Add worker-task-queue package

.gitignore

@@ -1,4 +1,5 @@
-/package-lock.json
-/node_modules
-/dist
+package-lock.json
+node_modules
+dist
 /polyfill
+/packages/worker-task-queue/processor

package.json

@@ -7,7 +7,9 @@
   "umd:main": "dist/task-worklet.js",
   "module": "dist/task-worklet.module.js",
   "scripts": {
-    "build": "microbundle -f umd,es && microbundle -f iife src/polyfill.js -o polyfill/index.js",
+    "build": "npm run -s build:main && npm run -s build:wtq",
+    "build:main": "microbundle -f umd,es && microbundle -f iife src/polyfill.js -o polyfill/index.js",
+    "build:wtq": "cd packages/worker-task-queue && npm run -s build",
     "test": "eslint \"{src,test}/**/*.test.{mjs,js}\" && karmatic --no-coverage"
   },
   "files": [
@@ -50,10 +52,15 @@
   "license": "Apache-2.0",
   "homepage": "https://github.com/developit/task-worklet",
   "devDependencies": {
+    "@babel/preset-env": "^7.15.0",
+    "@babel/preset-typescript": "^7.15.0",
+    "@babel/register": "^7.15.3",
+    "@types/jest": "^27.0.1",
     "eslint": "^7.9.0",
     "eslint-config-google": "^0.14.0",
     "eslint-config-prettier": "^6.11.0",
     "file-loader": "^6.1.0",
+    "jest": "^27.0.6",
     "karmatic": "^2.1.0",
     "microbundle": "^0.12.3",
     "prettier": "^2.1.2",

packages/worker-task-queue/README.md

@@ -0,0 +1,65 @@
+# `worker-task-queue`
+
+This is a standalone implementation of the cooperative multithreading model from [Task Worklet](https://github.com/developit/task-worklet) as a zero-dependency library for Web and Node.
+
+**main thread code:**
+
+```js
+import WorkerTaskQueue from 'worker-task-queue';
+
+// Set up the worker pool
+const queue = new WorkerTaskQueue({
+  // URL/path for our worker script:
+  workerUrl: '/path/to/worker.js',
+  // max pool size:
+  size: 4
+});
+
+function demo(image) {
+  // allocates a thread in the pool doesn't have one free:
+  const cropped = postTask('crop', image, { box: [10, 20, 30, 40] });
+
+  // subsequent tasks run on the same thread to eliminate data transfer:
+  let large = postTask('resize', cropped, { width: 1000, height: 1000 });
+  large = postTask('compress', large, quality);
+
+  // ... except when they get automatically parallelized by moving the input to a second thread:
+  let thumb = postTask('resize', cropped, { width: 200, height: 200 });
+  thumb = postTask('compress', thumb, quality);
+
+  // At this point we've only transferred one image to a background thread,
+  // and transferred another image between two threads.
+
+  // Only the final results are transferred back here, and only when we ask for them:
+  showPreview(await large.result, await thumb.result);
+}
+
+demo();
+```
+
+**worker code:**
+
+```js
+import { registerTask } from 'worker-task-queue/processor';
+
+registerTask('crop', class {
+  process(image, { box }) {
+    // complicated stuff in here
+    return image;
+  }
+});
+
+registerTask('resize', class {
+  process(image, { width, height }) {
+    // complicated stuff in here
+    return image;
+  }
+});
+
+registerTask('compress', class {
+  process(image, quality) {
+    // complicated stuff in here
+    return image;
+  }
+});
+```

packages/worker-task-queue/package.json

@@ -0,0 +1,66 @@
+{
+  "name": "worker-task-queue",
+  "version": "0.2.1",
+  "description": "Streamlined processing of tasks in a shared threadpool.",
+  "exports": {
+    "./processor": {
+      "module": "./processor/index.mjs",
+      "import": "./processor/index.mjs",
+      "default": "./processor/index.js"
+    },
+    ".": {
+      "module": "./dist/worker-task-queue.mjs",
+      "import": "./dist/worker-task-queue.mjs",
+      "default": "./dist/worker-task-queue.js"
+    }
+  },
+  "module": "./dist/worker-task-queue.mjs",
+  "main": "./dist/worker-task-queue.js",
+  "umd:main": "./dist/worker-task-queue.umd.js",
+  "scripts": {
+    "build": "microbundle src/index.ts -f es,cjs,umd && microbundle -f es,cjs,umd src/processor.ts -o processor/index.js",
+    "test": "../../node_modules/.bin/jest"
+  },
+  "files": [
+    "dist",
+    "processor",
+    "src"
+  ],
+  "babel": {
+    "env": {
+      "test": {
+        "presets": [
+          [
+            "@babel/preset-env",
+            {
+              "targets": {
+                "node": "current"
+              },
+              "modules": "commonjs"
+            }
+          ],
+          "@babel/preset-typescript"
+        ]
+      }
+    }
+  },
+  "repository": "developit/task-worklet",
+  "keywords": [
+    "tasks",
+    "task worklet",
+    "worker task queue",
+    "task queue",
+    "parallelization",
+    "off-main-thread",
+    "OMT",
+    "threads",
+    "multithreading"
+  ],
+  "author": "Jason Miller <[email protected]>",
+  "license": "Apache-2.0",
+  "homepage": "https://github.com/developit/task-worklet/packages/worker-task-queue",
+  "devDependencies": {
+    "microbundle": "^0.13.3",
+    "web-worker": "^1.0.0"
+  }
+}