pdfjs.parser.js

      //      /Root 20R
      //      /Info 10R
      //      /ID [ <81b14aafa313db63dbd6f981e49f94f4> ]
      //    >>
      // The parser goes through the entire stream << ... >> and provides
      // a getter interface for the key-value table
      var dict = parser.getObj();

      // The pdflib PDF generator can generate a nested trailer dictionary
      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) {
      // Example of cross-reference table:
      // xref
      // 0 1                    <-- subsection header (first obj #, obj count)
      // 0000000000 65535 f     <-- actual object (offset, generation #, f/n)
      // 23 2                   <-- subsection header ... and so on ...
      // 0000025518 00002 n
      // 0000025635 00000 n
      // trailer
      // ...

      var stream = parser.lexer.stream;
      var tableState = this.tableState;
      stream.pos = tableState.streamPos;
      parser.buf1 = tableState.parserBuf1;
      parser.buf2 = tableState.parserBuf2;

      // Outer loop is over subsection headers
      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');
        }
        // Inner loop is over objects themselves
        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;
          }

          // Validate entry obj
          if (!isInt(entry.offset) || !isInt(entry.gen) ||
              !(entry.free || entry.uncompressed)) {
            error('Invalid entry in XRef subsection: ' + first + ', ' + count);
          }

          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;
      }

      // Per issue 3248: hp scanners generate bad XRef
      if (first === 1 && this.entries[1] && this.entries[1].free) {
        // shifting the entries
        this.entries.shift();
      }

      // Sanity check: as per spec, first object must be free
      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)) {
        // Stores state of the stream as we process it so we can resume
        // from middle of stream in case of missing data error
        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 type field is absent, its default value is 1
          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() {
      // Simple scan through the PDF content to find objects,
      // trailers and XRef streams.
      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;
        // finding byte sequence
        while (offset < dataLength) {
          var i = 0;
          while (i < length && data[offset + i] === what[i]) {
            ++i;
          }
          if (i >= length) {
            break; // sequence found
          }
          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]);

      // Clear out any existing entries, since they may be bogus.
      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) { // %-comment
          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);

          // checking XRef stream suspect
          // (it shall have '/XRef' and next char is not a letter)
          var xrefTagOffset = skipUntil(content, 0, xrefBytes);
          if (xrefTagOffset < contentLength &&
              content[xrefTagOffset + 5] < 64) {
            xrefStms.push(position - stream.start);
            this.xrefstms[position - stream.start] = 1; // Avoid recursion
          }

          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;
        }
      }
      // reading XRef streams
      var i, ii;
      for (i = 0, ii = xrefStms.length; i < ii; ++i) {
        this.startXRefQueue.push(xrefStms[i]);
        this.xrefBlocks.push(xrefStms[i]);
        this.readXRef(/* recoveryMode */ true);
      }
      // finding main trailer
      var dict;
      for (i = 0, ii = trailers.length; i < ii; ++i) {
        stream.pos = trailers[i];
        var parser = new Parser(new Lexer(stream), true, this);
        var obj = parser.getObj();
        if (!isCmd(obj, 'trailer')) {
          continue;
        }
        // read the trailer dictionary
        if (!isDict(dict = parser.getObj())) {
          continue;
        }
        // taking the first one with 'ID'
        if (dict.has('ID')) {
          return dict;
        }
      }
      // no tailer with 'ID', taking last one (if exists)
      if (dict) {
        return dict;
      }
      // nothing helps
      // calling error() would reject worker with an UnknownErrorException.
      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;

          // Get dictionary
          if (isCmd(obj, 'xref')) {
            // Parse end-of-file XRef
            dict = this.processXRefTable(parser);
            if (!this.topDict) {
              this.topDict = dict;
            }

            // Recursively get other XRefs 'XRefStm', if any
            obj = dict.get('XRefStm');
            if (isInt(obj)) {
              var pos = obj;
              // ignore previously loaded xref streams
              // (possible infinite recursion)
              if (!(pos in this.xrefstms)) {
                this.xrefstms[pos] = 1;
                this.startXRefQueue.push(pos);
                this.xrefBlocks.push(pos);
              }
            }
          } else if (isInt(obj)) {
            // Parse in-stream XRef
            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');
          }

          // Recursively get previous dictionary, if any
          obj = dict.get('Prev');
          if (isInt(obj)) {
            this.startXRefQueue.push(obj);
            this.xrefBlocks.push(obj);
          } else if (isRef(obj)) {
            // The spec says Prev must not be a reference, i.e. "/Prev NNN"
            // This is a fallback for non-compliant PDFs, i.e. "/Prev NNN 0 R"
            this.startXRefQueue.push(obj.num);
            this.xrefBlocks.push(obj.num);
          }
          this.xrefBlocks.push(stream.pos);
          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) {
      if (!isRef(obj)) {
        return obj;
      }
      return this.fetch(obj);
    },

    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];
        return cacheEntry;
      }

      var xrefEntry = this.getEntry(num);

      // the referenced entry can be free
      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')) {
        // some bad PDFs use "obj1234" and really mean 1234
        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 = [];
      // read the object numbers to populate cache
      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);
        }
      }
      // read stream objects for cache
      for (i = 0; i < n; ++i) {
        entries.push(parser.getObj());
        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) {
      if (!isRef(obj)) {
        return Promise.resolve(obj);
      }
      return this.fetchAsync(obj);
    },

    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;
})();

/**
 * A NameTree is like a Dict but has some advantageous properties, see the
 * spec (7.9.6) for more details.
 * TODO: implement all the Dict functions and make this more efficent.
 */
var NameTree = (function NameTreeClosure() {
  function NameTree(root, xref) {
    this.root = root;
    this.xref = xref;
  }

  NameTree.prototype = {
    getAll: function NameTree_getAll() {
      var dict = {};
      if (!this.root) {
        return dict;
      }
      var xref = this.xref;
      // reading name tree
      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];
            if (processed.has(kid)) {
              error('invalid destinations');
            }
            queue.push(kid);
            processed.put(kid);
          }
          continue;
        }
        var names = obj.get('Names');
        if (names) {
          for (i = 0, n = names.length; i < n; i += 2) {
            dict[xref.fetchIfRef(names[i])] = xref.fetchIfRef(names[i + 1]);
          }
        }
      }
      return dict;
    },

    get: function NameTree_get(destinationId) {
      if (!this.root) {
        return null;
      }

      var xref = this.xref;
      var kidsOrNames = xref.fetchIfRef(this.root);
      var loopCount = 0;
      var MAX_NAMES_LEVELS = 10;
      var l, r, m;

      // Perform a binary search to quickly find the entry that
      // contains the named destination we are looking for.
      while (kidsOrNames.has('Kids')) {
        loopCount++;
        if (loopCount > MAX_NAMES_LEVELS) {
          warn('Search depth limit for named destionations has been reached.');
          return null;
        }

        var kids = kidsOrNames.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 (destinationId < xref.fetchIfRef(limits[0])) {
            r = m - 1;
          } else if (destinationId > xref.fetchIfRef(limits[1])) {
            l = m + 1;
          } else {
            kidsOrNames = xref.fetchIfRef(kids[m]);
            break;
          }
        }
        if (l > r) {
          return null;
        }
      }

      // If we get here, then we have found the right entry. Now
      // go through the named destinations in the Named dictionary
      // until we find the exact destination we're looking for.
      var names = kidsOrNames.get('Names');
      if (isArray(names)) {
        // Perform a binary search to reduce the lookup time.
        l = 0;
        r = names.length - 2;
        while (l <= r) {
          // Check only even indices (0, 2, 4, ...) because the
          // odd indices contain the actual D array.
          m = (l + r) & ~1;
          if (destinationId < xref.fetchIfRef(names[m])) {
            r = m - 2;
          } else if (destinationId > xref.fetchIfRef(names[m])) {
            l = m + 2;
          } else {
            return xref.fetchIfRef(names[m + 1]);
          }
        }
      }
      return null;
    }
  };
  return NameTree;
})();

/**
 * "A PDF file can refer to the contents of another file by using a File
 * Specification (PDF 1.1)", see the spec (7.11) for more details.
 * NOTE: Only embedded files are supported (as part of the attachments support)
 * TODO: support the 'URL' file system (with caching if !/V), portable
 * collections attributes and related files (/RF)
 */
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) {
    // Look for the filename in this order:
    // UF, F, Unix, Mac, DOS
    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');
    } else {
      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;
})();

/**
 * A helper for loading missing data in object graphs. It traverses the graph
 * depth first and queues up any objects that have missing data. Once it has
 * has traversed as many objects that are available it attempts to bundle the
 * missing data requests and then resume from the nodes that weren't ready.
 *
 * NOTE: It provides protection from circular references by keeping track of
 * of loaded references. However, you must be careful not to load any graphs
 * that have references to the catalog or other pages since that will cause the
 * entire PDF document object graph to be traversed.
 */
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();
      // Don't walk the graph if all the data is already loaded.
      if (!(this.xref.stream instanceof ChunkedStream) ||
          this.xref.stream.getMissingChunks().length === 0) {
        this.capability.resolve();
        return this.capability.promise;
      }

      this.refSet = new RefSet();
      // Setup the initial nodes to visit.
      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 = [];
      // DFS walk of the object graph.
      while (nodesToVisit.length) {
        var currentNode = nodesToVisit.pop();

        // Only references or chunked streams can cause missing data exceptions.
        if (isRef(currentNode)) {
          // Skip nodes that have already been visited.
          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];
            // Remove any reference nodes from the currrent refset so they
            // aren't skipped when we revist them.
            if (isRef(node)) {
              this.refSet.remove(node);
            }
          }
          this._walk(nodesToVisit);
        }.bind(this), this.capability.reject);
        return;
      }
      // Everything is loaded.
      this.refSet = null;
      this.capability.resolve();
    }
  };

  return ObjectLoader;
})();

exports.Catalog = Catalog;
exports.ObjectLoader = ObjectLoader;
exports.XRef = XRef;
}));

/* 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.
 */

'use strict';

(function (root, factory) {
  //if (typeof define === 'function' && define.amd) {
  //  define('pdfjs/core/document', ['exports', 'pdfjs/shared/util',
  //    'pdfjs/core/primitives', 'pdfjs/core/stream', 'pdfjs/core/obj',
  //    'pdfjs/core/parser', 'pdfjs/core/crypto'], factory);
  // } else if (typeof exports !== 'undefined') {
  //   factory(exports, require('../shared/util.js'), require('./primitives.js'),
  //     require('./stream.js'), require('./obj.js'), require('./parser.js'),
  //     require('./crypto.js'));
  //} else {
    factory((root.pdfjsCoreDocument = {}), root.pdfjsSharedUtil,
      root.pdfjsCorePrimitives, root.pdfjsCoreStream,
      root.pdfjsCoreObj, root.pdfjsCoreParser, root.pdfjsCoreCrypto);
  //}
}(window, function (exports, sharedUtil, corePrimitives, coreStream, coreObj,
                  coreParser, coreCrypto) {

var MissingDataException = sharedUtil.MissingDataException;
var Util = sharedUtil.Util;
var assert = sharedUtil.assert;
var error = sharedUtil.error;
var info = sharedUtil.info;
var isArray = sharedUtil.isArray;
var isArrayBuffer = sharedUtil.isArrayBuffer;
var isString = sharedUtil.isString;
var shadow = sharedUtil.shadow;
var stringToBytes = sharedUtil.stringToBytes;
var stringToPDFString = sharedUtil.stringToPDFString;
var warn = sharedUtil.warn;
var Dict = corePrimitives.Dict;
var isDict = corePrimitives.isDict;
var isName = corePrimitives.isName;
var isStream = corePrimitives.isStream;
var NullStream = coreStream.NullStream;
var Stream = coreStream.Stream;
var StreamsSequenceStream = coreStream.StreamsSequenceStream;
var Catalog = coreObj.Catalog;
var ObjectLoader = coreObj.ObjectLoader;
var XRef = coreObj.XRef;
var Lexer = coreParser.Lexer;
var Linearization = coreParser.Linearization;
var calculateMD5 = coreCrypto.calculateMD5;


/**
 * The `PDFDocument` holds all the data of the PDF file. Compared to the
 * `PDFDoc`, this one doesn't have any job management code.
 * Right now there exists one PDFDocument on the main thread + one object
 * for each worker. If there is no worker support enabled, there are two
 * `PDFDocument` objects on the main thread created.
 */
var PDFDocument = (function PDFDocumentClosure() {
  var FINGERPRINT_FIRST_BYTES = 1024;
  var EMPTY_FINGERPRINT = '\x00\x00\x00\x00\x00\x00\x00' +
    '\x00\x00\x00\x00\x00\x00\x00\x00\x00';