1 files changed, 79 insertions, 0 deletions

diff --git a/crates/server/src/vfs.rs b/crates/server/src/vfs.rs
new file mode 100644
index 000000000..a5c367494
--- /dev/null
+++ b/crates/server/src/vfs.rs
@@ -0,0 +1,79 @@
+use std::{
+    path::PathBuf,
+    thread,
+    fs,
+};
+
+use crossbeam_channel::{Sender, Receiver, bounded};
+use drop_bomb::DropBomb;
+use walkdir::WalkDir;
+
+use Result;
+
+
+pub struct FileEvent {
+    pub path: PathBuf,
+    pub kind: FileEventKind,
+}
+
+pub enum FileEventKind {
+    Add(String),
+    #[allow(unused)]
+    Remove,
+}
+
+pub struct Watcher {
+    thread: thread::JoinHandle<()>,
+    bomb: DropBomb,
+}
+
+impl Watcher {
+    pub fn stop(mut self) -> Result<()> {
+        self.bomb.defuse();
+        self.thread.join()
+            .map_err(|_| format_err!("file watcher died"))
+    }
+}
+
+pub fn watch(roots: Vec<PathBuf>) -> (Receiver<Vec<FileEvent>>, Watcher) {
+    let (sender, receiver) = bounded(16);
+    let thread = thread::spawn(move || run(roots, sender));
+    (receiver, Watcher {
+        thread,
+        bomb: DropBomb::new("Watcher should be stopped explicitly"),
+    })
+}
+
+fn run(roots: Vec<PathBuf>, sender: Sender<Vec<FileEvent>>) {
+    for root in roots {
+        let mut events = Vec::new();
+        for entry in WalkDir::new(root.as_path()) {
+            let entry = match entry {
+                Ok(entry) => entry,
+                Err(e) => {
+                    warn!("watcher error: {}", e);
+                    continue;
+                }
+            };
+            if !entry.file_type().is_file() {
+                continue;
+            }
+            let path = entry.path();
+            if path.extension().and_then(|os| os.to_str()) != Some("rs") {
+                continue;
+            }
+            let text = match fs::read_to_string(path) {
+                Ok(text) => text,
+                Err(e) => {
+                    warn!("watcher error: {}", e);
+                    continue;
+                }
+            };
+            events.push(FileEvent {
+                path: path.to_owned(),
+                kind: FileEventKind::Add(text),
+            })
+        }
+        sender.send(events)
+    }
+}