From f5161c28c1c5d95c872659046f7124ddefb5209a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20M=C3=BCller?= <deso@posteo.net>
Date: Wed, 14 May 2025 19:44:56 -0700
Subject: [PATCH] Save state file more eagerly

We built some infrastructure that informs the user about the currently
playing song based on the state file that MPD writes out. Unfortunately,
this state file is updated only periodically, but not immediately in
response to song changes, causing an undesirable delay.
To fix this issue, this change makes sure to write out said state file
eagerly when the currently playing song changed.
---
 src/Main.cxx          | 2 +-
 src/Main.hxx          | 3 +++
 src/PlayerControl.cxx | 4 ++++
 src/Playlist.cxx      | 4 ++++
 4 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/Main.cxx b/src/Main.cxx
index b45e2c..41446b 100644
--- a/src/Main.cxx
+++ b/src/Main.cxx
@@ -104,7 +104,7 @@ EventLoop *main_loop;
 
 Instance *instance;
 
-static StateFile *state_file;
+StateFile *state_file;
 
 static bool
 glue_daemonize_init(const struct options *options, Error &error)
diff --git a/src/Main.hxx b/src/Main.hxx
index a8ec18..838de3 100644
--- a/src/Main.hxx
+++ b/src/Main.hxx
@@ -23,6 +23,7 @@
 class ThreadId;
 class EventLoop;
 struct Instance;
+struct StateFile;
 
 extern ThreadId main_thread;
 
@@ -30,6 +31,8 @@ extern EventLoop *main_loop;
 
 extern Instance *instance;
 
+extern StateFile *state_file;
+
 /**
  * A entry point for application.
  * On non-Windows platforms this is called directly from main()
diff --git a/src/PlayerControl.cxx b/src/PlayerControl.cxx
index f18087..5e7f62 100644
--- a/src/PlayerControl.cxx
+++ b/src/PlayerControl.cxx
@@ -22,6 +22,8 @@
 #include "Idle.hxx"
 #include "Song.hxx"
 #include "DecoderControl.hxx"
+#include "Main.hxx"
+#include "StateFile.hxx"
 
 #include <cmath>
 
@@ -140,6 +142,8 @@ PlayerControl::SetPause(bool pause_flag)
 	}
 
 	Unlock();
+
+  state_file->Write();
 }
 
 void
diff --git a/src/Playlist.cxx b/src/Playlist.cxx
index 526f35..326c30 100644
--- a/src/Playlist.cxx
+++ b/src/Playlist.cxx
@@ -25,6 +25,8 @@
 #include "tag/Tag.hxx"
 #include "Idle.hxx"
 #include "Log.hxx"
+#include "Main.hxx"
+#include "StateFile.hxx"
 
 #include <assert.h>
 
@@ -147,6 +149,8 @@ playlist::UpdateQueuedSong(PlayerControl &pc, const Song *prev)
 		else
 			queued = next_order;
 	}
+
+  state_file->Write();
 }
 
 void
-- 
2.56.0