vscode源码分析【七】主进程启动消息通信服务

在mian.ts中的doStartup方法里，创建了一个命名管道服务
(src\vs\code\electron-main\main.ts)

server = await serve(environmentService.mainIPCHandle);
once(lifecycleService.onWillShutdown)(() => server.dispose());

传入的environmentService.mainIPCHandle是命名管道的识别路径，
一个有规则的字符串，规则如下：

function getWin32IPCHandle(userDataPath: string, type: string): string {
	const scope = crypto.createHash(‘md5‘).update(userDataPath).digest(‘hex‘);
	return `\\\\.\\pipe\\${scope}-${pkg.version}-${type}-sock`;
}

注意：每次启动程序，取这个字符串的时候，都会获得同样的值（而且这个值是会被缓存起来的）；
以后监听消息、发送消息，都根据这个字符串来；
创建服务的代码（serve）：

export function serve(hook: any): Promise<Server> {
	return new Promise<Server>((c, e) => {
		const server = createServer();
		server.on(‘error‘, e);
		server.listen(hook, () => {
			server.removeListener(‘error‘, e);
			c(new Server(server));
		});
	});
}

这个方法返回了一个Promise的对象，
c和e是Promise的参数，c代表成功时的回调，e代表失败时的回调（有点类似es6的Promise）
匿名函数内createServer就是nodejs里的原生接口，
Server类绑定了连接和断开的事件，暂时不细说；

回头看看main.ts   startup方法里有这么一句：

instantiationService.createInstance(CodeApplication, mainIpcServer, instanceEnvironment).startup();

这句显然是创建了CodeApplication的实例，然后执行了实例的startup方法
注意：创建这个实例的时候，把我们前面创建的mainIpcServer传递进去了；
CodeApplication（src\vs\code\electron-main\app.ts）的startup方法，还启动了Electron的IPCServer

const electronIpcServer = new ElectronIPCServer();

vscode把electron默认的通信机制也接入到了自己的事件体系内，有消息过来，会触发事件；
具体先不细说，后面再讲.
接着就跳转到同类型里的openFirstWindow方法（是不是很熟悉，我们在第一篇文章中讲到过这里）
在这里，给这两个服务（mainIpcServer和electronIpcServer ），创建了一堆信道：

const launchService = accessor.get(ILaunchService);
		const launchChannel = new LaunchChannel(launchService);
		this.mainIpcServer.registerChannel(‘launch‘, launchChannel);

		const updateService = accessor.get(IUpdateService);
		const updateChannel = new UpdateChannel(updateService);
		electronIpcServer.registerChannel(‘update‘, updateChannel);

		const issueService = accessor.get(IIssueService);
		const issueChannel = new IssueChannel(issueService);
		electronIpcServer.registerChannel(‘issue‘, issueChannel);

		const workspacesService = accessor.get(IWorkspacesMainService);
		const workspacesChannel = new WorkspacesChannel(workspacesService);
		electronIpcServer.registerChannel(‘workspaces‘, workspacesChannel);

		const windowsService = accessor.get(IWindowsService);
		const windowsChannel = new WindowsChannel(windowsService);
		electronIpcServer.registerChannel(‘windows‘, windowsChannel);
		sharedProcessClient.then(client => client.registerChannel(‘windows‘, windowsChannel));

		const menubarService = accessor.get(IMenubarService);
		const menubarChannel = new MenubarChannel(menubarService);
		electronIpcServer.registerChannel(‘menubar‘, menubarChannel);

		const urlService = accessor.get(IURLService);
		const urlChannel = new URLServiceChannel(urlService);
		electronIpcServer.registerChannel(‘url‘, urlChannel);

		const storageMainService = accessor.get(IStorageMainService);
		const storageChannel = this._register(new GlobalStorageDatabaseChannel(this.logService, storageMainService as StorageMainService));
		electronIpcServer.registerChannel(‘storage‘, storageChannel);

		const logLevelChannel = new LogLevelSetterChannel(accessor.get(ILogService));
		electronIpcServer.registerChannel(‘loglevel‘, logLevelChannel);

有存储、日志、菜单栏、工作台、升级.....等等
主要的通信还是用electronIpcServer 来干的，mainIpcServer只有一个launch信道；
下面我们看看消息是怎么传递的
我们随便打开一个信道的类型（src\vs\platform\windows\node\windowsIpc.ts）
它有两个主要的函数，listen和call，

	listen(_: unknown, event: string): Event<any> {
		switch (event) {
			case ‘onWindowOpen‘: return this.onWindowOpen;
			case ‘onWindowFocus‘: return this.onWindowFocus;
			case ‘onWindowBlur‘: return this.onWindowBlur;
			case ‘onWindowMaximize‘: return this.onWindowMaximize;
			case ‘onWindowUnmaximize‘: return this.onWindowUnmaximize;
			case ‘onRecentlyOpenedChange‘: return this.onRecentlyOpenedChange;
		}
		throw new Error(`Event not found: ${event}`);
	}

	call(_: unknown, command: string, arg?: any): Promise<any> {
		switch (command) {
			case ‘pickFileFolderAndOpen‘: return this.service.pickFileFolderAndOpen(arg);
			case ‘pickFileAndOpen‘: return this.service.pickFileAndOpen(arg);
			case ‘pickFolderAndOpen‘: return this.service.pickFolderAndOpen(arg);
			case ‘pickWorkspaceAndOpen‘: return this.service.pickWorkspaceAndOpen(arg);
			case ‘showMessageBox‘: return this.service.showMessageBox(arg[0], arg[1]);
			case ‘showSaveDialog‘: return this.service.showSaveDialog(arg[0], arg[1]);
			case ‘showOpenDialog‘: return this.service.showOpenDialog(arg[0], arg[1]);
//......

消息来了，进入listen函数，发送消息，进入call函数；
注意，消息来了，触发的也不是他自己的方法，我们看看它的构造函数：

	constructor(private service: IWindowsService) {
		this.onWindowOpen = Event.buffer(service.onWindowOpen, true);
		this.onWindowFocus = Event.buffer(service.onWindowFocus, true);
		this.onWindowBlur = Event.buffer(service.onWindowBlur, true);
		this.onWindowMaximize = Event.buffer(service.onWindowMaximize, true);
		this.onWindowUnmaximize = Event.buffer(service.onWindowUnmaximize, true);
		this.onRecentlyOpenedChange = Event.buffer(service.onRecentlyOpenedChange, true);
	}

看到没，触发的其实是一个事件，事件是关联到service实例的；
这个实例是这样创建的：

const windowsService = accessor.get(IWindowsService);

具体的代码在：src\vs\platform\windows\electron-browser\windowsService.ts

原文地址：https://www.cnblogs.com/liulun/p/11050725.html