From 64bde25d22083e1f057974b605512792d0f8a297 Mon Sep 17 00:00:00 2001
From: Christopher Willis-Ford <cwillisf@media.mit.edu>
Date: Tue, 22 Aug 2017 14:28:38 -0700
Subject: [PATCH] Offer a promise for extension worker init
---
src/extension-support/extension-manager.js | 62 ++++++++++++++++------
src/extension-support/extension-worker.js | 20 +++++--
2 files changed, 62 insertions(+), 20 deletions(-)
diff --git a/src/extension-support/extension-manager.js b/src/extension-support/extension-manager.js
index a453fb3a8..e02234031 100644
--- a/src/extension-support/extension-manager.js
+++ b/src/extension-support/extension-manager.js
@@ -28,16 +28,18 @@ const BlockType = require('./block-type');
* @property {string} color1 - the primary color for this category, in '#rrggbb' format
* @property {string} color2 - the secondary color for this category, in '#rrggbb' format
* @property {string} color3 - the tertiary color for this category, in '#rrggbb' format
+ * @property {Array.<BlockInfo> block - the blocks in this category
+ */
+
+/**
+ * @typedef {object} PendingExtensionWorker - Information about an extension worker still initializing
+ * @property {string} extensionURL - the URL of the extension to be loaded by this worker
+ * @property {Function} resolve - function to call on successful worker startup
+ * @property {Function} reject - function to call on failed worker startup
*/
class ExtensionManager {
constructor () {
- /**
- * The list of current active extension workers.
- * @type {Array.<ExtensionWorker>}
- */
- this.workers = [];
-
/**
* The ID number to provide to the next extension worker.
* @type {int}
@@ -45,10 +47,18 @@ class ExtensionManager {
this.nextExtensionWorker = 0;
/**
- * The list of extension URLs which have been requested but not yet loaded in a worker.
- * @type {Array}
+ * FIFO queue of extensions which have been requested but not yet loaded in a worker,
+ * along with promise resolution functions to call once the worker is ready or failed.
+ *
+ * @type {Array.<PendingExtensionWorker>}
*/
- this.pendingExtensionURLs = [];
+ this.pendingExtensions = [];
+
+ /**
+ * Map of worker ID to workers which have been allocated but have not yet finished initialization.
+ * @type {Array.<PendingExtensionWorker>}
+ */
+ this.pendingWorkers = [];
dispatch.setService('extensions', this).catch(e => {
log.error(`ExtensionManager was unable to register extension service: ${JSON.stringify(e)}`);
@@ -56,21 +66,29 @@ class ExtensionManager {
}
foo () {
- this.loadExtensionURL('extensions/example-extension.js');
+ return this.loadExtensionURL('extensions/example-extension.js');
}
+ /**
+ * Load an extension by URL
+ * @param {string} extensionURL - the URL for the extension to load
+ * @returns {Promise} resolved once the extension is loaded and initialized or rejected on failure
+ */
loadExtensionURL (extensionURL) {
- // If we `require` this at the global level it breaks non-webpack targets, including tests
- const ExtensionWorker = require('worker-loader!./extension-worker');
+ return new Promise((resolve, reject) => {
+ // If we `require` this at the global level it breaks non-webpack targets, including tests
+ const ExtensionWorker = require('worker-loader!./extension-worker');
- this.pendingExtensionURLs.push(extensionURL);
- dispatch.addWorker(new ExtensionWorker());
+ this.pendingExtensions.push({extensionURL, resolve, reject});
+ dispatch.addWorker(new ExtensionWorker());
+ });
}
allocateWorker () {
const id = this.nextExtensionWorker++;
- const extFile = this.pendingExtensionURLs.shift();
- return [id, extFile];
+ const workerInfo = this.pendingExtensions.shift();
+ this.pendingWorkers[id] = workerInfo;
+ return [id, workerInfo.extensionURL];
}
registerExtensionService (serviceName) {
@@ -79,6 +97,16 @@ class ExtensionManager {
});
}
+ onWorkerInit (id, e) {
+ const workerInfo = this.pendingWorkers[id];
+ delete this.pendingWorkers[id];
+ if (e) {
+ workerInfo.reject(e);
+ } else {
+ workerInfo.resolve(id);
+ }
+ }
+
_registerExtensionInfo (serviceName, extensionInfo) {
extensionInfo = this._prepareExtensionInfo(serviceName, extensionInfo);
dispatch.call('runtime', '_registerExtensionPrimitives', extensionInfo).catch(e => {
@@ -115,7 +143,7 @@ class ExtensionManager {
result.push(this._prepareBlockInfo(serviceName, blockInfo));
} catch (e) {
// TODO: more meaningful error reporting
- log.error(`Skipping malformed block: ${e}`);
+ log.error(`Skipping malformed block: ${JSON.stringify(e)}`);
}
return result;
}, []);
diff --git a/src/extension-support/extension-worker.js b/src/extension-support/extension-worker.js
index 8c4a57410..02406e08b 100644
--- a/src/extension-support/extension-worker.js
+++ b/src/extension-support/extension-worker.js
@@ -8,13 +8,23 @@ class ExtensionWorker {
constructor () {
this.nextExtensionId = 0;
+ this.initialRegistrations = [];
+
dispatch.waitForConnection.then(() => {
dispatch.call('extensions', 'allocateWorker').then(x => {
const [id, extension] = x;
this.workerId = id;
- // TODO: catch and report any exceptions here
- importScripts(extension);
+ try {
+ importScripts(extension);
+
+ const initialRegistrations = this.initialRegistrations;
+ this.initialRegistrations = null;
+
+ Promise.all(initialRegistrations).then(() => dispatch.call('extensions', 'onWorkerInit', id));
+ } catch (e) {
+ dispatch.call('extensions', 'onWorkerInit', id, e);
+ }
});
});
@@ -25,8 +35,12 @@ class ExtensionWorker {
const extensionId = this.nextExtensionId++;
this.extensions.push(extensionObject);
const serviceName = `extension.${this.workerId}.${extensionId}`;
- return dispatch.setService(serviceName, extensionObject)
+ const promise = dispatch.setService(serviceName, extensionObject)
.then(() => dispatch.call('extensions', 'registerExtensionService', serviceName));
+ if (this.initialRegistrations) {
+ this.initialRegistrations.push(promise);
+ }
+ return promise;
}
}