From 5dd0f454c197ccbce369ee88d47d5be8cd5e8265 Mon Sep 17 00:00:00 2001
From: Reto Brunner <reto@labrat.space>
Date: Mon, 24 Feb 2020 20:18:31 +0100
Subject: [PATCH] lib/msgstore: debounce directoryUpdateRequests

Apparently sending an event for every incoming messageInfo slows down
the application significantly.

Therefore this slows down the emmision rate, on the cost of being out of date
in some cases.
---
 lib/msgstore.go       | 20 +++++++++++++++++---
 worker/imap/worker.go |  2 ++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/lib/msgstore.go b/lib/msgstore.go
index ae58aaf..b1785c1 100644
--- a/lib/msgstore.go
+++ b/lib/msgstore.go
@@ -42,6 +42,9 @@ type MessageStore struct {
 
 	triggerNewEmail        func(*models.MessageInfo)
 	triggerDirectoryChange func()
+
+	dirInfoUpdateDebounce *time.Timer
+	dirInfoUpdateDelay    time.Duration
 }
 
 func NewMessageStore(worker *types.Worker,
@@ -50,6 +53,8 @@ func NewMessageStore(worker *types.Worker,
 	triggerNewEmail func(*models.MessageInfo),
 	triggerDirectoryChange func()) *MessageStore {
 
+	dirInfoUpdateDelay := 5 * time.Second
+
 	return &MessageStore{
 		Deleted:  make(map[uint32]interface{}),
 		DirInfo:  *dirInfo,
@@ -68,6 +73,9 @@ func NewMessageStore(worker *types.Worker,
 
 		triggerNewEmail:        triggerNewEmail,
 		triggerDirectoryChange: triggerDirectoryChange,
+
+		dirInfoUpdateDelay:    dirInfoUpdateDelay,
+		dirInfoUpdateDebounce: time.NewTimer(dirInfoUpdateDelay),
 	}
 }
 
@@ -267,9 +275,15 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 	}
 
 	if requestDirInfo {
-		store.worker.PostAction(&types.DirectoryInfoUpdateRequest{
-			Name: store.DirInfo.Name,
-		}, nil)
+		select {
+		case <-store.dirInfoUpdateDebounce.C:
+			store.worker.PostAction(&types.DirectoryInfoUpdateRequest{
+				Name: store.DirInfo.Name,
+			}, nil)
+			store.dirInfoUpdateDebounce.Reset(store.dirInfoUpdateDelay)
+		default:
+			// do nothing
+		}
 	}
 }
 
diff --git a/worker/imap/worker.go b/worker/imap/worker.go
index ddd95b6..1037f81 100644
--- a/worker/imap/worker.go
+++ b/worker/imap/worker.go
@@ -181,6 +181,8 @@ func (w *IMAPWorker) handleMessage(msg types.WorkerMessage) error {
 		w.handleAppendMessage(msg)
 	case *types.SearchDirectory:
 		w.handleSearchDirectory(msg)
+	case *types.DirectoryInfoUpdateRequest:
+		// not implemented
 	default:
 		reterr = errUnsupported
 	}