Fixes #28379: Run Task should be sorted using MRU list

src/vs/base/common/linkedMap.ts

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+interface Item<K, V> {
+	previous: Item<K, V> | undefined;
+	next: Item<K, V> | undefined;
+	key: K;
+	value: V;
+}
+
+export namespace Touch {
+	export const None: 0 = 0;
+	export const First: 1 = 1;
+	export const Last: 2 = 2;
+}
+
+export type Touch = 0 | 1 | 2;
+
+export class LinkedMap<K, V> {
+
+	private _map: Map<K, Item<K, V>>;
+	private _head: Item<K, V> | undefined;
+	private _tail: Item<K, V> | undefined;
+	private _size: number;
+
+	constructor() {
+		this._map = new Map<K, Item<K, V>>();
+		this._head = undefined;
+		this._tail = undefined;
+		this._size = 0;
+	}
+
+	public clear(): void {
+		this._map.clear();
+		this._head = undefined;
+		this._tail = undefined;
+		this._size = 0;
+	}
+
+	public isEmpty(): boolean {
+		return !this._head && !this._tail;
+	}
+
+	public get size(): number {
+		return this._size;
+	}
+
+	public has(key: K): boolean {
+		return this._map.has(key);
+	}
+
+	public get(key: K): V | undefined {
+		const item = this._map.get(key);
+		if (!item) {
+			return undefined;
+		}
+		return item.value;
+	}
+
+	public set(key: K, value: V, touch: Touch = Touch.None): void {
+		let item = this._map.get(key);
+		if (item) {
+			item.value = value;
+			if (touch !== Touch.None) {
+				this.touch(item, touch);
+			}
+		} else {
+			item = { key, value, next: undefined, previous: undefined };
+			switch (touch) {
+				case Touch.None:
+					this.addItemLast(item);
+					break;
+				case Touch.First:
+					this.addItemFirst(item);
+					break;
+				case Touch.Last:
+					this.addItemLast(item);
+					break;
+				default:
+					this.addItemLast(item);
+					break;
+			}
+			this._map.set(key, item);
+			this._size++;
+		}
+	}
+
+	public delete(key: K): boolean {
+		const item = this._map.get(key);
+		if (!item) {
+			return false;
+		}
+		this._map.delete(key);
+		this.removeItem(item);
+		this._size--;
+		return true;
+	}
+
+	public shift(): V | undefined {
+		if (!this._head && !this._tail) {
+			return undefined;
+		}
+		if (!this._head || !this._tail) {
+			throw new Error('Invalid list');
+		}
+		const item = this._head;
+		this._map.delete(item.key);
+		this.removeItem(item);
+		this._size--;
+		return item.value;
+	}
+
+	public forEach(callbackfn: (value: V, key: K, map: LinkedMap<K, V>) => void, thisArg?: any): void {
+		let current = this._head;
+		while (current) {
+			if (thisArg) {
+				callbackfn.bind(thisArg)(current.value, current.key, this);
+			} else {
+				callbackfn(current.value, current.key, this);
+			}
+			current = current.next;
+		}
+	}
+
+	public forEachReverse(callbackfn: (value: V, key: K, map: LinkedMap<K, V>) => void, thisArg?: any): void {
+		let current = this._tail;
+		while (current) {
+			if (thisArg) {
+				callbackfn.bind(thisArg)(current.value, current.key, this);
+			} else {
+				callbackfn(current.value, current.key, this);
+			}
+			current = current.previous;
+		}
+	}
+
+	public values(): V[] {
+		let result: V[] = [];
+		let current = this._head;
+		while (current) {
+			result.push(current.value);
+			current = current.next;
+		}
+		return result;
+	}
+
+	public keys(): K[] {
+		let result: K[] = [];
+		let current = this._head;
+		while (current) {
+			result.push(current.key);
+			current = current.next;
+		}
+		return result;
+	}
+
+	/* VS Code / Monaco editor runs on es5 which has no Symbol.iterator
+	public keys(): IterableIterator<K> {
+		let current = this._head;
+		let iterator: IterableIterator<K> = {
+			[Symbol.iterator]() {
+				return iterator;
+			},
+			next():IteratorResult<K> {
+				if (current) {
+					let result = { value: current.key, done: false };
+					current = current.next;
+					return result;
+				} else {
+					return { value: undefined, done: true };
+				}
+			}
+		};
+		return iterator;
+	}
+
+	public values(): IterableIterator<V> {
+		let current = this._head;
+		let iterator: IterableIterator<V> = {
+			[Symbol.iterator]() {
+				return iterator;
+			},
+			next():IteratorResult<V> {
+				if (current) {
+					let result = { value: current.value, done: false };
+					current = current.next;
+					return result;
+				} else {
+					return { value: undefined, done: true };
+				}
+			}
+		};
+		return iterator;
+	}
+	*/
+
+	private addItemFirst(item: Item<K, V>): void {
+		// First time Insert
+		if (!this._head && !this._tail) {
+			this._tail = item;
+		} else if (!this._head) {
+			throw new Error('Invalid list');
+		} else {
+			item.next = this._head;
+			this._head.previous = item;
+		}
+		this._head = item;
+	}
+
+	private addItemLast(item: Item<K, V>): void {
+		// First time Insert
+		if (!this._head && !this._tail) {
+			this._head = item;
+		} else if (!this._tail) {
+			throw new Error('Invalid list');
+		} else {
+			item.previous = this._tail;
+			this._tail.next = item;
+		}
+		this._tail = item;
+	}
+
+	private removeItem(item: Item<K, V>): void {
+		if (item === this._head && item === this._tail) {
+			this._head = undefined;
+			this._tail = undefined;
+		}
+		else if (item === this._head) {
+			this._head = item.next;
+		}
+		else if (item === this._tail) {
+			this._tail = item.previous;
+		}
+		else {
+			const next = item.next;
+			const previous = item.previous;
+			if (!next || !previous) {
+				throw new Error('Invalid list');
+			}
+			next.previous = previous;
+			previous.next = next;
+		}
+	}
+
+	private touch(item: Item<K, V>, touch: Touch): void {
+		if (!this._head || !this._tail) {
+			throw new Error('Invalid list');
+		}
+		if ((touch !== Touch.First && touch !== Touch.Last)) {
+			return;
+		}
+
+		if (touch === Touch.First) {
+			if (item === this._head) {
+				return;
+			}
+
+			const next = item.next;
+			const previous = item.previous;
+
+			// Unlink the item
+			if (item === this._tail) {
+				// previous must be defined since item was not head but is tail
+				// So there are more than on item in the map
+				previous!.next = undefined;
+				this._tail = previous;
+			}
+			else {
+				// Both next and previous are not undefined since item was neither head nor tail.
+				next!.previous = previous;
+				previous!.next = next;
+			}
+
+			// Insert the node at head
+			item.previous = undefined;
+			item.next = this._head;
+			this._head.previous = item;
+			this._head = item;
+		} else if (touch === Touch.Last) {
+			if (item === this._tail) {
+				return;
+			}
+
+			const next = item.next;
+			const previous = item.previous;
+
+			// Unlink the item.
+			if (item === this._head) {
+				// next must be defined since item was not tail but is head
+				// So there are more than on item in the map
+				next!.previous = undefined;
+				this._head = next;
+			} else {
+				// Both next and previous are not undefined since item was neither head nor tail.
+				next!.previous = previous;
+				previous!.next = next;
+			}
+			item.next = undefined;
+			item.previous = this._tail;
+			this._tail.next = item;
+			this._tail = item;
+		}
+	}
+}
\ No newline at end of file

src/vs/workbench/parts/tasks/browser/quickOpen.ts

@@ -8,6 +8,8 @@ import nls = require('vs/nls');
 import Filters = require('vs/base/common/filters');
 import { TPromise } from 'vs/base/common/winjs.base';
 import { Action, IAction } from 'vs/base/common/actions';
+import { IStringDictionary } from 'vs/base/common/collections';
+
 import Quickopen = require('vs/workbench/browser/quickopen');
 import QuickOpen = require('vs/base/parts/quickopen/common/quickOpen');
 import Model = require('vs/base/parts/quickopen/browser/quickOpenModel');
@@ -49,7 +51,7 @@ export abstract class QuickOpenHandler extends Quickopen.QuickOpenHandler {
 
 	constructor(
 		protected quickOpenService: IQuickOpenService,
-		protected taskService: ITaskService,
+		protected taskService: ITaskService
 	) {
 		super();
 
@@ -71,39 +73,39 @@ export abstract class QuickOpenHandler extends Quickopen.QuickOpenHandler {
 			if (tasks.length === 0) {
 				return new Model.QuickOpenModel(entries);
 			}
-			tasks = tasks.sort((a, b) => {
-				let aKind = a._source.kind;
-				let bKind = b._source.kind;
-				if (aKind === bKind) {
-					if (aKind === TaskSourceKind.Extension) {
-						let compare = a._source.label.localeCompare(b._source.label);
-						if (compare !== 0) {
-							return compare;
-						}
-					}
-					return a._label.localeCompare(b._label);
-				}
-				if (aKind === TaskSourceKind.Workspace) {
-					return -1;
-				} else {
-					return +1;
+			let recentlyUsedTasks = this.taskService.getRecentlyUsedTasks();
+			let recent: Task[] = [];
+			let others: Task[] = [];
+			let taskMap: IStringDictionary<Task> = Object.create(null);
+			tasks.forEach(task => taskMap[task.identifier] = task);
+			recentlyUsedTasks.keys().forEach(key => {
+				let task = taskMap[key];
+				if (task) {
+					recent.push(task);
 				}
 			});
-			let firstWorkspace: boolean = true;
-			let firstExtension: boolean = true;
-			let hadWorkspace: boolean = false;
 			for (let task of tasks) {
+				if (!recentlyUsedTasks.has(task.identifier)) {
+					others.push(task);
+				}
+			}
+			others = others.sort((a, b) => a._source.label.localeCompare(b._source.label));
+			let sortedTasks = recent.concat(others);
+			let recentlyUsed: boolean = recentlyUsedTasks.has(tasks[0].identifier);
+			let otherTasks: boolean = !recentlyUsedTasks.has(tasks[tasks.length - 1].identifier);
+			let hasRecentlyUsed: boolean = false;
+			for (let task of sortedTasks) {
 				let highlights = Filters.matchesContiguousSubString(input, task._label);
 				if (!highlights) {
 					continue;
 				}
-				if (task._source.kind === TaskSourceKind.Workspace && firstWorkspace) {
-					firstWorkspace = false;
-					hadWorkspace = true;
-					entries.push(new TaskGroupEntry(this.createEntry(this.taskService, task, highlights), nls.localize('configured', 'Configured Tasks'), false));
-				} else if (task._source.kind === TaskSourceKind.Extension && firstExtension) {
-					firstExtension = false;
-					entries.push(new TaskGroupEntry(this.createEntry(this.taskService, task, highlights), nls.localize('detected', 'Detected Tasks'), hadWorkspace));
+				if (recentlyUsed) {
+					recentlyUsed = false;
+					hasRecentlyUsed = true;
+					entries.push(new TaskGroupEntry(this.createEntry(this.taskService, task, highlights), nls.localize('recentlyUsed', 'recently used'), false));
+				} else if (!recentlyUsedTasks.has(task.identifier) && otherTasks) {
+					otherTasks = false;
+					entries.push(new TaskGroupEntry(this.createEntry(this.taskService, task, highlights), nls.localize('other tasks', 'other tasks'), hasRecentlyUsed));
 				} else {
 					entries.push(this.createEntry(this.taskService, task, highlights));
 				}

src/vs/workbench/parts/tasks/common/taskService.ts

@@ -8,6 +8,7 @@ import { TPromise } from 'vs/base/common/winjs.base';
 import { Action } from 'vs/base/common/actions';
 import { IEventEmitter } from 'vs/base/common/eventEmitter';
 import { TerminateResponse } from 'vs/base/common/processes';
+import { LinkedMap } from 'vs/base/common/linkedMap';
 import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
 import { Task, TaskSet } from 'vs/workbench/parts/tasks/common/tasks';
 import { ITaskSummary, TaskEvent, TaskType } from 'vs/workbench/parts/tasks/common/taskSystem';
@@ -43,6 +44,7 @@ export interface ITaskService extends IEventEmitter {
 	terminateAll(): TPromise<TerminateResponse>;
 	tasks(): TPromise<Task[]>;
 	getTasksForGroup(group: string): TPromise<Task[]>;
+	getRecentlyUsedTasks(): LinkedMap<string, string>;
 
 	customize(task: Task, openConfig?: boolean): TPromise<void>;
 

src/vs/workbench/parts/tasks/electron-browser/task.contribution.ts

@@ -29,6 +29,7 @@ import { TerminateResponse, TerminateResponseCode } from 'vs/base/common/process
 import * as strings from 'vs/base/common/strings';
 import { ValidationStatus, ValidationState } from 'vs/base/common/parsers';
 import * as UUID from 'vs/base/common/uuid';
+import { LinkedMap, Touch } from 'vs/base/common/linkedMap';
 
 import { Registry } from 'vs/platform/platform';
 import { ILifecycleService } from 'vs/platform/lifecycle/common/lifecycle';
@@ -45,7 +46,7 @@ import { CommandsRegistry } from 'vs/platform/commands/common/commands';
 import { KeybindingsRegistry } from 'vs/platform/keybinding/common/keybindingsRegistry';
 import { ServicesAccessor } from 'vs/platform/instantiation/common/instantiation';
 import { ProblemMatcherRegistry } from 'vs/platform/markers/common/problemMatcher';
-
+import { IStorageService, StorageScope } from 'vs/platform/storage/common/storage';
 
 import { IModeService } from 'vs/editor/common/services/modeService';
 import { IModelService } from 'vs/editor/common/services/modelService';
@@ -516,6 +517,7 @@ interface WorkspaceConfigurationResult {
 class TaskService extends EventEmitter implements ITaskService {
 
 	// private static autoDetectTelemetryName: string = 'taskServer.autoDetect';
+	private static RecentlyUsedTasks_Key = 'workbench.tasks.recentlyUsedTasks';
 
 	public _serviceBrand: any;
 	public static SERVICE_ID: string = 'taskService';
@@ -544,6 +546,7 @@ class TaskService extends EventEmitter implements ITaskService {
 
 	private _taskSystem: ITaskSystem;
 	private _taskSystemListeners: IDisposable[];
+	private _recentlyUsedTasks: LinkedMap<string, string>;
 
 	private _outputChannel: IOutputChannel;
 
@@ -559,7 +562,8 @@ class TaskService extends EventEmitter implements ITaskService {
 		@IEnvironmentService private environmentService: IEnvironmentService,
 		@IConfigurationResolverService private configurationResolverService: IConfigurationResolverService,
 		@ITerminalService private terminalService: ITerminalService,
-		@IWorkbenchEditorService private workbenchEditorService: IWorkbenchEditorService
+		@IWorkbenchEditorService private workbenchEditorService: IWorkbenchEditorService,
+		@IStorageService private storageService: IStorageService
 	) {
 
 		super();
@@ -689,6 +693,37 @@ class TaskService extends EventEmitter implements ITaskService {
 		return TPromise.as(this._taskSystem.getActiveTasks());
 	}
 
+	public getRecentlyUsedTasks(): LinkedMap<string, string> {
+		if (this._recentlyUsedTasks) {
+			return this._recentlyUsedTasks;
+		}
+		this._recentlyUsedTasks = new LinkedMap<string, string>();
+		let storageValue = this.storageService.get(TaskService.RecentlyUsedTasks_Key, StorageScope.WORKSPACE);
+		if (storageValue) {
+			try {
+				let values: string[] = JSON.parse(storageValue);
+				if (Array.isArray(values)) {
+					for (let value of values) {
+						this._recentlyUsedTasks.set(value, value);
+					}
+				}
+			} catch (error) {
+				// Ignore. We use the empty result
+			}
+		}
+		return this._recentlyUsedTasks;
+	}
+
+	private saveRecentlyUsedTasks(): void {
+		if (!this._recentlyUsedTasks) {
+			return;
+		}
+		let values = this._recentlyUsedTasks.values();
+		if (values.length > 30) {
+			values = values.slice(0, 30);
+		}
+		this.storageService.store(TaskService.RecentlyUsedTasks_Key, JSON.stringify(values), StorageScope.WORKSPACE);
+	}
 
 	public build(): TPromise<ITaskSummary> {
 		return this.getTaskSets().then((values) => {
@@ -896,6 +931,7 @@ class TaskService extends EventEmitter implements ITaskService {
 						throw new TaskError(Severity.Warning, nls.localize('TaskSystem.active', 'There is already a task running. Terminate it first before executing another task.'), TaskErrors.RunningTask);
 					}
 				}
+				this.getRecentlyUsedTasks().set(task.identifier, task.identifier, Touch.First);
 				return executeResult.promise;
 			});
 		});
@@ -1248,6 +1284,7 @@ class TaskService extends EventEmitter implements ITaskService {
 	}
 
 	public beforeShutdown(): boolean | TPromise<boolean> {
+		this.saveRecentlyUsedTasks();
 		if (this._taskSystem && this._taskSystem.isActiveSync()) {
 			if (this._taskSystem.canAutoTerminate() || this.messageService.confirm({
 				message: nls.localize('TaskSystem.runningTask', 'There is a task running. Do you want to terminate it?'),