/* * Copyright (C) 2019-2021 Yomichan Authors * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ /** * This class is used to connect Yomichan to a native component that is * used to parse text into individual terms. */ class Mecab { /** * Creates a new instance of the class. */ constructor() { this._port = null; this._sequence = 0; this._invocations = new Map(); this._eventListeners = new EventListenerCollection(); this._timeout = 5000; this._version = 1; this._remoteVersion = null; this._enabled = false; this._setupPortPromise = null; } /** * Returns whether or not the component is enabled. */ isEnabled() { return this._enabled; } /** * Changes whether or not the component connection is enabled. * @param enabled A boolean indicating whether or not the component should be enabled. */ setEnabled(enabled) { this._enabled = !!enabled; if (!this._enabled && this._port !== null) { this._clearPort(); } } /** * Disconnects the current port, but does not disable future connections. */ disconnect() { if (this._port !== null) { this._clearPort(); } } /** * Returns whether or not the connection to the native application is active. * @returns `true` if the connection is active, `false` otherwise. */ isConnected() { return (this._port !== null); } /** * Returns whether or not any invocation is currently active. * @returns `true` if an invocation is active, `false` otherwise. */ isActive() { return (this._invocations.size > 0); } /** * Gets the local API version being used. * @returns An integer representing the API version that Yomichan uses. */ getLocalVersion() { return this._version; } /** * Gets the version of the MeCab component. * @returns The version of the MeCab component, or `null` if the component was not found. */ async getVersion() { try { await this._setupPort(); } catch (e) { // NOP } return this._remoteVersion; } /** * Parses a string of Japanese text into arrays of lines and terms. * * Return value format: * ```js * [ * { * name: (string), * lines: [ * {term: (string), reading: (string), source: (string)}, * ... * ] * }, * ... * ] * ``` * @param text The string to parse. * @returns A collection of parsing results of the text. */ async parseText(text) { await this._setupPort(); const rawResults = await this._invoke('parse_text', {text}); return this._convertParseTextResults(rawResults); } // Private _onMessage({sequence, data}) { const invocation = this._invocations.get(sequence); if (typeof invocation === 'undefined') { return; } const {resolve, timer} = invocation; clearTimeout(timer); resolve(data); this._invocations.delete(sequence); } _onDisconnect() { if (this._port === null) { return; } const e = chrome.runtime.lastError; const error = new Error(e ? e.message : 'MeCab disconnected'); for (const {reject, timer} of this._invocations.values()) { clearTimeout(timer); reject(error); } this._clearPort(); } _invoke(action, params) { return new Promise((resolve, reject) => { if (this._port === null) { reject(new Error('Port disconnected')); } const sequence = this._sequence++; const timer = setTimeout(() => { this._invocations.delete(sequence); reject(new Error(`MeCab invoke timed out after ${this._timeout}ms`)); }, this._timeout); this._invocations.set(sequence, {resolve, reject, timer}, this._timeout); this._port.postMessage({action, params, sequence}); }); } _convertParseTextResults(rawResults) { const results = []; for (const [name, rawLines] of Object.entries(rawResults)) { const lines = []; for (const rawLine of rawLines) { const line = []; for (let {expression: term, reading, source} of rawLine) { if (typeof term !== 'string') { term = ''; } if (typeof reading !== 'string') { reading = ''; } if (typeof source !== 'string') { source = ''; } line.push({term, reading, source}); } lines.push(line); } results.push({name, lines}); } return results; } async _setupPort() { if (!this._enabled) { throw new Error('MeCab not enabled'); } if (this._setupPortPromise === null) { this._setupPortPromise = this._setupPort2(); } try { await this._setupPortPromise; } catch (e) { throw new Error(e.message); } } async _setupPort2() { const port = chrome.runtime.connectNative('yomichan_mecab'); this._eventListeners.addListener(port.onMessage, this._onMessage.bind(this)); this._eventListeners.addListener(port.onDisconnect, this._onDisconnect.bind(this)); this._port = port; try { const {version} = await this._invoke('get_version', {}); this._remoteVersion = version; if (version !== this._version) { throw new Error(`Unsupported MeCab native messenger version ${version}. Yomichan supports version ${this._version}.`); } } catch (e) { if (this._port === port) { this._clearPort(); } throw e; } } _clearPort() { this._port.disconnect(); this._port = null; this._invocations.clear(); this._eventListeners.removeAllEventListeners(); this._sequence = 0; this._setupPortPromise = null; } }