implement vfs events handling

crates/ra_vfs/src/lib.rs

@@ -15,14 +15,19 @@ mod arena;
 mod io;
 
 use std::{
+    mem,
     thread,
     cmp::Reverse,
     path::{Path, PathBuf},
     ffi::OsStr,
     sync::Arc,
+    fs,
 };
 
+use rustc_hash::{FxHashMap, FxHashSet};
 use relative_path::RelativePathBuf;
+use crossbeam_channel::Receiver;
+use walkdir::DirEntry;
 use thread_worker::{WorkerHandle};
 
 use crate::{
@@ -40,15 +45,25 @@ impl RootFilter {
     fn new(root: PathBuf) -> RootFilter {
         RootFilter {
             root,
-            file_filter: rs_extension_filter,
+            file_filter: has_rs_extension,
         }
     }
-    fn can_contain(&self, path: &Path) -> bool {
-        (self.file_filter)(path) && path.starts_with(&self.root)
+    /// Check if this root can contain `path`. NB: even if this returns
+    /// true, the `path` might actually be conained in some nested root.
+    fn can_contain(&self, path: &Path) -> Option<RelativePathBuf> {
+        if !(self.file_filter)(path) {
+            return None;
+        }
+        if !(path.starts_with(&self.root)) {
+            return None;
+        }
+        let path = path.strip_prefix(&self.root).unwrap();
+        let path = RelativePathBuf::from_path(path).unwrap();
+        Some(path)
     }
 }
 
-fn rs_extension_filter(p: &Path) -> bool {
+fn has_rs_extension(p: &Path) -> bool {
     p.extension() == Some(OsStr::new("rs"))
 }
 
@@ -82,10 +97,11 @@ struct VfsFileData {
     text: Arc<String>,
 }
 
-struct Vfs {
+pub struct Vfs {
     roots: Arena<VfsRoot, RootFilter>,
     files: Arena<VfsFile, VfsFileData>,
-    // pending_changes: Vec<PendingChange>,
+    root2files: FxHashMap<VfsRoot, FxHashSet<VfsFile>>,
+    pending_changes: Vec<VfsChange>,
     worker: io::Worker,
     worker_handle: WorkerHandle,
 }
@@ -97,33 +113,144 @@ impl Vfs {
         let mut res = Vfs {
             roots: Arena::default(),
             files: Arena::default(),
+            root2files: FxHashMap::default(),
             worker,
             worker_handle,
+            pending_changes: Vec::new(),
         };
 
         // A hack to make nesting work.
         roots.sort_by_key(|it| Reverse(it.as_os_str().len()));
-
-        for path in roots {
-            res.roots.alloc(RootFilter::new(path));
+        for (i, path) in roots.iter().enumerate() {
+            let root = res.roots.alloc(RootFilter::new(path.clone()));
+            let nested = roots[..i]
+                .iter()
+                .filter(|it| it.starts_with(path))
+                .map(|it| it.clone())
+                .collect::<Vec<_>>();
+            let filter = move |entry: &DirEntry| {
+                if entry.file_type().is_file() {
+                    has_rs_extension(entry.path())
+                } else {
+                    nested.iter().all(|it| it != entry.path())
+                }
+            };
+            let task = io::Task {
+                root,
+                path: path.clone(),
+                filter: Box::new(filter),
+            };
+            res.worker.inp.send(task);
         }
         res
     }
 
-    pub fn add_file_overlay(&mut self, path: &Path, content: String) {}
+    pub fn task_receiver(&self) -> &Receiver<io::TaskResult> {
+        &self.worker.out
+    }
 
-    pub fn change_file_overlay(&mut self, path: &Path, new_content: String) {}
+    pub fn handle_task(&mut self, task: io::TaskResult) {
+        let mut files = Vec::new();
+        for (path, text) in task.files {
+            let text = Arc::new(text);
+            let file = self.add_file(task.root, path.clone(), Arc::clone(&text));
+            files.push((file, path, text));
+        }
+        let change = VfsChange::AddRoot {
+            root: task.root,
+            files,
+        };
+        self.pending_changes.push(change);
+    }
 
-    pub fn remove_file_overlay(&mut self, path: &Path) {}
+    pub fn add_file_overlay(&mut self, path: &Path, text: String) {
+        if let Some((root, path, file)) = self.find_root(path) {
+            let text = Arc::new(text);
+            let change = if let Some(file) = file {
+                self.change_file(file, Arc::clone(&text));
+                VfsChange::ChangeFile { file, text }
+            } else {
+                let file = self.add_file(root, path.clone(), Arc::clone(&text));
+                VfsChange::AddFile {
+                    file,
+                    text,
+                    root,
+                    path,
+                }
+            };
+            self.pending_changes.push(change);
+        }
+    }
+
+    pub fn change_file_overlay(&mut self, path: &Path, new_text: String) {
+        if let Some((_root, _path, file)) = self.find_root(path) {
+            let file = file.expect("can't change a file which wasn't added");
+            let text = Arc::new(new_text);
+            self.change_file(file, Arc::clone(&text));
+            let change = VfsChange::ChangeFile { file, text };
+            self.pending_changes.push(change);
+        }
+    }
+
+    pub fn remove_file_overlay(&mut self, path: &Path) {
+        if let Some((root, path, file)) = self.find_root(path) {
+            let file = file.expect("can't remove a file which wasn't added");
+            let full_path = path.to_path(&self.roots[root].root);
+            let change = if let Ok(text) = fs::read_to_string(&full_path) {
+                let text = Arc::new(text);
+                self.change_file(file, Arc::clone(&text));
+                VfsChange::ChangeFile { file, text }
+            } else {
+                self.remove_file(file);
+                VfsChange::RemoveFile { file }
+            };
+            self.pending_changes.push(change);
+        }
+    }
 
     pub fn commit_changes(&mut self) -> Vec<VfsChange> {
-        unimplemented!()
+        mem::replace(&mut self.pending_changes, Vec::new())
     }
 
     pub fn shutdown(self) -> thread::Result<()> {
         let _ = self.worker.shutdown();
         self.worker_handle.shutdown()
     }
+
+    fn add_file(&mut self, root: VfsRoot, path: RelativePathBuf, text: Arc<String>) -> VfsFile {
+        let data = VfsFileData { root, path, text };
+        let file = self.files.alloc(data);
+        self.root2files
+            .entry(root)
+            .or_insert_with(FxHashSet::default)
+            .insert(file);
+        file
+    }
+
+    fn change_file(&mut self, file: VfsFile, new_text: Arc<String>) {
+        self.files[file].text = new_text;
+    }
+
+    fn remove_file(&mut self, file: VfsFile) {
+        //FIXME: use arena with removal
+        self.files[file].text = Default::default();
+        self.files[file].path = Default::default();
+        let root = self.files[file].root;
+        let removed = self.root2files.get_mut(&root).unwrap().remove(&file);
+        assert!(removed);
+    }
+
+    fn find_root(&self, path: &Path) -> Option<(VfsRoot, RelativePathBuf, Option<VfsFile>)> {
+        let (root, path) = self
+            .roots
+            .iter()
+            .find_map(|(root, data)| data.can_contain(path).map(|it| (root, it)))?;
+        let file = self.root2files[&root]
+            .iter()
+            .map(|&it| it)
+            .find(|&file| self.files[file].path == path);
+        Some((root, path, file))
+    }
 }
 
 #[derive(Debug, Clone)]