08f9718a37
- Ensure that `database.files` actually contains an Array, rather than some arbitrary data. - Only try to lookup an existing entry when the `database` existed on load, since there's obviously nothing to find when `database.files = []` was set (this case is very common in the MOZCENTRAL build since `sessionStorage` is being used there).
108 lines
3.2 KiB
JavaScript
108 lines
3.2 KiB
JavaScript
/* Copyright 2012 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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const DEFAULT_VIEW_HISTORY_CACHE_SIZE = 20;
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/**
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* View History - This is a utility for saving various view parameters for
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* recently opened files.
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*
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* The way that the view parameters are stored depends on how PDF.js is built,
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* for 'gulp <flag>' the following cases exist:
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* - MOZCENTRAL - uses sessionStorage.
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* - GENERIC or CHROME - uses localStorage, if it is available.
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*/
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class ViewHistory {
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constructor(fingerprint, cacheSize = DEFAULT_VIEW_HISTORY_CACHE_SIZE) {
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this.fingerprint = fingerprint;
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this.cacheSize = cacheSize;
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this._initializedPromise = this._readFromStorage().then(databaseStr => {
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const database = JSON.parse(databaseStr || "{}");
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let index = -1;
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if (!Array.isArray(database.files)) {
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database.files = [];
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} else {
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while (database.files.length >= this.cacheSize) {
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database.files.shift();
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}
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for (let i = 0, ii = database.files.length; i < ii; i++) {
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const branch = database.files[i];
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if (branch.fingerprint === this.fingerprint) {
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index = i;
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break;
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}
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}
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}
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if (index === -1) {
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index = database.files.push({ fingerprint: this.fingerprint }) - 1;
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}
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this.file = database.files[index];
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this.database = database;
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});
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}
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async _writeToStorage() {
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const databaseStr = JSON.stringify(this.database);
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if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
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sessionStorage.setItem("pdfjs.history", databaseStr);
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return;
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}
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localStorage.setItem("pdfjs.history", databaseStr);
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}
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async _readFromStorage() {
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if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
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return sessionStorage.getItem("pdfjs.history");
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}
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return localStorage.getItem("pdfjs.history");
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}
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async set(name, val) {
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await this._initializedPromise;
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this.file[name] = val;
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return this._writeToStorage();
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}
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async setMultiple(properties) {
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await this._initializedPromise;
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for (const name in properties) {
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this.file[name] = properties[name];
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}
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return this._writeToStorage();
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}
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async get(name, defaultValue) {
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await this._initializedPromise;
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const val = this.file[name];
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return val !== undefined ? val : defaultValue;
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}
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async getMultiple(properties) {
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await this._initializedPromise;
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const values = Object.create(null);
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for (const name in properties) {
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const val = this.file[name];
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values[name] = val !== undefined ? val : properties[name];
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}
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return values;
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}
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}
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export { ViewHistory };
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