pdfjs-dist/lib/web/view_history.js

/* Copyright 2017 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
'use strict';
var DEFAULT_VIEW_HISTORY_CACHE_SIZE = 20;
var ViewHistory = function ViewHistoryClosure() {
 function ViewHistory(fingerprint, cacheSize) {
  this.fingerprint = fingerprint;
  this.cacheSize = cacheSize || DEFAULT_VIEW_HISTORY_CACHE_SIZE;
  this.isInitializedPromiseResolved = false;
  this.initializedPromise = this._readFromStorage().then(function (databaseStr) {
   this.isInitializedPromiseResolved = true;
   var database = JSON.parse(databaseStr || '{}');
   if (!('files' in database)) {
    database.files = [];
   }
   if (database.files.length >= this.cacheSize) {
    database.files.shift();
   }
   var index;
   for (var i = 0, length = database.files.length; i < length; i++) {
    var branch = database.files[i];
    if (branch.fingerprint === this.fingerprint) {
     index = i;
     break;
    }
   }
   if (typeof index !== 'number') {
    index = database.files.push({ fingerprint: this.fingerprint }) - 1;
   }
   this.file = database.files[index];
   this.database = database;
  }.bind(this));
 }
 ViewHistory.prototype = {
  _writeToStorage: function ViewHistory_writeToStorage() {
   return new Promise(function (resolve) {
    var databaseStr = JSON.stringify(this.database);
    localStorage.setItem('pdfjs.history', databaseStr);
    resolve();
   }.bind(this));
  },
  _readFromStorage: function ViewHistory_readFromStorage() {
   return new Promise(function (resolve) {
    var value = localStorage.getItem('pdfjs.history');
    if (!value) {
     var databaseStr = localStorage.getItem('database');
     if (databaseStr) {
      try {
       var database = JSON.parse(databaseStr);
       if (typeof database.files[0].fingerprint === 'string') {
        localStorage.setItem('pdfjs.history', databaseStr);
        localStorage.removeItem('database');
        value = databaseStr;
       }
      } catch (ex) {
      }
     }
    }
    resolve(value);
   });
  },
  set: function ViewHistory_set(name, val) {
   if (!this.isInitializedPromiseResolved) {
    return;
   }
   this.file[name] = val;
   return this._writeToStorage();
  },
  setMultiple: function ViewHistory_setMultiple(properties) {
   if (!this.isInitializedPromiseResolved) {
    return;
   }
   for (var name in properties) {
    this.file[name] = properties[name];
   }
   return this._writeToStorage();
  },
  get: function ViewHistory_get(name, defaultValue) {
   if (!this.isInitializedPromiseResolved) {
    return defaultValue;
   }
   return this.file[name] || defaultValue;
  }
 };
 return ViewHistory;
}();
exports.ViewHistory = ViewHistory;