From b582d51c90f2324b38e97651f7734fb645442e7d Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Fri, 24 May 2024 17:21:23 -0700
Subject: [PATCH] daemon: Add message channel for sending commands to the
 daemon object

---
 src/daemon/mod.rs  | 33 ++++++++++++++++++++++++++++++++-
 src/daemon/root.rs |  5 +++--
 src/daemon/user.rs |  5 +++--
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/src/daemon/mod.rs b/src/daemon/mod.rs
index a826e2c..0cda9bd 100644
--- a/src/daemon/mod.rs
+++ b/src/daemon/mod.rs
@@ -11,6 +11,7 @@ use std::fmt::Debug;
 use std::marker::PhantomData;
 use std::path::PathBuf;
 use tokio::signal::unix::{signal, SignalKind};
+use tokio::sync::mpsc::{self, Receiver, Sender};
 use tokio::task::JoinSet;
 use tokio_util::sync::CancellationToken;
 use tracing::{error, info};
@@ -18,7 +19,7 @@ use tracing_subscriber::layer::SubscriberExt;
 use tracing_subscriber::registry::LookupSpan;
 use zbus::connection::Connection;
 
-use crate::daemon::config::{read_config, read_state};
+use crate::daemon::config::{read_config, read_state, write_state};
 use crate::sls::{LogLayer, LogReceiver};
 use crate::Service;
 
@@ -55,13 +56,21 @@ pub(crate) trait DaemonContext: Sized {
 pub(crate) struct Daemon<C: DaemonContext> {
     services: JoinSet<Result<()>>,
     token: CancellationToken,
+    channel: Receiver<DaemonCommand>,
     _context: PhantomData<C>,
 }
 
+#[derive(Debug)]
+pub(crate) enum DaemonCommand {
+    ReadConfig,
+    WriteState,
+}
+
 impl<C: DaemonContext> Daemon<C> {
     pub(crate) async fn new<S: SubscriberExt + Send + Sync + for<'a> LookupSpan<'a>>(
         subscriber: S,
         connection: Connection,
+        channel: Receiver<DaemonCommand>,
     ) -> Result<Daemon<C>> {
         let services = JoinSet::new();
         let token = CancellationToken::new();
@@ -74,6 +83,7 @@ impl<C: DaemonContext> Daemon<C> {
         let mut daemon = Daemon {
             services,
             token,
+            channel,
             _context: PhantomData::default(),
         };
         daemon.add_service(log_receiver);
@@ -128,6 +138,10 @@ impl<C: DaemonContext> Daemon<C> {
                     }
                     None => Err(anyhow!("SIGHUP machine broke")),
                 },
+                msg = self.channel.recv() => match msg {
+                    Some(msg) => self.handle_message(&mut context, msg).await,
+                    None => Err(anyhow!("All senders have been closed")),
+                },
                 _ = sigquit.recv() => Err(anyhow!("Got SIGQUIT")),
             }
             .inspect_err(|e| error!("Encountered error running: {e}"));
@@ -150,4 +164,21 @@ impl<C: DaemonContext> Daemon<C> {
 
         res.inspect_err(|e| error!("Encountered error: {e}"))
     }
+
+    async fn handle_message(&mut self, context: &mut C, cmd: DaemonCommand) -> Result<()> {
+        match cmd {
+            DaemonCommand::ReadConfig => match read_config(context).await {
+                Ok(config) => context.reload(config, self).await,
+                Err(error) => {
+                    error!("Failed to load configuration: {error}");
+                    Ok(())
+                }
+            },
+            DaemonCommand::WriteState => write_state(context).await,
+        }
+    }
+}
+
+pub(crate) fn channel() -> (Sender<DaemonCommand>, Receiver<DaemonCommand>) {
+    mpsc::channel(10)
 }
diff --git a/src/daemon/root.rs b/src/daemon/root.rs
index 1a8f621..18dbf6f 100644
--- a/src/daemon/root.rs
+++ b/src/daemon/root.rs
@@ -14,7 +14,7 @@ use tracing_subscriber::{fmt, Registry};
 use zbus::connection::Connection;
 use zbus::ConnectionBuilder;
 
-use crate::daemon::{Daemon, DaemonContext};
+use crate::daemon::{channel, Daemon, DaemonContext};
 use crate::ds_inhibit::Inhibitor;
 use crate::manager::root::SteamOSManager;
 use crate::path;
@@ -93,6 +93,7 @@ pub async fn daemon() -> Result<()> {
 
     let stdout_log = fmt::layer();
     let subscriber = Registry::default().with(stdout_log);
+    let (_tx, rx) = channel();
 
     let connection = match create_connection().await {
         Ok(c) => c,
@@ -104,7 +105,7 @@ pub async fn daemon() -> Result<()> {
     };
 
     let context = RootContext {};
-    let mut daemon = Daemon::new(subscriber, connection.clone()).await?;
+    let mut daemon = Daemon::new(subscriber, connection.clone(), rx).await?;
 
     let ftrace = Ftrace::init(connection.clone()).await?;
     daemon.add_service(ftrace);
diff --git a/src/daemon/user.rs b/src/daemon/user.rs
index 18eb64f..9ea7ee7 100644
--- a/src/daemon/user.rs
+++ b/src/daemon/user.rs
@@ -16,7 +16,7 @@ use xdg::BaseDirectories;
 use zbus::connection::Connection;
 use zbus::ConnectionBuilder;
 
-use crate::daemon::{Daemon, DaemonContext};
+use crate::daemon::{channel, Daemon, DaemonContext};
 use crate::manager::user::SteamOSManager;
 use crate::path;
 
@@ -103,6 +103,7 @@ pub async fn daemon() -> Result<()> {
 
     let stdout_log = fmt::layer();
     let subscriber = Registry::default().with(stdout_log);
+    let (_tx, rx) = channel();
 
     let (_session, system) = match create_connections().await {
         Ok(c) => c,
@@ -114,7 +115,7 @@ pub async fn daemon() -> Result<()> {
     };
 
     let context = UserContext {};
-    let mut daemon = Daemon::new(subscriber, system).await?;
+    let mut daemon = Daemon::new(subscriber, system, rx).await?;
 
     daemon.run(context).await
 }