pdf.js/src/display/api.js

/* Copyright 2012 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.
 */
/* globals pdfjsFilePath, pdfjsVersion, pdfjsBuild, requirejs, pdfjsLibs,
           __webpack_require__ */

'use strict';

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define('pdfjs/display/api', ['exports', 'pdfjs/shared/util',
      'pdfjs/display/font_loader', 'pdfjs/display/canvas',
      'pdfjs/display/metadata', 'pdfjs/display/dom_utils',
      'require'], factory);
  } else if (typeof exports !== 'undefined') {
    factory(exports, require('../shared/util.js'), require('./font_loader.js'),
      require('./canvas.js'), require('./metadata.js'),
      require('./dom_utils.js'));
  } else {
    factory((root.pdfjsDisplayAPI = {}), root.pdfjsSharedUtil,
      root.pdfjsDisplayFontLoader, root.pdfjsDisplayCanvas,
      root.pdfjsDisplayMetadata, root.pdfjsDisplayDOMUtils);
  }
}(this, function (exports, sharedUtil, displayFontLoader, displayCanvas,
                  displayMetadata, displayDOMUtils, amdRequire) {

var InvalidPDFException = sharedUtil.InvalidPDFException;
var MessageHandler = sharedUtil.MessageHandler;
var MissingPDFException = sharedUtil.MissingPDFException;
var PageViewport = sharedUtil.PageViewport;
var PasswordResponses = sharedUtil.PasswordResponses;
var PasswordException = sharedUtil.PasswordException;
var StatTimer = sharedUtil.StatTimer;
var UnexpectedResponseException = sharedUtil.UnexpectedResponseException;
var UnknownErrorException = sharedUtil.UnknownErrorException;
var Util = sharedUtil.Util;
var createPromiseCapability = sharedUtil.createPromiseCapability;
var error = sharedUtil.error;
var deprecated = sharedUtil.deprecated;
var getVerbosityLevel = sharedUtil.getVerbosityLevel;
var info = sharedUtil.info;
var isInt = sharedUtil.isInt;
var isArray = sharedUtil.isArray;
var isArrayBuffer = sharedUtil.isArrayBuffer;
var isSameOrigin = sharedUtil.isSameOrigin;
var loadJpegStream = sharedUtil.loadJpegStream;
var stringToBytes = sharedUtil.stringToBytes;
var globalScope = sharedUtil.globalScope;
var warn = sharedUtil.warn;
var FontFaceObject = displayFontLoader.FontFaceObject;
var FontLoader = displayFontLoader.FontLoader;
var CanvasGraphics = displayCanvas.CanvasGraphics;
var createScratchCanvas = displayCanvas.createScratchCanvas;
var Metadata = displayMetadata.Metadata;
var getDefaultSetting = displayDOMUtils.getDefaultSetting;

var DEFAULT_RANGE_CHUNK_SIZE = 65536; // 2^16 = 65536

var isWorkerDisabled = false;
var workerSrc;
var isPostMessageTransfersDisabled = false;

var fakeWorkerFilesLoader = null;
var useRequireEnsure = false;
if (typeof PDFJSDev !== 'undefined' &&
    PDFJSDev.test('GENERIC && !SINGLE_FILE')) {
  // For GENERIC build we need add support of different fake file loaders
  // for different  frameworks.
  if (typeof window === 'undefined') {
    // node.js - disable worker and set require.ensure.
    isWorkerDisabled = true;
    if (typeof require.ensure === 'undefined') {
      require.ensure = require('node-ensure');
    }
    useRequireEnsure = true;
  }
  if (typeof __webpack_require__ !== 'undefined') {
    useRequireEnsure = true;
  }
  if (typeof requirejs !== 'undefined' && requirejs.toUrl) {
    workerSrc = requirejs.toUrl('pdfjs-dist/build/pdf.worker.js');
  }
  var dynamicLoaderSupported =
    typeof requirejs !== 'undefined' && requirejs.load;
  fakeWorkerFilesLoader = useRequireEnsure ? (function (callback) {
    require.ensure([], function () {
      var worker = require('./pdf.worker.js');
      callback(worker.WorkerMessageHandler);
    });
  }) : dynamicLoaderSupported ? (function (callback) {
    requirejs(['pdfjs-dist/build/pdf.worker'], function (worker) {
      callback(worker.WorkerMessageHandler);
    });
  }) : null;
}

/**
 * Document initialization / loading parameters object.
 *
 * @typedef {Object} DocumentInitParameters
 * @property {string}     url   - The URL of the PDF.
 * @property {TypedArray|Array|string} data - Binary PDF data. Use typed arrays
 *   (Uint8Array) to improve the memory usage. If PDF data is BASE64-encoded,
 *   use atob() to convert it to a binary string first.
 * @property {Object}     httpHeaders - Basic authentication headers.
 * @property {boolean}    withCredentials - Indicates whether or not cross-site
 *   Access-Control requests should be made using credentials such as cookies
 *   or authorization headers. The default is false.
 * @property {string}     password - For decrypting password-protected PDFs.
 * @property {TypedArray} initialData - A typed array with the first portion or
 *   all of the pdf data. Used by the extension since some data is already
 *   loaded before the switch to range requests.
 * @property {number}     length - The PDF file length. It's used for progress
 *   reports and range requests operations.
 * @property {PDFDataRangeTransport} range
 * @property {number}     rangeChunkSize - Optional parameter to specify
 *   maximum number of bytes fetched per range request. The default value is
 *   2^16 = 65536.
 * @property {PDFWorker}  worker - The worker that will be used for the loading
 *   and parsing of the PDF data.
 * @property {string} docBaseUrl - (optional) The base URL of the document,
 *   used when attempting to recover valid absolute URLs for annotations, and
 *   outline items, that (incorrectly) only specify relative URLs.
 */

/**
 * @typedef {Object} PDFDocumentStats
 * @property {Array} streamTypes - Used stream types in the document (an item
 *   is set to true if specific stream ID was used in the document).
 * @property {Array} fontTypes - Used font type in the document (an item is set
 *   to true if specific font ID was used in the document).
 */

/**
 * This is the main entry point for loading a PDF and interacting with it.
 * NOTE: If a URL is used to fetch the PDF data a standard XMLHttpRequest(XHR)
 * is used, which means it must follow the same origin rules that any XHR does
 * e.g. No cross domain requests without CORS.
 *
 * @param {string|TypedArray|DocumentInitParameters|PDFDataRangeTransport} src
 * Can be a url to where a PDF is located, a typed array (Uint8Array)
 * already populated with data or parameter object.
 *
 * @param {PDFDataRangeTransport} pdfDataRangeTransport (deprecated) It is used
 * if you want to manually serve range requests for data in the PDF.
 *
 * @param {function} passwordCallback (deprecated) It is used to request a
 * password if wrong or no password was provided. The callback receives two
 * parameters: function that needs to be called with new password and reason
 * (see {PasswordResponses}).
 *
 * @param {function} progressCallback (deprecated) It is used to be able to
 * monitor the loading progress of the PDF file (necessary to implement e.g.
 * a loading bar). The callback receives an {Object} with the properties:
 * {number} loaded and {number} total.
 *
 * @return {PDFDocumentLoadingTask}
 */
function getDocument(src, pdfDataRangeTransport,
                     passwordCallback, progressCallback) {
  var task = new PDFDocumentLoadingTask();

  // Support of the obsolete arguments (for compatibility with API v1.0)
  if (arguments.length > 1) {
    deprecated('getDocument is called with pdfDataRangeTransport, ' +
               'passwordCallback or progressCallback argument');
  }
  if (pdfDataRangeTransport) {
    if (!(pdfDataRangeTransport instanceof PDFDataRangeTransport)) {
      // Not a PDFDataRangeTransport instance, trying to add missing properties.
      pdfDataRangeTransport = Object.create(pdfDataRangeTransport);
      pdfDataRangeTransport.length = src.length;
      pdfDataRangeTransport.initialData = src.initialData;
      if (!pdfDataRangeTransport.abort) {
        pdfDataRangeTransport.abort = function () {};
      }
    }
    src = Object.create(src);
    src.range = pdfDataRangeTransport;
  }
  task.onPassword = passwordCallback || null;
  task.onProgress = progressCallback || null;

  var source;
  if (typeof src === 'string') {
    source = { url: src };
  } else if (isArrayBuffer(src)) {
    source = { data: src };
  } else if (src instanceof PDFDataRangeTransport) {
    source = { range: src };
  } else {
    if (typeof src !== 'object') {
      error('Invalid parameter in getDocument, need either Uint8Array, ' +
        'string or a parameter object');
    }
    if (!src.url && !src.data && !src.range) {
      error('Invalid parameter object: need either .data, .range or .url');
    }

    source = src;
  }

  var params = {};
  var rangeTransport = null;
  var worker = null;
  for (var key in source) {
    if (key === 'url' && typeof window !== 'undefined') {
      // The full path is required in the 'url' field.
      params[key] = new URL(source[key], window.location).href;
      continue;
    } else if (key === 'range') {
      rangeTransport = source[key];
      continue;
    } else if (key === 'worker') {
      worker = source[key];
      continue;
    } else if (key === 'data' && !(source[key] instanceof Uint8Array)) {
      // Converting string or array-like data to Uint8Array.
      var pdfBytes = source[key];
      if (typeof pdfBytes === 'string') {
        params[key] = stringToBytes(pdfBytes);
      } else if (typeof pdfBytes === 'object' && pdfBytes !== null &&
                 !isNaN(pdfBytes.length)) {
        params[key] = new Uint8Array(pdfBytes);
      } else if (isArrayBuffer(pdfBytes)) {
        params[key] = new Uint8Array(pdfBytes);
      } else {
        error('Invalid PDF binary data: either typed array, string or ' +
              'array-like object is expected in the data property.');
      }
      continue;
    }
    params[key] = source[key];
  }

  params.rangeChunkSize = params.rangeChunkSize || DEFAULT_RANGE_CHUNK_SIZE;

  if (!worker) {
    // Worker was not provided -- creating and owning our own.
    worker = new PDFWorker();
    task._worker = worker;
  }
  var docId = task.docId;
  worker.promise.then(function () {
    if (task.destroyed) {
      throw new Error('Loading aborted');
    }
    return _fetchDocument(worker, params, rangeTransport, docId).then(
        function (workerId) {
      if (task.destroyed) {
        throw new Error('Loading aborted');
      }
      var messageHandler = new MessageHandler(docId, workerId, worker.port);
      var transport = new WorkerTransport(messageHandler, task, rangeTransport);
      task._transport = transport;
      messageHandler.send('Ready', null);
    });
  }).catch(task._capability.reject);

  return task;
}

/**
 * Starts fetching of specified PDF document/data.
 * @param {PDFWorker} worker
 * @param {Object} source
 * @param {PDFDataRangeTransport} pdfDataRangeTransport
 * @param {string} docId Unique document id, used as MessageHandler id.
 * @returns {Promise} The promise, which is resolved when worker id of
 *                    MessageHandler is known.
 * @private
 */
function _fetchDocument(worker, source, pdfDataRangeTransport, docId) {
  if (worker.destroyed) {
    return Promise.reject(new Error('Worker was destroyed'));
  }

  source.disableAutoFetch = getDefaultSetting('disableAutoFetch');
  source.disableStream = getDefaultSetting('disableStream');
  source.chunkedViewerLoading = !!pdfDataRangeTransport;
  if (pdfDataRangeTransport) {
    source.length = pdfDataRangeTransport.length;
    source.initialData = pdfDataRangeTransport.initialData;
  }
  return worker.messageHandler.sendWithPromise('GetDocRequest', {
    docId: docId,
    source: source,
    disableRange: getDefaultSetting('disableRange'),
    maxImageSize: getDefaultSetting('maxImageSize'),
    cMapUrl: getDefaultSetting('cMapUrl'),
    cMapPacked: getDefaultSetting('cMapPacked'),
    disableFontFace: getDefaultSetting('disableFontFace'),
    disableCreateObjectURL: getDefaultSetting('disableCreateObjectURL'),
    postMessageTransfers: getDefaultSetting('postMessageTransfers') &&
                          !isPostMessageTransfersDisabled,
    docBaseUrl: source.docBaseUrl,
  }).then(function (workerId) {
    if (worker.destroyed) {
      throw new Error('Worker was destroyed');
    }
    return workerId;
  });
}

/**
 * PDF document loading operation.
 * @class
 * @alias PDFDocumentLoadingTask
 */
var PDFDocumentLoadingTask = (function PDFDocumentLoadingTaskClosure() {
  var nextDocumentId = 0;

  /** @constructs PDFDocumentLoadingTask */
  function PDFDocumentLoadingTask() {
    this._capability = createPromiseCapability();
    this._transport = null;
    this._worker = null;

    /**
     * Unique document loading task id -- used in MessageHandlers.
     * @type {string}
     */
    this.docId = 'd' + (nextDocumentId++);

    /**
     * Shows if loading task is destroyed.
     * @type {boolean}
     */
    this.destroyed = false;

    /**
     * Callback to request a password if wrong or no password was provided.
     * The callback receives two parameters: function that needs to be called
     * with new password and reason (see {PasswordResponses}).
     */
    this.onPassword = null;

    /**
     * Callback to be able to monitor the loading progress of the PDF file
     * (necessary to implement e.g. a loading bar). The callback receives
     * an {Object} with the properties: {number} loaded and {number} total.
     */
    this.onProgress = null;

    /**
     * Callback to when unsupported feature is used. The callback receives
     * an {UNSUPPORTED_FEATURES} argument.
     */
    this.onUnsupportedFeature = null;
  }

  PDFDocumentLoadingTask.prototype =
      /** @lends PDFDocumentLoadingTask.prototype */ {
    /**
     * @return {Promise}
     */
    get promise() {
      return this._capability.promise;
    },

    /**
     * Aborts all network requests and destroys worker.
     * @return {Promise} A promise that is resolved after destruction activity
     *                   is completed.
     */
    destroy: function () {
      this.destroyed = true;

      var transportDestroyed = !this._transport ? Promise.resolve() :
        this._transport.destroy();
      return transportDestroyed.then(function () {
        this._transport = null;
        if (this._worker) {
          this._worker.destroy();
          this._worker = null;
        }
      }.bind(this));
    },

    /**
     * Registers callbacks to indicate the document loading completion.
     *
     * @param {function} onFulfilled The callback for the loading completion.
     * @param {function} onRejected The callback for the loading failure.
     * @return {Promise} A promise that is resolved after the onFulfilled or
     *                   onRejected callback.
     */
    then: function PDFDocumentLoadingTask_then(onFulfilled, onRejected) {
      return this.promise.then.apply(this.promise, arguments);
    }
  };

  return PDFDocumentLoadingTask;
})();

/**
 * Abstract class to support range requests file loading.
 * @class
 * @alias PDFDataRangeTransport
 * @param {number} length
 * @param {Uint8Array} initialData
 */
var PDFDataRangeTransport = (function pdfDataRangeTransportClosure() {
  function PDFDataRangeTransport(length, initialData) {
    this.length = length;
    this.initialData = initialData;

    this._rangeListeners = [];
    this._progressListeners = [];
    this._progressiveReadListeners = [];
    this._readyCapability = createPromiseCapability();
  }
  PDFDataRangeTransport.prototype =
      /** @lends PDFDataRangeTransport.prototype */ {
    addRangeListener:
        function PDFDataRangeTransport_addRangeListener(listener) {
      this._rangeListeners.push(listener);
    },

    addProgressListener:
        function PDFDataRangeTransport_addProgressListener(listener) {
      this._progressListeners.push(listener);
    },

    addProgressiveReadListener:
        function PDFDataRangeTransport_addProgressiveReadListener(listener) {
      this._progressiveReadListeners.push(listener);
    },

    onDataRange: function PDFDataRangeTransport_onDataRange(begin, chunk) {
      var listeners = this._rangeListeners;
      for (var i = 0, n = listeners.length; i < n; ++i) {
        listeners[i](begin, chunk);
      }
    },

    onDataProgress: function PDFDataRangeTransport_onDataProgress(loaded) {
      this._readyCapability.promise.then(function () {
        var listeners = this._progressListeners;
        for (var i = 0, n = listeners.length; i < n; ++i) {
          listeners[i](loaded);
        }
      }.bind(this));
    },

    onDataProgressiveRead:
        function PDFDataRangeTransport_onDataProgress(chunk) {
      this._readyCapability.promise.then(function () {
        var listeners = this._progressiveReadListeners;
        for (var i = 0, n = listeners.length; i < n; ++i) {
          listeners[i](chunk);
        }
      }.bind(this));
    },

    transportReady: function PDFDataRangeTransport_transportReady() {
      this._readyCapability.resolve();
    },

    requestDataRange:
        function PDFDataRangeTransport_requestDataRange(begin, end) {
      throw new Error('Abstract method PDFDataRangeTransport.requestDataRange');
    },

    abort: function PDFDataRangeTransport_abort() {
    }
  };
  return PDFDataRangeTransport;
})();

/**
 * Proxy to a PDFDocument in the worker thread. Also, contains commonly used
 * properties that can be read synchronously.
 * @class
 * @alias PDFDocumentProxy
 */
var PDFDocumentProxy = (function PDFDocumentProxyClosure() {
  function PDFDocumentProxy(pdfInfo, transport, loadingTask) {
    this.pdfInfo = pdfInfo;
    this.transport = transport;
    this.loadingTask = loadingTask;
  }
  PDFDocumentProxy.prototype = /** @lends PDFDocumentProxy.prototype */ {
    /**
     * @return {number} Total number of pages the PDF contains.
     */
    get numPages() {
      return this.pdfInfo.numPages;
    },
    /**
     * @return {string} A unique ID to identify a PDF. Not guaranteed to be
     * unique.
     */
    get fingerprint() {
      return this.pdfInfo.fingerprint;
    },
    /**
     * @param {number} pageNumber The page number to get. The first page is 1.
     * @return {Promise} A promise that is resolved with a {@link PDFPageProxy}
     * object.
     */
    getPage: function PDFDocumentProxy_getPage(pageNumber) {
      return this.transport.getPage(pageNumber);
    },
    /**
     * @param {{num: number, gen: number}} ref The page reference. Must have
     *   the 'num' and 'gen' properties.
     * @return {Promise} A promise that is resolved with the page index that is
     * associated with the reference.
     */
    getPageIndex: function PDFDocumentProxy_getPageIndex(ref) {
      return this.transport.getPageIndex(ref);
    },
    /**
     * @return {Promise} A promise that is resolved with a lookup table for
     * mapping named destinations to reference numbers.
     *
     * This can be slow for large documents: use getDestination instead
     */
    getDestinations: function PDFDocumentProxy_getDestinations() {
      return this.transport.getDestinations();
    },
    /**
     * @param {string} id The named destination to get.
     * @return {Promise} A promise that is resolved with all information
     * of the given named destination.
     */
    getDestination: function PDFDocumentProxy_getDestination(id) {
      return this.transport.getDestination(id);
    },
    /**
     * @return {Promise} A promise that is resolved with:
     *   an Array containing the pageLabels that correspond to the pageIndexes,
     *   or `null` when no pageLabels are present in the PDF file.
     */
    getPageLabels: function PDFDocumentProxy_getPageLabels() {
      return this.transport.getPageLabels();
    },
    /**
     * @return {Promise} A promise that is resolved with a lookup table for
     * mapping named attachments to their content.
     */
    getAttachments: function PDFDocumentProxy_getAttachments() {
      return this.transport.getAttachments();
    },
    /**
     * @return {Promise} A promise that is resolved with an array of all the
     * JavaScript strings in the name tree.
     */
    getJavaScript: function PDFDocumentProxy_getJavaScript() {
      return this.transport.getJavaScript();
    },
    /**
     * @return {Promise} A promise that is resolved with an {Array} that is a
     * tree outline (if it has one) of the PDF. The tree is in the format of:
     * [
     *  {
     *   title: string,
     *   bold: boolean,
     *   italic: boolean,
     *   color: rgb Uint8Array,
     *   dest: dest obj,
     *   url: string,
     *   items: array of more items like this
     *  },
     *  ...
     * ].
     */
    getOutline: function PDFDocumentProxy_getOutline() {
      return this.transport.getOutline();
    },
    /**
     * @return {Promise} A promise that is resolved with an {Object} that has
     * info and metadata properties.  Info is an {Object} filled with anything
     * available in the information dictionary and similarly metadata is a
     * {Metadata} object with information from the metadata section of the PDF.
     */
    getMetadata: function PDFDocumentProxy_getMetadata() {
      return this.transport.getMetadata();
    },
    /**
     * @return {Promise} A promise that is resolved with a TypedArray that has
     * the raw data from the PDF.
     */
    getData: function PDFDocumentProxy_getData() {
      return this.transport.getData();
    },
    /**
     * @return {Promise} A promise that is resolved when the document's data
     * is loaded. It is resolved with an {Object} that contains the length
     * property that indicates size of the PDF data in bytes.
     */
    getDownloadInfo: function PDFDocumentProxy_getDownloadInfo() {
      return this.transport.downloadInfoCapability.promise;
    },
    /**
     * @return {Promise} A promise this is resolved with current stats about
     * document structures (see {@link PDFDocumentStats}).
     */
    getStats: function PDFDocumentProxy_getStats() {
      return this.transport.getStats();
    },
    /**
     * Cleans up resources allocated by the document, e.g. created @font-face.
     */
    cleanup: function PDFDocumentProxy_cleanup() {
      this.transport.startCleanup();
    },
    /**
     * Destroys current document instance and terminates worker.
     */
    destroy: function PDFDocumentProxy_destroy() {
      return this.loadingTask.destroy();
    }
  };
  return PDFDocumentProxy;
})();

/**
 * Page getTextContent parameters.
 *
 * @typedef {Object} getTextContentParameters
 * @property {boolean} normalizeWhitespace - replaces all occurrences of
 *   whitespace with standard spaces (0x20). The default value is `false`.
 * @property {boolean} disableCombineTextItems - do not attempt to combine
 *   same line {@link TextItem}'s. The default value is `false`.
 */

/**
 * Page text content.
 *
 * @typedef {Object} TextContent
 * @property {array} items - array of {@link TextItem}
 * @property {Object} styles - {@link TextStyles} objects, indexed by font name.
 */

/**
 * Page text content part.
 *
 * @typedef {Object} TextItem
 * @property {string} str - text content.
 * @property {string} dir - text direction: 'ttb', 'ltr' or 'rtl'.
 * @property {array} transform - transformation matrix.
 * @property {number} width - width in device space.
 * @property {number} height - height in device space.
 * @property {string} fontName - font name used by pdf.js for converted font.
 */

/**
 * Text style.
 *
 * @typedef {Object} TextStyle
 * @property {number} ascent - font ascent.
 * @property {number} descent - font descent.
 * @property {boolean} vertical - text is in vertical mode.
 * @property {string} fontFamily - possible font family
 */

/**
 * Page annotation parameters.
 *
 * @typedef {Object} GetAnnotationsParameters
 * @property {string} intent - Determines the annotations that will be fetched,
 *                    can be either 'display' (viewable annotations) or 'print'
 *                    (printable annotations).
 *                    If the parameter is omitted, all annotations are fetched.
 */

/**
 * Page render parameters.
 *
 * @typedef {Object} RenderParameters
 * @property {Object} canvasContext - A 2D context of a DOM Canvas object.
 * @property {PageViewport} viewport - Rendering viewport obtained by
 *                                calling of PDFPage.getViewport method.
 * @property {string} intent - Rendering intent, can be 'display' or 'print'
 *                    (default value is 'display').
 * @property {boolean} renderInteractiveForms - (optional) Whether or not
 *                     interactive form elements are rendered in the display
 *                     layer. If so, we do not render them on canvas as well.
 * @property {Array}  transform - (optional) Additional transform, applied
 *                    just before viewport transform.
 * @property {Object} imageLayer - (optional) An object that has beginLayout,
 *                    endLayout and appendImage functions.
 * @property {function} continueCallback - (deprecated) A function that will be
 *                      called each time the rendering is paused.  To continue
 *                      rendering call the function that is the first argument
 *                      to the callback.
 */

/**
 * PDF page operator list.
 *
 * @typedef {Object} PDFOperatorList
 * @property {Array} fnArray - Array containing the operator functions.
 * @property {Array} argsArray - Array containing the arguments of the
 *                               functions.
 */

/**
 * Proxy to a PDFPage in the worker thread.
 * @class
 * @alias PDFPageProxy
 */
var PDFPageProxy = (function PDFPageProxyClosure() {
  function PDFPageProxy(pageIndex, pageInfo, transport) {
    this.pageIndex = pageIndex;
    this.pageInfo = pageInfo;
    this.transport = transport;
    this.stats = new StatTimer();
    this.stats.enabled = getDefaultSetting('enableStats');
    this.commonObjs = transport.commonObjs;
    this.objs = new PDFObjects();
    this.cleanupAfterRender = false;
    this.pendingCleanup = false;
    this.intentStates = Object.create(null);
    this.destroyed = false;
  }
  PDFPageProxy.prototype = /** @lends PDFPageProxy.prototype */ {
    /**
     * @return {number} Page number of the page. First page is 1.
     */
    get pageNumber() {
      return this.pageIndex + 1;
    },
    /**
     * @return {number} The number of degrees the page is rotated clockwise.
     */
    get rotate() {
      return this.pageInfo.rotate;
    },
    /**
     * @return {Object} The reference that points to this page. It has 'num' and
     * 'gen' properties.
     */
    get ref() {
      return this.pageInfo.ref;
    },
    /**
     * @return {number} The default size of units in 1/72nds of an inch.
     */
    get userUnit() {
      return this.pageInfo.userUnit;
    },
    /**
     * @return {Array} An array of the visible portion of the PDF page in the
     * user space units - [x1, y1, x2, y2].
     */
    get view() {
      return this.pageInfo.view;
    },
    /**
     * @param {number} scale The desired scale of the viewport.
     * @param {number} rotate Degrees to rotate the viewport. If omitted this
     * defaults to the page rotation.
     * @return {PageViewport} Contains 'width' and 'height' properties
     * along with transforms required for rendering.
     */
    getViewport: function PDFPageProxy_getViewport(scale, rotate) {
      if (arguments.length < 2) {
        rotate = this.rotate;
      }
      return new PageViewport(this.view, scale, rotate, 0, 0);
    },
    /**
     * @param {GetAnnotationsParameters} params - Annotation parameters.
     * @return {Promise} A promise that is resolved with an {Array} of the
     * annotation objects.
     */
    getAnnotations: function PDFPageProxy_getAnnotations(params) {
      var intent = (params && params.intent) || null;

      if (!this.annotationsPromise || this.annotationsIntent !== intent) {
        this.annotationsPromise = this.transport.getAnnotations(this.pageIndex,
                                                                intent);
        this.annotationsIntent = intent;
      }
      return this.annotationsPromise;
    },
    /**
     * Begins the process of rendering a page to the desired context.
     * @param {RenderParameters} params Page render parameters.
     * @return {RenderTask} An object that contains the promise, which
     *                      is resolved when the page finishes rendering.
     */
    render: function PDFPageProxy_render(params) {
      var stats = this.stats;
      stats.time('Overall');

      // If there was a pending destroy cancel it so no cleanup happens during
      // this call to render.
      this.pendingCleanup = false;

      var renderingIntent = (params.intent === 'print' ? 'print' : 'display');
      var renderInteractiveForms = (params.renderInteractiveForms === true ?
                                    true : /* Default */ false);

      if (!this.intentStates[renderingIntent]) {
        this.intentStates[renderingIntent] = Object.create(null);
      }
      var intentState = this.intentStates[renderingIntent];

      // If there's no displayReadyCapability yet, then the operatorList
      // was never requested before. Make the request and create the promise.
      if (!intentState.displayReadyCapability) {
        intentState.receivingOperatorList = true;
        intentState.displayReadyCapability = createPromiseCapability();
        intentState.operatorList = {
          fnArray: [],
          argsArray: [],
          lastChunk: false
        };

        this.stats.time('Page Request');
        this.transport.messageHandler.send('RenderPageRequest', {
          pageIndex: this.pageNumber - 1,
          intent: renderingIntent,
          renderInteractiveForms: renderInteractiveForms,
        });
      }

      var internalRenderTask = new InternalRenderTask(complete, params,
                                                      this.objs,
                                                      this.commonObjs,
                                                      intentState.operatorList,
                                                      this.pageNumber);
      internalRenderTask.useRequestAnimationFrame = renderingIntent !== 'print';
      if (!intentState.renderTasks) {
        intentState.renderTasks = [];
      }
      intentState.renderTasks.push(internalRenderTask);
      var renderTask = internalRenderTask.task;

      // Obsolete parameter support
      if (params.continueCallback) {
        deprecated('render is used with continueCallback parameter');
        renderTask.onContinue = params.continueCallback;
      }

      var self = this;
      intentState.displayReadyCapability.promise.then(
        function pageDisplayReadyPromise(transparency) {
          if (self.pendingCleanup) {
            complete();
            return;
          }
          stats.time('Rendering');
          internalRenderTask.initializeGraphics(transparency);
          internalRenderTask.operatorListChanged();
        },
        function pageDisplayReadPromiseError(reason) {
          complete(reason);
        }
      );

      function complete(error) {
        var i = intentState.renderTasks.indexOf(internalRenderTask);
        if (i >= 0) {
          intentState.renderTasks.splice(i, 1);
        }

        if (self.cleanupAfterRender) {
          self.pendingCleanup = true;
        }
        self._tryCleanup();

        if (error) {
          internalRenderTask.capability.reject(error);
        } else {
          internalRenderTask.capability.resolve();
        }
        stats.timeEnd('Rendering');
        stats.timeEnd('Overall');
      }

      return renderTask;
    },

    /**
     * @return {Promise} A promise resolved with an {@link PDFOperatorList}
     * object that represents page's operator list.
     */
    getOperatorList: function PDFPageProxy_getOperatorList() {
      function operatorListChanged() {
        if (intentState.operatorList.lastChunk) {
          intentState.opListReadCapability.resolve(intentState.operatorList);

          var i = intentState.renderTasks.indexOf(opListTask);
          if (i >= 0) {
            intentState.renderTasks.splice(i, 1);
          }
        }
      }

      var renderingIntent = 'oplist';
      if (!this.intentStates[renderingIntent]) {
        this.intentStates[renderingIntent] = Object.create(null);
      }
      var intentState = this.intentStates[renderingIntent];
      var opListTask;

      if (!intentState.opListReadCapability) {
        opListTask = {};
        opListTask.operatorListChanged = operatorListChanged;
        intentState.receivingOperatorList = true;
        intentState.opListReadCapability = createPromiseCapability();
        intentState.renderTasks = [];
        intentState.renderTasks.push(opListTask);
        intentState.operatorList = {
          fnArray: [],
          argsArray: [],
          lastChunk: false
        };

        this.transport.messageHandler.send('RenderPageRequest', {
          pageIndex: this.pageIndex,
          intent: renderingIntent
        });
      }
      return intentState.opListReadCapability.promise;
    },

    /**
     * @param {getTextContentParameters} params - getTextContent parameters.
     * @return {Promise} That is resolved a {@link TextContent}
     * object that represent the page text content.
     */
    getTextContent: function PDFPageProxy_getTextContent(params) {
      return this.transport.messageHandler.sendWithPromise('GetTextContent', {
        pageIndex: this.pageNumber - 1,
        normalizeWhitespace: (params && params.normalizeWhitespace === true ?
                              true : /* Default */ false),
        combineTextItems: (params && params.disableCombineTextItems === true ?
                           false : /* Default */ true),
      });
    },

    /**
     * Destroys page object.
     */
    _destroy: function PDFPageProxy_destroy() {
      this.destroyed = true;
      this.transport.pageCache[this.pageIndex] = null;

      var waitOn = [];
      Object.keys(this.intentStates).forEach(function(intent) {
        if (intent === 'oplist') {
          // Avoid errors below, since the renderTasks are just stubs.
          return;
        }
        var intentState = this.intentStates[intent];
        intentState.renderTasks.forEach(function(renderTask) {
          var renderCompleted = renderTask.capability.promise.
            catch(function () {}); // ignoring failures
          waitOn.push(renderCompleted);
          renderTask.cancel();
        });
      }, this);
      this.objs.clear();
      this.annotationsPromise = null;
      this.pendingCleanup = false;
      return Promise.all(waitOn);
    },

    /**
     * Cleans up resources allocated by the page. (deprecated)
     */
    destroy: function() {
      deprecated('page destroy method, use cleanup() instead');
      this.cleanup();
    },

    /**
     * Cleans up resources allocated by the page.
     */
    cleanup: function PDFPageProxy_cleanup() {
      this.pendingCleanup = true;
      this._tryCleanup();
    },
    /**
     * For internal use only. Attempts to clean up if rendering is in a state
     * where that's possible.
     * @ignore
     */
    _tryCleanup: function PDFPageProxy_tryCleanup() {
      if (!this.pendingCleanup ||
          Object.keys(this.intentStates).some(function(intent) {
            var intentState = this.intentStates[intent];
            return (intentState.renderTasks.length !== 0 ||
                    intentState.receivingOperatorList);
          }, this)) {
        return;
      }

      Object.keys(this.intentStates).forEach(function(intent) {
        delete this.intentStates[intent];
      }, this);
      this.objs.clear();
      this.annotationsPromise = null;
      this.pendingCleanup = false;
    },
    /**
     * For internal use only.
     * @ignore
     */
    _startRenderPage: function PDFPageProxy_startRenderPage(transparency,
                                                            intent) {
      var intentState = this.intentStates[intent];
      // TODO Refactor RenderPageRequest to separate rendering
      // and operator list logic
      if (intentState.displayReadyCapability) {
        intentState.displayReadyCapability.resolve(transparency);
      }
    },
    /**
     * For internal use only.
     * @ignore
     */
    _renderPageChunk: function PDFPageProxy_renderPageChunk(operatorListChunk,
                                                            intent) {
      var intentState = this.intentStates[intent];
      var i, ii;
      // Add the new chunk to the current operator list.
      for (i = 0, ii = operatorListChunk.length; i < ii; i++) {
        intentState.operatorList.fnArray.push(operatorListChunk.fnArray[i]);
        intentState.operatorList.argsArray.push(
          operatorListChunk.argsArray[i]);
      }
      intentState.operatorList.lastChunk = operatorListChunk.lastChunk;

      // Notify all the rendering tasks there are more operators to be consumed.
      for (i = 0; i < intentState.renderTasks.length; i++) {
        intentState.renderTasks[i].operatorListChanged();
      }

      if (operatorListChunk.lastChunk) {
        intentState.receivingOperatorList = false;
        this._tryCleanup();
      }
    }
  };
  return PDFPageProxy;
})();

/**
 * PDF.js web worker abstraction, it controls instantiation of PDF documents and
 * WorkerTransport for them.  If creation of a web worker is not possible,
 * a "fake" worker will be used instead.
 * @class
 */
var PDFWorker = (function PDFWorkerClosure() {
  var nextFakeWorkerId = 0;

  function getWorkerSrc() {
    if (typeof workerSrc !== 'undefined') {
      return workerSrc;
    }
    if (getDefaultSetting('workerSrc')) {
      return getDefaultSetting('workerSrc');
    }
    if (typeof PDFJSDev !== 'undefined' &&
        PDFJSDev.test('PRODUCTION && !(MOZCENTRAL || FIREFOX)') &&
        pdfjsFilePath) {
      return pdfjsFilePath.replace(/\.js$/i, '.worker.js');
    }
    error('No PDFJS.workerSrc specified');
  }

  var fakeWorkerFilesLoadedCapability;

  // Loads worker code into main thread.
  function setupFakeWorkerGlobal() {
    var WorkerMessageHandler;
    if (fakeWorkerFilesLoadedCapability) {
      return fakeWorkerFilesLoadedCapability.promise;
    }
    fakeWorkerFilesLoadedCapability = createPromiseCapability();
    // In the developer build load worker_loader which in turn loads all the
    // other files and resolves the promise. In production only the
    // pdf.worker.js file is needed.
    if (typeof PDFJSDev === 'undefined' || !PDFJSDev.test('PRODUCTION')) {
      if (typeof amdRequire === 'function') {
        amdRequire(['pdfjs/core/network', 'pdfjs/core/worker'],
            function (network, worker) {
          WorkerMessageHandler = worker.WorkerMessageHandler;
          fakeWorkerFilesLoadedCapability.resolve(WorkerMessageHandler);
        });
      } else if (typeof require === 'function') {
        var worker = require('../core/worker.js');
        WorkerMessageHandler = worker.WorkerMessageHandler;
        fakeWorkerFilesLoadedCapability.resolve(WorkerMessageHandler);
      } else {
        throw new Error('AMD or CommonJS must be used to load fake worker.');
      }
    } else if (PDFJSDev.test('SINGLE_FILE')) {
      WorkerMessageHandler = pdfjsLibs.pdfjsCoreWorker.WorkerMessageHandler;
      fakeWorkerFilesLoadedCapability.resolve(WorkerMessageHandler);
    } else {
      var loader = fakeWorkerFilesLoader || function (callback) {
        Util.loadScript(getWorkerSrc(), function () {
          callback(window.pdfjsDistBuildPdfWorker.WorkerMessageHandler);
        });
      };
      loader(fakeWorkerFilesLoadedCapability.resolve);
    }
    return fakeWorkerFilesLoadedCapability.promise;
  }

  function FakeWorkerPort(defer) {
    this._listeners = [];
    this._defer = defer;
    this._deferred = Promise.resolve(undefined);
  }
  FakeWorkerPort.prototype = {
    postMessage: function (obj, transfers) {
      function cloneValue(value) {
        // Trying to perform a structured clone close to the spec, including
        // transfers.
        if (typeof value !== 'object' || value === null) {
          return value;
        }
        if (cloned.has(value)) { // already cloned the object
          return cloned.get(value);
        }
        var result;
        var buffer;
        if ((buffer = value.buffer) && isArrayBuffer(buffer)) {
          // We found object with ArrayBuffer (typed array).
          var transferable = transfers && transfers.indexOf(buffer) >= 0;
          if (value === buffer) {
            // Special case when we are faking typed arrays in compatibility.js.
            result = value;
          } else if (transferable) {
            result = new value.constructor(buffer, value.byteOffset,
                                           value.byteLength);
          } else {
            result = new value.constructor(value);
          }
          cloned.set(value, result);
          return result;
        }
        result = isArray(value) ? [] : {};
        cloned.set(value, result); // adding to cache now for cyclic references
        // Cloning all value and object properties, however ignoring properties
        // defined via getter.
        for (var i in value) {
          var desc, p = value;
          while (!(desc = Object.getOwnPropertyDescriptor(p, i))) {
            p = Object.getPrototypeOf(p);
          }
          if (typeof desc.value === 'undefined' ||
              typeof desc.value === 'function') {
            continue;
          }
          result[i] = cloneValue(desc.value);
        }
        return result;
      }

      if (!this._defer) {
        this._listeners.forEach(function (listener) {
          listener.call(this, {data: obj});
        }, this);
        return;
      }

      var cloned = new WeakMap();
      var e = {data: cloneValue(obj)};
      this._deferred.then(function () {
        this._listeners.forEach(function (listener) {
          listener.call(this, e);
        }, this);
      }.bind(this));
    },
    addEventListener: function (name, listener) {
      this._listeners.push(listener);
    },
    removeEventListener: function (name, listener) {
      var i = this._listeners.indexOf(listener);
      this._listeners.splice(i, 1);
    },
    terminate: function () {
      this._listeners = [];
    }
  };

  function createCDNWrapper(url) {
    // We will rely on blob URL's property to specify origin.
    // We want this function to fail in case if createObjectURL or Blob do not
    // exist or fail for some reason -- our Worker creation will fail anyway.
    var wrapper = 'importScripts(\'' + url + '\');';
    return URL.createObjectURL(new Blob([wrapper]));
  }

  function PDFWorker(name) {
    this.name = name;
    this.destroyed = false;

    this._readyCapability = createPromiseCapability();
    this._port = null;
    this._webWorker = null;
    this._messageHandler = null;
    this._initialize();
  }

  PDFWorker.prototype =  /** @lends PDFWorker.prototype */ {
    get promise() {
      return this._readyCapability.promise;
    },

    get port() {
      return this._port;
    },

    get messageHandler() {
      return this._messageHandler;
    },

    _initialize: function PDFWorker_initialize() {
      // If worker support isn't disabled explicit and the browser has worker
      // support, create a new web worker and test if it/the browser fulfills
      // all requirements to run parts of pdf.js in a web worker.
      // Right now, the requirement is, that an Uint8Array is still an
      // Uint8Array as it arrives on the worker. (Chrome added this with v.15.)
      if ((typeof PDFJSDev === 'undefined' || !PDFJSDev.test('SINGLE_FILE')) &&
          !isWorkerDisabled && !getDefaultSetting('disableWorker') &&
          typeof Worker !== 'undefined') {
        var workerSrc = getWorkerSrc();

        try {
          // Wraps workerSrc path into blob URL, if the former does not belong
          // to the same origin.
          if (typeof PDFJSDev !== 'undefined' && PDFJSDev.test('GENERIC') &&
              !isSameOrigin(window.location.href, workerSrc)) {
            workerSrc = createCDNWrapper(
              new URL(workerSrc, window.location).href);
          }

          // Some versions of FF can't create a worker on localhost, see:
          // https://bugzilla.mozilla.org/show_bug.cgi?id=683280
          var worker = new Worker(workerSrc);
          var messageHandler = new MessageHandler('main', 'worker', worker);
          var terminateEarly = function() {
            worker.removeEventListener('error', onWorkerError);
            messageHandler.destroy();
            worker.terminate();
            if (this.destroyed) {
              this._readyCapability.reject(new Error('Worker was destroyed'));
            } else {
              // Fall back to fake worker if the termination is caused by an
              // error (e.g. NetworkError / SecurityError).
              this._setupFakeWorker();
            }
          }.bind(this);

          var onWorkerError = function(event) {
            if (!this._webWorker) {
              // Worker failed to initialize due to an error. Clean up and fall
              // back to the fake worker.
              terminateEarly();
            }
          }.bind(this);
          worker.addEventListener('error', onWorkerError);

          messageHandler.on('test', function PDFWorker_test(data) {
            worker.removeEventListener('error', onWorkerError);
            if (this.destroyed) {
              terminateEarly();
              return; // worker was destroyed
            }
            var supportTypedArray = data && data.supportTypedArray;
            if (supportTypedArray) {
              this._messageHandler = messageHandler;
              this._port = worker;
              this._webWorker = worker;
              if (!data.supportTransfers) {
                isPostMessageTransfersDisabled = true;
              }
              this._readyCapability.resolve();
              // Send global setting, e.g. verbosity level.
              messageHandler.send('configure', {
                verbosity: getVerbosityLevel()
              });
            } else {
              this._setupFakeWorker();
              messageHandler.destroy();
              worker.terminate();
            }
          }.bind(this));

          messageHandler.on('console_log', function (data) {
            console.log.apply(console, data);
          });
          messageHandler.on('console_error', function (data) {
            console.error.apply(console, data);
          });

          messageHandler.on('ready', function (data) {
            worker.removeEventListener('error', onWorkerError);
            if (this.destroyed) {
              terminateEarly();
              return; // worker was destroyed
            }
            try {
              sendTest();
            } catch (e) {
              // We need fallback to a faked worker.
              this._setupFakeWorker();
            }
          }.bind(this));

          var sendTest = function () {
            var postMessageTransfers =
              getDefaultSetting('postMessageTransfers') &&
              !isPostMessageTransfersDisabled;
            var testObj = new Uint8Array([postMessageTransfers ? 255 : 0]);
            // Some versions of Opera throw a DATA_CLONE_ERR on serializing the
            // typed array. Also, checking if we can use transfers.
            try {
              messageHandler.send('test', testObj, [testObj.buffer]);
            } catch (ex) {
              info('Cannot use postMessage transfers');
              testObj[0] = 0;
              messageHandler.send('test', testObj);
            }
          };

          // It might take time for worker to initialize (especially when AMD
          // loader is used). We will try to send test immediately, and then
          // when 'ready' message will arrive. The worker shall process only
          // first received 'test'.
          sendTest();
          return;
        } catch (e) {
          info('The worker has been disabled.');
        }
      }
      // Either workers are disabled, not supported or have thrown an exception.
      // Thus, we fallback to a faked worker.
      this._setupFakeWorker();
    },

    _setupFakeWorker: function PDFWorker_setupFakeWorker() {
      if (!isWorkerDisabled && !getDefaultSetting('disableWorker')) {
        warn('Setting up fake worker.');
        isWorkerDisabled = true;
      }

      setupFakeWorkerGlobal().then(function (WorkerMessageHandler) {
        if (this.destroyed) {
          this._readyCapability.reject(new Error('Worker was destroyed'));
          return;
        }

        // We cannot turn on proper fake port simulation (this includes
        // structured cloning) when typed arrays are not supported. Relying
        // on a chance that messages will be sent in proper order.
        var isTypedArraysPresent = Uint8Array !== Float32Array;
        var port = new FakeWorkerPort(isTypedArraysPresent);
        this._port = port;

        // All fake workers use the same port, making id unique.
        var id = 'fake' + (nextFakeWorkerId++);

        // If the main thread is our worker, setup the handling for the
        // messages -- the main thread sends to it self.
        var workerHandler = new MessageHandler(id + '_worker', id, port);
        WorkerMessageHandler.setup(workerHandler, port);

        var messageHandler = new MessageHandler(id, id + '_worker', port);
        this._messageHandler = messageHandler;
        this._readyCapability.resolve();
      }.bind(this));
    },

    /**
     * Destroys the worker instance.
     */
    destroy: function PDFWorker_destroy() {
      this.destroyed = true;
      if (this._webWorker) {
        // We need to terminate only web worker created resource.
        this._webWorker.terminate();
        this._webWorker = null;
      }
      this._port = null;
      if (this._messageHandler) {
        this._messageHandler.destroy();
        this._messageHandler = null;
      }
    }
  };

  return PDFWorker;
})();

/**
 * For internal use only.
 * @ignore
 */
var WorkerTransport = (function WorkerTransportClosure() {
  function WorkerTransport(messageHandler, loadingTask, pdfDataRangeTransport) {
    this.messageHandler = messageHandler;
    this.loadingTask = loadingTask;
    this.pdfDataRangeTransport = pdfDataRangeTransport;
    this.commonObjs = new PDFObjects();
    this.fontLoader = new FontLoader(loadingTask.docId);

    this.destroyed = false;
    this.destroyCapability = null;

    this.pageCache = [];
    this.pagePromises = [];
    this.downloadInfoCapability = createPromiseCapability();

    this.setupMessageHandler();
  }
  WorkerTransport.prototype = {
    destroy: function WorkerTransport_destroy() {
      if (this.destroyCapability) {
        return this.destroyCapability.promise;
      }

      this.destroyed = true;
      this.destroyCapability = createPromiseCapability();

      var waitOn = [];
      // We need to wait for all renderings to be completed, e.g.
      // timeout/rAF can take a long time.
      this.pageCache.forEach(function (page) {
        if (page) {
          waitOn.push(page._destroy());
        }
      });
      this.pageCache = [];
      this.pagePromises = [];
      var self = this;
      // We also need to wait for the worker to finish its long running tasks.
      var terminated = this.messageHandler.sendWithPromise('Terminate', null);
      waitOn.push(terminated);
      Promise.all(waitOn).then(function () {
        self.fontLoader.clear();
        if (self.pdfDataRangeTransport) {
          self.pdfDataRangeTransport.abort();
          self.pdfDataRangeTransport = null;
        }
        if (self.messageHandler) {
          self.messageHandler.destroy();
          self.messageHandler = null;
        }
        self.destroyCapability.resolve();
      }, this.destroyCapability.reject);
      return this.destroyCapability.promise;
    },

    setupMessageHandler:
      function WorkerTransport_setupMessageHandler() {
      var messageHandler = this.messageHandler;

      function updatePassword(password) {
        messageHandler.send('UpdatePassword', password);
      }

      var pdfDataRangeTransport = this.pdfDataRangeTransport;
      if (pdfDataRangeTransport) {
        pdfDataRangeTransport.addRangeListener(function(begin, chunk) {
          messageHandler.send('OnDataRange', {
            begin: begin,
            chunk: chunk
          });
        });

        pdfDataRangeTransport.addProgressListener(function(loaded) {
          messageHandler.send('OnDataProgress', {
            loaded: loaded
          });
        });

        pdfDataRangeTransport.addProgressiveReadListener(function(chunk) {
          messageHandler.send('OnDataRange', {
            chunk: chunk
          });
        });

        messageHandler.on('RequestDataRange',
          function transportDataRange(data) {
            pdfDataRangeTransport.requestDataRange(data.begin, data.end);
          }, this);
      }

      messageHandler.on('GetDoc', function transportDoc(data) {
        var pdfInfo = data.pdfInfo;
        this.numPages = data.pdfInfo.numPages;
        var loadingTask = this.loadingTask;
        var pdfDocument = new PDFDocumentProxy(pdfInfo, this, loadingTask);
        this.pdfDocument = pdfDocument;
        loadingTask._capability.resolve(pdfDocument);
      }, this);

      messageHandler.on('NeedPassword',
                        function transportNeedPassword(exception) {
        var loadingTask = this.loadingTask;
        if (loadingTask.onPassword) {
          return loadingTask.onPassword(updatePassword,
                                        PasswordResponses.NEED_PASSWORD);
        }
        loadingTask._capability.reject(
          new PasswordException(exception.message, exception.code));
      }, this);

      messageHandler.on('IncorrectPassword',
                        function transportIncorrectPassword(exception) {
        var loadingTask = this.loadingTask;
        if (loadingTask.onPassword) {
          return loadingTask.onPassword(updatePassword,
                                        PasswordResponses.INCORRECT_PASSWORD);
        }
        loadingTask._capability.reject(
          new PasswordException(exception.message, exception.code));
      }, this);

      messageHandler.on('InvalidPDF', function transportInvalidPDF(exception) {
        this.loadingTask._capability.reject(
          new InvalidPDFException(exception.message));
      }, this);

      messageHandler.on('MissingPDF', function transportMissingPDF(exception) {
        this.loadingTask._capability.reject(
          new MissingPDFException(exception.message));
      }, this);

      messageHandler.on('UnexpectedResponse',
                        function transportUnexpectedResponse(exception) {
        this.loadingTask._capability.reject(
          new UnexpectedResponseException(exception.message, exception.status));
      }, this);

      messageHandler.on('UnknownError',
                        function transportUnknownError(exception) {
        this.loadingTask._capability.reject(
          new UnknownErrorException(exception.message, exception.details));
      }, this);

      messageHandler.on('DataLoaded', function transportPage(data) {
        this.downloadInfoCapability.resolve(data);
      }, this);

      messageHandler.on('PDFManagerReady', function transportPage(data) {
        if (this.pdfDataRangeTransport) {
          this.pdfDataRangeTransport.transportReady();
        }
      }, this);

      messageHandler.on('StartRenderPage', function transportRender(data) {
        if (this.destroyed) {
          return; // Ignore any pending requests if the worker was terminated.
        }
        var page = this.pageCache[data.pageIndex];

        page.stats.timeEnd('Page Request');
        page._startRenderPage(data.transparency, data.intent);
      }, this);

      messageHandler.on('RenderPageChunk', function transportRender(data) {
        if (this.destroyed) {
          return; // Ignore any pending requests if the worker was terminated.
        }
        var page = this.pageCache[data.pageIndex];

        page._renderPageChunk(data.operatorList, data.intent);
      }, this);

      messageHandler.on('commonobj', function transportObj(data) {
        if (this.destroyed) {
          return; // Ignore any pending requests if the worker was terminated.
        }

        var id = data[0];
        var type = data[1];
        if (this.commonObjs.hasData(id)) {
          return;
        }

        switch (type) {
          case 'Font':
            var exportedData = data[2];

            if ('error' in exportedData) {
              var exportedError = exportedData.error;
              warn('Error during font loading: ' + exportedError);
              this.commonObjs.resolve(id, exportedError);
              break;
            }
            var fontRegistry = null;
            if (getDefaultSetting('pdfBug') && globalScope.FontInspector &&
                globalScope['FontInspector'].enabled) {
              fontRegistry = {
                registerFont: function (font, url) {
                  globalScope['FontInspector'].fontAdded(font, url);
                }
              };
            }
            var font = new FontFaceObject(exportedData, {
              isEvalSuported: getDefaultSetting('isEvalSupported'),
              disableFontFace: getDefaultSetting('disableFontFace'),
              fontRegistry: fontRegistry
            });

            this.fontLoader.bind(
              [font],
              function fontReady(fontObjs) {
                this.commonObjs.resolve(id, font);
              }.bind(this)
            );
            break;
          case 'FontPath':
            this.commonObjs.resolve(id, data[2]);
            break;
          default:
            error('Got unknown common object type ' + type);
        }
      }, this);

      messageHandler.on('obj', function transportObj(data) {
        if (this.destroyed) {
          return; // Ignore any pending requests if the worker was terminated.
        }

        var id = data[0];
        var pageIndex = data[1];
        var type = data[2];
        var pageProxy = this.pageCache[pageIndex];
        var imageData;
        if (pageProxy.objs.hasData(id)) {
          return;
        }

        switch (type) {
          case 'JpegStream':
            imageData = data[3];
            loadJpegStream(id, imageData, pageProxy.objs);
            break;
          case 'Image':
            imageData = data[3];
            pageProxy.objs.resolve(id, imageData);

            // heuristics that will allow not to store large data
            var MAX_IMAGE_SIZE_TO_STORE = 8000000;
            if (imageData && 'data' in imageData &&
                imageData.data.length > MAX_IMAGE_SIZE_TO_STORE) {
              pageProxy.cleanupAfterRender = true;
            }
            break;
          default:
            error('Got unknown object type ' + type);
        }
      }, this);

      messageHandler.on('DocProgress', function transportDocProgress(data) {
        if (this.destroyed) {
          return; // Ignore any pending requests if the worker was terminated.
        }

        var loadingTask = this.loadingTask;
        if (loadingTask.onProgress) {
          loadingTask.onProgress({
            loaded: data.loaded,
            total: data.total
          });
        }
      }, this);

      messageHandler.on('PageError', function transportError(data) {
        if (this.destroyed) {
          return; // Ignore any pending requests if the worker was terminated.
        }

        var page = this.pageCache[data.pageNum - 1];
        var intentState = page.intentStates[data.intent];

        if (intentState.displayReadyCapability) {
          intentState.displayReadyCapability.reject(data.error);
        } else {
          error(data.error);
        }

        if (intentState.operatorList) {
          // Mark operator list as complete.
          intentState.operatorList.lastChunk = true;
          for (var i = 0; i < intentState.renderTasks.length; i++) {
            intentState.renderTasks[i].operatorListChanged();
          }
        }
      }, this);

      messageHandler.on('UnsupportedFeature',
          function transportUnsupportedFeature(data) {
        if (this.destroyed) {
          return; // Ignore any pending requests if the worker was terminated.
        }
        var featureId = data.featureId;
        var loadingTask = this.loadingTask;
        if (loadingTask.onUnsupportedFeature) {
          loadingTask.onUnsupportedFeature(featureId);
        }
        _UnsupportedManager.notify(featureId);
      }, this);

      messageHandler.on('JpegDecode', function(data) {
        if (this.destroyed) {
          return Promise.reject(new Error('Worker was destroyed'));
        }

        var imageUrl = data[0];
        var components = data[1];
        if (components !== 3 && components !== 1) {
          return Promise.reject(
            new Error('Only 3 components or 1 component can be returned'));
        }

        return new Promise(function (resolve, reject) {
          var img = new Image();
          img.onload = function () {
            var width = img.width;
            var height = img.height;
            var size = width * height;
            var rgbaLength = size * 4;
            var buf = new Uint8Array(size * components);
            var tmpCanvas = createScratchCanvas(width, height);
            var tmpCtx = tmpCanvas.getContext('2d');
            tmpCtx.drawImage(img, 0, 0);
            var data = tmpCtx.getImageData(0, 0, width, height).data;
            var i, j;

            if (components === 3) {
              for (i = 0, j = 0; i < rgbaLength; i += 4, j += 3) {
                buf[j] = data[i];
                buf[j + 1] = data[i + 1];
                buf[j + 2] = data[i + 2];
              }
            } else if (components === 1) {
              for (i = 0, j = 0; i < rgbaLength; i += 4, j++) {
                buf[j] = data[i];
              }
            }
            resolve({ data: buf, width: width, height: height});
          };
          img.onerror = function () {
            reject(new Error('JpegDecode failed to load image'));
          };
          img.src = imageUrl;
        });
      }, this);
    },

    getData: function WorkerTransport_getData() {
      return this.messageHandler.sendWithPromise('GetData', null);
    },

    getPage: function WorkerTransport_getPage(pageNumber, capability) {
      if (!isInt(pageNumber) || pageNumber <= 0 || pageNumber > this.numPages) {
        return Promise.reject(new Error('Invalid page request'));
      }

      var pageIndex = pageNumber - 1;
      if (pageIndex in this.pagePromises) {
        return this.pagePromises[pageIndex];
      }
      var promise = this.messageHandler.sendWithPromise('GetPage', {
        pageIndex: pageIndex
      }).then(function (pageInfo) {
        if (this.destroyed) {
          throw new Error('Transport destroyed');
        }
        var page = new PDFPageProxy(pageIndex, pageInfo, this);
        this.pageCache[pageIndex] = page;
        return page;
      }.bind(this));
      this.pagePromises[pageIndex] = promise;
      return promise;
    },

    getPageIndex: function WorkerTransport_getPageIndexByRef(ref) {
      return this.messageHandler.sendWithPromise('GetPageIndex', {
        ref: ref,
      }).catch(function (reason) {
        return Promise.reject(new Error(reason));
      });
    },

    getAnnotations: function WorkerTransport_getAnnotations(pageIndex, intent) {
      return this.messageHandler.sendWithPromise('GetAnnotations', {
        pageIndex: pageIndex,
        intent: intent,
      });
    },

    getDestinations: function WorkerTransport_getDestinations() {
      return this.messageHandler.sendWithPromise('GetDestinations', null);
    },

    getDestination: function WorkerTransport_getDestination(id) {
      return this.messageHandler.sendWithPromise('GetDestination', { id: id });
    },

    getPageLabels: function WorkerTransport_getPageLabels() {
      return this.messageHandler.sendWithPromise('GetPageLabels', null);
    },

    getAttachments: function WorkerTransport_getAttachments() {
      return this.messageHandler.sendWithPromise('GetAttachments', null);
    },

    getJavaScript: function WorkerTransport_getJavaScript() {
      return this.messageHandler.sendWithPromise('GetJavaScript', null);
    },

    getOutline: function WorkerTransport_getOutline() {
      return this.messageHandler.sendWithPromise('GetOutline', null);
    },

    getMetadata: function WorkerTransport_getMetadata() {
      return this.messageHandler.sendWithPromise('GetMetadata', null).
        then(function transportMetadata(results) {
        return {
          info: results[0],
          metadata: (results[1] ? new Metadata(results[1]) : null)
        };
      });
    },

    getStats: function WorkerTransport_getStats() {
      return this.messageHandler.sendWithPromise('GetStats', null);
    },

    startCleanup: function WorkerTransport_startCleanup() {
      this.messageHandler.sendWithPromise('Cleanup', null).
        then(function endCleanup() {
        for (var i = 0, ii = this.pageCache.length; i < ii; i++) {
          var page = this.pageCache[i];
          if (page) {
            page.cleanup();
          }
        }
        this.commonObjs.clear();
        this.fontLoader.clear();
      }.bind(this));
    }
  };
  return WorkerTransport;

})();

/**
 * A PDF document and page is built of many objects. E.g. there are objects
 * for fonts, images, rendering code and such. These objects might get processed
 * inside of a worker. The `PDFObjects` implements some basic functions to
 * manage these objects.
 * @ignore
 */
var PDFObjects = (function PDFObjectsClosure() {
  function PDFObjects() {
    this.objs = Object.create(null);
  }

  PDFObjects.prototype = {
    /**
     * Internal function.
     * Ensures there is an object defined for `objId`.
     */
    ensureObj: function PDFObjects_ensureObj(objId) {
      if (this.objs[objId]) {
        return this.objs[objId];
      }

      var obj = {
        capability: createPromiseCapability(),
        data: null,
        resolved: false
      };
      this.objs[objId] = obj;

      return obj;
    },

    /**
     * If called *without* callback, this returns the data of `objId` but the
     * object needs to be resolved. If it isn't, this function throws.
     *
     * If called *with* a callback, the callback is called with the data of the
     * object once the object is resolved. That means, if you call this
     * function and the object is already resolved, the callback gets called
     * right away.
     */
    get: function PDFObjects_get(objId, callback) {
      // If there is a callback, then the get can be async and the object is
      // not required to be resolved right now
      if (callback) {
        this.ensureObj(objId).capability.promise.then(callback);
        return null;
      }

      // If there isn't a callback, the user expects to get the resolved data
      // directly.
      var obj = this.objs[objId];

      // If there isn't an object yet or the object isn't resolved, then the
      // data isn't ready yet!
      if (!obj || !obj.resolved) {
        error('Requesting object that isn\'t resolved yet ' + objId);
      }

      return obj.data;
    },

    /**
     * Resolves the object `objId` with optional `data`.
     */
    resolve: function PDFObjects_resolve(objId, data) {
      var obj = this.ensureObj(objId);

      obj.resolved = true;
      obj.data = data;
      obj.capability.resolve(data);
    },

    isResolved: function PDFObjects_isResolved(objId) {
      var objs = this.objs;

      if (!objs[objId]) {
        return false;
      } else {
        return objs[objId].resolved;
      }
    },

    hasData: function PDFObjects_hasData(objId) {
      return this.isResolved(objId);
    },

    /**
     * Returns the data of `objId` if object exists, null otherwise.
     */
    getData: function PDFObjects_getData(objId) {
      var objs = this.objs;
      if (!objs[objId] || !objs[objId].resolved) {
        return null;
      } else {
        return objs[objId].data;
      }
    },

    clear: function PDFObjects_clear() {
      this.objs = Object.create(null);
    }
  };
  return PDFObjects;
})();

/**
 * Allows controlling of the rendering tasks.
 * @class
 * @alias RenderTask
 */
var RenderTask = (function RenderTaskClosure() {
  function RenderTask(internalRenderTask) {
    this._internalRenderTask = internalRenderTask;

    /**
     * Callback for incremental rendering -- a function that will be called
     * each time the rendering is paused.  To continue rendering call the
     * function that is the first argument to the callback.
     * @type {function}
     */
    this.onContinue = null;
  }

  RenderTask.prototype = /** @lends RenderTask.prototype */ {
    /**
     * Promise for rendering task completion.
     * @return {Promise}
     */
    get promise() {
      return this._internalRenderTask.capability.promise;
    },

    /**
     * Cancels the rendering task. If the task is currently rendering it will
     * not be cancelled until graphics pauses with a timeout. The promise that
     * this object extends will resolved when cancelled.
     */
    cancel: function RenderTask_cancel() {
      this._internalRenderTask.cancel();
    },

    /**
     * Registers callbacks to indicate the rendering task completion.
     *
     * @param {function} onFulfilled The callback for the rendering completion.
     * @param {function} onRejected The callback for the rendering failure.
     * @return {Promise} A promise that is resolved after the onFulfilled or
     *                   onRejected callback.
     */
    then: function RenderTask_then(onFulfilled, onRejected) {
      return this.promise.then.apply(this.promise, arguments);
    }
  };

  return RenderTask;
})();

/**
 * For internal use only.
 * @ignore
 */
var InternalRenderTask = (function InternalRenderTaskClosure() {

  function InternalRenderTask(callback, params, objs, commonObjs, operatorList,
                              pageNumber) {
    this.callback = callback;
    this.params = params;
    this.objs = objs;
    this.commonObjs = commonObjs;
    this.operatorListIdx = null;
    this.operatorList = operatorList;
    this.pageNumber = pageNumber;
    this.running = false;
    this.graphicsReadyCallback = null;
    this.graphicsReady = false;
    this.useRequestAnimationFrame = false;
    this.cancelled = false;
    this.capability = createPromiseCapability();
    this.task = new RenderTask(this);
    // caching this-bound methods
    this._continueBound = this._continue.bind(this);
    this._scheduleNextBound = this._scheduleNext.bind(this);
    this._nextBound = this._next.bind(this);
  }

  InternalRenderTask.prototype = {

    initializeGraphics:
        function InternalRenderTask_initializeGraphics(transparency) {

      if (this.cancelled) {
        return;
      }
      if (getDefaultSetting('pdfBug') && globalScope.StepperManager &&
          globalScope.StepperManager.enabled) {
        this.stepper = globalScope.StepperManager.create(this.pageNumber - 1);
        this.stepper.init(this.operatorList);
        this.stepper.nextBreakPoint = this.stepper.getNextBreakPoint();
      }

      var params = this.params;
      this.gfx = new CanvasGraphics(params.canvasContext, this.commonObjs,
                                    this.objs, params.imageLayer);

      this.gfx.beginDrawing(params.transform, params.viewport, transparency);
      this.operatorListIdx = 0;
      this.graphicsReady = true;
      if (this.graphicsReadyCallback) {
        this.graphicsReadyCallback();
      }
    },

    cancel: function InternalRenderTask_cancel() {
      this.running = false;
      this.cancelled = true;
      this.callback('cancelled');
    },

    operatorListChanged: function InternalRenderTask_operatorListChanged() {
      if (!this.graphicsReady) {
        if (!this.graphicsReadyCallback) {
          this.graphicsReadyCallback = this._continueBound;
        }
        return;
      }

      if (this.stepper) {
        this.stepper.updateOperatorList(this.operatorList);
      }

      if (this.running) {
        return;
      }
      this._continue();
    },

    _continue: function InternalRenderTask__continue() {
      this.running = true;
      if (this.cancelled) {
        return;
      }
      if (this.task.onContinue) {
        this.task.onContinue.call(this.task, this._scheduleNextBound);
      } else {
        this._scheduleNext();
      }
    },

    _scheduleNext: function InternalRenderTask__scheduleNext() {
      if (this.useRequestAnimationFrame && typeof window !== 'undefined') {
        window.requestAnimationFrame(this._nextBound);
      } else {
        Promise.resolve(undefined).then(this._nextBound);
      }
    },

    _next: function InternalRenderTask__next() {
      if (this.cancelled) {
        return;
      }
      this.operatorListIdx = this.gfx.executeOperatorList(this.operatorList,
                                        this.operatorListIdx,
                                        this._continueBound,
                                        this.stepper);
      if (this.operatorListIdx === this.operatorList.argsArray.length) {
        this.running = false;
        if (this.operatorList.lastChunk) {
          this.gfx.endDrawing();
          this.callback();
        }
      }
    }

  };

  return InternalRenderTask;
})();

/**
 * (Deprecated) Global observer of unsupported feature usages. Use
 * onUnsupportedFeature callback of the {PDFDocumentLoadingTask} instance.
 */
var _UnsupportedManager = (function UnsupportedManagerClosure() {
  var listeners = [];
  return {
    listen: function (cb) {
      deprecated('Global UnsupportedManager.listen is used: ' +
                 ' use PDFDocumentLoadingTask.onUnsupportedFeature instead');
      listeners.push(cb);
    },
    notify: function (featureId) {
      for (var i = 0, ii = listeners.length; i < ii; i++) {
        listeners[i](featureId);
      }
    }
  };
})();

if (typeof pdfjsVersion !== 'undefined') {
  exports.version = pdfjsVersion;
}
if (typeof pdfjsBuild !== 'undefined') {
  exports.build = pdfjsBuild;
}

exports.getDocument = getDocument;
exports.PDFDataRangeTransport = PDFDataRangeTransport;
exports.PDFWorker = PDFWorker;
exports.PDFDocumentProxy = PDFDocumentProxy;
exports.PDFPageProxy = PDFPageProxy;
exports._UnsupportedManager = _UnsupportedManager;
}));