Switch to file ids

crates/server/src/path_map.rs

@@ -0,0 +1,47 @@
+use std::path::{PathBuf, Path};
+use im;
+use libanalysis::{FileId};
+
+#[derive(Debug, Default, Clone)]
+pub struct PathMap {
+    next_id: u32,
+    path2id: im::HashMap<PathBuf, FileId>,
+    id2path: im::HashMap<FileId, PathBuf>,
+}
+
+impl PathMap {
+    pub fn new() -> PathMap {
+        Default::default()
+    }
+
+    pub fn get_or_insert(&mut self, path: PathBuf) -> FileId {
+        self.path2id.get(path.as_path())
+            .map(|&id| id)
+            .unwrap_or_else(|| {
+                let id = self.new_file_id();
+                self.insert(path, id);
+                id
+            })
+    }
+
+    pub fn get_id(&self, path: &Path) -> Option<FileId> {
+        self.path2id.get(path).map(|&id| id)
+    }
+
+    pub fn get_path(&self, id: FileId) -> &Path {
+        self.id2path.get(&id)
+            .unwrap()
+            .as_path()
+    }
+
+    fn insert(&mut self, path: PathBuf, id: FileId) {
+        self.path2id.insert(path.clone(), id);
+        self.id2path.insert(id, path.clone());
+    }
+
+    fn new_file_id(&mut self) -> FileId {
+        let id = FileId(self.next_id);
+        self.next_id += 1;
+        id
+    }
+}