From 64d9e04c1bb23f80de653d807791bdc4465214bb Mon Sep 17 00:00:00 2001
From: Wodann <wodannson@gmail.com>
Date: Fri, 4 Oct 2019 10:46:46 +0200
Subject: [PATCH] feat(compiler_daemon): add compiler daemon that detects
 changed files and recompiles them

---
 crates/mun_compiler_daemon/Cargo.toml | 10 ++++++++
 crates/mun_compiler_daemon/src/lib.rs | 34 +++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 crates/mun_compiler_daemon/Cargo.toml
 create mode 100644 crates/mun_compiler_daemon/src/lib.rs

diff --git a/crates/mun_compiler_daemon/Cargo.toml b/crates/mun_compiler_daemon/Cargo.toml
new file mode 100644
index 000000000..a1ff3a87b
--- /dev/null
+++ b/crates/mun_compiler_daemon/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "mun_compiler_daemon"
+version = "0.1.0"
+authors = ["Wodann <wodannson@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+failure = "0.1.5"
+mun_compiler = { path = "../mun_compiler" }
+notify = "4.0.12"
diff --git a/crates/mun_compiler_daemon/src/lib.rs b/crates/mun_compiler_daemon/src/lib.rs
new file mode 100644
index 000000000..019baa851
--- /dev/null
+++ b/crates/mun_compiler_daemon/src/lib.rs
@@ -0,0 +1,34 @@
+use std::sync::mpsc::channel;
+use std::time::Duration;
+
+use failure::Error;
+use mun_compiler::CompilerOptions;
+use notify::{RecommendedWatcher, RecursiveMode, Watcher};
+
+pub fn main(options: &CompilerOptions) -> Result<(), Error> {
+    // Need to canonicalize path to do comparisons
+    let input_path = options.input.canonicalize()?;
+
+    // Compile at least once
+    mun_compiler::main(&options)?;
+
+    let (tx, rx) = channel();
+
+    let mut watcher: RecommendedWatcher = Watcher::new(tx, Duration::from_millis(10))?;
+    watcher.watch(&input_path, RecursiveMode::NonRecursive)?;
+
+    loop {
+        use notify::DebouncedEvent::*;
+        match rx.recv() {
+            Ok(Write(ref path)) => {
+                // TODO: Check whether file contents changed (using sha hash?)
+                if *path == input_path {
+                    mun_compiler::main(&options)?;
+                    println!("Compiled: {}", path.to_string_lossy());
+                }
+            }
+            Ok(_) => (),
+            Err(e) => eprintln!("Watcher error: {:?}", e),
+        }
+    }
+}