libs/events: remove unused event cache (#7807)

libs/events/event_cache.go

@@ -1,39 +0,0 @@
-package events
-
-import "context"
-
-// An EventCache buffers events for a Fireable
-// All events are cached. Filtering happens on Flush
-type EventCache struct {
-	evsw   Fireable
-	events []eventInfo
-}
-
-// Create a new EventCache with an EventSwitch as backend
-func NewEventCache(evsw Fireable) *EventCache {
-	return &EventCache{
-		evsw: evsw,
-	}
-}
-
-// a cached event
-type eventInfo struct {
-	event string
-	data  EventData
-}
-
-// Cache an event to be fired upon finality.
-func (evc *EventCache) FireEvent(event string, data EventData) {
-	// append to list (go will grow our backing array exponentially)
-	evc.events = append(evc.events, eventInfo{event, data})
-}
-
-// Fire events by running evsw.FireEvent on all cached events. Blocks.
-// Clears cached events
-func (evc *EventCache) Flush(ctx context.Context) {
-	for _, ei := range evc.events {
-		evc.evsw.FireEvent(ctx, ei.event, ei.data)
-	}
-	// Clear the buffer, since we only add to it with append it's safe to just set it to nil and maybe safe an allocation
-	evc.events = nil
-}

libs/events/event_cache_test.go

@@ -1,49 +0,0 @@
-package events
-
-import (
-	"context"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"github.com/tendermint/tendermint/libs/log"
-)
-
-func TestEventCache_Flush(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	logger := log.NewTestingLogger(t)
-	evsw := NewEventSwitch(logger)
-	err := evsw.Start(ctx)
-	require.NoError(t, err)
-
-	err = evsw.AddListenerForEvent("nothingness", "", func(_ context.Context, data EventData) error {
-		// Check we are not initializing an empty buffer full of zeroed eventInfos in the EventCache
-		require.FailNow(t, "We should never receive a message on this switch since none are fired")
-		return nil
-	})
-	require.NoError(t, err)
-
-	evc := NewEventCache(evsw)
-	evc.Flush(ctx)
-	// Check after reset
-	evc.Flush(ctx)
-	fail := true
-	pass := false
-	err = evsw.AddListenerForEvent("somethingness", "something", func(_ context.Context, data EventData) error {
-		if fail {
-			require.FailNow(t, "Shouldn't see a message until flushed")
-		}
-		pass = true
-		return nil
-	})
-	require.NoError(t, err)
-
-	evc.FireEvent("something", struct{ int }{1})
-	evc.FireEvent("something", struct{ int }{2})
-	evc.FireEvent("something", struct{ int }{3})
-	fail = false
-	evc.Flush(ctx)
-	assert.True(t, pass)
-}