scratch-vm/src/extension-support/extension-manager.js
Michael "Z" Goddard a5009b4c59
delay extension evaluation until that extension is installed
Reduce the amount of code that needs to evaluated before we can
starting the target project if there is one. It is key to note that the
music extension includes ~2MB of base64 encoded sound samples. This
skips evaluating those samples and decoding base64 into binary typed
arrays.
2019-03-06 11:11:44 -05:00

374 lines
16 KiB
JavaScript

const dispatch = require('../dispatch/central-dispatch');
const log = require('../util/log');
const maybeFormatMessage = require('../util/maybe-format-message');
const BlockType = require('./block-type');
// These extensions are currently built into the VM repository but should not be loaded at startup.
// TODO: move these out into a separate repository?
// TODO: change extension spec so that library info, including extension ID, can be collected through static methods
const builtinExtensions = {
pen: () => require('../extensions/scratch3_pen'),
wedo2: () => require('../extensions/scratch3_wedo2'),
music: () => require('../extensions/scratch3_music'),
microbit: () => require('../extensions/scratch3_microbit'),
text2speech: () => require('../extensions/scratch3_text2speech'),
translate: () => require('../extensions/scratch3_translate'),
videoSensing: () => require('../extensions/scratch3_video_sensing'),
speech2text: () => require('../extensions/scratch3_speech2text'),
ev3: () => require('../extensions/scratch3_ev3'),
makeymakey: () => require('../extensions/scratch3_makeymakey')
// todo: only load this extension once we have a compatible way to load its
// Vernier module dependency.
// gdxfor: () => require('../extensions/scratch3_gdx_for')
};
/**
* @typedef {object} ArgumentInfo - Information about an extension block argument
* @property {ArgumentType} type - the type of value this argument can take
* @property {*|undefined} default - the default value of this argument (default: blank)
*/
/**
* @typedef {object} ConvertedBlockInfo - Raw extension block data paired with processed data ready for scratch-blocks
* @property {ExtensionBlockMetadata} info - the raw block info
* @property {object} json - the scratch-blocks JSON definition for this block
* @property {string} xml - the scratch-blocks XML definition for this block
*/
/**
* @typedef {object} CategoryInfo - Information about a block category
* @property {string} id - the unique ID of this category
* @property {string} name - the human-readable name of this category
* @property {string|undefined} blockIconURI - optional URI for the block icon image
* @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.<ConvertedBlockInfo>} blocks - the blocks, separators, etc. in this category
* @property {Array.<object>} menus - the menus provided by 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 (runtime) {
/**
* The ID number to provide to the next extension worker.
* @type {int}
*/
this.nextExtensionWorker = 0;
/**
* 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.pendingExtensions = [];
/**
* Map of worker ID to workers which have been allocated but have not yet finished initialization.
* @type {Array.<PendingExtensionWorker>}
*/
this.pendingWorkers = [];
/**
* Set of loaded extension URLs/IDs (equivalent for built-in extensions).
* @type {Set.<string>}
* @private
*/
this._loadedExtensions = new Map();
/**
* Keep a reference to the runtime so we can construct internal extension objects.
* TODO: remove this in favor of extensions accessing the runtime as a service.
* @type {Runtime}
*/
this.runtime = runtime;
dispatch.setService('extensions', this).catch(e => {
log.error(`ExtensionManager was unable to register extension service: ${JSON.stringify(e)}`);
});
}
/**
* Check whether an extension is registered or is in the process of loading. This is intended to control loading or
* adding extensions so it may return `true` before the extension is ready to be used. Use the promise returned by
* `loadExtensionURL` if you need to wait until the extension is truly ready.
* @param {string} extensionID - the ID of the extension.
* @returns {boolean} - true if loaded, false otherwise.
*/
isExtensionLoaded (extensionID) {
return this._loadedExtensions.has(extensionID);
}
/**
* Load an extension by URL or internal extension ID
* @param {string} extensionURL - the URL for the extension to load OR the ID of an internal extension
* @returns {Promise} resolved once the extension is loaded and initialized or rejected on failure
*/
loadExtensionURL (extensionURL) {
if (builtinExtensions.hasOwnProperty(extensionURL)) {
/** @TODO dupe handling for non-builtin extensions. See commit 670e51d33580e8a2e852b3b038bb3afc282f81b9 */
if (this.isExtensionLoaded(extensionURL)) {
const message = `Rejecting attempt to load a second extension with ID ${extensionURL}`;
log.warn(message);
return Promise.reject(new Error(message));
}
const extension = builtinExtensions[extensionURL]();
const extensionInstance = new extension(this.runtime);
return this._registerInternalExtension(extensionInstance).then(serviceName => {
this._loadedExtensions.set(extensionURL, serviceName);
});
}
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?name=extension-worker.js!./extension-worker');
this.pendingExtensions.push({extensionURL, resolve, reject});
dispatch.addWorker(new ExtensionWorker());
});
}
/**
* Regenerate blockinfo for any loaded extensions
* @returns {Promise} resolved once all the extensions have been reinitialized
*/
refreshBlocks () {
const allPromises = Array.from(this._loadedExtensions.values()).map(serviceName =>
dispatch.call(serviceName, 'getInfo')
.then(info => {
info = this._prepareExtensionInfo(serviceName, info);
dispatch.call('runtime', '_refreshExtensionPrimitives', info);
})
.catch(e => {
log.error(`Failed to refresh buildtin extension primitives: ${JSON.stringify(e)}`);
})
);
return Promise.all(allPromises);
}
allocateWorker () {
const id = this.nextExtensionWorker++;
const workerInfo = this.pendingExtensions.shift();
this.pendingWorkers[id] = workerInfo;
return [id, workerInfo.extensionURL];
}
/**
* Collect extension metadata from the specified service and begin the extension registration process.
* @param {string} serviceName - the name of the service hosting the extension.
*/
registerExtensionService (serviceName) {
dispatch.call(serviceName, 'getInfo').then(info => {
this._registerExtensionInfo(serviceName, info);
});
}
/**
* Called by an extension worker to indicate that the worker has finished initialization.
* @param {int} id - the worker ID.
* @param {*?} e - the error encountered during initialization, if any.
*/
onWorkerInit (id, e) {
const workerInfo = this.pendingWorkers[id];
delete this.pendingWorkers[id];
if (e) {
workerInfo.reject(e);
} else {
workerInfo.resolve(id);
}
}
/**
* Register an internal (non-Worker) extension object
* @param {object} extensionObject - the extension object to register
* @returns {Promise} resolved once the extension is fully registered or rejected on failure
*/
_registerInternalExtension (extensionObject) {
const extensionInfo = extensionObject.getInfo();
const fakeWorkerId = this.nextExtensionWorker++;
const serviceName = `extension_${fakeWorkerId}_${extensionInfo.id}`;
return dispatch.setService(serviceName, extensionObject)
.then(() => {
dispatch.call('extensions', 'registerExtensionService', serviceName);
return serviceName;
});
}
/**
* Sanitize extension info then register its primitives with the VM.
* @param {string} serviceName - the name of the service hosting the extension
* @param {ExtensionInfo} extensionInfo - the extension's metadata
* @private
*/
_registerExtensionInfo (serviceName, extensionInfo) {
extensionInfo = this._prepareExtensionInfo(serviceName, extensionInfo);
dispatch.call('runtime', '_registerExtensionPrimitives', extensionInfo).catch(e => {
log.error(`Failed to register primitives for extension on service ${serviceName}:`, e);
});
}
/**
* Modify the provided text as necessary to ensure that it may be used as an attribute value in valid XML.
* @param {string} text - the text to be sanitized
* @returns {string} - the sanitized text
* @private
*/
_sanitizeID (text) {
return text.toString().replace(/[<"&]/, '_');
}
/**
* Apply minor cleanup and defaults for optional extension fields.
* TODO: make the ID unique in cases where two copies of the same extension are loaded.
* @param {string} serviceName - the name of the service hosting this extension block
* @param {ExtensionInfo} extensionInfo - the extension info to be sanitized
* @returns {ExtensionInfo} - a new extension info object with cleaned-up values
* @private
*/
_prepareExtensionInfo (serviceName, extensionInfo) {
extensionInfo = Object.assign({}, extensionInfo);
if (!/^[a-z0-9]+$/i.test(extensionInfo.id)) {
throw new Error('Invalid extension id');
}
extensionInfo.name = extensionInfo.name || extensionInfo.id;
extensionInfo.blocks = extensionInfo.blocks || [];
extensionInfo.targetTypes = extensionInfo.targetTypes || [];
extensionInfo.blocks = extensionInfo.blocks.reduce((results, blockInfo) => {
try {
let result;
switch (blockInfo) {
case '---': // separator
result = '---';
break;
default: // an ExtensionBlockMetadata object
result = this._prepareBlockInfo(serviceName, blockInfo);
break;
}
results.push(result);
} catch (e) {
// TODO: more meaningful error reporting
log.error(`Error processing block: ${e.message}, Block:\n${JSON.stringify(blockInfo)}`);
}
return results;
}, []);
extensionInfo.menus = extensionInfo.menus || [];
extensionInfo.menus = this._prepareMenuInfo(serviceName, extensionInfo.menus);
return extensionInfo;
}
/**
* Prepare extension menus. e.g. setup binding for dynamic menu functions.
* @param {string} serviceName - the name of the service hosting this extension block
* @param {Array.<MenuInfo>} menus - the menu defined by the extension.
* @returns {Array.<MenuInfo>} - a menuInfo object with all preprocessing done.
* @private
*/
_prepareMenuInfo (serviceName, menus) {
const menuNames = Object.getOwnPropertyNames(menus);
for (let i = 0; i < menuNames.length; i++) {
const item = menuNames[i];
// If the value is a string, it should be the name of a function in the
// extension object to call to populate the menu whenever it is opened.
// Set up the binding for the function object here so
// we can use it later when converting the menu for Scratch Blocks.
if (typeof menus[item] === 'string') {
const serviceObject = dispatch.services[serviceName];
const menuName = menus[item];
menus[item] = this._getExtensionMenuItems.bind(this, serviceObject, menuName);
}
}
return menus;
}
/**
* Fetch the items for a particular extension menu, providing the target ID for context.
* @param {object} extensionObject - the extension object providing the menu.
* @param {string} menuName - the name of the menu function to call.
* @returns {Array} menu items ready for scratch-blocks.
* @private
*/
_getExtensionMenuItems (extensionObject, menuName) {
// Fetch the items appropriate for the target currently being edited. This assumes that menus only
// collect items when opened by the user while editing a particular target.
const editingTarget = this.runtime.getEditingTarget() || this.runtime.getTargetForStage();
const editingTargetID = editingTarget ? editingTarget.id : null;
const extensionMessageContext = this.runtime.makeMessageContextForTarget(editingTarget);
// TODO: Fix this to use dispatch.call when extensions are running in workers.
const menuFunc = extensionObject[menuName];
const menuItems = menuFunc.call(extensionObject, editingTargetID).map(
item => {
item = maybeFormatMessage(item, extensionMessageContext);
switch (typeof item) {
case 'object':
return [
maybeFormatMessage(item.text, extensionMessageContext),
item.value
];
case 'string':
return [item, item];
default:
return item;
}
});
if (!menuItems || menuItems.length < 1) {
throw new Error(`Extension menu returned no items: ${menuName}`);
}
return menuItems;
}
/**
* Apply defaults for optional block fields.
* @param {string} serviceName - the name of the service hosting this extension block
* @param {ExtensionBlockMetadata} blockInfo - the block info from the extension
* @returns {ExtensionBlockMetadata} - a new block info object which has values for all relevant optional fields.
* @private
*/
_prepareBlockInfo (serviceName, blockInfo) {
blockInfo = Object.assign({}, {
blockType: BlockType.COMMAND,
terminal: false,
blockAllThreads: false,
arguments: {}
}, blockInfo);
blockInfo.opcode = this._sanitizeID(blockInfo.opcode);
blockInfo.text = blockInfo.text || blockInfo.opcode;
if (blockInfo.blockType !== BlockType.EVENT) {
blockInfo.func = blockInfo.func ? this._sanitizeID(blockInfo.func) : blockInfo.opcode;
/**
* This is only here because the VM performs poorly when blocks return promises.
* @TODO make it possible for the VM to resolve a promise and continue during the same Scratch "tick"
*/
if (dispatch._isRemoteService(serviceName)) {
blockInfo.func = dispatch.call.bind(dispatch, serviceName, blockInfo.func);
} else {
const serviceObject = dispatch.services[serviceName];
const func = serviceObject[blockInfo.func];
if (func) {
blockInfo.func = func.bind(serviceObject);
} else if (blockInfo.blockType !== BlockType.EVENT) {
throw new Error(`Could not find extension block function called ${blockInfo.func}`);
}
}
} else if (blockInfo.func) {
log.warn(`Ignoring function "${blockInfo.func}" for event block ${blockInfo.opcode}`);
}
return blockInfo;
}
}
module.exports = ExtensionManager;