKListener) (queue.Queue, error) {
 				return qu, nil
 			},
 			outputs.Group{},

libbeat/publisher/pipeline/module.go

@@ -166,7 +166,7 @@ func loadOutput(
 func createQueueBuilder(
 	config common.ConfigNamespace,
 	monitors Monitors,
-) (func(queue.Eventer) (queue.Queue, error), error) {
+) (func(queue.ACKListener) (queue.Queue, error), error) {
 	queueType := defaultQueueType
 	if b := config.Name(); b != "" {
 		queueType = b
@@ -187,7 +187,7 @@ func createQueueBuilder(
 		monitoring.NewString(queueReg, "name").Set(queueType)
 	}
 
-	return func(eventer queue.Eventer) (queue.Queue, error) {
-		return queueFactory(eventer, monitors.Logger, queueConfig)
+	return func(ackListener queue.ACKListener) (queue.Queue, error) {
+		return queueFactory(ackListener, monitors.Logger, queueConfig)
 	}, nil
 }

libbeat/publisher/pipeline/pipeline.go

@@ -136,7 +136,7 @@ type waitCloser struct {
 	events sync.WaitGroup
 }
 
-type queueFactory func(queue.Eventer) (queue.Queue, error)
+type queueFactory func(queue.ACKListener) (queue.Queue, error)
 
 // New create a new Pipeline instance from a queue instance and a set of outputs.
 // The new pipeline will take ownership of queue and outputs. On Close, the

libbeat/publisher/queue/memqueue/ackloop.go

@@ -112,8 +112,8 @@ func (l *ackLoop) handleBatchSig() int {
 	}
 
 	if count > 0 {
-		if e := l.broker.eventer; e != nil {
-			e.OnACK(count)
+		if listener := l.broker.ackListener; listener != nil {
+			listener.OnACK(count)
 		}
 
 		// report acks to waiting clients

libbeat/publisher/queue/memqueue/broker.go

@@ -55,15 +55,15 @@ type broker struct {
 	acks          chan int
 	scheduledACKs chan chanList
 
-	eventer queue.Eventer
+	ackListener queue.ACKListener
 
 	// wait group for worker shutdown
 	wg          sync.WaitGroup
 	waitOnClose bool
 }
 
 type Settings struct {
-	Eventer        queue.Eventer
+	ACKListener    queue.ACKListener
 	Events         int
 	FlushMinEvents int
 	FlushTimeout   time.Duration
@@ -87,7 +87,9 @@ func init() {
 	queue.RegisterType("mem", create)
 }
 
-func create(eventer queue.Eventer, logger *logp.Logger, cfg *common.Config) (queue.Queue, error) {
+func create(
+	ackListener queue.ACKListener, logger *logp.Logger, cfg *common.Config,
+) (queue.Queue, error) {
 	config := defaultConfig
 	if err := cfg.Unpack(&config); err != nil {
 		return nil, err
@@ -98,7 +100,7 @@ func create(eventer queue.Eventer, logger *logp.Logger, cfg *common.Config) (que
 	}
 
 	return NewQueue(logger, Settings{
-		Eventer:        eventer,
+		ACKListener:    ackListener,
 		Events:         config.Events,
 		FlushMinEvents: config.FlushMinEvents,
 		FlushTimeout:   config.FlushTimeout,
@@ -152,7 +154,7 @@ func NewQueue(
 
 		waitOnClose: settings.WaitOnClose,
 
-		eventer: settings.Eventer,
+		ackListener: settings.ACKListener,
 	}
 
 	var eventLoop interface {

libbeat/publisher/queue/queue.go

@@ -27,11 +27,11 @@ import (
 )
 
 // Factory for creating a queue used by a pipeline instance.
-type Factory func(Eventer, *logp.Logger, *common.Config) (Queue, error)
+type Factory func(ACKListener, *logp.Logger, *common.Config) (Queue, error)
 
-// Eventer listens to special events to be send by queue implementations.
-type Eventer interface {
-	OnACK(int) // number of consecutively published messages, acked by producers
+// ACKListener listens to special events to be send by queue implementations.
+type ACKListener interface {
+	OnACK(eventCount int) // number of consecutively published events acked by producers
 }
 
 // Queue is responsible for accepting, forwarding and ACKing events.

libbeat/publisher/queue/spool/inbroker.go

@@ -27,8 +27,8 @@ import (
 )
 
 type inBroker struct {
-	ctx     *spoolCtx
-	eventer queue.Eventer
+	ctx         *spoolCtx
+	ackListener queue.ACKListener
 
 	// active state handler
 	state func(*inBroker) bool
@@ -73,7 +73,7 @@ const (
 
 func newInBroker(
 	ctx *spoolCtx,
-	eventer queue.Eventer,
+	ackListener queue.ACKListener,
 	qu *pq.Queue,
 	codec codecID,
 	flushTimeout time.Duration,
@@ -90,9 +90,9 @@ func newInBroker(
 	}
 
 	b := &inBroker{
-		ctx:     ctx,
-		eventer: eventer,
-		state:   (*inBroker).stateEmpty,
+		ctx:         ctx,
+		ackListener: ackListener,
+		state:       (*inBroker).stateEmpty,
 
 		// API
 		events:    make(chan pushRequest, inEventChannelSize),
@@ -134,8 +134,8 @@ func (b *inBroker) onFlush(n uint) {
 		return
 	}
 
-	if b.eventer != nil {
-		b.eventer.OnACK(int(n))
+	if b.ackListener != nil {
+		b.ackListener.OnACK(int(n))
 	}
 	b.ctx.logger.Debug("inbroker: flushed events:", n)
 	b.bufferedEvents -= n

libbeat/publisher/queue/spool/module.go

@@ -39,7 +39,9 @@ func init() {
 	queue.RegisterType("spool", create)
 }
 
-func create(eventer queue.Eventer, logp *logp.Logger, cfg *common.Config) (queue.Queue, error) {
+func create(
+	ackListener queue.ACKListener, logp *logp.Logger, cfg *common.Config,
+) (queue.Queue, error) {
 	cfgwarn.Beta("Spooling to disk is beta")
 
 	config := defaultConfig()
@@ -63,7 +65,7 @@ func create(eventer queue.Eventer, logp *logp.Logger, cfg *common.Config) (queue
 	}
 
 	return NewSpool(log, path, Settings{
-		Eventer:           eventer,
+		ACKListener:       ackListener,
 		Mode:              config.File.Permissions,
 		WriteBuffer:       uint(config.Write.BufferSize),
 		WriteFlushTimeout: config.Write.FlushTimeout,

libbeat/publisher/queue/spool/spool.go

@@ -64,7 +64,7 @@ type Settings struct {
 	// buffer be flushed and reset to its original size.
 	WriteBuffer uint
 
-	Eventer queue.Eventer
+	ACKListener queue.ACKListener
 
 	WriteFlushTimeout time.Duration
 	WriteFlushEvents  uint
@@ -134,7 +134,8 @@ func NewSpool(logger logger, path string, settings Settings) (*Spool, error) {
 	if inFlushTimeout < minInFlushTimeout {
 		inFlushTimeout = minInFlushTimeout
 	}
-	inBroker, err := newInBroker(inCtx, settings.Eventer, queue, settings.Codec,
+	inBroker, err := newInBroker(
+		inCtx, settings.ACKListener, queue, settings.Codec,
 		inFlushTimeout, settings.WriteFlushEvents)
 	if err != nil {
 		return nil, err