start working on event debouncer

events.go

@@ -3,8 +3,60 @@ package gocql
 import (
 	"log"
 	"net"
+	"sync"
+	"time"
 )
 
+type eventDeouncer struct {
+	mu     sync.Mutex
+	events []frame // TODO: possibly use a chan here
+
+	callback func([]frame)
+	quit     chan struct{}
+}
+
+func (e *eventDeouncer) flusher() {
+	ticker := time.NewTicker(1 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			e.mu.Lock()
+			e.flush()
+			e.mu.Unlock()
+		case <-e.quit:
+			return
+		}
+	}
+}
+
+// flush must be called with mu locked
+func (e *eventDeouncer) flush() {
+	if len(e.events) == 0 {
+		return
+	}
+
+	// TODO: can this be done in a nicer way?
+	events := make([]frame, len(e.events))
+	copy(events, e.events)
+	e.events = e.events[:0]
+
+	go e.callback(events)
+}
+
+func (e *eventDeouncer) handleEvent(frame frame) {
+	e.mu.Lock()
+
+	const maxEvents = 100
+	e.events = append(e.events, frame)
+	// TODO: probably need a warning to track if this threshold is too low
+	if len(e.events) > maxEvents {
+		e.flush()
+	}
+	e.mu.Unlock()
+}
+
 func (s *Session) handleEvent(framer *framer) {
 	// TODO(zariel): need to debounce events frames, and possible also events
 	defer framerPool.Put(framer)