feat: use pool of worker threads for rendering

kiva · Jan 9, 2024 · 4d856dd · 4d856dd
1 parent 952f822
commit 4d856dd
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Showing 2 changed files with 90 additions and 85 deletions.
diff --git a/server/vue-middleware.js b/server/vue-middleware.js
@@ -1,9 +1,9 @@
 const fs = require('fs');
 const path = require('path');
-const { Worker, SHARE_ENV } = require('worker_threads');
+const { SHARE_ENV } = require('worker_threads');
+const workerpool = require('workerpool');
 const Bowser = require('bowser');
 const cookie = require('cookie');
-const log = require('./util/log');
 const protectedRoutes = require('./util/protectedRoutes.js');
 const tracer = require('./util/ddTrace');
 
@@ -40,6 +40,20 @@ module.exports = function createMiddleware({
 	// eslint-disable-next-line no-param-reassign
 	clientManifest.publicPath = config.app.publicPath || '/';
 
+	// Create a worker pool to render the app
+	const pool = workerpool.pool(path.resolve(__dirname, 'vue-worker.js'), {
+		workerType: 'thread',
+		workerThreadOpts: {
+			workerData: {
+				clientManifest,
+				serverBundle,
+				serverConfig: config.server,
+				template,
+			},
+			env: SHARE_ENV,
+		},
+	});
+
 	function middleware(req, res, next) {
 		const cookies = cookie.parse(req.headers.cookie || '');
 		const userAgent = req.get('user-agent');
@@ -65,42 +79,22 @@ module.exports = function createMiddleware({
 			res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate');
 		}
 
-		// Create a worker thread to render the app
-		const worker = new Worker(path.resolve(__dirname, 'vue-worker.js'), {
-			workerData: {
-				clientManifest,
-				context,
-				serverBundle,
-				serverConfig: config.server,
-				template,
-			},
-			env: SHARE_ENV,
-		});
-
-		// Send the rendered html back to the client
-		worker.on('message', ({ error, html, setCookies }) => {
-			// set any cookies created during the app render
-			setCookies.forEach(setCookie => res.append('Set-Cookie', setCookie));
-
-			if (error) {
-				handleError(error, req, res, next);
-			} else {
-				// send the final rendered html
-				res.send(html);
-			}
-		});
-
-		// Handle any errors that occur in the worker
-		worker.on('error', err => {
-			handleError(err, req, res, next);
-		});
+		// render the app using the worker pool
+		pool.exec('render', [context])
+			.then(({ error, html, setCookies }) => {
+				// set any cookies created during the app render
+				setCookies.forEach(setCookie => res.append('Set-Cookie', setCookie));
 
-		// Handle the worker exiting
-		worker.on('exit', code => {
-			if (code !== 0) {
-				log.error(new Error(`Worker stopped with exit code ${code}`));
-			}
-		});
+				if (error) {
+					handleError(error, req, res, next);
+				} else {
+					// send the final rendered html
+					res.send(html);
+				}
+			})
+			.catch(err => {
+				handleError(err, req, res, next);
+			});
 	}
 
 	return tracer.wrap('vue-middleware', middleware);

diff --git a/server/vue-worker.js b/server/vue-worker.js
@@ -1,5 +1,6 @@
-const { parentPort, workerData } = require('worker_threads');
 const { createBundleRenderer } = require('vue-server-renderer');
+const { workerData } = require('worker_threads');
+const workerpool = require('workerpool');
 const initCache = require('./util/initCache');
 const log = require('./util/log');
 const vueSsrCache = require('./util/vueSsrCache');
@@ -8,14 +9,12 @@ const getSessionCookies = require('./util/getSessionCookies');
 
 const {
 	clientManifest,
-	context,
 	serverBundle,
 	serverConfig,
 	template,
 } = workerData;
 
 const isProd = process.env.NODE_ENV === 'production';
-const s = Date.now();
 const cache = initCache(serverConfig);
 
 // create a new renderer instance
@@ -29,52 +28,64 @@ const renderer = createBundleRenderer(serverBundle, {
 	shouldPrefetch: () => false,
 });
 
-// get graphql api possible types for the graphql client
-const typesPromise = getGqlPossibleTypes(serverConfig.graphqlUri, cache)
-	.finally(() => {
-		if (!isProd) {
-			log.info(`fragment fetch: ${Date.now() - s}ms`);
-		}
-	});
+async function render(context) {
+	const s = Date.now();
 
-// fetch initial session cookies in case starting session with this request
-const cookiePromise = getSessionCookies(serverConfig.sessionUri, context.cookies)
-	.finally(() => {
-		if (!isProd) {
-			log.info(`session fetch: ${Date.now() - s}ms`);
-		}
-	});
-
-const setCookies = [];
+	// get graphql api possible types for the graphql client
+	const typesPromise = getGqlPossibleTypes(serverConfig.graphqlUri, cache)
+		.finally(() => {
+			if (!isProd) {
+				log.info(`fragment fetch: ${Date.now() - s}ms`);
+			}
+		});
 
-Promise.all([typesPromise, cookiePromise])
-	.then(([types, cookieInfo]) => {
-		// add fetched types to rendering context
-		context.config.graphqlPossibleTypes = types;
-		// update cookies in the rendering context with any newly fetched session cookies
-		context.cookies = Object.assign(context.cookies, cookieInfo.cookies);
-		// forward any newly fetched 'Set-Cookie' headers
-		context.setCookies = [...cookieInfo.setCookies];
-		// render the app
-		return renderer.renderToString(context);
-	}).then(html => {
-		// collect any cookies created during the app render
-		setCookies.concat(context.setCookies);
-		// send the final rendered html
-		parentPort.postMessage({
-			html,
-			setCookies,
+	// fetch initial session cookies in case starting session with this request
+	const cookiePromise = getSessionCookies(serverConfig.sessionUri, context.cookies)
+		.finally(() => {
+			if (!isProd) {
+				log.info(`session fetch: ${Date.now() - s}ms`);
+			}
 		});
-		if (!isProd) {
-			log.info(`whole request: ${Date.now() - s}ms`);
-		}
-	}).catch(err => {
-		// collect any cookies created during the app render
-		setCookies.concat(context.setCookies);
-		// send the error
-		parentPort.postMessage({
-			error: err,
-			// only send cookies if there is a redirect url
-			setCookies: err.url ? setCookies : [],
+
+	const setCookies = [];
+
+	return Promise.all([typesPromise, cookiePromise])
+		.then(([types, cookieInfo]) => {
+			// add fetched types to rendering context
+			context.config.graphqlPossibleTypes = types;
+			// update cookies in the rendering context with any newly fetched session cookies
+			context.cookies = Object.assign(context.cookies, cookieInfo.cookies);
+			// forward any newly fetched 'Set-Cookie' headers
+			context.setCookies = [...cookieInfo.setCookies];
+			// render the app
+			return renderer.renderToString(context);
+		})
+		.then(html => {
+			// collect any cookies created during the app render
+			setCookies.concat(context.setCookies);
+			// send the final rendered html
+			return {
+				html,
+				setCookies,
+			};
+		})
+		.catch(err => {
+			// collect any cookies created during the app render
+			setCookies.concat(context.setCookies);
+			// send the error
+			return {
+				error: err,
+				// only send cookies if there is a redirect url
+				setCookies: err.url ? setCookies : [],
+			};
+		})
+		.finally(() => {
+			if (!isProd) {
+				log.info(`whole request: ${Date.now() - s}ms`);
+			}
 		});
-	});
+}
+
+workerpool.worker({
+	render,
+});