Introduce worker pools

.github/workflows/cd.release.yml

@@ -22,7 +22,7 @@ jobs:
         if: ${{ steps.release.outputs.release_created }}
       - uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 18
           registry-url: 'https://registry.npmjs.org'
         if: ${{ steps.release.outputs.release_created }}
       # if you are using Yarn, substitute the command below with `yarn install --frozen-lockfile`

.github/workflows/ci.coverage.yml

@@ -11,10 +11,10 @@ jobs:
 
     - uses: actions/checkout@v1
 
-    - name: Use Node.js 10.x
+    - name: Use Node.js 18.x
       uses: actions/setup-node@v1
       with:
-        node-version: 10.x
+        node-version: 18
 
     - name: npm install, npm test, npm run coverage
       run: |

.github/workflows/ci.test.yml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [windows-latest, ubuntu-latest, macos-latest]
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [16.x, 18.x, 20.x]
 
     steps:
       - uses: actions/checkout@v2

.npmrc

@@ -0,0 +1 @@
+engine-strict=true

package.json

@@ -10,11 +10,11 @@
   ],
   "scripts": {
     "debug": "node scripts/debug.js",
-    "lint": "node_modules/.bin/eslint -- src test ./",
-    "lint:fix": "node_modules/.bin/eslint --fix src test ./",
+    "lint": "eslint -- src test ./",
+    "lint:fix": "eslint --fix src test ./",
     "test:only": "nyc mocha test/main.test.js && mocha test/output.test.js",
     "test": "nyc mocha test/main.test.js && mocha test/output.test.js && npm run lint",
-    "coverage": "node_modules/.bin/nyc report --reporter=lcovonly"
+    "coverage": "nyc report --reporter=lcovonly"
   },
   "repository": {
     "type": "git",
@@ -48,6 +48,7 @@
     "oslllo-potrace": "^2.0.1",
     "oslllo-svg2": "^2.0.2",
     "oslllo-validator": "^3.1.0",
+    "piscina": "^4.1.0",
     "yargs": "^16.2.0"
   },
   "devDependencies": {
@@ -62,5 +63,8 @@
     "mocha-lcov-reporter": "^1.3.0",
     "nyc": "^15.1.0",
     "stopwatch-node": "^1.1.0"
+  },
+  "engines": {
+    "node": ">=16.0.0"
   }
 }

src/processor.js

@@ -1,10 +1,13 @@
 "use strict";
 
-const fs = require("fs");
 const path = require("path");
-const Svg = require("./svg");
 const is = require("oslllo-validator");
 const Progress = require("./progress");
+const Piscina = require("piscina");
+
+const workerPool = new Piscina({
+  filename: path.resolve(__dirname, "tracer.js")
+});
 
 const Processor = function (fixer) {
   this.fixer = fixer;
@@ -34,14 +37,23 @@ Processor.prototype = {
       try {
         this.setup();
         var svgs = this.source;
+
+        const resolution = this.fixer.options.get("traceResolution");
+
         svgs = svgs.map((source) => {
           var destination = path.join(this.destination, path.basename(source));
 
-          return { source, destination };
+          return { source, destination, resolution };
         });
-        for (var i = 0; i < svgs.length; i++) {
-          await this.instance(svgs[i]);
-        }
+
+        const workerPromises = svgs.map(async (svg) => {
+          await workerPool.run(svg);
+          // eslint-disable-next-line no-empty-function
+          this.tick(() => {});
+        });
+
+        await Promise.all(workerPromises);
+
         this.teardown();
         resolve(this.fixer);
       } catch (err) {
@@ -68,19 +80,6 @@ Processor.prototype = {
       this.progress.stop();
     }
   },
-  instance: function ({ source, destination }) {
-    return new Promise(async (resolve, reject) => {
-      try {
-        var resolution = this.fixer.options.get("traceResolution");
-        var svg = new Svg(source, resolution);
-        var fixed = await svg.process();
-        fs.writeFileSync(destination, fixed);
-        this.tick(() => resolve());
-      } catch (err) {
-        reject(err);
-      }
-    });
-  },
 };
 
 module.exports = Processor;

src/tracer.js

@@ -0,0 +1,10 @@
+"use strict";
+
+const fs = require("fs/promises");
+const Svg = require("./svg");
+
+module.exports = async ({ source, destination, resolution }) => {
+  const svg = new Svg(source, resolution);
+  const fixed = await svg.process();
+  await fs.writeFile(destination, fixed);
+};

test/src/test.cli.js

@@ -5,7 +5,7 @@ const { emptyDir, isEmptyDir } = require(".");
 const { exec } = require("child_process");
 const { assert, path2 } = require("./helper");
 
-const timeout = 20000;
+const timeout = 30000;
 var destination = "temp";
 
 if (!fs.existsSync(destination)) {