WIP: uglify - use workerpool

lib/processors/uglifier.js

@@ -1,45 +1,42 @@
-const terser = require("terser");
-/**
- * Preserve comments which contain:
- * <ul>
- *  <li>copyright notice</li>
- *  <li>license terms</li>
- *  <li>"@ui5-bundle"</li>
- *  <li>"@ui5-bundle-raw-include"</li>
- * </ul>
- *
- * @type {RegExp}
- */
-const copyrightCommentsAndBundleCommentPattern = /copyright|\(c\)(?:[0-9]+|\s+[0-9A-za-z])|released under|license|\u00a9|^@ui5-bundle-raw-include |^@ui5-bundle /i;
+const workerpool = require("workerpool");
+let _pool;
+
+// Use up to 5 workers, depending on available CPUs
+// Using more workers doesn't seem to improve overall performance
+const maxWorkers = Math.max(Math.min((require("os").cpus().length || 4) - 1, 5), 1);
+
+function pool({taskUtil}) {
+	if (!_pool) {
+		_pool = workerpool.pool(__dirname + "/uglifier_worker.js", {
+			workerType: "auto",
+			maxWorkers
+		});
+		taskUtil.registerCleanupTask(() => {
+			_pool.terminate();
+			_pool = null;
+		});
+	}
+	return _pool;
+}
 
 /**
  * Minifies the supplied resources.
  *
  * @public
  * @alias module:@ui5/builder.processors.uglifier
+ * @param {module:@ui5/builder.tasks.TaskUtil|object} [parameters.taskUtil] TaskUtil
  * @param {object} parameters Parameters
  * @param {module:@ui5/fs.Resource[]} parameters.resources List of resources to be processed
  * @returns {Promise<module:@ui5/fs.Resource[]>} Promise resolving with uglified resources
  */
-module.exports = function({resources}) {
+module.exports = function({resources, taskUtil}) {
 	return Promise.all(resources.map(async (resource) => {
 		const code = await resource.getString();
-		try {
-			const result = await terser.minify({
-				[resource.getPath()]: code
-			}, {
-				output: {
-					comments: copyrightCommentsAndBundleCommentPattern,
-					wrap_func_args: false
-				},
-				compress: false
-			});
-			resource.setString(result.code);
-			return resource;
-		} catch (err) {
-			throw new Error(
-				`Uglification failed with error: ${err.message} in file ${err.filename} ` +
-				`(line ${err.line}, col ${err.col}, pos ${err.pos})`);
-		}
+		const uglifiedCode = await pool({taskUtil}).exec("uglify", [{
+			filePath: resource.getPath(),
+			code
+		}]);
+		resource.setString(uglifiedCode);
+		return resource;
 	}));
 };

lib/processors/uglifier_worker.js

@@ -0,0 +1,39 @@
+const workerpool = require("workerpool");
+const terser = require("terser");
+/**
+ * Preserve comments which contain:
+ * <ul>
+ *  <li>copyright notice</li>
+ *  <li>license terms</li>
+ *  <li>"@ui5-bundle"</li>
+ *  <li>"@ui5-bundle-raw-include"</li>
+ * </ul>
+ *
+ * @type {RegExp}
+ */
+const copyrightCommentsAndBundleCommentPattern =
+	/copyright|\(c\)(?:[0-9]+|\s+[0-9A-za-z])|released under|license|\u00a9|^@ui5-bundle-raw-include |^@ui5-bundle /i;
+
+async function uglify({filePath, code}) {
+	try {
+		const result = terser.minify({
+			[filePath]: code
+		}, {
+			output: {
+				comments: copyrightCommentsAndBundleCommentPattern,
+				wrap_func_args: false
+			},
+			compress: false
+		});
+		return result.code;
+	} catch (error) {
+		throw new Error(
+			`Uglification failed with error: ${error.message} in file ${error.filename} ` +
+			`(line ${error.line}, col ${error.col}, pos ${error.pos})`);
+	}
+}
+
+// create a worker and register public functions
+workerpool.worker({
+	uglify
+});

lib/tasks/uglify.js

@@ -9,13 +9,15 @@ const uglifyProcessor = require("../processors/uglifier");
  * @param {module:@ui5/fs.DuplexCollection} parameters.workspace DuplexCollection to read and write files
  * @param {object} parameters.options Options
  * @param {string} parameters.options.pattern Pattern to locate the files to be processed
+ * @param {module:@ui5/builder.tasks.TaskUtil|object} parameters.taskUtil TaskUtil
  * @returns {Promise<undefined>} Promise resolving with <code>undefined</code> once data has been written
  */
-module.exports = function({workspace, options: {pattern}}) {
+module.exports = function({workspace, options: {pattern}, taskUtil}) {
 	return workspace.byGlobSource(pattern)
 		.then((allResources) => {
 			return uglifyProcessor({
-				resources: allResources
+				resources: allResources,
+				taskUtil
 			});
 		})
 		.then((processedResources) => {

lib/types/application/ApplicationBuilder.js

@@ -148,7 +148,8 @@ class ApplicationBuilder extends AbstractBuilder {
 				workspace: resourceCollections.workspace,
 				options: {
 					pattern: "/**/*.js"
-				}
+				},
+				taskUtil
 			});
 		});
 

lib/types/library/LibraryBuilder.js

@@ -174,7 +174,8 @@ class LibraryBuilder extends AbstractBuilder {
 				workspace: resourceCollections.workspace,
 				options: {
 					pattern: "/resources/**/*.js"
-				}
+				},
+				taskUtil
 			});
 		});
 

package.json

@@ -120,6 +120,7 @@
 		"semver": "^7.3.2",
 		"slash": "^3.0.0",
 		"terser": "^5.3.2",
+		"workerpool": "^6.0.1",
 		"xml2js": "^0.4.23",
 		"yazl": "^2.5.1"
 	},