fork-openpgpjs/src/worker/async_proxy.js
2018-03-05 21:36:53 -08:00

144 lines
4.5 KiB
JavaScript

// GPG4Browsers - An OpenPGP implementation in javascript
// Copyright (C) 2011 Recurity Labs GmbH
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 3.0 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
import util from '../util.js';
import crypto from '../crypto';
import packet from '../packet';
/**
* Message handling
*/
function handleMessage(id) {
return function(event) {
const msg = event.data;
switch (msg.event) {
case 'method-return':
if (msg.err) {
// fail
const err = new Error(msg.err);
// add worker stack
err.workerStack = msg.stack;
this.tasks[msg.id].reject(err);
} else {
// success
this.tasks[msg.id].resolve(msg.data);
}
delete this.tasks[msg.id];
this.workers[id].requests--;
break;
case 'request-seed':
this.seedRandom(id, msg.amount);
break;
default:
throw new Error('Unknown Worker Event.');
}
};
}
/**
* Initializes a new proxy and loads the web worker
* @constructor
* @param {String} path The path to the worker or 'openpgp.worker.js' by default
* @param {Number} n number of workers to initialize
* @param {Object} config config The worker configuration
* @param {Array<Object>} worker alternative to path parameter: web worker initialized with 'openpgp.worker.js'
* @return {Promise}
*/
export default function AsyncProxy({ path='openpgp.worker.js', n = 1, workers = [], config } = {}) {
if (workers.length) {
this.workers = workers;
}
else {
this.workers = [];
while (this.workers.length < n) {
this.workers.push(new Worker(path));
}
}
let workerId = 0;
this.workers.forEach(worker => {
worker.requests = 0;
worker.onmessage = handleMessage(workerId++).bind(this);
worker.onerror = e => {
throw new Error('Unhandled error in openpgp worker: ' + e.message + ' (' + e.filename + ':' + e.lineno + ')');
};
if (config) {
worker.postMessage({ event:'configure', config });
}
});
// Cannot rely on task order being maintained, use object keyed by request ID to track tasks
this.tasks = {};
this.currentID = 0;
}
/**
* Get new request ID
* @return {integer} New unique request ID
*/
AsyncProxy.prototype.getID = function() {
return this.currentID++;
};
/**
* Send message to worker with random data
* @param {Integer} size Number of bytes to send
*/
AsyncProxy.prototype.seedRandom = async function(id, size) {
const buf = await crypto.random.getRandomBytes(size);
this.workers[id].postMessage({ event:'seed-random', buf }, util.getTransferables(buf));
};
/**
* Terminates the workers
*/
AsyncProxy.prototype.terminate = function() {
this.workers.forEach(worker => {
worker.terminate();
});
};
/**
* Generic proxy function that handles all commands from the public api.
* @param {String} method the public api function to be delegated to the worker thread
* @param {Object} options the api function's options
* @return {Promise} see the corresponding public api functions for their return types
*/
AsyncProxy.prototype.delegate = function(method, options) {
const id = this.getID();
const requests = this.workers.map(worker => worker.requests);
const minRequests = Math.min(requests);
let workerId = 0;
for(; workerId < this.workers.length; workerId++) {
if (this.workers[workerId].requests === minRequests) {
break;
}
}
return new Promise((resolve, reject) => {
// clone packets (for web worker structured cloning algorithm)
this.workers[workerId].postMessage({ id:id, event:method, options:packet.clone.clonePackets(options) }, util.getTransferables(options));
this.workers[workerId].requests++;
// remember to handle parsing cloned packets from worker
this.tasks[id] = { resolve: data => resolve(packet.clone.parseClonedPackets(data, method)), reject };
});
};