debounce and queue decoration request, fixes #40210

src/vs/workbench/api/electron-browser/mainThreadDecorations.ts

@@ -7,21 +7,69 @@
 import URI, { UriComponents } from 'vs/base/common/uri';
 import { Emitter } from 'vs/base/common/event';
 import { IDisposable, dispose } from 'vs/base/common/lifecycle';
-import { ExtHostContext, MainContext, IExtHostContext, MainThreadDecorationsShape, ExtHostDecorationsShape } from '../node/extHost.protocol';
+import { ExtHostContext, MainContext, IExtHostContext, MainThreadDecorationsShape, ExtHostDecorationsShape, DecorationData, DecorationRequest } from '../node/extHost.protocol';
 import { extHostNamedCustomer } from 'vs/workbench/api/electron-browser/extHostCustomers';
 import { IDecorationsService, IDecorationData } from 'vs/workbench/services/decorations/browser/decorations';
 
+class DecorationRequestsQueue {
+
+	private _idPool = 0;
+	private _requests: DecorationRequest[] = [];
+	private _resolver: { [id: number]: Function } = Object.create(null);
+
+	private _timer: number;
+
+	constructor(
+		private _proxy: ExtHostDecorationsShape
+	) {
+		//
+	}
+
+	enqueue(handle: number, uri: URI): Thenable<DecorationData> {
+		return new Promise((resolve, reject) => {
+			const id = ++this._idPool;
+			this._requests.push({ id, handle, uri });
+			this._resolver[id] = resolve;
+			this._processQueue();
+		});
+	}
+
+	private _processQueue(): void {
+		if (typeof this._timer === 'number') {
+			// already queued
+			return;
+		}
+		this._timer = setTimeout(() => {
+			// make request
+			const requests = this._requests;
+			const resolver = this._resolver;
+			this._proxy.$provideDecorations(requests).then(data => {
+				for (const id in resolver) {
+					resolver[id](data[id]);
+				}
+			});
+
+			// reset
+			this._requests = [];
+			this._resolver = [];
+			this._timer = void 0;
+		}, 0);
+	}
+}
+
 @extHostNamedCustomer(MainContext.MainThreadDecorations)
 export class MainThreadDecorations implements MainThreadDecorationsShape {
 
 	private readonly _provider = new Map<number, [Emitter<URI[]>, IDisposable]>();
 	private readonly _proxy: ExtHostDecorationsShape;
+	private readonly _requestQueue: DecorationRequestsQueue;
 
 	constructor(
 		context: IExtHostContext,
 		@IDecorationsService private readonly _decorationsService: IDecorationsService
 	) {
 		this._proxy = context.getProxy(ExtHostContext.ExtHostDecorations);
+		this._requestQueue = new DecorationRequestsQueue(this._proxy);
 	}
 
 	dispose() {
@@ -30,12 +78,12 @@ export class MainThreadDecorations implements MainThreadDecorationsShape {
 	}
 
 	$registerDecorationProvider(handle: number, label: string): void {
-		let emitter = new Emitter<URI[]>();
-		let registration = this._decorationsService.registerDecorationsProvider({
+		const emitter = new Emitter<URI[]>();
+		const registration = this._decorationsService.registerDecorationsProvider({
 			label,
 			onDidChange: emitter.event,
 			provideDecorations: (uri) => {
-				return this._proxy.$provideDecorations(handle, uri).then(data => {
+				return this._requestQueue.enqueue(handle, uri).then(data => {
 					if (!data) {
 						return undefined;
 					}

src/vs/workbench/api/node/extHost.protocol.ts

@@ -719,10 +719,17 @@ export interface ExtHostDebugServiceShape {
 }
 
 
+export interface DecorationRequest {
+	readonly id: number;
+	readonly handle: number;
+	readonly uri: UriComponents;
+}
+
 export type DecorationData = [number, boolean, string, string, ThemeColor, string];
+export type DecorationReply = { [id: number]: DecorationData };
 
 export interface ExtHostDecorationsShape {
-	$provideDecorations(handle: number, uri: UriComponents): TPromise<DecorationData>;
+	$provideDecorations(requests: DecorationRequest[]): TPromise<DecorationReply>;
 }
 
 export interface ExtHostWindowShape {

src/vs/workbench/api/node/extHostDecorations.ts

@@ -5,8 +5,8 @@
 'use strict';
 
 import * as vscode from 'vscode';
-import URI, { UriComponents } from 'vs/base/common/uri';
-import { MainContext, IMainContext, ExtHostDecorationsShape, MainThreadDecorationsShape, DecorationData } from 'vs/workbench/api/node/extHost.protocol';
+import URI from 'vs/base/common/uri';
+import { MainContext, IMainContext, ExtHostDecorationsShape, MainThreadDecorationsShape, DecorationData, DecorationRequest, DecorationReply } from 'vs/workbench/api/node/extHost.protocol';
 import { TPromise } from 'vs/base/common/winjs.base';
 import { Disposable } from 'vs/workbench/api/node/extHostTypes';
 import { asWinJsPromise } from 'vs/base/common/async';
@@ -38,10 +38,19 @@ export class ExtHostDecorations implements ExtHostDecorationsShape {
 		});
 	}
 
-	$provideDecorations(handle: number, data: UriComponents): TPromise<DecorationData> {
+	$provideDecorations(requests: DecorationRequest[]): TPromise<DecorationReply> {
+		const result: DecorationReply = Object.create(null);
+		return TPromise.join(requests.map(request => {
+			const { handle, uri, id } = request;
 			const provider = this._provider.get(handle);
-		return asWinJsPromise(token => provider.provideDecoration(URI.revive(data), token)).then(data => {
-			return data && <DecorationData>[data.priority, data.bubble, data.title, data.abbreviation, data.color, data.source];
+			return asWinJsPromise(token => provider.provideDecoration(URI.revive(uri), token)).then(data => {
+				result[id] = data && <DecorationData>[data.priority, data.bubble, data.title, data.abbreviation, data.color, data.source];
+			}, err => {
+				console.error(err);
+			});
+
+		})).then(() => {
+			return result;
 		});
 	}
 }