From 4465c672abb442b6c9d1e411dedddefbe03633f4 Mon Sep 17 00:00:00 2001
From: alemi <me@alemi.dev>
Date: Sun, 5 Jun 2022 20:05:39 +0200
Subject: [PATCH] feat: added wrapper for native background worker

---
 Cargo.toml         | 13 ++++++++++++-
 src/main.rs        |  9 ++++++++-
 src/util/mod.rs    |  1 +
 src/util/worker.rs | 40 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 61 insertions(+), 2 deletions(-)
 create mode 100644 src/util/mod.rs
 create mode 100644 src/util/worker.rs

diff --git a/Cargo.toml b/Cargo.toml
index ce9521d..c186629 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,8 +18,19 @@ chrono = { version = "0.4", features = ["wasmbind"] }
 eframe = { version = "0.18", features = ["persistence"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
+jq-rs = "0.4"
+rusqlite = { version = "0.27" }
 ehttp = "0.2.0"
-# web:
+reqwest = { version = "0.11", features = ["json"] }
+
+# native only dependancies:
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+tokio = { version = "1", features = ["full"] } # TODO do we need full features?
+
+# web only dependancies:
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 console_error_panic_hook = "0.1.6"
 tracing-wasm = "0.2"
+
+[env]
+JQ_LIB_DIR="/usr/lib"
diff --git a/src/main.rs b/src/main.rs
index 8f94d92..4c46ef4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,15 +1,22 @@
 mod app;
+mod util;
 
 use app::App;
 
+use crate::util::worker::{BackgroundWorker, NativeBackgroundWorker};
+
 // When compiling natively:
 #[cfg(not(target_arch = "wasm32"))]
 fn main() {
 	let native_options = eframe::NativeOptions::default();
 
-	eframe::run_native(
+	let worker = NativeBackgroundWorker::start();
+
+	eframe::run_native( // TODO replace this with a loop that ends so we can cleanly exit the background worker
 		"2b2t queue stats",
 		native_options,
 		Box::new(|cc| Box::new(App::new(cc))),
 	);
+
+	// worker.stop();
 }
diff --git a/src/util/mod.rs b/src/util/mod.rs
new file mode 100644
index 0000000..4ff7f34
--- /dev/null
+++ b/src/util/mod.rs
@@ -0,0 +1 @@
+pub(crate) mod worker;
\ No newline at end of file
diff --git a/src/util/worker.rs b/src/util/worker.rs
new file mode 100644
index 0000000..cfb3557
--- /dev/null
+++ b/src/util/worker.rs
@@ -0,0 +1,40 @@
+use tokio::{runtime::Runtime, sync::oneshot::Sender};
+
+pub(crate) trait BackgroundWorker {
+	fn start() -> Self;  // TODO make it return an error? Can we even do anything without a background worker
+	fn task<T>(&self, task:T) where T : std::future::Future<Output = ()> + core::marker::Send + 'static;
+	fn stop(self);   // TODO make it return an error? Can we even do anything without a background worker
+}
+
+pub(crate) struct NativeBackgroundWorker {
+	runtime : Runtime,
+	end_tx : Sender<bool>,
+	worker : std::thread::JoinHandle<bool>,
+}
+
+impl BackgroundWorker for NativeBackgroundWorker {
+	fn start() -> Self {
+		let runtime = Runtime::new().expect("Failed creating Tokio runtime");
+		let (end_tx, end_rx) = tokio::sync::oneshot::channel::<bool>();
+		let r_handle = runtime.handle().clone();
+		let worker = std::thread::spawn(move ||{
+			r_handle.block_on(async {
+				end_rx.await.expect("Error shutting down")
+			})
+		});
+		NativeBackgroundWorker {
+			runtime : runtime,
+			end_tx : end_tx,
+			worker : worker,
+		}
+	}
+
+	fn task<T>(&self, task:T) where T : std::future::Future<Output = ()> + core::marker::Send + 'static {
+		self.runtime.spawn(task);
+	}
+
+	fn stop(self) {
+		self.end_tx.send(true).expect("Failed signaling termination");
+		self.worker.join().expect("Failed joining main worker thread");
+	}
+}
\ No newline at end of file