Add worker api

package.json

@@ -14,24 +14,31 @@
   "types": "dist/index.d.ts",
   "scripts": {
     "test": "jest",
-    "bundle": "rm -rf lib && webpack --config ./webpack/lib.config.ts && webpack --config ./webpack/lib.min.config.ts",
-    "build": "rm -rf dist && tsc && yarn bundle"
+    "bundle": "rm -rf lib && webpack --config ./webpack/lib.config.ts && webpack --config ./webpack/lib.min.config.ts && webpack --config ./webpack/lib.worker.config.ts",
+    "build": "rm -rf dist && tsc && yarn bundle",
+    "preyalc": "yarn build",
+    "build-local": "yalc publish --push",
+    "build-local-watch": "nodemon -w src/ -w worker/ -e js,ts -x 'yarn run build-local'"
   },
   "devDependencies": {
     "@types/jest": "^24.0.13",
     "@types/node": "^10.12.21",
     "jest": "^24.8.0",
+    "nodemon": "^2.0.2",
     "prando": "^5.1.0",
     "prettier": "^1.16.4",
     "ts-jest": "^24.0.2",
     "ts-loader": "^5.3.3",
     "ts-node": "^8.0.2",
     "typescript": "^3.2.4",
     "webpack": "^4.29.5",
-    "webpack-cli": "^3.2.3"
+    "webpack-cli": "^3.2.3",
+    "worker-loader": "^2.0.0",
+    "yalc": "^1.0.0-pre.35"
   },
   "dependencies": {
-    "ml-levenberg-marquardt": "^1.0.3"
+    "ml-levenberg-marquardt": "^1.0.3",
+    "uuid": "^7.0.1"
   },
   "publishConfig": {
     "registry": "https://wombat-dressing-room.appspot.com"

webpack/lib.worker.config.ts

@@ -0,0 +1,37 @@
+import * as path from 'path';
+
+export default {
+  mode: 'production',
+  module: {
+    rules: [
+      {
+        test: /(\.ts$|\.js$)/,
+        exclude: /node_modules/,
+        use: ['ts-loader'],
+      },
+      {
+        test: /(\.worker\.ts$|\.worker\.js$)/,
+        exclude: /node_modules/,
+        use: [
+          {
+            loader: 'worker-loader',
+            options: { fallback: false, inline: true },
+          },
+          'ts-loader',
+        ],
+      },
+    ],
+  },
+  resolve: {
+    extensions: ['.ts', '.js'],
+  },
+  entry: {
+    lib: path.resolve(__dirname, '../worker/worker-lib.ts'),
+  },
+  output: {
+    filename: 'umap-worker-js.js',
+    libraryTarget: 'commonjs2',
+    path: path.resolve(__dirname, '../lib'),
+  },
+  optimization: { minimize: true },
+};

worker/tsconfig.json

@@ -0,0 +1,4 @@
+{
+  "extends": "../tsconfig.json",
+  "include": ["./*.ts"]
+}

worker/umap.worker.ts

@@ -0,0 +1,25 @@
+import { UMAP } from '../src/lib';
+
+async function messageHandler({ data: { id, method, args } }) {
+  console.log(
+    `UMAPWorker: received instruction to execute 'umap.${method}' with ${args.length} args`
+  );
+  switch (method) {
+    case 'fit': {
+      const umap = new UMAP();
+      const embedding = await umap.fit(args[0]);
+      // @ts-ignore
+      postMessage({ id, method, results: { embedding } });
+      break;
+    }
+    default: {
+      // @ts-ignore
+      postMessage({
+        id,
+        error: `Unknown method requested of UMAPWorker: 'umap.${method}'`,
+      });
+    }
+  }
+}
+
+onmessage = messageHandler;

worker/worker-lib.ts

@@ -0,0 +1,59 @@
+import { v4 as uuid } from 'uuid';
+
+// @ts-ignore
+import UMAPWorker from './umap.worker';
+
+const requests = {};
+
+function onError(id, error) {
+  console.error(error);
+  try {
+    requests[id].reject(error.message);
+  } finally {
+    delete requests[id];
+  }
+}
+
+function onMessage({ data: { error, id, method, results } }) {
+  if (error) {
+    onError(id, new Error(error));
+  }
+  switch (method) {
+    case 'fit': {
+      const { embedding } = results;
+      if (requests[id]) {
+        requests[id].resolve(embedding);
+      } else {
+        requests[id].reject(
+          `Could not find existing UMAPWorker request with id ${id}`
+        );
+      }
+      delete requests[id];
+      break;
+    }
+    default: {
+      throw new Error(
+        `Unknown method performed by UMAPWorker: 'umap.${method}'`
+      );
+    }
+  }
+}
+
+const worker = new UMAPWorker();
+worker.onerror = onError;
+worker.onmessage = onMessage;
+
+class UMAPWorkerWrapper {
+  fit(data) {
+    const id = uuid();
+    worker.postMessage({ id, method: 'fit', args: [data] });
+
+    const promise = new Promise((resolve, reject) => {
+      requests[id] = { resolve, reject };
+    });
+
+    return promise;
+  }
+}
+
+export { UMAPWorkerWrapper as UMAP };