pdfjs-dist/lib/core/obj.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 sharedUtil = require('../shared/util.js');
var corePrimitives = require('./primitives.js');
var coreCrypto = require('./crypto.js');
var coreParser = require('./parser.js');
var coreChunkedStream = require('./chunked_stream.js');
var coreColorSpace = require('./colorspace.js');
var InvalidPDFException = sharedUtil.InvalidPDFException;
var MissingDataException = sharedUtil.MissingDataException;
var XRefParseException = sharedUtil.XRefParseException;
var assert = sharedUtil.assert;
var bytesToString = sharedUtil.bytesToString;
var createPromiseCapability = sharedUtil.createPromiseCapability;
var error = sharedUtil.error;
var info = sharedUtil.info;
var isArray = sharedUtil.isArray;
var isBool = sharedUtil.isBool;
var isInt = sharedUtil.isInt;
var isString = sharedUtil.isString;
var shadow = sharedUtil.shadow;
var stringToPDFString = sharedUtil.stringToPDFString;
var stringToUTF8String = sharedUtil.stringToUTF8String;
var warn = sharedUtil.warn;
var createValidAbsoluteUrl = sharedUtil.createValidAbsoluteUrl;
var Util = sharedUtil.Util;
var Ref = corePrimitives.Ref;
var RefSet = corePrimitives.RefSet;
var RefSetCache = corePrimitives.RefSetCache;
var isName = corePrimitives.isName;
var isCmd = corePrimitives.isCmd;
var isDict = corePrimitives.isDict;
var isRef = corePrimitives.isRef;
var isRefsEqual = corePrimitives.isRefsEqual;
var isStream = corePrimitives.isStream;
var CipherTransformFactory = coreCrypto.CipherTransformFactory;
var Lexer = coreParser.Lexer;
var Parser = coreParser.Parser;
var ChunkedStream = coreChunkedStream.ChunkedStream;
var ColorSpace = coreColorSpace.ColorSpace;
var Catalog = function CatalogClosure() {
 function Catalog(pdfManager, xref, pageFactory) {
  this.pdfManager = pdfManager;
  this.xref = xref;
  this.catDict = xref.getCatalogObj();
  this.fontCache = new RefSetCache();
  this.builtInCMapCache = Object.create(null);
  assert(isDict(this.catDict), 'catalog object is not a dictionary');
  this.pageFactory = pageFactory;
  this.pagePromises = [];
 }
 Catalog.prototype = {
  get metadata() {
   var streamRef = this.catDict.getRaw('Metadata');
   if (!isRef(streamRef)) {
    return shadow(this, 'metadata', null);
   }
   var encryptMetadata = !this.xref.encrypt ? false : this.xref.encrypt.encryptMetadata;
   var stream = this.xref.fetch(streamRef, !encryptMetadata);
   var metadata;
   if (stream && isDict(stream.dict)) {
    var type = stream.dict.get('Type');
    var subtype = stream.dict.get('Subtype');
    if (isName(type, 'Metadata') && isName(subtype, 'XML')) {
     try {
      metadata = stringToUTF8String(bytesToString(stream.getBytes()));
     } catch (e) {
      info('Skipping invalid metadata.');
     }
    }
   }
   return shadow(this, 'metadata', metadata);
  },
  get toplevelPagesDict() {
   var pagesObj = this.catDict.get('Pages');
   assert(isDict(pagesObj), 'invalid top-level pages dictionary');
   return shadow(this, 'toplevelPagesDict', pagesObj);
  },
  get documentOutline() {
   var obj = null;
   try {
    obj = this.readDocumentOutline();
   } catch (ex) {
    if (ex instanceof MissingDataException) {
     throw ex;
    }
    warn('Unable to read document outline');
   }
   return shadow(this, 'documentOutline', obj);
  },
  readDocumentOutline: function Catalog_readDocumentOutline() {
   var obj = this.catDict.get('Outlines');
   if (!isDict(obj)) {
    return null;
   }
   obj = obj.getRaw('First');
   if (!isRef(obj)) {
    return null;
   }
   var root = { items: [] };
   var queue = [{
     obj: obj,
     parent: root
    }];
   var processed = new RefSet();
   processed.put(obj);
   var xref = this.xref, blackColor = new Uint8Array(3);
   while (queue.length > 0) {
    var i = queue.shift();
    var outlineDict = xref.fetchIfRef(i.obj);
    if (outlineDict === null) {
     continue;
    }
    assert(outlineDict.has('Title'), 'Invalid outline item');
    var data = {
     url: null,
     dest: null
    };
    Catalog.parseDestDictionary({
     destDict: outlineDict,
     resultObj: data,
     docBaseUrl: this.pdfManager.docBaseUrl
    });
    var title = outlineDict.get('Title');
    var flags = outlineDict.get('F') || 0;
    var color = outlineDict.getArray('C'), rgbColor = blackColor;
    if (isArray(color) && color.length === 3 && (color[0] !== 0 || color[1] !== 0 || color[2] !== 0)) {
     rgbColor = ColorSpace.singletons.rgb.getRgb(color, 0);
    }
    var outlineItem = {
     dest: data.dest,
     url: data.url,
     unsafeUrl: data.unsafeUrl,
     newWindow: data.newWindow,
     title: stringToPDFString(title),
     color: rgbColor,
     count: outlineDict.get('Count'),
     bold: !!(flags & 2),
     italic: !!(flags & 1),
     items: []
    };
    i.parent.items.push(outlineItem);
    obj = outlineDict.getRaw('First');
    if (isRef(obj) && !processed.has(obj)) {
     queue.push({
      obj: obj,
      parent: outlineItem
     });
     processed.put(obj);
    }
    obj = outlineDict.getRaw('Next');
    if (isRef(obj) && !processed.has(obj)) {
     queue.push({
      obj: obj,
      parent: i.parent
     });
     processed.put(obj);
    }
   }
   return root.items.length > 0 ? root.items : null;
  },
  get numPages() {
   var obj = this.toplevelPagesDict.get('Count');
   assert(isInt(obj), 'page count in top level pages object is not an integer');
   return shadow(this, 'num', obj);
  },
  get destinations() {
   function fetchDestination(dest) {
    return isDict(dest) ? dest.get('D') : dest;
   }
   var xref = this.xref;
   var dests = {}, nameTreeRef, nameDictionaryRef;
   var obj = this.catDict.get('Names');
   if (obj && obj.has('Dests')) {
    nameTreeRef = obj.getRaw('Dests');
   } else if (this.catDict.has('Dests')) {
    nameDictionaryRef = this.catDict.get('Dests');
   }
   if (nameDictionaryRef) {
    obj = nameDictionaryRef;
    obj.forEach(function catalogForEach(key, value) {
     if (!value) {
      return;
     }
     dests[key] = fetchDestination(value);
    });
   }
   if (nameTreeRef) {
    var nameTree = new NameTree(nameTreeRef, xref);
    var names = nameTree.getAll();
    for (var name in names) {
     dests[name] = fetchDestination(names[name]);
    }
   }
   return shadow(this, 'destinations', dests);
  },
  getDestination: function Catalog_getDestination(destinationId) {
   function fetchDestination(dest) {
    return isDict(dest) ? dest.get('D') : dest;
   }
   var xref = this.xref;
   var dest = null, nameTreeRef, nameDictionaryRef;
   var obj = this.catDict.get('Names');
   if (obj && obj.has('Dests')) {
    nameTreeRef = obj.getRaw('Dests');
   } else if (this.catDict.has('Dests')) {
    nameDictionaryRef = this.catDict.get('Dests');
   }
   if (nameDictionaryRef) {
    var value = nameDictionaryRef.get(destinationId);
    if (value) {
     dest = fetchDestination(value);
    }
   }
   if (nameTreeRef) {
    var nameTree = new NameTree(nameTreeRef, xref);
    dest = fetchDestination(nameTree.get(destinationId));
   }
   return dest;
  },
  get pageLabels() {
   var obj = null;
   try {
    obj = this.readPageLabels();
   } catch (ex) {
    if (ex instanceof MissingDataException) {
     throw ex;
    }
    warn('Unable to read page labels.');
   }
   return shadow(this, 'pageLabels', obj);
  },
  readPageLabels: function Catalog_readPageLabels() {
   var obj = this.catDict.getRaw('PageLabels');
   if (!obj) {
    return null;
   }
   var pageLabels = new Array(this.numPages);
   var style = null;
   var prefix = '';
   var numberTree = new NumberTree(obj, this.xref);
   var nums = numberTree.getAll();
   var currentLabel = '', currentIndex = 1;
   for (var i = 0, ii = this.numPages; i < ii; i++) {
    if (i in nums) {
     var labelDict = nums[i];
     assert(isDict(labelDict), 'The PageLabel is not a dictionary.');
     var type = labelDict.get('Type');
     assert(!type || isName(type, 'PageLabel'), 'Invalid type in PageLabel dictionary.');
     var s = labelDict.get('S');
     assert(!s || isName(s), 'Invalid style in PageLabel dictionary.');
     style = s ? s.name : null;
     var p = labelDict.get('P');
     assert(!p || isString(p), 'Invalid prefix in PageLabel dictionary.');
     prefix = p ? stringToPDFString(p) : '';
     var st = labelDict.get('St');
     assert(!st || isInt(st) && st >= 1, 'Invalid start in PageLabel dictionary.');
     currentIndex = st || 1;
    }
    switch (style) {
    case 'D':
     currentLabel = currentIndex;
     break;
    case 'R':
    case 'r':
     currentLabel = Util.toRoman(currentIndex, style === 'r');
     break;
    case 'A':
    case 'a':
     var LIMIT = 26;
     var A_UPPER_CASE = 0x41, A_LOWER_CASE = 0x61;
     var baseCharCode = style === 'a' ? A_LOWER_CASE : A_UPPER_CASE;
     var letterIndex = currentIndex - 1;
     var character = String.fromCharCode(baseCharCode + letterIndex % LIMIT);
     var charBuf = [];
     for (var j = 0, jj = letterIndex / LIMIT | 0; j <= jj; j++) {
      charBuf.push(character);
     }
     currentLabel = charBuf.join('');
     break;
    default:
     assert(!style, 'Invalid style "' + style + '" in PageLabel dictionary.');
    }
    pageLabels[i] = prefix + currentLabel;
    currentLabel = '';
    currentIndex++;
   }
   return pageLabels;
  },
  get attachments() {
   var xref = this.xref;
   var attachments = null, nameTreeRef;
   var obj = this.catDict.get('Names');
   if (obj) {
    nameTreeRef = obj.getRaw('EmbeddedFiles');
   }
   if (nameTreeRef) {
    var nameTree = new NameTree(nameTreeRef, xref);
    var names = nameTree.getAll();
    for (var name in names) {
     var fs = new FileSpec(names[name], xref);
     if (!attachments) {
      attachments = Object.create(null);
     }
     attachments[stringToPDFString(name)] = fs.serializable;
    }
   }
   return shadow(this, 'attachments', attachments);
  },
  get javaScript() {
   var xref = this.xref;
   var obj = this.catDict.get('Names');
   var javaScript = [];
   function appendIfJavaScriptDict(jsDict) {
    var type = jsDict.get('S');
    if (!isName(type, 'JavaScript')) {
     return;
    }
    var js = jsDict.get('JS');
    if (isStream(js)) {
     js = bytesToString(js.getBytes());
    } else if (!isString(js)) {
     return;
    }
    javaScript.push(stringToPDFString(js));
   }
   if (obj && obj.has('JavaScript')) {
    var nameTree = new NameTree(obj.getRaw('JavaScript'), xref);
    var names = nameTree.getAll();
    for (var name in names) {
     var jsDict = names[name];
     if (isDict(jsDict)) {
      appendIfJavaScriptDict(jsDict);
     }
    }
   }
   var openactionDict = this.catDict.get('OpenAction');
   if (isDict(openactionDict, 'Action')) {
    var actionType = openactionDict.get('S');
    if (isName(actionType, 'Named')) {
     var action = openactionDict.get('N');
     if (isName(action, 'Print')) {
      javaScript.push('print({});');
     }
    } else {
     appendIfJavaScriptDict(openactionDict);
    }
   }
   return shadow(this, 'javaScript', javaScript);
  },
  cleanup: function Catalog_cleanup() {
   var promises = [];
   this.fontCache.forEach(function (promise) {
    promises.push(promise);
   });
   return Promise.all(promises).then(function (translatedFonts) {
    for (var i = 0, ii = translatedFonts.length; i < ii; i++) {
     var font = translatedFonts[i].dict;
     delete font.translated;
    }
    this.fontCache.clear();
    this.builtInCMapCache = Object.create(null);
   }.bind(this));
  },
  getPage: function Catalog_getPage(pageIndex) {
   if (!(pageIndex in this.pagePromises)) {
    this.pagePromises[pageIndex] = this.getPageDict(pageIndex).then(function (a) {
     var dict = a[0];
     var ref = a[1];
     return this.pageFactory.createPage(pageIndex, dict, ref, this.fontCache, this.builtInCMapCache);
    }.bind(this));
   }
   return this.pagePromises[pageIndex];
  },
  getPageDict: function Catalog_getPageDict(pageIndex) {
   var capability = createPromiseCapability();
   var nodesToVisit = [this.catDict.getRaw('Pages')];
   var currentPageIndex = 0;
   var xref = this.xref;
   function next() {
    while (nodesToVisit.length) {
     var currentNode = nodesToVisit.pop();
     if (isRef(currentNode)) {
      xref.fetchAsync(currentNode).then(function (obj) {
       if (isDict(obj, 'Page') || isDict(obj) && !obj.has('Kids')) {
        if (pageIndex === currentPageIndex) {
         capability.resolve([
          obj,
          currentNode
         ]);
        } else {
         currentPageIndex++;
         next();
        }
        return;
       }
       nodesToVisit.push(obj);
       next();
      }, capability.reject);
      return;
     }
     assert(isDict(currentNode), 'page dictionary kid reference points to wrong type of object');
     var count = currentNode.get('Count');
     if (currentPageIndex + count <= pageIndex) {
      currentPageIndex += count;
      continue;
     }
     var kids = currentNode.get('Kids');
     assert(isArray(kids), 'page dictionary kids object is not an array');
     for (var last = kids.length - 1; last >= 0; last--) {
      nodesToVisit.push(kids[last]);
     }
    }
    capability.reject('Page index ' + pageIndex + ' not found.');
   }
   next();
   return capability.promise;
  },
  getPageIndex: function Catalog_getPageIndex(pageRef) {
   var xref = this.xref;
   function pagesBeforeRef(kidRef) {
    var total = 0;
    var parentRef;
    return xref.fetchAsync(kidRef).then(function (node) {
     if (isRefsEqual(kidRef, pageRef) && !isDict(node, 'Page') && !(isDict(node) && !node.has('Type') && node.has('Contents'))) {
      throw new Error('The reference does not point to a /Page Dict.');
     }
     if (!node) {
      return null;
     }
     assert(isDict(node), 'node must be a Dict.');
     parentRef = node.getRaw('Parent');
     return node.getAsync('Parent');
    }).then(function (parent) {
     if (!parent) {
      return null;
     }
     assert(isDict(parent), 'parent must be a Dict.');
     return parent.getAsync('Kids');
    }).then(function (kids) {
     if (!kids) {
      return null;
     }
     var kidPromises = [];
     var found = false;
     for (var i = 0; i < kids.length; i++) {
      var kid = kids[i];
      assert(isRef(kid), 'kid must be a Ref.');
      if (kid.num === kidRef.num) {
       found = true;
       break;
      }
      kidPromises.push(xref.fetchAsync(kid).then(function (kid) {
       if (kid.has('Count')) {
        var count = kid.get('Count');
        total += count;
       } else {
        total++;
       }
      }));
     }
     if (!found) {
      error('kid ref not found in parents kids');
     }
     return Promise.all(kidPromises).then(function () {
      return [
       total,
       parentRef
      ];
     });
    });
   }
   var total = 0;
   function next(ref) {
    return pagesBeforeRef(ref).then(function (args) {
     if (!args) {
      return total;
     }
     var count = args[0];
     var parentRef = args[1];
     total += count;
     return next(parentRef);
    });
   }
   return next(pageRef);
  }
 };
 Catalog.parseDestDictionary = function Catalog_parseDestDictionary(params) {
  function addDefaultProtocolToUrl(url) {
   if (url.indexOf('www.') === 0) {
    return 'http://' + url;
   }
   return url;
  }
  function tryConvertUrlEncoding(url) {
   try {
    return stringToUTF8String(url);
   } catch (e) {
    return url;
   }
  }
  var destDict = params.destDict;
  if (!isDict(destDict)) {
   warn('Catalog_parseDestDictionary: "destDict" must be a dictionary.');
   return;
  }
  var resultObj = params.resultObj;
  if (typeof resultObj !== 'object') {
   warn('Catalog_parseDestDictionary: "resultObj" must be an object.');
   return;
  }
  var docBaseUrl = params.docBaseUrl || null;
  var action = destDict.get('A'), url, dest;
  if (isDict(action)) {
   var linkType = action.get('S').name;
   switch (linkType) {
   case 'URI':
    url = action.get('URI');
    if (isName(url)) {
     url = '/' + url.name;
    } else if (isString(url)) {
     url = addDefaultProtocolToUrl(url);
    }
    break;
   case 'GoTo':
    dest = action.get('D');
    break;
   case 'Launch':
   case 'GoToR':
    var urlDict = action.get('F');
    if (isDict(urlDict)) {
     url = urlDict.get('F') || null;
    } else if (isString(urlDict)) {
     url = urlDict;
    }
    var remoteDest = action.get('D');
    if (remoteDest) {
     if (isName(remoteDest)) {
      remoteDest = remoteDest.name;
     }
     if (isString(url)) {
      var baseUrl = url.split('#')[0];
      if (isString(remoteDest)) {
       url = baseUrl + '#' + (/^\d+$/.test(remoteDest) ? 'nameddest=' : '') + remoteDest;
      } else if (isArray(remoteDest)) {
       url = baseUrl + '#' + JSON.stringify(remoteDest);
      }
     }
    }
    var newWindow = action.get('NewWindow');
    if (isBool(newWindow)) {
     resultObj.newWindow = newWindow;
    }
    break;
   case 'Named':
    var namedAction = action.get('N');
    if (isName(namedAction)) {
     resultObj.action = namedAction.name;
    }
    break;
   case 'JavaScript':
    var jsAction = action.get('JS'), js;
    if (isStream(jsAction)) {
     js = bytesToString(jsAction.getBytes());
    } else if (isString(jsAction)) {
     js = jsAction;
    }
    if (js) {
     var URL_OPEN_METHODS = [
      'app.launchURL',
      'window.open'
     ];
     var regex = new RegExp('^\\s*(' + URL_OPEN_METHODS.join('|').split('.').join('\\.') + ')\\((?:\'|\")([^\'\"]*)(?:\'|\")(?:,\\s*(\\w+)\\)|\\))', 'i');
     var jsUrl = regex.exec(stringToPDFString(js));
     if (jsUrl && jsUrl[2]) {
      url = jsUrl[2];
      if (jsUrl[3] === 'true' && jsUrl[1] === 'app.launchURL') {
       resultObj.newWindow = true;
      }
      break;
     }
    }
   default:
    warn('Catalog_parseDestDictionary: Unrecognized link type "' + linkType + '".');
    break;
   }
  } else if (destDict.has('Dest')) {
   dest = destDict.get('Dest');
  }
  if (isString(url)) {
   url = tryConvertUrlEncoding(url);
   var absoluteUrl = createValidAbsoluteUrl(url, docBaseUrl);
   if (absoluteUrl) {
    resultObj.url = absoluteUrl.href;
   }
   resultObj.unsafeUrl = url;
  }
  if (dest) {
   if (isName(dest)) {
    dest = dest.name;
   }
   if (isString(dest) || isArray(dest)) {
    resultObj.dest = dest;
   }
  }
 };
 return Catalog;
}();
var XRef = function XRefClosure() {
 function XRef(stream, pdfManager) {
  this.stream = stream;
  this.pdfManager = pdfManager;
  this.entries = [];
  this.xrefstms = Object.create(null);
  this.cache = [];
  this.stats = {
   streamTypes: [],
   fontTypes: []
  };
 }
 XRef.prototype = {
  setStartXRef: function XRef_setStartXRef(startXRef) {
   this.startXRefQueue = [startXRef];
  },
  parse: function XRef_parse(recoveryMode) {
   var trailerDict;
   if (!recoveryMode) {
    trailerDict = this.readXRef();
   } else {
    warn('Indexing all PDF objects');
    trailerDict = this.indexObjects();
   }
   trailerDict.assignXref(this);
   this.trailer = trailerDict;
   var encrypt = trailerDict.get('Encrypt');
   if (isDict(encrypt)) {
    var ids = trailerDict.get('ID');
    var fileId = ids && ids.length ? ids[0] : '';
    encrypt.suppressEncryption = true;
    this.encrypt = new CipherTransformFactory(encrypt, fileId, this.pdfManager.password);
   }
   if (!(this.root = trailerDict.get('Root'))) {
    error('Invalid root reference');
   }
  },
  processXRefTable: function XRef_processXRefTable(parser) {
   if (!('tableState' in this)) {
    this.tableState = {
     entryNum: 0,
     streamPos: parser.lexer.stream.pos,
     parserBuf1: parser.buf1,
     parserBuf2: parser.buf2
    };
   }
   var obj = this.readXRefTable(parser);
   if (!isCmd(obj, 'trailer')) {
    error('Invalid XRef table: could not find trailer dictionary');
   }
   var dict = parser.getObj();
   if (!isDict(dict) && dict.dict) {
    dict = dict.dict;
   }
   if (!isDict(dict)) {
    error('Invalid XRef table: could not parse trailer dictionary');
   }
   delete this.tableState;
   return dict;
  },
  readXRefTable: function XRef_readXRefTable(parser) {
   var stream = parser.lexer.stream;
   var tableState = this.tableState;
   stream.pos = tableState.streamPos;
   parser.buf1 = tableState.parserBuf1;
   parser.buf2 = tableState.parserBuf2;
   var obj;
   while (true) {
    if (!('firstEntryNum' in tableState) || !('entryCount' in tableState)) {
     if (isCmd(obj = parser.getObj(), 'trailer')) {
      break;
     }
     tableState.firstEntryNum = obj;
     tableState.entryCount = parser.getObj();
    }
    var first = tableState.firstEntryNum;
    var count = tableState.entryCount;
    if (!isInt(first) || !isInt(count)) {
     error('Invalid XRef table: wrong types in subsection header');
    }
    for (var i = tableState.entryNum; i < count; i++) {
     tableState.streamPos = stream.pos;
     tableState.entryNum = i;
     tableState.parserBuf1 = parser.buf1;
     tableState.parserBuf2 = parser.buf2;
     var entry = {};
     entry.offset = parser.getObj();
     entry.gen = parser.getObj();
     var type = parser.getObj();
     if (isCmd(type, 'f')) {
      entry.free = true;
     } else if (isCmd(type, 'n')) {
      entry.uncompressed = true;
     }
     if (!isInt(entry.offset) || !isInt(entry.gen) || !(entry.free || entry.uncompressed)) {
      error('Invalid entry in XRef subsection: ' + first + ', ' + count);
     }
     if (i === 0 && entry.free && first === 1) {
      first = 0;
     }
     if (!this.entries[i + first]) {
      this.entries[i + first] = entry;
     }
    }
    tableState.entryNum = 0;
    tableState.streamPos = stream.pos;
    tableState.parserBuf1 = parser.buf1;
    tableState.parserBuf2 = parser.buf2;
    delete tableState.firstEntryNum;
    delete tableState.entryCount;
   }
   if (this.entries[0] && !this.entries[0].free) {
    error('Invalid XRef table: unexpected first object');
   }
   return obj;
  },
  processXRefStream: function XRef_processXRefStream(stream) {
   if (!('streamState' in this)) {
    var streamParameters = stream.dict;
    var byteWidths = streamParameters.get('W');
    var range = streamParameters.get('Index');
    if (!range) {
     range = [
      0,
      streamParameters.get('Size')
     ];
    }
    this.streamState = {
     entryRanges: range,
     byteWidths: byteWidths,
     entryNum: 0,
     streamPos: stream.pos
    };
   }
   this.readXRefStream(stream);
   delete this.streamState;
   return stream.dict;
  },
  readXRefStream: function XRef_readXRefStream(stream) {
   var i, j;
   var streamState = this.streamState;
   stream.pos = streamState.streamPos;
   var byteWidths = streamState.byteWidths;
   var typeFieldWidth = byteWidths[0];
   var offsetFieldWidth = byteWidths[1];
   var generationFieldWidth = byteWidths[2];
   var entryRanges = streamState.entryRanges;
   while (entryRanges.length > 0) {
    var first = entryRanges[0];
    var n = entryRanges[1];
    if (!isInt(first) || !isInt(n)) {
     error('Invalid XRef range fields: ' + first + ', ' + n);
    }
    if (!isInt(typeFieldWidth) || !isInt(offsetFieldWidth) || !isInt(generationFieldWidth)) {
     error('Invalid XRef entry fields length: ' + first + ', ' + n);
    }
    for (i = streamState.entryNum; i < n; ++i) {
     streamState.entryNum = i;
     streamState.streamPos = stream.pos;
     var type = 0, offset = 0, generation = 0;
     for (j = 0; j < typeFieldWidth; ++j) {
      type = type << 8 | stream.getByte();
     }
     if (typeFieldWidth === 0) {
      type = 1;
     }
     for (j = 0; j < offsetFieldWidth; ++j) {
      offset = offset << 8 | stream.getByte();
     }
     for (j = 0; j < generationFieldWidth; ++j) {
      generation = generation << 8 | stream.getByte();
     }
     var entry = {};
     entry.offset = offset;
     entry.gen = generation;
     switch (type) {
     case 0:
      entry.free = true;
      break;
     case 1:
      entry.uncompressed = true;
      break;
     case 2:
      break;
     default:
      error('Invalid XRef entry type: ' + type);
     }
     if (!this.entries[first + i]) {
      this.entries[first + i] = entry;
     }
    }
    streamState.entryNum = 0;
    streamState.streamPos = stream.pos;
    entryRanges.splice(0, 2);
   }
  },
  indexObjects: function XRef_indexObjects() {
   var TAB = 0x9, LF = 0xA, CR = 0xD, SPACE = 0x20;
   var PERCENT = 0x25, LT = 0x3C;
   function readToken(data, offset) {
    var token = '', ch = data[offset];
    while (ch !== LF && ch !== CR && ch !== LT) {
     if (++offset >= data.length) {
      break;
     }
     token += String.fromCharCode(ch);
     ch = data[offset];
    }
    return token;
   }
   function skipUntil(data, offset, what) {
    var length = what.length, dataLength = data.length;
    var skipped = 0;
    while (offset < dataLength) {
     var i = 0;
     while (i < length && data[offset + i] === what[i]) {
      ++i;
     }
     if (i >= length) {
      break;
     }
     offset++;
     skipped++;
    }
    return skipped;
   }
   var objRegExp = /^(\d+)\s+(\d+)\s+obj\b/;
   var trailerBytes = new Uint8Array([
    116,
    114,
    97,
    105,
    108,
    101,
    114
   ]);
   var startxrefBytes = new Uint8Array([
    115,
    116,
    97,
    114,
    116,
    120,
    114,
    101,
    102
   ]);
   var endobjBytes = new Uint8Array([
    101,
    110,
    100,
    111,
    98,
    106
   ]);
   var xrefBytes = new Uint8Array([
    47,
    88,
    82,
    101,
    102
   ]);
   this.entries.length = 0;
   var stream = this.stream;
   stream.pos = 0;
   var buffer = stream.getBytes();
   var position = stream.start, length = buffer.length;
   var trailers = [], xrefStms = [];
   while (position < length) {
    var ch = buffer[position];
    if (ch === TAB || ch === LF || ch === CR || ch === SPACE) {
     ++position;
     continue;
    }
    if (ch === PERCENT) {
     do {
      ++position;
      if (position >= length) {
       break;
      }
      ch = buffer[position];
     } while (ch !== LF && ch !== CR);
     continue;
    }
    var token = readToken(buffer, position);
    var m;
    if (token.indexOf('xref') === 0 && (token.length === 4 || /\s/.test(token[4]))) {
     position += skipUntil(buffer, position, trailerBytes);
     trailers.push(position);
     position += skipUntil(buffer, position, startxrefBytes);
    } else if (m = objRegExp.exec(token)) {
     if (typeof this.entries[m[1]] === 'undefined') {
      this.entries[m[1]] = {
       offset: position - stream.start,
       gen: m[2] | 0,
       uncompressed: true
      };
     }
     var contentLength = skipUntil(buffer, position, endobjBytes) + 7;
     var content = buffer.subarray(position, position + contentLength);
     var xrefTagOffset = skipUntil(content, 0, xrefBytes);
     if (xrefTagOffset < contentLength && content[xrefTagOffset + 5] < 64) {
      xrefStms.push(position - stream.start);
      this.xrefstms[position - stream.start] = 1;
     }
     position += contentLength;
    } else if (token.indexOf('trailer') === 0 && (token.length === 7 || /\s/.test(token[7]))) {
     trailers.push(position);
     position += skipUntil(buffer, position, startxrefBytes);
    } else {
     position += token.length + 1;
    }
   }
   var i, ii;
   for (i = 0, ii = xrefStms.length; i < ii; ++i) {
    this.startXRefQueue.push(xrefStms[i]);
    this.readXRef(true);
   }
   var dict;
   for (i = 0, ii = trailers.length; i < ii; ++i) {
    stream.pos = trailers[i];
    var parser = new Parser(new Lexer(stream), true, this, true);
    var obj = parser.getObj();
    if (!isCmd(obj, 'trailer')) {
     continue;
    }
    dict = parser.getObj();
    if (!isDict(dict)) {
     continue;
    }
    if (dict.has('ID')) {
     return dict;
    }
   }
   if (dict) {
    return dict;
   }
   throw new InvalidPDFException('Invalid PDF structure');
  },
  readXRef: function XRef_readXRef(recoveryMode) {
   var stream = this.stream;
   try {
    while (this.startXRefQueue.length) {
     var startXRef = this.startXRefQueue[0];
     stream.pos = startXRef + stream.start;
     var parser = new Parser(new Lexer(stream), true, this);
     var obj = parser.getObj();
     var dict;
     if (isCmd(obj, 'xref')) {
      dict = this.processXRefTable(parser);
      if (!this.topDict) {
       this.topDict = dict;
      }
      obj = dict.get('XRefStm');
      if (isInt(obj)) {
       var pos = obj;
       if (!(pos in this.xrefstms)) {
        this.xrefstms[pos] = 1;
        this.startXRefQueue.push(pos);
       }
      }
     } else if (isInt(obj)) {
      if (!isInt(parser.getObj()) || !isCmd(parser.getObj(), 'obj') || !isStream(obj = parser.getObj())) {
       error('Invalid XRef stream');
      }
      dict = this.processXRefStream(obj);
      if (!this.topDict) {
       this.topDict = dict;
      }
      if (!dict) {
       error('Failed to read XRef stream');
      }
     } else {
      error('Invalid XRef stream header');
     }
     obj = dict.get('Prev');
     if (isInt(obj)) {
      this.startXRefQueue.push(obj);
     } else if (isRef(obj)) {
      this.startXRefQueue.push(obj.num);
     }
     this.startXRefQueue.shift();
    }
    return this.topDict;
   } catch (e) {
    if (e instanceof MissingDataException) {
     throw e;
    }
    info('(while reading XRef): ' + e);
   }
   if (recoveryMode) {
    return;
   }
   throw new XRefParseException();
  },
  getEntry: function XRef_getEntry(i) {
   var xrefEntry = this.entries[i];
   if (xrefEntry && !xrefEntry.free && xrefEntry.offset) {
    return xrefEntry;
   }
   return null;
  },
  fetchIfRef: function XRef_fetchIfRef(obj, suppressEncryption) {
   if (!isRef(obj)) {
    return obj;
   }
   return this.fetch(obj, suppressEncryption);
  },
  fetch: function XRef_fetch(ref, suppressEncryption) {
   assert(isRef(ref), 'ref object is not a reference');
   var num = ref.num;
   if (num in this.cache) {
    var cacheEntry = this.cache[num];
    if (isDict(cacheEntry) && !cacheEntry.objId) {
     cacheEntry.objId = ref.toString();
    }
    return cacheEntry;
   }
   var xrefEntry = this.getEntry(num);
   if (xrefEntry === null) {
    return this.cache[num] = null;
   }
   if (xrefEntry.uncompressed) {
    xrefEntry = this.fetchUncompressed(ref, xrefEntry, suppressEncryption);
   } else {
    xrefEntry = this.fetchCompressed(xrefEntry, suppressEncryption);
   }
   if (isDict(xrefEntry)) {
    xrefEntry.objId = ref.toString();
   } else if (isStream(xrefEntry)) {
    xrefEntry.dict.objId = ref.toString();
   }
   return xrefEntry;
  },
  fetchUncompressed: function XRef_fetchUncompressed(ref, xrefEntry, suppressEncryption) {
   var gen = ref.gen;
   var num = ref.num;
   if (xrefEntry.gen !== gen) {
    error('inconsistent generation in XRef');
   }
   var stream = this.stream.makeSubStream(xrefEntry.offset + this.stream.start);
   var parser = new Parser(new Lexer(stream), true, this);
   var obj1 = parser.getObj();
   var obj2 = parser.getObj();
   var obj3 = parser.getObj();
   if (!isInt(obj1) || parseInt(obj1, 10) !== num || !isInt(obj2) || parseInt(obj2, 10) !== gen || !isCmd(obj3)) {
    error('bad XRef entry');
   }
   if (!isCmd(obj3, 'obj')) {
    if (obj3.cmd.indexOf('obj') === 0) {
     num = parseInt(obj3.cmd.substring(3), 10);
     if (!isNaN(num)) {
      return num;
     }
    }
    error('bad XRef entry');
   }
   if (this.encrypt && !suppressEncryption) {
    xrefEntry = parser.getObj(this.encrypt.createCipherTransform(num, gen));
   } else {
    xrefEntry = parser.getObj();
   }
   if (!isStream(xrefEntry)) {
    this.cache[num] = xrefEntry;
   }
   return xrefEntry;
  },
  fetchCompressed: function XRef_fetchCompressed(xrefEntry, suppressEncryption) {
   var tableOffset = xrefEntry.offset;
   var stream = this.fetch(new Ref(tableOffset, 0));
   if (!isStream(stream)) {
    error('bad ObjStm stream');
   }
   var first = stream.dict.get('First');
   var n = stream.dict.get('N');
   if (!isInt(first) || !isInt(n)) {
    error('invalid first and n parameters for ObjStm stream');
   }
   var parser = new Parser(new Lexer(stream), false, this);
   parser.allowStreams = true;
   var i, entries = [], num, nums = [];
   for (i = 0; i < n; ++i) {
    num = parser.getObj();
    if (!isInt(num)) {
     error('invalid object number in the ObjStm stream: ' + num);
    }
    nums.push(num);
    var offset = parser.getObj();
    if (!isInt(offset)) {
     error('invalid object offset in the ObjStm stream: ' + offset);
    }
   }
   for (i = 0; i < n; ++i) {
    entries.push(parser.getObj());
    if (isCmd(parser.buf1, 'endobj')) {
     parser.shift();
    }
    num = nums[i];
    var entry = this.entries[num];
    if (entry && entry.offset === tableOffset && entry.gen === i) {
     this.cache[num] = entries[i];
    }
   }
   xrefEntry = entries[xrefEntry.gen];
   if (xrefEntry === undefined) {
    error('bad XRef entry for compressed object');
   }
   return xrefEntry;
  },
  fetchIfRefAsync: function XRef_fetchIfRefAsync(obj, suppressEncryption) {
   if (!isRef(obj)) {
    return Promise.resolve(obj);
   }
   return this.fetchAsync(obj, suppressEncryption);
  },
  fetchAsync: function XRef_fetchAsync(ref, suppressEncryption) {
   var streamManager = this.stream.manager;
   var xref = this;
   return new Promise(function tryFetch(resolve, reject) {
    try {
     resolve(xref.fetch(ref, suppressEncryption));
    } catch (e) {
     if (e instanceof MissingDataException) {
      streamManager.requestRange(e.begin, e.end).then(function () {
       tryFetch(resolve, reject);
      }, reject);
      return;
     }
     reject(e);
    }
   });
  },
  getCatalogObj: function XRef_getCatalogObj() {
   return this.root;
  }
 };
 return XRef;
}();
var NameOrNumberTree = function NameOrNumberTreeClosure() {
 function NameOrNumberTree(root, xref) {
  throw new Error('Cannot initialize NameOrNumberTree.');
 }
 NameOrNumberTree.prototype = {
  getAll: function NameOrNumberTree_getAll() {
   var dict = Object.create(null);
   if (!this.root) {
    return dict;
   }
   var xref = this.xref;
   var processed = new RefSet();
   processed.put(this.root);
   var queue = [this.root];
   while (queue.length > 0) {
    var i, n;
    var obj = xref.fetchIfRef(queue.shift());
    if (!isDict(obj)) {
     continue;
    }
    if (obj.has('Kids')) {
     var kids = obj.get('Kids');
     for (i = 0, n = kids.length; i < n; i++) {
      var kid = kids[i];
      assert(!processed.has(kid), 'Duplicate entry in "' + this._type + '" tree.');
      queue.push(kid);
      processed.put(kid);
     }
     continue;
    }
    var entries = obj.get(this._type);
    if (isArray(entries)) {
     for (i = 0, n = entries.length; i < n; i += 2) {
      dict[xref.fetchIfRef(entries[i])] = xref.fetchIfRef(entries[i + 1]);
     }
    }
   }
   return dict;
  },
  get: function NameOrNumberTree_get(key) {
   if (!this.root) {
    return null;
   }
   var xref = this.xref;
   var kidsOrEntries = xref.fetchIfRef(this.root);
   var loopCount = 0;
   var MAX_LEVELS = 10;
   var l, r, m;
   while (kidsOrEntries.has('Kids')) {
    if (++loopCount > MAX_LEVELS) {
     warn('Search depth limit reached for "' + this._type + '" tree.');
     return null;
    }
    var kids = kidsOrEntries.get('Kids');
    if (!isArray(kids)) {
     return null;
    }
    l = 0;
    r = kids.length - 1;
    while (l <= r) {
     m = l + r >> 1;
     var kid = xref.fetchIfRef(kids[m]);
     var limits = kid.get('Limits');
     if (key < xref.fetchIfRef(limits[0])) {
      r = m - 1;
     } else if (key > xref.fetchIfRef(limits[1])) {
      l = m + 1;
     } else {
      kidsOrEntries = xref.fetchIfRef(kids[m]);
      break;
     }
    }
    if (l > r) {
     return null;
    }
   }
   var entries = kidsOrEntries.get(this._type);
   if (isArray(entries)) {
    l = 0;
    r = entries.length - 2;
    while (l <= r) {
     m = l + r & ~1;
     var currentKey = xref.fetchIfRef(entries[m]);
     if (key < currentKey) {
      r = m - 2;
     } else if (key > currentKey) {
      l = m + 2;
     } else {
      return xref.fetchIfRef(entries[m + 1]);
     }
    }
   }
   return null;
  }
 };
 return NameOrNumberTree;
}();
var NameTree = function NameTreeClosure() {
 function NameTree(root, xref) {
  this.root = root;
  this.xref = xref;
  this._type = 'Names';
 }
 Util.inherit(NameTree, NameOrNumberTree, {});
 return NameTree;
}();
var NumberTree = function NumberTreeClosure() {
 function NumberTree(root, xref) {
  this.root = root;
  this.xref = xref;
  this._type = 'Nums';
 }
 Util.inherit(NumberTree, NameOrNumberTree, {});
 return NumberTree;
}();
var FileSpec = function FileSpecClosure() {
 function FileSpec(root, xref) {
  if (!root || !isDict(root)) {
   return;
  }
  this.xref = xref;
  this.root = root;
  if (root.has('FS')) {
   this.fs = root.get('FS');
  }
  this.description = root.has('Desc') ? stringToPDFString(root.get('Desc')) : '';
  if (root.has('RF')) {
   warn('Related file specifications are not supported');
  }
  this.contentAvailable = true;
  if (!root.has('EF')) {
   this.contentAvailable = false;
   warn('Non-embedded file specifications are not supported');
  }
 }
 function pickPlatformItem(dict) {
  if (dict.has('UF')) {
   return dict.get('UF');
  } else if (dict.has('F')) {
   return dict.get('F');
  } else if (dict.has('Unix')) {
   return dict.get('Unix');
  } else if (dict.has('Mac')) {
   return dict.get('Mac');
  } else if (dict.has('DOS')) {
   return dict.get('DOS');
  }
  return null;
 }
 FileSpec.prototype = {
  get filename() {
   if (!this._filename && this.root) {
    var filename = pickPlatformItem(this.root) || 'unnamed';
    this._filename = stringToPDFString(filename).replace(/\\\\/g, '\\').replace(/\\\//g, '/').replace(/\\/g, '/');
   }
   return this._filename;
  },
  get content() {
   if (!this.contentAvailable) {
    return null;
   }
   if (!this.contentRef && this.root) {
    this.contentRef = pickPlatformItem(this.root.get('EF'));
   }
   var content = null;
   if (this.contentRef) {
    var xref = this.xref;
    var fileObj = xref.fetchIfRef(this.contentRef);
    if (fileObj && isStream(fileObj)) {
     content = fileObj.getBytes();
    } else {
     warn('Embedded file specification points to non-existing/invalid ' + 'content');
    }
   } else {
    warn('Embedded file specification does not have a content');
   }
   return content;
  },
  get serializable() {
   return {
    filename: this.filename,
    content: this.content
   };
  }
 };
 return FileSpec;
}();
var ObjectLoader = function () {
 function mayHaveChildren(value) {
  return isRef(value) || isDict(value) || isArray(value) || isStream(value);
 }
 function addChildren(node, nodesToVisit) {
  var value;
  if (isDict(node) || isStream(node)) {
   var map;
   if (isDict(node)) {
    map = node.map;
   } else {
    map = node.dict.map;
   }
   for (var key in map) {
    value = map[key];
    if (mayHaveChildren(value)) {
     nodesToVisit.push(value);
    }
   }
  } else if (isArray(node)) {
   for (var i = 0, ii = node.length; i < ii; i++) {
    value = node[i];
    if (mayHaveChildren(value)) {
     nodesToVisit.push(value);
    }
   }
  }
 }
 function ObjectLoader(obj, keys, xref) {
  this.obj = obj;
  this.keys = keys;
  this.xref = xref;
  this.refSet = null;
  this.capability = null;
 }
 ObjectLoader.prototype = {
  load: function ObjectLoader_load() {
   var keys = this.keys;
   this.capability = createPromiseCapability();
   if (!(this.xref.stream instanceof ChunkedStream) || this.xref.stream.getMissingChunks().length === 0) {
    this.capability.resolve();
    return this.capability.promise;
   }
   this.refSet = new RefSet();
   var nodesToVisit = [];
   for (var i = 0; i < keys.length; i++) {
    nodesToVisit.push(this.obj[keys[i]]);
   }
   this._walk(nodesToVisit);
   return this.capability.promise;
  },
  _walk: function ObjectLoader_walk(nodesToVisit) {
   var nodesToRevisit = [];
   var pendingRequests = [];
   while (nodesToVisit.length) {
    var currentNode = nodesToVisit.pop();
    if (isRef(currentNode)) {
     if (this.refSet.has(currentNode)) {
      continue;
     }
     try {
      var ref = currentNode;
      this.refSet.put(ref);
      currentNode = this.xref.fetch(currentNode);
     } catch (e) {
      if (!(e instanceof MissingDataException)) {
       throw e;
      }
      nodesToRevisit.push(currentNode);
      pendingRequests.push({
       begin: e.begin,
       end: e.end
      });
     }
    }
    if (currentNode && currentNode.getBaseStreams) {
     var baseStreams = currentNode.getBaseStreams();
     var foundMissingData = false;
     for (var i = 0; i < baseStreams.length; i++) {
      var stream = baseStreams[i];
      if (stream.getMissingChunks && stream.getMissingChunks().length) {
       foundMissingData = true;
       pendingRequests.push({
        begin: stream.start,
        end: stream.end
       });
      }
     }
     if (foundMissingData) {
      nodesToRevisit.push(currentNode);
     }
    }
    addChildren(currentNode, nodesToVisit);
   }
   if (pendingRequests.length) {
    this.xref.stream.manager.requestRanges(pendingRequests).then(function pendingRequestCallback() {
     nodesToVisit = nodesToRevisit;
     for (var i = 0; i < nodesToRevisit.length; i++) {
      var node = nodesToRevisit[i];
      if (isRef(node)) {
       this.refSet.remove(node);
      }
     }
     this._walk(nodesToVisit);
    }.bind(this), this.capability.reject);
    return;
   }
   this.refSet = null;
   this.capability.resolve();
  }
 };
 return ObjectLoader;
}();
exports.Catalog = Catalog;
exports.ObjectLoader = ObjectLoader;
exports.XRef = XRef;
exports.FileSpec = FileSpec;