From 0f04acaa40f6f0362e36495135e3326f38d07b6c Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Mon, 29 Jun 2020 00:30:27 -0400
Subject: [PATCH] persist last seen on shutdown

---
 irc/client.go | 24 +++++++++++++++++++++---
 irc/server.go |  3 +++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/irc/client.go b/irc/client.go
index b9ba587d..bc36a41c 100644
--- a/irc/client.go
+++ b/irc/client.go
@@ -1724,7 +1724,7 @@ func (client *Client) wakeWriter() {
 
 func (client *Client) writeLoop() {
 	for {
-		client.performWrite()
+		client.performWrite(0)
 		client.writerSemaphore.Release()
 
 		client.stateMutex.RLock()
@@ -1737,9 +1737,9 @@ func (client *Client) writeLoop() {
 	}
 }
 
-func (client *Client) performWrite() {
+func (client *Client) performWrite(additionalDirtyBits uint) {
 	client.stateMutex.Lock()
-	dirtyBits := client.dirtyBits
+	dirtyBits := client.dirtyBits | additionalDirtyBits
 	client.dirtyBits = 0
 	account := client.account
 	client.stateMutex.Unlock()
@@ -1775,3 +1775,21 @@ func (client *Client) performWrite() {
 		client.server.accounts.saveModes(account, uModes)
 	}
 }
+
+// Blocking store; see Channel.Store and Socket.BlockingWrite
+func (client *Client) Store(dirtyBits uint) (err error) {
+	defer func() {
+		client.stateMutex.Lock()
+		isDirty := client.dirtyBits != 0
+		client.stateMutex.Unlock()
+
+		if isDirty {
+			client.wakeWriter()
+		}
+	}()
+
+	client.writerSemaphore.Acquire()
+	defer client.writerSemaphore.Release()
+	client.performWrite(dirtyBits)
+	return nil
+}
diff --git a/irc/server.go b/irc/server.go
index 98725553..8a5fbfb8 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -116,6 +116,9 @@ func (server *Server) Shutdown() {
 	//TODO(dan): Make sure we disallow new nicks
 	for _, client := range server.clients.AllClients() {
 		client.Notice("Server is shutting down")
+		if client.AlwaysOn() {
+			client.Store(IncludeLastSeen)
+		}
 	}
 
 	if err := server.store.Close(); err != nil {