kiwix-js-pwa/www/js/lib/cache.js
2024-12-01 22:49:00 +00:00

1031 lines
45 KiB
JavaScript

/**
* cache.js : Provide a cache for assets from the ZIM archive using indexedDB, localStorage or memory cache
*
* Copyright 2018 Mossroy, Jaifroid and contributors
* License GPL v3:
*
* This file is part of Kiwix.
*
* Kiwix 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.
*
* Kiwix 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 Kiwix (file LICENSE-GPLv3.txt). If not, see <http://www.gnu.org/licenses/>
*/
/* globals params, appstate, caches, assetsCache */
'use strict';
import settingsStore from './settingsStore.js';
import uiUtil from './uiUtil.js';
const CACHEAPI = params.cacheAPI; // Set the database or cache name here, and synchronize with Service Worker
const CACHEIDB = params.cacheIDB; // Slightly different name to disambiguate
var objStore = 'kiwix-assets'; // Name of the object store
const APPCACHE = 'kiwix-appCache-' + params.appVersion; // Ensure this is the same as in Service Worker
// DEV: Regex below defines the permitted MIME types for the cache; add further types as needed
var regexpMimeTypes = /\b(?:javascript|css|ico|html)\b/;
/**
* Tests the enviornment's caching capabilities and sets assetsCache.capability to the supported level
*
* @param {Function} callback Function to indicate that the capability level has been set
*/
function test (callback) {
// Test for indexedDB capability
if (typeof assetsCache.capability !== 'undefined') {
callback(true);
return;
}
// Set baseline capability
assetsCache.capability = 'memory';
idxDB('count', function (result) {
if (result !== false) {
assetsCache.capability = 'indexedDB|' + assetsCache.capability;
} else {
console.log('inexedDB is not supported');
}
// Test for Cache API
if ('caches' in window && /https?:/i.test(window.location.protocol)) {
assetsCache.capability = 'cacheAPI|' + assetsCache.capability;
} else {
console.log('CacheAPI is not supported' + (/https?:/i.test(window.location.protocol) ? ''
: ' with the ' + window.location.protocol + ' protocol'));
}
// Test for localCache capability (this is a fallback, indexedDB is preferred because it permits more storage)
if (typeof Storage !== 'undefined') {
try {
// If localStorage is really supported, this won't produce an error
// eslint-disable-next-line no-unused-vars
var item = window.localStorage.length;
assetsCache.capability = assetsCache.capability + '|localStorage';
} catch (err) {
console.log('localStorage is not supported');
}
}
console.log('Setting storage type to ' + assetsCache.capability.match(/^[^|]+/)[0]);
if (/localStorage/.test(assetsCache.capability)) {
console.debug("DEV: 'UnknownError' may be produced as part of localStorage capability detection");
}
callback(result);
});
}
/**
* Counts the numnber of cached assets
*
* @param {Function} callback which will receive an array containing [cacheType, cacheCount]
*/
function count (callback) {
test(function (result) {
var type = null;
var description = null;
var cacheCount = null;
switch (assetsCache.capability.match(/^[^|]+/)[0]) {
case 'memory':
type = 'memory';
description = 'Memory';
cacheCount = assetsCache.size;
break;
case 'localStorage':
type = 'localStorage';
description = 'LocalStorage';
cacheCount = localStorage.length;
break;
case 'indexedDB':
type = 'indexedDB';
description = 'IndexedDB';
// Sometimes we already have the count as a result of test, so no need to look again
if (typeof result !== 'boolean' && (result === 0 || result > 0)) {
cacheCount = result;
} else {
idxDB('count', function (cacheCount) {
callback({ type: type, description: description, count: cacheCount });
});
}
break;
case 'cacheAPI':
type = 'cacheAPI';
description = 'CacheAPI';
caches.open(CACHEAPI).then(function (cache) {
cache.keys().then(function (keys) {
callback({ type: type, description: description, count: keys.length });
});
});
break;
default:
// User has turned off caching
type = 'none';
description = 'None';
cacheCount = 'null';
}
if (cacheCount || cacheCount === 0) {
callback({ type: type, description: description, count: cacheCount });
}
});
// Refresh instructions to Service Worker
if (navigator.serviceWorker && navigator.serviceWorker.controller) {
// Create a Message Channel
var channel = new MessageChannel();
navigator.serviceWorker.controller.postMessage({
action: {
assetsCache: params.assetsCache && params.contentInjectionMode === 'serviceworker' ? 'enable' : 'disable',
appCache: params.appCache ? 'enable' : 'disable',
checkCache: window.location.href
}
}, [channel.port2]);
}
}
/**
* Opens an IndexedDB database and adds or retrieves a key-value pair to it, or performs utility commands
* on the database
*
* @param {String} keyOrCommand The key of the value to be written or read, or commands 'clear' (clears objStore),
* 'count' (counts number of objects in objStore), 'delete' (deletes a record with key passed in valueOrCallback),
* 'deleteNonCurrent' (deletes all databases that do not match CACHEIDB - but only works in Chromium currently)
* @param {Variable} valueOrCallback The value to write, or a callback function for read and command transactions
* @param {Function} callback Callback for write transactions only - mandatory for delete and write transactions
*/
function idxDB (keyOrCommand, valueOrCallback, callback) {
var value = callback ? valueOrCallback : null;
var rtnFn = callback || valueOrCallback;
if (typeof window.indexedDB === 'undefined') {
rtnFn(false);
return;
}
// Delete all non-curren IdxDB databases (only works in Chromium currently)
if (keyOrCommand === 'deleteNonCurrent') {
if (indexedDB.databases) {
var result = 0;
indexedDB.databases().then(function (dbs) {
dbs.forEach(function (db) {
if (db.name !== CACHEIDB) {
result++;
indexedDB.deleteDatabase(db.name);
}
});
}).then(function () {
rtnFn(result);
});
} else {
rtnFn(false);
}
return;
}
// Open (or create) the database
var open = indexedDB.open(CACHEIDB, 1);
open.onerror = function (e) {
// Suppress error reporting if testing (older versions of Firefox support indexedDB but cannot use it with
// the file:// protocol, so will report an error)
if (assetsCache.capability !== 'test') {
console.error('IndexedDB failed to open: ' + open.error.message);
}
rtnFn(false);
};
// Create the schema
open.onupgradeneeded = function () {
var db = open.result;
// eslint-disable-next-line no-unused-vars
var store = db.createObjectStore(objStore);
};
open.onsuccess = function () {
// Start a new transaction
var db = open.result;
// Set the store to readwrite or read only according to presence or not of value variable
var tx = value !== null || /clear|delete/.test(keyOrCommand) ? db.transaction(objStore, 'readwrite') : db.transaction(objStore);
var store = tx.objectStore(objStore);
var processData;
// Process commands
if (keyOrCommand === 'clear') {
// Delete all keys and values in the store
processData = store.clear();
} else if (keyOrCommand === 'count') {
// Count the objects in the store
processData = store.count();
} else if (keyOrCommand === 'delete') {
// Delete the record with key set to value
processData = store.delete(value);
} else {
// Request addition or retrieval of data
processData = value !== null ? store.put(value, keyOrCommand) : store.get(keyOrCommand);
}
// Call the callback with the result
processData.onsuccess = function (e) {
if (keyOrCommand === 'delete') {
rtnFn(true);
} else {
rtnFn(processData.result);
}
};
processData.onerror = function (e) {
console.error('IndexedDB command failed: ' + processData.error);
rtnFn(false);
};
// Close the db when the transaction is done
tx.oncomplete = function () {
db.close();
};
};
}
/**
* Opens a CacheAPI cache and adds or retrieves a key-value pair to it, or performs utility commands
* on the cache. This interface also allows the use of callbacks inside the Cache Promise API for ease of
* interoperability with the interface for idxDB code above.
*
* @param {String} keyOrCommand The key of the value to be written or read, or commands 'clear' (clears cache),
* 'delete' (deletes a record with key passed in valueOrCallback)
* @param {Variable} valueOrCallback The value to write, or a callback function for read and command transactions
* @param {Function} callback Callback for write transactions only
* @param {String} mimetype The MIME type of any content to be stored
*/
function cacheAPI (keyOrCommand, valueOrCallback, callback, mimetype) {
var value = callback ? valueOrCallback : null;
var rtnFn = callback || valueOrCallback;
// Process commands
if (keyOrCommand === 'clear') {
caches.delete(CACHEAPI).then(rtnFn);
} else if (keyOrCommand === 'delete') {
caches.open(CACHEAPI).then(function (cache) {
cache.delete(value).then(rtnFn);
});
} else if (value === null) {
// Request retrieval of data
caches.open(CACHEAPI).then(function (cache) {
cache.match('../' + keyOrCommand).then(function (response) {
if (!response) {
rtnFn(null);
} else {
response.text().then(function (data) {
rtnFn(data);
});
}
}).catch(function (err) {
console.error('Unable to match assets from Cache API!', err);
rtnFn(null);
});
});
} else {
// Request storing of data in cache
caches.open(CACHEAPI).then(function (cache) {
var contentLength;
if (typeof value === 'string') {
var m = encodeURIComponent(value).match(/%[89ABab]/g);
contentLength = value.length + (m ? m.length : 0);
} else {
contentLength = value.byteLength || value.length;
}
var headers = new Headers();
if (contentLength) headers.set('Content-Length', contentLength);
// Prevent CORS issues in PWAs
// if (contentLength) headers.set('Access-Control-Allow-Origin', '*');
headers.set('Content-Security-Policy', 'sandbox allow-scripts allow-same-origin allow-modals allow-popups allow-forms');
if (mimetype) headers.set('Content-Type', mimetype);
var responseInit = {
status: 200,
statusText: 'OK',
headers: headers
};
var httpResponse = new Response(value, responseInit);
cache.put('../' + keyOrCommand, httpResponse).then(function () {
rtnFn(true);
}).catch(function (err) {
console.error('Unable to store assets in Cache API!', err);
rtnFn(null);
});
});
}
}
/**
* Stores information about the last visited page in a cookie and, if available, in localStorage or indexedDB
*
* @param {String} zimFile The filename (or name of first file in set) of the ZIM archive
* @param {String} article The URL of the article (including namespace)
* @param {String} content The content of the page to be stored
* @param {Function} callback Callback function to report the outcome of the operation
*/
function setArticle (zimFile, article, content, callback) {
// Prevent storage if user has deselected the option in Configuration
if (!params.rememberLastPage) {
callback(-1);
return;
}
settingsStore.setItem(zimFile, article, Infinity);
setItem(zimFile, content, 'text/html', function (response) {
callback(response);
});
}
/**
* Retrieves article contents from cache only if the article's key has been stored in settings store
* (since checking the store is synchronous, it prevents unnecessary async cache lookups)
*
* @param {String} zimFile The filename (or name of first file in set) of the ZIM archive
* @param {String} article The URL of the article to be retrieved (including namespace)
* @param {Function} callback The function to call with the result
*/
function getArticle (zimFile, article, callback) {
if (settingsStore.getItem(zimFile) === article) {
getItem(zimFile, callback);
} else {
callback(false);
}
}
/**
* Caches the contents of an asset in memory or local storage
*
* @param {String} key The database key of the asset to cache
* @param {String} contents The file contents to be stored in the cache
* @param {String} mimetype The MIME type of the contents
* @param {Function} callback Callback function to report outcome of operation
* @param {Boolean} isAsset Optional indicator that a file is an asset
*/
function setItem (key, contents, mimetype, callback, isAsset) {
// Prevent use of storage if user has deselected the option in Configuration
// or if the asset is of the wrong type
if (params.assetsCache === false || !regexpMimeTypes.test(mimetype)) {
callback(-1);
return;
}
// Check if we're actually setting an article
// DEV: This code seems to cause more trouble than it's worth with zimit-based archives
// The code remembers the last loaded article for each ZIM, but because zimit archives often load assets which are misclassified as html MIME types,
// the code below ends up caching an "article" which cannot in fact be loaded as an article
if (!/zimit/.test(params.zimType)) {
var keyArticle = key.match(/([^/]+)\/([AC]\/.+$)/);
if (keyArticle && !isAsset && /\bx?html\b/i.test(mimetype) && !/\.(png|gif|jpe?g|css|js|mpe?g|webp|webm|woff2?|eot|mp[43])(\?|$)/i.test(key)) { // We're setting an article, so go to setArticle function
setArticle(keyArticle[1], keyArticle[2], contents, callback);
return;
}
}
if (/^localStorage/.test(assetsCache.capability)) {
localStorage.setItem(key, contents);
} else {
assetsCache.set(key, contents);
}
if (/^indexedDB/.test(assetsCache.capability)) {
idxDB(key, contents, function (result) {
callback(result);
});
} else if (/^cacheAPI/.test(assetsCache.capability)) {
cacheAPI(key, contents, function (result) {
callback(result);
}, mimetype);
} else {
callback(key);
}
}
/**
* Retrieves a ZIM file asset that has been cached with the addItem function
* either from the memory cache or local storage
*
* @param {String} key The database key of the asset to retrieve
* @param {Function} callback The function to call with the result
*/
function getItem (key, callback) {
// Only look up assets of the type stored in the cache
if (params.assetsCache === false) {
callback(false);
return;
}
// Check if we're actually calling an article
// DEV: With new ZIM types, we can't know we're retrieving an article...
// var keyArticle = key.match(/([^/]+)\/(A\/.+$)/);
// if (keyArticle) { // We're retrieving an article, so go to getArticle function
// getArticle(keyArticle[1], keyArticle[2], callback);
// return;
// }
var contents = null;
if (assetsCache.has(key)) {
contents = assetsCache.get(key);
callback(contents);
} else if (/^localStorage/.test(assetsCache.capability)) {
contents = localStorage.getItem(key);
callback(contents);
} else if (/^cacheAPI/.test(assetsCache.capability)) {
cacheAPI(key, function (contents) {
callback(contents);
});
} else if (/^indexedDB/.test(assetsCache.capability)) {
idxDB(key, function (contents) {
if (typeof contents !== 'undefined') {
// Also store in fast memory cache to prevent repaints
assetsCache.set(key, contents);
}
callback(contents);
});
} else {
callback(contents);
}
}
/**
* Gets an item from the cache, or extracts it from the ZIM if it is not cached. After extracting
* an item from the ZIM, it is added to the cache if it is of the type specified in regexpKeyTypes.
*
* @param {Object} selectedArchive The ZIM archive picked by the user
* @param {String} key The cache key of the item to retrieve
* @param {Object} dirEntry If the item's dirEntry has already been looked up, it can optionally be
* supplied here (saves a redundant dirEntry lookup)
* @returns {Promise<String|Uint8Array>} A Promise for the content
*/
function getItemFromCacheOrZIM (selectedArchive, key, dirEntry) {
return new Promise(function (resolve, reject) {
// First check if the item is already in the cache
var title = key.replace(/^[^/]+\//, '');
getItem(key, function (result) {
if (result !== null && result !== false && typeof result !== 'undefined') {
// console.debug("Cache supplied " + title);
if (/\.css$/.test(title)) {
assetsCache.cssLoading--;
if (assetsCache.cssLoading <= 0) {
document.getElementById('articleContent').style.display = '';
}
}
resolve(result);
return;
}
// Bypass getting dirEntry if we already have it
var getDirEntry = dirEntry ? function () { return Promise.resolve(dirEntry); }
: selectedArchive['getDirEntryByPath'];
// Read data from ZIM
getDirEntry(title).then(function (resolvedDirEntry) {
if (resolvedDirEntry === null) {
console.log('Error: asset file not found: ' + title);
resolve(null);
} else {
var mimetype = resolvedDirEntry.getMimetype();
if (resolvedDirEntry.nullify) {
console.debug('Zimit filter prevented access to ' + resolvedDirEntry.url + '. Storing empty contents in cache.');
setItem(key, '', mimetype, function () {});
resolve('');
return;
}
var shortTitle = key.replace(/[^/]+\//g, '').substring(0, 18);
// Since there was no result, post UI messages and look up asset in ZIM
if (/\bx?html\b/.test(mimetype) && !resolvedDirEntry.isAsset &&
!/\.(png|gif|jpe?g|svg|css|js|mpe?g|webp|webm|woff2?|eot|mp[43])(\?|$)/i.test(resolvedDirEntry.url)) {
uiUtil.pollSpinner('Loading ' + shortTitle + '...');
} else if (/(css|javascript|video|vtt)/i.test(mimetype)) {
uiUtil.pollSpinner('Getting ' + shortTitle + '...');
}
// Set the read function to use according to filetype
var readFile = /\b(?:x?html|css|javascript)\b/i.test(mimetype)
? selectedArchive['readUtf8File'] : selectedArchive['readBinaryFile'];
readFile(resolvedDirEntry, function (fileDirEntry, content) {
if (!fileDirEntry && !content) {
console.warn('Could not read asset ' + title);
return;
}
if (regexpMimeTypes.test(mimetype)) {
console.debug('Cache retrieved ' + title + ' from ZIM');
// Process any pre-cache transforms
content = transform(content, title.replace(/^.*\.([^.]+)$/, '$1'));
}
// Hide article while it is rendering
if (!fileDirEntry.isAsset && /\bx?html\b/i.test(mimetype) && !/\.(png|gif|jpe?g|svg|css|js|mpe?g|webp|webm|woff2?|eot|mp[34])(\?|$)/i.test(key)) {
// Count CSS so we can attempt to show article before JS/images are fully loaded
var cssCount = content.match(/<(?:link)[^>]+?href=["']([^"']+)[^>]+>/ig);
assetsCache.cssLoading = cssCount ? cssCount.length : 0;
if (assetsCache.cssLoading && appstate.target === 'iframe') document.getElementById('articleContent').style.display = 'none';
}
if (/\bcss\b/i.test(mimetype)) {
assetsCache.cssLoading--;
if (assetsCache.cssLoading <= 0) {
document.getElementById('articleContent').style.display = '';
}
}
setItem(key, content, mimetype, function (result) {
if (result === -1) {
// Cache rejected item due to user settings
} else if (result) {
console.log('Cache: stored asset ' + title);
} else {
console.error('Cache: failed to store asset ' + title);
}
}, fileDirEntry.isAsset);
resolve(content);
});
}
}).catch(function (e) {
reject(new Error('Could not find DirEntry for asset ' + title, e));
});
});
});
}
/**
* Clears caches (including cookie) according to the scope represented by the 'items' variable
*
* @param {String} items 'lastpages' (last visited pages of various archives), 'all' or 'reset'
* @param {Function} callback Callback function to report the number of items cleared
*/
function clear (items, callback) {
if (!/lastpages|all|reset/.test(items)) {
if (callback) callback(false);
return;
}
// Delete cookie entries with a key containing '.zim' or '.zimaa' etc. followed by article namespace
var itemsCount = 0;
var key;
var capability = assetsCache.capability;
var zimRegExp = /(?:^|;)\s*([^=]+)=([^;]*)/ig;
var currentCookies = document.cookie;
var cookieCrumb = zimRegExp.exec(currentCookies);
while (cookieCrumb !== null) {
if (/\.zim\w{0,2}=/i.test(decodeURIComponent(cookieCrumb[0]))) {
key = cookieCrumb[1];
// This expiry date will cause the browser to delete the cookie on next page refresh
document.cookie = key + '=;expires=Thu, 21 Sep 1979 00:00:01 UTC;';
if (items === 'lastpages') {
assetsCache.delete(key);
// See note on loose test below
if (/localStorage/.test(capability)) {
localStorage.removeItem(key);
}
if (/indexedDB/.test(capability)) {
idxDB('delete', key, function () {});
}
if (/cacheAPI/.test(capability)) {
cacheAPI('delete', key, function () {});
}
itemsCount++;
}
}
cookieCrumb = zimRegExp.exec(currentCookies);
}
if (items === 'all' || items === 'reset') {
var result;
if (/^(memory|indexedDB|cacheAPI)/.test(capability)) {
itemsCount += assetsCache.size;
result = 'assetsCache';
}
// Delete and reinitialize assetsCache
assetsCache = new Map();
assetsCache.capability = capability;
// Loose test here ensures we clear localStorage even if it wasn't being used in this session
if (/localStorage/.test(capability)) {
if (items === 'reset') {
itemsCount += localStorage.length;
localStorage.clear();
} else {
for (var i = localStorage.length; i--;) {
key = localStorage.key(i);
if (/\.zim\w{0,2}/i.test(key)) {
localStorage.removeItem(key);
itemsCount++;
}
}
}
result = result ? result + ' and localStorage' : 'localStorage';
}
// Loose test here ensures we clear indexedDB even if it wasn't being used in this session
if (/indexedDB/.test(capability)) {
result = result ? result + ' and indexedDB' : 'indexedDB';
idxDB('count', function (number) {
itemsCount += number;
idxDB('clear', function () {
result = result ? result + ' (' + itemsCount + ' items deleted)' : 'no assets to delete';
console.log('cache.clear: ' + result);
if (!/^cacheAPI/.test(capability) && callback) callback(itemsCount);
});
});
}
// No need to use loose test here because cacheAPI trumps the others
if (/^cacheAPI/.test(capability)) {
result = result ? result + ' and cacheAPI' : 'cacheAPI';
count(function (number) {
itemsCount += number[1];
cacheAPI('clear', function () {
result = result ? result + ' (' + itemsCount + ' items deleted)' : 'no assets to delete';
console.log('cache.clear: ' + result);
if (callback) callback(itemsCount);
});
});
}
}
if (!/^cacheAPI|indexedDB/.test(capability)) {
result = result ? result + ' (' + itemsCount + ' items deleted)' : 'no assets to delete';
console.log('cache.clear: ' + result);
if (callback) callback(itemsCount);
}
}
/**
* Replaces all assets that have the given attribute in the html string with inline tags containing content
* from the cache entries corresponding to the given zimFile
* Function is intended for link or script tags, but could be extended
* Returns the substituted html in the callback function (even if no substitutions were made)
*
* @param {String} html The html string to process
* @param {String} tags The html tag or tags ('link|script') containing the asset to replace;
* multiple tags must be separated with a pipe
* @param {String} attribute The attribute that stores the URL to be substituted
* @param {String} zimFile The name of the ZIM file (or first file in the file set)
* @param {Object} selectedArchive The archive selected by the user in app.js
* @param {Function} callback The function to call with the substituted html
*/
function replaceAssetRefsWithUri (html, tags, attribute, zimFile, selectedArchive, callback) {
// Creates an array of all link tags that have the given attribute
var regexpTagsWithAttribute = new RegExp('<(?:' + tags + ')[^>]+?' + attribute + '=["\']([^"\']+)[^>]+>', 'ig');
var titles = [];
var tagArray = regexpTagsWithAttribute.exec(html);
while (tagArray !== null) {
titles.push([tagArray[0],
decodeURIComponent(tagArray[1])]);
tagArray = regexpTagsWithAttribute.exec(html);
}
if (!titles.length) {
callback(html);
}
// Iterate through the erray of titles, populating the HTML string with substituted tags containing
// a reference to the content from the Cache or from the ZIM
assetsCache.busy = titles.length;
titles.forEach(function (title) {
getItemFromCacheOrZIM(selectedArchive, zimFile + '/' + title[1], function (assetContent) {
assetsCache.busy--;
if (assetContent || assetContent === '') {
var newAssetTag = uiUtil.createNewAssetElement(title[0], attribute, assetContent);
html = html.replace(title[0], newAssetTag);
}
if (!assetsCache.busy) callback(html);
});
});
}
/**
* Provides "Server Side" transformation of textual content "served" to app.js
* For performance reasons, this is only hooked into content extracted from the ZIM: the transformed
* content will then be cached in its transformed state
*
* @param {String} string The string to transform
* @param {String} filter An optional filter: only transforms which match the filter will be executed
* @returns {String} The tranformed content
*/
function transform (string, filter) {
switch (filter) {
case 'html':
// Filter to remove any BOM (causes quirks mode in browser)
string = string.replace(/^[^<]*/, '');
// Filter to open all heading sections
string = string.replace(/(class=["'][^"']*?collapsible-(?:heading|block)(?!\s+open-block))/g,
'$1 open-block');
break;
}
return string;
}
/**
* Provide method to verify File System Access API permissions
*
* @param {Object} fileHandle The file handle that we wish to verify with the Native Filesystem API
* @param {Boolean} withWrite Indicates read only or read/write persmissions
* @returns {Promise<Boolean>} A Promise for a Boolean value indicating whether permission has been granted or not
*/
function verifyPermission (fileHandle, withWrite) {
if (params.useOPFS) return Promise.resolve(true); // No permission prompt required for OPFS
var opts = withWrite ? { mode: 'readwrite' } : {};
return fileHandle.queryPermission(opts).then(function (permission) {
if (permission === 'granted') return true;
return fileHandle.requestPermission(opts).then(function (permission) {
if (permission === 'granted') return true;
console.error('Permission for ' + fileHandle.name + ' was not granted: ' + permission);
return false;
}).catch(function (error) {
console.warn('Cannot use previously picked file handle programmatically (this is normal) ' + fileHandle.name, error);
});
});
}
/**
* Download an archive directly into the picked folder (primarily for use with the Origin Private File System)
*
* @param {String} archiveName The name of the archive to download (will be used as the filename)
* @param {String} archiveUrl An optional URL to download the archive from (if not supplied, will use params.kiwixDownloadServer)
* @param {Function} callback Callback function to report the progress of the download
* @returns {Promise<FileSystemFileHandle>} A Promise for a FileHandle object representing the downloaded file
*/
function downloadArchiveToPickedFolder (archiveName, archiveUrl, callback) {
archiveUrl = archiveUrl || params.kiwixDownloadServer + archiveName;
if (params.pickedFolder && params.pickedFolder.getFileHandle) {
return verifyPermission(params.pickedFolder, true).then(function (permission) {
if (permission) {
return params.pickedFolder.getFileHandle(archiveName, { create: true }).then(function (fileHandle) {
return fileHandle.createWritable().then(function (writer) {
return fetch(archiveUrl).then(function (response) {
if (!response.ok) {
return writer.close().then(function () {
// Delete the file
params.pickedFolder.removeEntry(archiveName).then(function () {
throw new Error('HTTP error, status = ' + response.status);
});
});
}
var loaded = 0;
var reported = 0;
return new Response(
new ReadableStream({
start: function (controller) {
var reader = response.body.getReader();
var processResult = function (result) {
if (result.done) {
return controller.close();
}
loaded += result.value.byteLength;
if (loaded - reported >= 1048576) { // 1024 * 1024
reported = loaded;
if (callback) {
callback(reported);
} else console.debug('Downloaded ' + reported + ' bytes so far...');
}
controller.enqueue(result.value);
return reader.read().then(processResult);
};
return reader.read().then(processResult);
}
})
).body.pipeTo(writer).then(function () {
if (callback) callback('completed');
return true;
}).catch(function (err) {
console.error('Error downloading archive', err);
if (callback) callback('error');
writer.close().then(function () {
// Delete the file
params.pickedFolder.removeEntry(archiveName).then(function () {
throw err;
});
});
});
});
});
});
} else {
throw (new Error('Write permission not granted!'));
}
}).catch(function (err) {
console.error('Error downloading archive', err);
throw err;
});
} else {
return Promise.reject(new Error('No picked folder available!'));
}
}
/**
* Imports the picked files into the OPFS file system
*
* @param {Array} files An array of File objects to import
*/
function importOPFSEntries (files) {
return Promise.all(files.map(function (file) {
return params.pickedFolder.getFileHandle(file.name, { create: true }).then(function (fileHandle) {
return fileHandle.createWritable().then(function (writer) {
uiUtil.pollOpsPanel('<span class="glyphicon glyphicon-refresh spinning"></span>&emsp;<b>Please wait:</b> Importing ' + file.name + '...', true);
return writer.write(file).then(function () {
uiUtil.pollOpsPanel('<span class="glyphicon glyphicon-refresh spinning"></span>&emsp;<b>Please wait:</b> Imported ' + file.name + '...', true);
return writer.close();
});
});
});
}));
}
/**
* Exports an entry from the OPFS file system to the user-visible file system
*
* @param {String} name The filename of the entry to export
* @returns {Promise<Boolean>} A Promise for a Boolean value indicating whether the export was successful
*/
function exportOPFSEntry (name) {
if (navigator && navigator.storage && 'getDirectory' in navigator.storage) {
return navigator.storage.getDirectory().then(function (dir) {
return dir.getFileHandle(name).then(function (fileHandle) {
try {
// Obtain a file handle to a new file in the user-visible file system
// with the same name as the file in the origin private file system.
return window.showSaveFilePicker({
suggestedName: fileHandle.name || ''
}).then(function (saveHandle) {
return saveHandle.createWritable().then(function (writable) {
return fileHandle.getFile().then(function (file) {
return writable.write(file).then(function () {
writable.close();
return true;
});
});
});
});
} catch (err) {
console.error(err.name, err.message);
return false;
}
}).catch(function (err) {
console.error('Unable to get file handle from OPFS', err);
return false;
});
}).catch(function (err) {
console.error('Unable to get directory from OPFS', err);
return false;
});
}
}
/**
* Deletes an entry from the OPFS file system
*
* @param {String} name The filename of the entry to delete
*/
function deleteOPFSEntry (name) {
if (navigator && navigator.storage && 'getDirectory' in navigator.storage) {
return navigator.storage.getDirectory().then(function (dirHandle) {
return iterateOPFSEntries().then(function (entries) {
var baseName = name.replace(/\.zim[^.]*$/i, '');
entries.forEach(function (entry) {
if (~entry.indexOf(baseName)) {
return dirHandle.removeEntry(entry).then(function () {
console.log('Deleted ' + entry + ' from OPFS');
populateOPFSStorageQuota();
}).catch(function (err) {
console.error('Unable to delete ' + entry + ' from OPFS', err);
});
}
});
}).catch(function (err) {
console.error('Unable to get directory from OPFS', err);
});
}).catch(function (err) {
console.error('Unable to get directory from OPFS', err);
});
}
}
/**
* Iterates an iterable entry list of files using the File System API and returns an array of entries found
*
* @param {Iterator} entries An asychronous iterator of entries derived from a directory handle
* @param {Array} archives An array to which to add the entries (may be an empty array)
* @param {Boolean} noFilter An optional flag to indicate that no filtering should be applied to the entries
* @returns {Promise<Array>} A Promise for an array of entries in the file system directory
*/
function iterateAsyncDirEntries (entries, archives, noFilter) {
return entries.next().then(function (result) {
if (!result.done) {
var entry = result.value[1];
if (/\.zim(\w\w)?$/.test(entry.name)) {
if (noFilter) archives.push(entry);
// Hide all parts of split file except first in UI
else if (/\.zim(aa)?$/.test(entry.name)) archives.push(entry.name);
// In an Electron app, we should be able to get the path of the files
if (window.fs && !params.pickedFolder.path) {
entry.getFile().then(function (file) {
params.pickedFolder.path = file.path;
});
}
}
return iterateAsyncDirEntries(entries, archives, noFilter);
} else {
// We've processed all the entries
return archives;
}
}).catch(function (err) {
throw err;
});
}
/**
* Iterates the OPFS file system and returns an array of entries found
*
* @returns {Promise<Array>} A Promise for an array of entries in the OPFS file system
*/
function iterateOPFSEntries () {
if (navigator && navigator.storage && 'getDirectory' in navigator.storage) {
return navigator.storage.getDirectory().then(function (dirHandle) {
var entries = dirHandle.entries();
return iterateAsyncDirEntries(entries, []).then(function (archiveList) {
return archiveList;
}).catch(function (err) {
console.error('Unable to iterate OPFS entries', err);
throw err;
});
});
}
}
/**
* Gets the OPFS storage quota and populates the OPFSQuota panel
*
* @returns {Promise} A Promise that populates the OPFSQuota panel
*/
function populateOPFSStorageQuota () {
if (navigator && navigator.storage && ('estimate' in navigator.storage)) {
return navigator.storage.estimate().then(function (estimate) {
var percent = ((estimate.usage / estimate.quota) * 100).toFixed(2);
appstate.OPFSQuota = estimate.quota - estimate.usage;
document.getElementById('OPFSQuota').innerHTML =
'<b>OPFS storage quota:</b><br />Used:&nbsp;<b>' + percent + '%</b>; Remaining:&nbsp;<b>' +
(appstate.OPFSQuota / 1024 / 1024 / 1024).toFixed(2) + '&nbsp;GB</b>';
});
}
}
/**
* Request persistent storage for the app
* This function should be called when OPFS access is first requested
*
* @returns {Promise} A Promise that resolves when persistent storage is granted
*/
function requestPersistentStorage () {
if (navigator.storage && navigator.storage.persist) {
return navigator.storage.persisted().then(function (isPersisted) {
if (!isPersisted) {
return navigator.storage.persist().then(function (permission) {
if (permission) {
console.log('Persistent Storage granted.');
} else {
console.warn('Persistent Storage denied (this is normal in Chromium browsers).');
}
return true;
});
} else {
console.debug('Persistent Storage already granted.');
return true;
}
});
} else {
console.warn('Persistent Storage API not supported!');
return Promise.resolve(false);
}
}
/**
* Wraps a semaphor in a Promise. A function can signal that it is done by setting a sempahor to true,
* if it has first set it to false at the outset of the procedure. Ensure no other functions use the same
* sempahor. The semaphor must be an object key of the app-wide assetsCache object.
*
* @param {String} semaphor The name of a semaphor key in the assetsCache object
* @param {String|Object} value An optional value or object to pass in the resolved promise
* @returns {Promise} A promise that resolves when assetsCache[semaphor] is true
*/
function wait (semaphor, value) {
var p = new Promise(function (resolve) {
setTimeout(function awaitCache () {
if (assetsCache[semaphor]) {
return resolve(value);
}
setTimeout(awaitCache, 300);
}, 0);
});
return p;
}
export default {
APPCACHE: APPCACHE,
CACHEAPI: CACHEAPI,
test: test,
count: count,
idxDB: idxDB,
cacheAPI: cacheAPI,
setArticle: setArticle,
getArticle: getArticle,
setItem: setItem,
getItem: getItem,
clear: clear,
wait: wait,
getItemFromCacheOrZIM: getItemFromCacheOrZIM,
replaceAssetRefsWithUri: replaceAssetRefsWithUri,
verifyPermission: verifyPermission,
downloadArchiveToPickedFolder: downloadArchiveToPickedFolder,
importOPFSEntries: importOPFSEntries,
exportOPFSEntry: exportOPFSEntry,
deleteOPFSEntry: deleteOPFSEntry,
iterateAsyncDirEntries: iterateAsyncDirEntries,
iterateOPFSEntries: iterateOPFSEntries,
populateOPFSStorageQuota: populateOPFSStorageQuota,
requestPersistentStorage: requestPersistentStorage
};