pdfjs.parser.js

        return p[1];
      }
    } else {
      var result = this.findTableCode(2, 6, blackTable3);
      if (result[0]) {
        return result[1];
      }

      result = this.findTableCode(7, 12, blackTable2, 64);
      if (result[0]) {
        return result[1];
      }

      result = this.findTableCode(10, 13, blackTable1);
      if (result[0]) {
        return result[1];
      }
    }
    info('bad black code');
    this.eatBits(1);
    return 1;
  };

  CCITTFaxStream.prototype.lookBits = function CCITTFaxStream_lookBits(n) {
    var c;
    while (this.inputBits < n) {
      if ((c = this.str.getByte()) === -1) {
        if (this.inputBits === 0) {
          return EOF;
        }
        return ((this.inputBuf << (n - this.inputBits)) &
                (0xFFFF >> (16 - n)));
      }
      this.inputBuf = (this.inputBuf << 8) + c;
      this.inputBits += 8;
    }
    return (this.inputBuf >> (this.inputBits - n)) & (0xFFFF >> (16 - n));
  };

  CCITTFaxStream.prototype.eatBits = function CCITTFaxStream_eatBits(n) {
    if ((this.inputBits -= n) < 0) {
      this.inputBits = 0;
    }
  };

  return CCITTFaxStream;
})();

var LZWStream = (function LZWStreamClosure() {
  function LZWStream(str, maybeLength, earlyChange) {
    this.str = str;
    this.dict = str.dict;
    this.cachedData = 0;
    this.bitsCached = 0;

    var maxLzwDictionarySize = 4096;
    var lzwState = {
      earlyChange: earlyChange,
      codeLength: 9,
      nextCode: 258,
      dictionaryValues: new Uint8Array(maxLzwDictionarySize),
      dictionaryLengths: new Uint16Array(maxLzwDictionarySize),
      dictionaryPrevCodes: new Uint16Array(maxLzwDictionarySize),
      currentSequence: new Uint8Array(maxLzwDictionarySize),
      currentSequenceLength: 0
    };
    for (var i = 0; i < 256; ++i) {
      lzwState.dictionaryValues[i] = i;
      lzwState.dictionaryLengths[i] = 1;
    }
    this.lzwState = lzwState;

    DecodeStream.call(this, maybeLength);
  }

  LZWStream.prototype = Object.create(DecodeStream.prototype);

  LZWStream.prototype.readBits = function LZWStream_readBits(n) {
    var bitsCached = this.bitsCached;
    var cachedData = this.cachedData;
    while (bitsCached < n) {
      var c = this.str.getByte();
      if (c === -1) {
        this.eof = true;
        return null;
      }
      cachedData = (cachedData << 8) | c;
      bitsCached += 8;
    }
    this.bitsCached = (bitsCached -= n);
    this.cachedData = cachedData;
    this.lastCode = null;
    return (cachedData >>> bitsCached) & ((1 << n) - 1);
  };

  LZWStream.prototype.readBlock = function LZWStream_readBlock() {
    var blockSize = 512;
    var estimatedDecodedSize = blockSize * 2, decodedSizeDelta = blockSize;
    var i, j, q;

    var lzwState = this.lzwState;
    if (!lzwState) {
      return; // eof was found
    }

    var earlyChange = lzwState.earlyChange;
    var nextCode = lzwState.nextCode;
    var dictionaryValues = lzwState.dictionaryValues;
    var dictionaryLengths = lzwState.dictionaryLengths;
    var dictionaryPrevCodes = lzwState.dictionaryPrevCodes;
    var codeLength = lzwState.codeLength;
    var prevCode = lzwState.prevCode;
    var currentSequence = lzwState.currentSequence;
    var currentSequenceLength = lzwState.currentSequenceLength;

    var decodedLength = 0;
    var currentBufferLength = this.bufferLength;
    var buffer = this.ensureBuffer(this.bufferLength + estimatedDecodedSize);

    for (i = 0; i < blockSize; i++) {
      var code = this.readBits(codeLength);
      var hasPrev = currentSequenceLength > 0;
      if (code < 256) {
        currentSequence[0] = code;
        currentSequenceLength = 1;
      } else if (code >= 258) {
        if (code < nextCode) {
          currentSequenceLength = dictionaryLengths[code];
          for (j = currentSequenceLength - 1, q = code; j >= 0; j--) {
            currentSequence[j] = dictionaryValues[q];
            q = dictionaryPrevCodes[q];
          }
        } else {
          currentSequence[currentSequenceLength++] = currentSequence[0];
        }
      } else if (code === 256) {
        codeLength = 9;
        nextCode = 258;
        currentSequenceLength = 0;
        continue;
      } else {
        this.eof = true;
        delete this.lzwState;
        break;
      }

      if (hasPrev) {
        dictionaryPrevCodes[nextCode] = prevCode;
        dictionaryLengths[nextCode] = dictionaryLengths[prevCode] + 1;
        dictionaryValues[nextCode] = currentSequence[0];
        nextCode++;
        codeLength = (nextCode + earlyChange) & (nextCode + earlyChange - 1) ?
          codeLength : Math.min(Math.log(nextCode + earlyChange) /
          0.6931471805599453 + 1, 12) | 0;
      }
      prevCode = code;

      decodedLength += currentSequenceLength;
      if (estimatedDecodedSize < decodedLength) {
        do {
          estimatedDecodedSize += decodedSizeDelta;
        } while (estimatedDecodedSize < decodedLength);
        buffer = this.ensureBuffer(this.bufferLength + estimatedDecodedSize);
      }
      for (j = 0; j < currentSequenceLength; j++) {
        buffer[currentBufferLength++] = currentSequence[j];
      }
    }
    lzwState.nextCode = nextCode;
    lzwState.codeLength = codeLength;
    lzwState.prevCode = prevCode;
    lzwState.currentSequenceLength = currentSequenceLength;

    this.bufferLength = currentBufferLength;
  };

  return LZWStream;
})();

var NullStream = (function NullStreamClosure() {
  function NullStream() {
    Stream.call(this, new Uint8Array(0));
  }

  NullStream.prototype = Stream.prototype;

  return NullStream;
})();

// TODO refactor to remove dependency on parser.js
function _setCoreParser(coreParser_) {
  coreParser = coreParser_;
  EOF = coreParser_.EOF;
  Lexer = coreParser_.Lexer;
}
exports._setCoreParser = _setCoreParser;

// TODO refactor to remove dependency on colorspace.js
function _setCoreColorSpace(coreColorSpace_) {
  coreColorSpace = coreColorSpace_;
  ColorSpace = coreColorSpace_.ColorSpace;
}
exports._setCoreColorSpace = _setCoreColorSpace;

exports.Ascii85Stream = Ascii85Stream;
exports.AsciiHexStream = AsciiHexStream;
exports.CCITTFaxStream = CCITTFaxStream;
exports.DecryptStream = DecryptStream;
exports.DecodeStream = DecodeStream;
exports.FlateStream = FlateStream;
exports.Jbig2Stream = Jbig2Stream;
exports.JpegStream = JpegStream;
exports.JpxStream = JpxStream;
exports.NullStream = NullStream;
exports.PredictorStream = PredictorStream;
exports.RunLengthStream = RunLengthStream;
exports.Stream = Stream;
exports.StreamsSequenceStream = StreamsSequenceStream;
exports.StringStream = StringStream;
exports.LZWStream = LZWStream;
}));

/* 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/parser', ['exports', 'pdfjs/shared/util',
  //    'pdfjs/core/primitives', 'pdfjs/core/stream'], factory);
  // } else if (typeof exports !== 'undefined') {
  //   factory(exports, require('../shared/util.js'), require('./primitives.js'),
  //     require('./stream.js'));
  //} else {
    factory((root.pdfjsCoreParser = {}), root.pdfjsSharedUtil,
      root.pdfjsCorePrimitives, root.pdfjsCoreStream);
  //}
}(window, function (exports, sharedUtil, corePrimitives, coreStream) {

var MissingDataException = sharedUtil.MissingDataException;
var StreamType = sharedUtil.StreamType;
var assert = sharedUtil.assert;
var error = sharedUtil.error;
var info = sharedUtil.info;
var isArray = sharedUtil.isArray;
var isInt = sharedUtil.isInt;
var isNum = sharedUtil.isNum;
var isString = sharedUtil.isString;
var warn = sharedUtil.warn;
var Cmd = corePrimitives.Cmd;
var Dict = corePrimitives.Dict;
var Name = corePrimitives.Name;
var Ref = corePrimitives.Ref;
var isCmd = corePrimitives.isCmd;
var isDict = corePrimitives.isDict;
var isName = corePrimitives.isName;
var Ascii85Stream = coreStream.Ascii85Stream;
var AsciiHexStream = coreStream.AsciiHexStream;
var CCITTFaxStream = coreStream.CCITTFaxStream;
var FlateStream = coreStream.FlateStream;
var Jbig2Stream = coreStream.Jbig2Stream;
var JpegStream = coreStream.JpegStream;
var JpxStream = coreStream.JpxStream;
var LZWStream = coreStream.LZWStream;
var NullStream = coreStream.NullStream;
var PredictorStream = coreStream.PredictorStream;
var RunLengthStream = coreStream.RunLengthStream;

var EOF = {};

function isEOF(v) {
  return (v === EOF);
}

var MAX_LENGTH_TO_CACHE = 1000;

var Parser = (function ParserClosure() {
  function Parser(lexer, allowStreams, xref) {
    this.lexer = lexer;
    this.allowStreams = allowStreams;
    this.xref = xref;
    this.imageCache = {};
    this.refill();
  }

  Parser.prototype = {
    refill: function Parser_refill() {
      this.buf1 = this.lexer.getObj();
      this.buf2 = this.lexer.getObj();
    },
    shift: function Parser_shift() {
      if (isCmd(this.buf2, 'ID')) {
        this.buf1 = this.buf2;
        this.buf2 = null;
      } else {
        this.buf1 = this.buf2;
        this.buf2 = this.lexer.getObj();
      }
    },
    tryShift: function Parser_tryShift() {
      try {
        this.shift();
        return true;
      } catch (e) {
        if (e instanceof MissingDataException) {
          throw e;
        }
        // Upon failure, the caller should reset this.lexer.pos to a known good
        // state and call this.shift() twice to reset the buffers.
        return false;
      }
    },
    getObj: function Parser_getObj(cipherTransform) {
      var buf1 = this.buf1;
      this.shift();

      if (buf1 instanceof Cmd) {
        switch (buf1.cmd) {
          case 'BI': // inline image
            return this.makeInlineImage(cipherTransform);
          case '[': // array
            var array = [];
            while (!isCmd(this.buf1, ']') && !isEOF(this.buf1)) {
              array.push(this.getObj(cipherTransform));
            }
            if (isEOF(this.buf1)) {
              error('End of file inside array');
            }
            this.shift();
            return array;
          case '<<': // dictionary or stream
            var dict = new Dict(this.xref);
            while (!isCmd(this.buf1, '>>') && !isEOF(this.buf1)) {
              if (!isName(this.buf1)) {
                info('Malformed dictionary: key must be a name object');
                this.shift();
                continue;
              }
              var pos = this.lexer.stream.pos;
              var key = this.buf1.name;
              dict.set('#' +key+ '_offset', pos);
              this.shift();
              if (isEOF(this.buf1)) {
                break;
              }
              dict.set(key, this.getObj(cipherTransform));
              
            }
            if (isEOF(this.buf1)) {
              error('End of file inside dictionary');
            }

            // Stream objects are not allowed inside content streams or
            // object streams.
            if (isCmd(this.buf2, 'stream')) {
              return (this.allowStreams ?
                      this.makeStream(dict, cipherTransform) : dict);
            }
            this.shift();
            return dict;
          default: // simple object
            return buf1;
        }
      }

      if (isInt(buf1)) { // indirect reference or integer
        var num = buf1;
        if (isInt(this.buf1) && isCmd(this.buf2, 'R')) {
          var ref = new Ref(num, this.buf1);
          this.shift();
          this.shift();
          return ref;
        }
        return num;
      }

      if (isString(buf1)) { // string
        var str = buf1;
        if (cipherTransform) {
          str = cipherTransform.decryptString(str);
        }
        return str;
      }

      // simple object
      return buf1;
    },
    /**
     * Find the end of the stream by searching for the /EI\s/.
     * @returns {number} The inline stream length.
     */
    findDefaultInlineStreamEnd:
        function Parser_findDefaultInlineStreamEnd(stream) {
      var E = 0x45, I = 0x49, SPACE = 0x20, LF = 0xA, CR = 0xD;
      var startPos = stream.pos, state = 0, ch, i, n, followingBytes;
      while ((ch = stream.getByte()) !== -1) {
        if (state === 0) {
          state = (ch === E) ? 1 : 0;
        } else if (state === 1) {
          state = (ch === I) ? 2 : 0;
        } else {
          assert(state === 2);
          if (ch === SPACE || ch === LF || ch === CR) {
            // Let's check the next five bytes are ASCII... just be sure.
            n = 5;
            followingBytes = stream.peekBytes(n);
            for (i = 0; i < n; i++) {
              ch = followingBytes[i];
              if (ch !== LF && ch !== CR && (ch < SPACE || ch > 0x7F)) {
                // Not a LF, CR, SPACE or any visible ASCII character, i.e.
                // it's binary stuff. Resetting the state.
                state = 0;
                break;
              }
            }
            if (state === 2) {
              break;  // Finished!
            }
          } else {
            state = 0;
          }
        }
      }
      return ((stream.pos - 4) - startPos);
    },
    /**
     * Find the EOI (end-of-image) marker 0xFFD9 of the stream.
     * @returns {number} The inline stream length.
     */
    findDCTDecodeInlineStreamEnd:
        function Parser_findDCTDecodeInlineStreamEnd(stream) {
      var startPos = stream.pos, foundEOI = false, b, markerLength, length;
      while ((b = stream.getByte()) !== -1) {
        if (b !== 0xFF) { // Not a valid marker.
          continue;
        }
        switch (stream.getByte()) {
          case 0x00: // Byte stuffing.
            // 0xFF00 appears to be a very common byte sequence in JPEG images.
            break;

          case 0xFF: // Fill byte.
            // Avoid skipping a valid marker, resetting the stream position.
            stream.skip(-1);
            break;

          case 0xD9: // EOI
            foundEOI = true;
            break;

          case 0xC0: // SOF0
          case 0xC1: // SOF1
          case 0xC2: // SOF2
          case 0xC3: // SOF3

          case 0xC5: // SOF5
          case 0xC6: // SOF6
          case 0xC7: // SOF7

          case 0xC9: // SOF9
          case 0xCA: // SOF10
          case 0xCB: // SOF11

          case 0xCD: // SOF13
          case 0xCE: // SOF14
          case 0xCF: // SOF15

          case 0xC4: // DHT
          case 0xCC: // DAC

          case 0xDA: // SOS
          case 0xDB: // DQT
          case 0xDC: // DNL
          case 0xDD: // DRI
          case 0xDE: // DHP
          case 0xDF: // EXP

          case 0xE0: // APP0
          case 0xE1: // APP1
          case 0xE2: // APP2
          case 0xE3: // APP3
          case 0xE4: // APP4
          case 0xE5: // APP5
          case 0xE6: // APP6
          case 0xE7: // APP7
          case 0xE8: // APP8
          case 0xE9: // APP9
          case 0xEA: // APP10
          case 0xEB: // APP11
          case 0xEC: // APP12
          case 0xED: // APP13
          case 0xEE: // APP14
          case 0xEF: // APP15

          case 0xFE: // COM
            // The marker should be followed by the length of the segment.
            markerLength = stream.getUint16();
            if (markerLength > 2) {
              // |markerLength| contains the byte length of the marker segment,
              // including its own length (2 bytes) and excluding the marker.
              stream.skip(markerLength - 2); // Jump to the next marker.
            } else {
              // The marker length is invalid, resetting the stream position.
              stream.skip(-2);
            }
            break;
        }
        if (foundEOI) {
          break;
        }
      }
      length = stream.pos - startPos;
      if (b === -1) {
        warn('Inline DCTDecode image stream: ' +
             'EOI marker not found, searching for /EI/ instead.');
        stream.skip(-length); // Reset the stream position.
        return this.findDefaultInlineStreamEnd(stream);
      }
      this.inlineStreamSkipEI(stream);
      return length;
    },
    /**
     * Find the EOD (end-of-data) marker '~>' (i.e. TILDE + GT) of the stream.
     * @returns {number} The inline stream length.
     */
    findASCII85DecodeInlineStreamEnd:
        function Parser_findASCII85DecodeInlineStreamEnd(stream) {
      var TILDE = 0x7E, GT = 0x3E;
      var startPos = stream.pos, ch, length;
      while ((ch = stream.getByte()) !== -1) {
        if (ch === TILDE && stream.peekByte() === GT) {
          stream.skip();
          break;
        }
      }
      length = stream.pos - startPos;
      if (ch === -1) {
        warn('Inline ASCII85Decode image stream: ' +
             'EOD marker not found, searching for /EI/ instead.');
        stream.skip(-length); // Reset the stream position.
        return this.findDefaultInlineStreamEnd(stream);
      }
      this.inlineStreamSkipEI(stream);
      return length;
    },
    /**
     * Find the EOD (end-of-data) marker '>' (i.e. GT) of the stream.
     * @returns {number} The inline stream length.
     */
    findASCIIHexDecodeInlineStreamEnd:
        function Parser_findASCIIHexDecodeInlineStreamEnd(stream) {
      var GT = 0x3E;
      var startPos = stream.pos, ch, length;
      while ((ch = stream.getByte()) !== -1) {
        if (ch === GT) {
          break;
        }
      }
      length = stream.pos - startPos;
      if (ch === -1) {
        warn('Inline ASCIIHexDecode image stream: ' +
             'EOD marker not found, searching for /EI/ instead.');
        stream.skip(-length); // Reset the stream position.
        return this.findDefaultInlineStreamEnd(stream);
      }
      this.inlineStreamSkipEI(stream);
      return length;
    },
    /**
     * Skip over the /EI/ for streams where we search for an EOD marker.
     */
    inlineStreamSkipEI: function Parser_inlineStreamSkipEI(stream) {
      var E = 0x45, I = 0x49;
      var state = 0, ch;
      while ((ch = stream.getByte()) !== -1) {
        if (state === 0) {
          state = (ch === E) ? 1 : 0;
        } else if (state === 1) {
          state = (ch === I) ? 2 : 0;
        } else if (state === 2) {
          break;
        }
      }
    },
    makeInlineImage: function Parser_makeInlineImage(cipherTransform) {
      var lexer = this.lexer;
      var stream = lexer.stream;

      // Parse dictionary.
      var dict = new Dict(this.xref);
      while (!isCmd(this.buf1, 'ID') && !isEOF(this.buf1)) {
        if (!isName(this.buf1)) {
          error('Dictionary key must be a name object');
        }
        var key = this.buf1.name;
        this.shift();
        if (isEOF(this.buf1)) {
          break;
        }
        dict.set(key, this.getObj(cipherTransform));
      }

      // Extract the name of the first (i.e. the current) image filter.
      var filter = dict.get('Filter', 'F'), filterName;
      if (isName(filter)) {
        filterName = filter.name;
      } else if (isArray(filter) && isName(filter[0])) {
        filterName = filter[0].name;
      }

      // Parse image stream.
      var startPos = stream.pos, length, i, ii;
      if (filterName === 'DCTDecode' || filterName === 'DCT') {
        length = this.findDCTDecodeInlineStreamEnd(stream);
      } else if (filterName === 'ASCII85Decide' || filterName === 'A85') {
        length = this.findASCII85DecodeInlineStreamEnd(stream);
      } else if (filterName === 'ASCIIHexDecode' || filterName === 'AHx') {
        length = this.findASCIIHexDecodeInlineStreamEnd(stream);
      } else {
        length = this.findDefaultInlineStreamEnd(stream);
      }
      var imageStream = stream.makeSubStream(startPos, length, dict);

      // Cache all images below the MAX_LENGTH_TO_CACHE threshold by their
      // adler32 checksum.
      var adler32;
      if (length < MAX_LENGTH_TO_CACHE) {
        var imageBytes = imageStream.getBytes();
        imageStream.reset();

        var a = 1;
        var b = 0;
        for (i = 0, ii = imageBytes.length; i < ii; ++i) {
          // No modulo required in the loop if imageBytes.length < 5552.
          a += imageBytes[i] & 0xff;
          b += a;
        }
        adler32 = ((b % 65521) << 16) | (a % 65521);

        if (this.imageCache.adler32 === adler32) {
          this.buf2 = Cmd.get('EI');
          this.shift();

          this.imageCache[adler32].reset();
          return this.imageCache[adler32];
        }
      }

      if (cipherTransform) {
        imageStream = cipherTransform.createStream(imageStream, length);
      }

      imageStream = this.filter(imageStream, dict, length);
      imageStream.dict = dict;
      if (adler32 !== undefined) {
        imageStream.cacheKey = 'inline_' + length + '_' + adler32;
        this.imageCache[adler32] = imageStream;
      }

      this.buf2 = Cmd.get('EI');
      this.shift();

      return imageStream;
    },
    makeStream: function Parser_makeStream(dict, cipherTransform) {
      var lexer = this.lexer;
      var stream = lexer.stream;

      // get stream start position
      lexer.skipToNextLine();
      var pos = stream.pos - 1;

      // get length
      var length = dict.get('Length');
      if (!isInt(length)) {
        info('Bad ' + length + ' attribute in stream');
        length = 0;
      }

      // skip over the stream data
      stream.pos = pos + length;
      lexer.nextChar();

      // Shift '>>' and check whether the new object marks the end of the stream
      if (this.tryShift() && isCmd(this.buf2, 'endstream')) {
        this.shift(); // 'stream'
      } else {
        // bad stream length, scanning for endstream
        stream.pos = pos;
        var SCAN_BLOCK_SIZE = 2048;
        var ENDSTREAM_SIGNATURE_LENGTH = 9;
        var ENDSTREAM_SIGNATURE = [0x65, 0x6E, 0x64, 0x73, 0x74, 0x72, 0x65,
                                   0x61, 0x6D];
        var skipped = 0, found = false, i, j;
        while (stream.pos < stream.end) {
          var scanBytes = stream.peekBytes(SCAN_BLOCK_SIZE);
          var scanLength = scanBytes.length - ENDSTREAM_SIGNATURE_LENGTH;
          if (scanLength <= 0) {
            break;
          }
          found = false;
          for (i = 0, j = 0; i < scanLength; i++) {
            var b = scanBytes[i];
            if (b !== ENDSTREAM_SIGNATURE[j]) {
              i -= j;
              j = 0;
            } else {
              j++;
              if (j >= ENDSTREAM_SIGNATURE_LENGTH) {
                i++;
                found = true;
                break;
              }
            }
          }
          if (found) {
            skipped += i - ENDSTREAM_SIGNATURE_LENGTH;
            stream.pos += i - ENDSTREAM_SIGNATURE_LENGTH;
            break;
          }
          skipped += scanLength;
          stream.pos += scanLength;
        }
        if (!found) {
          error('Missing endstream');
        }
        length = skipped;

        lexer.nextChar();
        this.shift();
        this.shift();
      }
      this.shift(); // 'endstream'

      stream = stream.makeSubStream(pos, length, dict);
      if (cipherTransform) {
        stream = cipherTransform.createStream(stream, length);
      }
      stream = this.filter(stream, dict, length);
      stream.dict = dict;
      return stream;
    },
    filter: function Parser_filter(stream, dict, length) {
      var filter = dict.get('Filter', 'F');
      var params = dict.get('DecodeParms', 'DP');
      if (isName(filter)) {
        return this.makeFilter(stream, filter.name, length, params);
      }

      var maybeLength = length;
      if (isArray(filter)) {
        var filterArray = filter;
        var paramsArray = params;
        for (var i = 0, ii = filterArray.length; i < ii; ++i) {
          filter = filterArray[i];
          if (!isName(filter)) {
            error('Bad filter name: ' + filter);
          }

          params = null;
          if (isArray(paramsArray) && (i in paramsArray)) {
            params = paramsArray[i];
          }
          stream = this.makeFilter(stream, filter.name, maybeLength, params);
          // after the first stream the length variable is invalid
          maybeLength = null;
        }
      }
      return stream;
    },
    makeFilter: function Parser_makeFilter(stream, name, maybeLength, params) {
      if (stream.dict.get('Length') === 0 && !maybeLength) {
        warn('Empty "' + name + '" stream.');
        return new NullStream(stream);
      }
      try {
        if (params && this.xref) {
          params = this.xref.fetchIfRef(params);
        }
        var xrefStreamStats = this.xref.stats.streamTypes;
        if (name === 'FlateDecode' || name === 'Fl') {
          xrefStreamStats[StreamType.FLATE] = true;
          if (params) {
            return new PredictorStream(new FlateStream(stream, maybeLength),
                                       maybeLength, params);
          }
          return new FlateStream(stream, maybeLength);
        }
        if (name === 'LZWDecode' || name === 'LZW') {
          xrefStreamStats[StreamType.LZW] = true;
          var earlyChange = 1;
          if (params) {
            if (params.has('EarlyChange')) {
              earlyChange = params.get('EarlyChange');
            }
            return new PredictorStream(
              new LZWStream(stream, maybeLength, earlyChange),
              maybeLength, params);
          }
          return new LZWStream(stream, maybeLength, earlyChange);
        }
        if (name === 'DCTDecode' || name === 'DCT') {
          xrefStreamStats[StreamType.DCT] = true;
          return new JpegStream(stream, maybeLength, stream.dict, this.xref);
        }
        if (name === 'JPXDecode' || name === 'JPX') {
          xrefStreamStats[StreamType.JPX] = true;
          return new JpxStream(stream, maybeLength, stream.dict);
        }
        if (name === 'ASCII85Decode' || name === 'A85') {
          xrefStreamStats[StreamType.A85] = true;
          return new Ascii85Stream(stream, maybeLength);
        }
        if (name === 'ASCIIHexDecode' || name === 'AHx') {
          xrefStreamStats[StreamType.AHX] = true;
          return new AsciiHexStream(stream, maybeLength);
        }
        if (name === 'CCITTFaxDecode' || name === 'CCF') {
          xrefStreamStats[StreamType.CCF] = true;
          return new CCITTFaxStream(stream, maybeLength, params);
        }
        if (name === 'RunLengthDecode' || name === 'RL') {
          xrefStreamStats[StreamType.RL] = true;
          return new RunLengthStream(stream, maybeLength);
        }
        if (name === 'JBIG2Decode') {
          xrefStreamStats[StreamType.JBIG] = true;
          return new Jbig2Stream(stream, maybeLength, stream.dict);
        }
        warn('filter "' + name + '" not supported yet');
        return stream;
      } catch (ex) {
        if (ex instanceof MissingDataException) {
          throw ex;
        }
        warn('Invalid stream: \"' + ex + '\"');
        return new NullStream(stream);
      }
    }
  };

  return Parser;
})();

var Lexer = (function LexerClosure() {
  function Lexer(stream, knownCommands) {
    this.stream = stream;
    this.nextChar();

    // While lexing, we build up many strings one char at a time. Using += for
    // this can result in lots of garbage strings. It's better to build an
    // array of single-char strings and then join() them together at the end.
    // And reusing a single array (i.e. |this.strBuf|) over and over for this
    // purpose uses less memory than using a new array for each string.
    this.strBuf = [];

    // The PDFs might have "glued" commands with other commands, operands or
    // literals, e.g. "q1". The knownCommands is a dictionary of the valid
    // commands and their prefixes. The prefixes are built the following way:
    // if there a command that is a prefix of the other valid command or
    // literal (e.g. 'f' and 'false') the following prefixes must be included,
    // 'fa', 'fal', 'fals'. The prefixes are not needed, if the command has no
    // other commands or literals as a prefix. The knowCommands is optional.
    this.knownCommands = knownCommands;
  }

  Lexer.isSpace = function Lexer_isSpace(ch) {
    // Space is one of the following characters: SPACE, TAB, CR or LF.
    return (ch === 0x20 || ch === 0x09 || ch === 0x0D || ch === 0x0A);
  };

  // A '1' in this array means the character is white space. A '1' or
  // '2' means the character ends a name or command.
  var specialChars = [
    1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, // 0x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 1x
    1, 0, 0, 0, 0, 2, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, // 2x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, // 3x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 4x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 5x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 6x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 7x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 8x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 9x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ax
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // bx
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // cx
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // dx
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ex
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0  // fx
  ];

  function toHexDigit(ch) {
    if (ch >= 0x30 && ch <= 0x39) { // '0'-'9'
      return ch & 0x0F;
    }
    if ((ch >= 0x41 && ch <= 0x46) || (ch >= 0x61 && ch <= 0x66)) {
      // 'A'-'F', 'a'-'f'
      return (ch & 0x0F) + 9;
    }
    return -1;
  }

  Lexer.prototype = {
    nextChar: function Lexer_nextChar() {
      return (this.currentChar = this.stream.getByte());
    },
    peekChar: function Lexer_peekChar() {
      return this.stream.peekByte();
    },
    getNumber: function Lexer_getNumber() {
      var ch = this.currentChar;
      var eNotation = false;
      var divideBy = 0; // different from 0 if it's a floating point value
      var sign = 1;

      if (ch === 0x2D) { // '-'
        sign = -1;
        ch = this.nextChar();

        if (ch === 0x2D) { // '-'
          // Ignore double negative (this is consistent with Adobe Reader).
          ch = this.nextChar();
        }
      } else if (ch === 0x2B) { // '+'
        ch = this.nextChar();
      }
      if (ch === 0x2E) { // '.'
        divideBy = 10;
        ch = this.nextChar();
      }
      if (ch < 0x30 || ch > 0x39) { // '0' - '9'
        error('Invalid number: ' + String.fromCharCode(ch));
        return 0;
      }

      var baseValue = ch - 0x30; // '0'
      var powerValue = 0;
      var powerValueSign = 1;

      while ((ch = this.nextChar()) >= 0) {
        if (0x30 <= ch && ch <= 0x39) { // '0' - '9'
          var currentDigit = ch - 0x30; // '0'
          if (eNotation) { // We are after an 'e' or 'E'
            powerValue = powerValue * 10 + currentDigit;
          } else {
            if (divideBy !== 0) { // We are after a point
              divideBy *= 10;
            }
            baseValue = baseValue * 10 + currentDigit;
          }
        } else if (ch === 0x2E) { // '.'
          if (divideBy === 0) {
            divideBy = 1;
          } else {
            // A number can have only one '.'
            break;
          }
        } else if (ch === 0x2D) { // '-'
          // ignore minus signs in the middle of numbers to match
          // Adobe's behavior
          warn('Badly formated number');
        } else if (ch === 0x45 || ch === 0x65) { // 'E', 'e'
          // 'E' can be either a scientific notation or the beginning of a new
          // operator
          ch = this.peekChar();
          if (ch === 0x2B || ch === 0x2D) { // '+', '-'
            powerValueSign = (ch === 0x2D) ? -1 : 1;
            this.nextChar(); // Consume the sign character
          } else if (ch < 0x30 || ch > 0x39) { // '0' - '9'
            // The 'E' must be the beginning of a new operator
            break;
          }
          eNotation = true;
        } else {
          // the last character doesn't belong to us
          break;
        }
      }

      if (divideBy !== 0) {
        baseValue /= divideBy;
      }
      if (eNotation) {
        baseValue *= Math.pow(10, powerValueSign * powerValue);
      }
      return sign * baseValue;