feat: improve watcher performance (#35)

Author: pd93

CHANGELOG.md

@@ -6,6 +6,8 @@
 - Added a new command: `Task: Show Debug Panel` to show the Task debug panel (#25 by @pd93).
 - Added the ability to sort tasks in the tree view (#20 by @pd93).
   - Configurable via `task.tree.sort` setting (values: `"default"` (default), `"alphanumeric"` or `"none"`).
+- Added a cancel/timeout to file watcher to improve performance when making lots of file changes (#35 by @pd93).
+  - For example, `git stash pop` of a lot of `.yml` files would cause a huge lag spike as multiple update calls were made.
 
 ## v0.1.1 - 2021-03-27
 

src/task.ts

@@ -8,6 +8,7 @@ export class TaskExtension {
     private _taskfiles: models.Taskfile[] = [];
     private _activityBar: elements.ActivityBar;
     private _watcher: vscode.FileSystemWatcher;
+    private _changeTimeout: NodeJS.Timeout | null = null;
 
     constructor() {
         this._activityBar = new elements.ActivityBar();
@@ -209,10 +210,19 @@ export class TaskExtension {
 
     private async _onDidTaskfileChange() {
         log.info("Detected changes to taskfile");
-        // If manual updating is turned off (update on save)
-        if (settings.updateOn !== "manual") {
-            await this.refresh(false);
+
+        // If there's already a timeout scheduled, cancel it to debounce the changes
+        if (this._changeTimeout) {
+            clearTimeout(this._changeTimeout);
         }
+
+        // Schedule a new timeout to refresh the task files after 500ms
+        this._changeTimeout = setTimeout(async () => {
+            // If manual updating is turned off (update on save)
+            if (settings.updateOn !== "manual") {
+                await this.refresh(false);
+            }
+        }, 200);
     }
 
     private _onDidChangeConfiguration(event: vscode.ConfigurationChangeEvent) {