feat(api): parameterize filter subscriptions

waku/v2/api/filter/filter.go

@@ -14,8 +14,6 @@ import (
 	"go.uber.org/zap"
 )
 
-const MultiplexChannelBuffer = 100
-
 type FilterConfig struct {
 	MaxPeers int       `json:"maxPeers"`
 	Peers    []peer.ID `json:"peers"`
@@ -44,14 +42,46 @@ type Sub struct {
 	id                    string
 }
 
+type subscribeParameters struct {
+	batchInterval          time.Duration
+	multiplexChannelBuffer int
+}
+
+type SubscribeOptions func(*subscribeParameters)
+
+func WithBatchInterval(t time.Duration) SubscribeOptions {
+	return func(params *subscribeParameters) {
+		params.batchInterval = t
+	}
+}
+
+func WithMultiplexChannelBuffer(value int) SubscribeOptions {
+	return func(params *subscribeParameters) {
+		params.multiplexChannelBuffer = value
+	}
+}
+
+func defaultOptions() []SubscribeOptions {
+	return []SubscribeOptions{
+		WithBatchInterval(5 * time.Second),
+		WithMultiplexChannelBuffer(100),
+	}
+}
+
 // Subscribe
-func Subscribe(ctx context.Context, wf *filter.WakuFilterLightNode, contentFilter protocol.ContentFilter, config FilterConfig, log *zap.Logger) (*Sub, error) {
+func Subscribe(ctx context.Context, wf *filter.WakuFilterLightNode, contentFilter protocol.ContentFilter, config FilterConfig, log *zap.Logger, opts ...SubscribeOptions) (*Sub, error) {
+	optList := append(defaultOptions(), opts...)
+	params := new(subscribeParameters)
+	for _, opt := range optList {
+		opt(params)
+	}
+
 	sub := new(Sub)
 	sub.id = uuid.NewString()
 	sub.wf = wf
 	sub.ctx, sub.cancel = context.WithCancel(ctx)
 	sub.subs = make(subscription.SubscriptionSet)
-	sub.DataCh = make(chan *protocol.Envelope, MultiplexChannelBuffer)
+	sub.DataCh = make(chan *protocol.Envelope, params.multiplexChannelBuffer)
 	sub.ContentFilter = contentFilter
 	sub.Config = config
 	sub.log = log.Named("filter-api").With(zap.String("apisub-id", sub.id), zap.Stringer("content-filter", sub.ContentFilter))
@@ -66,7 +96,7 @@ func Subscribe(ctx context.Context, wf *filter.WakuFilterLightNode, contentFilte
 		}
 	}
 
-	go sub.subscriptionLoop()
+	go sub.subscriptionLoop(params.batchInterval)
 	return sub, nil
 }
 
@@ -78,8 +108,8 @@ func (apiSub *Sub) Unsubscribe(contentFilter protocol.ContentFilter) {
 	}
 }
 
-func (apiSub *Sub) subscriptionLoop() {
-	ticker := time.NewTicker(5 * time.Second)
+func (apiSub *Sub) subscriptionLoop(batchInterval time.Duration) {
+	ticker := time.NewTicker(batchInterval)
 	defer ticker.Stop()
 	for {
 		select {