meteor-desktop/skeleton/modules/autoupdate/assetBundle.js

Build a Meteor's desktop client with hot code push.

/**
 This is a slightly modified JS port of hot code push android client from here:
 https://github.com/meteor/cordova-plugin-meteor-webapp

 The MIT License (MIT)

 Copyright (c) 2015 Meteor Development Group

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.

 This file is based on:
 /cordova-plugin-meteor-webapp/blob/master/src/android/AssetBundle.java

 */

import path from 'path';
import fs from 'fs';
import url from 'url';

import AssetManifest from './assetManifest';

/**
 * Represent single asset in the bundle.
 *
 * @property {string} filePath
 * @property {string} urlPath
 * @property {string} fileType
 * @property {number} size
 * @property {bool}   cacheable
 * @property {string} hash
 * @property {string} sourceMapFilePath
 * @property {string} sourceMapUrlPath
 * @property {AssetBundle} bundle
 * @constructor
 */
function Asset(filePath, urlPath, fileType, cacheable, hash, sourceMapUrlPath, size, bundle) {
    this.filePath = filePath;
    this.urlPath = urlPath;
    this.fileType = fileType;
    this.cacheable = cacheable;
    this.hash = hash;
    this.entrySize = size;
    this.sourceMapUrlPath = sourceMapUrlPath;
    this.bundle = bundle;

    this.getFile = function getFile() {
        return path.join(this.bundle.directoryUri, filePath);
    };
}

export default class AssetBundle {
    /**
     * Represents assets bundle.
     *
     * @param {object}         log               - Winston reference.
     * @param {string}         directoryUri      - Where the bundle lies in the file system.
     * @param {AssetManifest=} manifest          - Bundle's manifest.
     * @param {AssetBundle=}   parentAssetBundle - Parent asset bundle.
     * @param {Object=}        desktopVersion    - Object with desktop version and compatibility
     *                                             version.
     * @constructor
     */
    constructor(log, directoryUri, manifest, parentAssetBundle, desktopVersion = {}) {
        this.log = log.getLoggerFor('AssetBundle');
        this.log.verbose(`making bundle object for ${directoryUri}`);

        this.directoryUri = directoryUri;

        this.runtimeConfig = null;
        this.appId = null;
        this.desktopVersion = desktopVersion;
        this.rootUrlString = null;
        this.matcher = new RegExp(
            '__meteor_runtime_config__ = JSON.parse\\(decodeURIComponent\\("([^"]*)"\\)\\)'
        );

        this.parentAssetBundle = parentAssetBundle;

        if (manifest === undefined) {
            this.log.verbose(`loading manifest from ${directoryUri}`);
            this.manifest = this.loadAssetManifest();
        } else {
            this.manifest = manifest;
        }

        this.version = this.manifest.version;
        this.cordovaCompatibilityVersion = this.manifest.cordovaCompatibilityVersion;
        if (!desktopVersion.version) {
            this.log.verbose(`trying to read desktop version for ${this.version}`);
            this.desktopVersion = this.loadDesktopVersion();
            this.log.verbose(`the desktop version is ${this.desktopVersion.version}`);
        } else {
            this.log.debug(`the desktop version was provided by constructor and is ${this.desktopVersion.version}`);
        }

        this.ownAssetsByURLPath = {};

        // Filter assets that are only in this bundle. Rest can be taken from the parent.
        this.manifest.entries.forEach((entry) => {
            const urlPath = url.parse(entry.urlPath).pathname;

            if (parentAssetBundle === undefined
                || parentAssetBundle.cachedAssetForUrlPath(urlPath, entry.hash) === null) {
                this.addAsset(new Asset(
                    entry.filePath,
                    urlPath,
                    entry.fileType,
                    entry.cacheable,
                    entry.hash,
                    entry.sourceMapUrlPath,
                    entry.size,
                    this
                ));
            }

            if (entry.sourceMapFilePath !== null && entry.sourceMapUrlPath !== null) {
                if (parentAssetBundle === undefined ||
                    parentAssetBundle
                        .cachedAssetForUrlPath(entry.sourceMapUrlPath, null) === null) {
                    this.addAsset(new Asset(
                        entry.sourceMapFilePath,
                        entry.sourceMapUrlPath,
                        'json',
                        true,
                        null,
                        null,
                        entry.size,
                        this
                    ));
                }
            }
        });

        const indexFile = new Asset('index.html', '/', 'html', false, null, null, null, this);
        this.addAsset(indexFile);
        this.indexFile = indexFile;
    }

    /**
     * Load this bundle's desktop version if present.
     *
     * @private
     */
    loadDesktopVersion() {
        const desktopVersionPath = path.join(this.directoryUri, '_desktop.json');
        const desktopVersionFallbackPath =
            path.join(this.directoryUri, 'app', 'version.desktop.json');
        try {
            return JSON.parse(fs.readFileSync(desktopVersionPath, 'UTF-8'));
        } catch (e) {
            try {
                return JSON.parse(fs.readFileSync(desktopVersionFallbackPath, 'UTF-8'));
            } catch (err) {
                return {};
            }
        }
    }

    writeDesktopVersion() {
        if (this.desktopVersion.version) {
            fs.writeFileSync(
                path.join(this.directoryUri, '_desktop.json'),
                JSON.stringify(this.desktopVersion, null, '\t')
            );
        }
    }

    /**
     * Get index.html path.
     * @returns {string}
     */
    getIndexFile() {
        return this.indexFile;
    }

    /**
     * Directory uri getter.
     * @returns {string}
     */
    getDirectoryUri() {
        return this.directoryUri;
    }

    /**
     * Parent asset bundle getter.
     * @returns {null|AssetBundle}
     */
    getParentAssetBundle() {
        return this.parentAssetBundle;
    }

    /**
     * Returns an cacheable or hash equal asset.
     *
     * @param {string}      urlPath - The url path of the asset.
     * @param {string|null} hash    - Hash of the asset.
     * @returns {null|Asset}
     */
    cachedAssetForUrlPath(urlPath, hash) {
        if (!(urlPath in this.ownAssetsByURLPath)) return null;
        const asset = this.ownAssetsByURLPath[urlPath];

        // If the asset is not cacheable, we require a matching hash.
        if ((asset.cacheable && hash === null) || (asset.hash !== null && asset.hash === hash)) {
            return asset;
        }

        return null;
    }

    /**
     * Returns an array of own assets.
     *
     * @returns {Array}
     */
    getOwnAssets() {
        return Object.keys(this.ownAssetsByURLPath)
            .reduce((arr, key) => {
                arr.push(this.ownAssetsByURLPath[key]);
                return arr;
            }, []);
    }

    /**
     * Version getter.
     * @returns {string}
     */
    getVersion() {
        return this.version;
    }

    /**
     * Loads runtime config.
     *
     * @returns {Object}
     */
    getRuntimeConfig() {
        if (this.runtimeConfig === null) {
            this.runtimeConfig = this.loadRuntimeConfig(
                path.join(this.directoryUri, this.indexFile.filePath)
            );
        }
        return this.runtimeConfig;
    }

    /**
     * App id getter.
     *
     * @returns {String}
     */
    getAppId() {
        if (this.appId === null) {
            const runtimeConfig = this.getRuntimeConfig();
            if (runtimeConfig !== null) {
                if (!('appId' in runtimeConfig)) {
                    this.log.error('error reading APP_ID from runtime config');
                } else {
                    this.appId = runtimeConfig.appId;
                }
            }
        }
        return this.appId;
    }

    /**
     * Return ROOT_URL from runtime config.
     *
     * @returns {string}
     */
    getRootUrlString() {
        if (this.rootUrlString === null) {
            const runtimeConfig = this.getRuntimeConfig();
            if (runtimeConfig !== null) {
                if (!('ROOT_URL' in runtimeConfig)) {
                    this.log.error('error reading ROOT_URL from runtime config');
                } else {
                    this.rootUrlString = runtimeConfig.ROOT_URL;
                }
            }
        }
        return this.rootUrlString;
    }

    /**
     * Changes bundle directory uri.
     *
     * @param {string} directoryUri - New directory path.
     */
    didMoveToDirectoryAtUri(directoryUri) {
        this.directoryUri = directoryUri;
    }

    /**
     * Returns asset queried by url path.
     * !UNUSED! Left in case of implementation change.
     *
     * @param {string} urlPath - Url path of the asset.
     *
     * @returns {Asset|null}
     */
    assetForUrlPath(urlPath) {
        let asset = null;
        if (urlPath in this.ownAssetsByURLPath) {
            asset = this.ownAssetsByURLPath[urlPath];
        } else if (this.parentAssetBundle) {
            asset = this.parentAssetBundle.assetForUrlPath(urlPath);
        }
        return asset;
    }

    /**
     * Load this bundle's asset manifest.
     *
     * @private
     * @returns {AssetManifest}
     */
    loadAssetManifest() {
        const manifestPath = path.join(this.directoryUri, 'program.json');
        try {
            return new AssetManifest(
                this.log,
                fs.readFileSync(manifestPath, 'UTF-8')
            );
        } catch (e) {
            const msg = `error loading asset manifest: ${e.message}`;
            this.log.error(msg);
            this.log.debug(e);
            throw new Error(msg);
        }
    }

    /**
     * Extracts and parses runtime config.
     * TODO: no negative path errors in case loadRuntimeConfig fails?
     *
     * @param {string} index - Path for index.html.
     * @private
     * @returns {null}
     */
    loadRuntimeConfig(index) {
        let content;
        try {
            content = fs.readFileSync(index, 'UTF-8');
        } catch (e) {
            this.log.error(`error loading index file: ${e.message}`);
            return null;
        }

        if (!this.matcher.test(content)) {
            this.log.error('could not find runtime config in index file');
            return null;
        }

        try {
            const matches = content.match(this.matcher);
            return JSON.parse(decodeURIComponent(matches[1]));
        } catch (e) {
            this.log.error('could not find runtime config in index file');
            return null;
        }
    }

    /**
     * Adds an asset to own assets collection.
     *
     * @param {Asset} asset - Asset to add.
     * @private
     */
    addAsset(asset) {
        this.ownAssetsByURLPath[asset.urlPath] = asset;
    }
}

module.exports = AssetBundle;