pdfjs.parser.js

     * @returns {Object} Object that contains 'x' and 'y' properties of the
     * point in the viewport coordinate space.
     * @see {@link convertToPdfPoint}
     * @see {@link convertToViewportRectangle}
     */
    convertToViewportPoint: function PageViewport_convertToViewportPoint(x, y) {
      return Util.applyTransform([x, y], this.transform);
    },
    /**
     * Converts PDF rectangle to the viewport coordinates.
     * @param rect {Array} xMin, yMin, xMax and yMax coordinates.
     * @returns {Array} Contains corresponding coordinates of the rectangle
     * in the viewport coordinate space.
     * @see {@link convertToViewportPoint}
     */
    convertToViewportRectangle:
      function PageViewport_convertToViewportRectangle(rect) {
      var tl = Util.applyTransform([rect[0], rect[1]], this.transform);
      var br = Util.applyTransform([rect[2], rect[3]], this.transform);
      return [tl[0], tl[1], br[0], br[1]];
    },
    /**
     * Converts viewport coordinates to the PDF location. For examples, useful
     * for converting canvas pixel location into PDF one.
     * @param x {number} X coordinate.
     * @param y {number} Y coordinate.
     * @returns {Object} Object that contains 'x' and 'y' properties of the
     * point in the PDF coordinate space.
     * @see {@link convertToViewportPoint}
     */
    convertToPdfPoint: function PageViewport_convertToPdfPoint(x, y) {
      return Util.applyInverseTransform([x, y], this.transform);
    }
  };
  return PageViewport;
})();

var PDFStringTranslateTable = [
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0x2D8, 0x2C7, 0x2C6, 0x2D9, 0x2DD, 0x2DB, 0x2DA, 0x2DC, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x2022, 0x2020, 0x2021, 0x2026, 0x2014,
  0x2013, 0x192, 0x2044, 0x2039, 0x203A, 0x2212, 0x2030, 0x201E, 0x201C,
  0x201D, 0x2018, 0x2019, 0x201A, 0x2122, 0xFB01, 0xFB02, 0x141, 0x152, 0x160,
  0x178, 0x17D, 0x131, 0x142, 0x153, 0x161, 0x17E, 0, 0x20AC
];

function stringToPDFString(str) {
  var i, n = str.length, strBuf = [];
  if (str[0] === '\xFE' && str[1] === '\xFF') {
    // UTF16BE BOM
    for (i = 2; i < n; i += 2) {
      strBuf.push(String.fromCharCode(
        (str.charCodeAt(i) << 8) | str.charCodeAt(i + 1)));
    }
  } else {
    for (i = 0; i < n; ++i) {
      var code = PDFStringTranslateTable[str.charCodeAt(i)];
      strBuf.push(code ? String.fromCharCode(code) : str.charAt(i));
    }
  }
  return strBuf.join('');
}

function stringToUTF8String(str) {
  return decodeURIComponent(escape(str));
}

function utf8StringToString(str) {
  return unescape(encodeURIComponent(str));
}

function isEmptyObj(obj) {
  for (var key in obj) {
    return false;
  }
  return true;
}

function isBool(v) {
  return typeof v === 'boolean';
}

function isInt(v) {
  return typeof v === 'number' && ((v | 0) === v);
}

function isNum(v) {
  return typeof v === 'number';
}

function isString(v) {
  return typeof v === 'string';
}

function isArray(v) {
  return v instanceof Array;
}

function isArrayBuffer(v) {
  return typeof v === 'object' && v !== null && v.byteLength !== undefined;
}

/**
 * Promise Capability object.
 *
 * @typedef {Object} PromiseCapability
 * @property {Promise} promise - A promise object.
 * @property {function} resolve - Fullfills the promise.
 * @property {function} reject - Rejects the promise.
 */

/**
 * Creates a promise capability object.
 * @alias PDFJS.createPromiseCapability
 *
 * @return {PromiseCapability} A capability object contains:
 * - a Promise, resolve and reject methods.
 */
function createPromiseCapability() {
  var capability = {};
  capability.promise = new Promise(function (resolve, reject) {
    capability.resolve = resolve;
    capability.reject = reject;
  });
  return capability;
}

PDFJS.createPromiseCapability = createPromiseCapability;

/**
 * Polyfill for Promises:
 * The following promise implementation tries to generally implement the
 * Promise/A+ spec. Some notable differences from other promise libaries are:
 * - There currently isn't a seperate deferred and promise object.
 * - Unhandled rejections eventually show an error if they aren't handled.
 *
 * Based off of the work in:
 * https://bugzilla.mozilla.org/show_bug.cgi?id=810490
 */
(function PromiseClosure() {
  if (globalScope.Promise) {
    // Promises existing in the DOM/Worker, checking presence of all/resolve
    if (typeof globalScope.Promise.all !== 'function') {
      globalScope.Promise.all = function (iterable) {
        var count = 0, results = [], resolve, reject;
        var promise = new globalScope.Promise(function (resolve_, reject_) {
          resolve = resolve_;
          reject = reject_;
        });
        iterable.forEach(function (p, i) {
          count++;
          p.then(function (result) {
            results[i] = result;
            count--;
            if (count === 0) {
              resolve(results);
            }
          }, reject);
        });
        if (count === 0) {
          resolve(results);
        }
        return promise;
      };
    }
    if (typeof globalScope.Promise.resolve !== 'function') {
      globalScope.Promise.resolve = function (value) {
        return new globalScope.Promise(function (resolve) { resolve(value); });
      };
    }
    if (typeof globalScope.Promise.reject !== 'function') {
      globalScope.Promise.reject = function (reason) {
        return new globalScope.Promise(function (resolve, reject) {
          reject(reason);
        });
      };
    }
    if (typeof globalScope.Promise.prototype.catch !== 'function') {
      globalScope.Promise.prototype.catch = function (onReject) {
        return globalScope.Promise.prototype.then(undefined, onReject);
      };
    }
    return;
  }
//#if !MOZCENTRAL
  var STATUS_PENDING = 0;
  var STATUS_RESOLVED = 1;
  var STATUS_REJECTED = 2;

  // In an attempt to avoid silent exceptions, unhandled rejections are
  // tracked and if they aren't handled in a certain amount of time an
  // error is logged.
  var REJECTION_TIMEOUT = 500;

  var HandlerManager = {
    handlers: [],
    running: false,
    unhandledRejections: [],
    pendingRejectionCheck: false,

    scheduleHandlers: function scheduleHandlers(promise) {
      if (promise._status === STATUS_PENDING) {
        return;
      }

      this.handlers = this.handlers.concat(promise._handlers);
      promise._handlers = [];

      if (this.running) {
        return;
      }
      this.running = true;

      setTimeout(this.runHandlers.bind(this), 0);
    },

    runHandlers: function runHandlers() {
      var RUN_TIMEOUT = 1; // ms
      var timeoutAt = Date.now() + RUN_TIMEOUT;
      while (this.handlers.length > 0) {
        var handler = this.handlers.shift();

        var nextStatus = handler.thisPromise._status;
        var nextValue = handler.thisPromise._value;

        try {
          if (nextStatus === STATUS_RESOLVED) {
            if (typeof handler.onResolve === 'function') {
              nextValue = handler.onResolve(nextValue);
            }
          } else if (typeof handler.onReject === 'function') {
              nextValue = handler.onReject(nextValue);
              nextStatus = STATUS_RESOLVED;

              if (handler.thisPromise._unhandledRejection) {
                this.removeUnhandeledRejection(handler.thisPromise);
              }
          }
        } catch (ex) {
          nextStatus = STATUS_REJECTED;
          nextValue = ex;
        }

        handler.nextPromise._updateStatus(nextStatus, nextValue);
        if (Date.now() >= timeoutAt) {
          break;
        }
      }

      if (this.handlers.length > 0) {
        setTimeout(this.runHandlers.bind(this), 0);
        return;
      }

      this.running = false;
    },

    addUnhandledRejection: function addUnhandledRejection(promise) {
      this.unhandledRejections.push({
        promise: promise,
        time: Date.now()
      });
      this.scheduleRejectionCheck();
    },

    removeUnhandeledRejection: function removeUnhandeledRejection(promise) {
      promise._unhandledRejection = false;
      for (var i = 0; i < this.unhandledRejections.length; i++) {
        if (this.unhandledRejections[i].promise === promise) {
          this.unhandledRejections.splice(i);
          i--;
        }
      }
    },

    scheduleRejectionCheck: function scheduleRejectionCheck() {
      if (this.pendingRejectionCheck) {
        return;
      }
      this.pendingRejectionCheck = true;
      setTimeout(function rejectionCheck() {
        this.pendingRejectionCheck = false;
        var now = Date.now();
        for (var i = 0; i < this.unhandledRejections.length; i++) {
          if (now - this.unhandledRejections[i].time > REJECTION_TIMEOUT) {
            var unhandled = this.unhandledRejections[i].promise._value;
            var msg = 'Unhandled rejection: ' + unhandled;
            if (unhandled.stack) {
              msg += '\n' + unhandled.stack;
            }
            warn(msg);
            this.unhandledRejections.splice(i);
            i--;
          }
        }
        if (this.unhandledRejections.length) {
          this.scheduleRejectionCheck();
        }
      }.bind(this), REJECTION_TIMEOUT);
    }
  };

  function Promise(resolver) {
    this._status = STATUS_PENDING;
    this._handlers = [];
    try {
      resolver.call(this, this._resolve.bind(this), this._reject.bind(this));
    } catch (e) {
      this._reject(e);
    }
  }
  /**
   * Builds a promise that is resolved when all the passed in promises are
   * resolved.
   * @param {array} array of data and/or promises to wait for.
   * @return {Promise} New dependant promise.
   */
  Promise.all = function Promise_all(promises) {
    var resolveAll, rejectAll;
    var deferred = new Promise(function (resolve, reject) {
      resolveAll = resolve;
      rejectAll = reject;
    });
    var unresolved = promises.length;
    var results = [];
    if (unresolved === 0) {
      resolveAll(results);
      return deferred;
    }
    function reject(reason) {
      if (deferred._status === STATUS_REJECTED) {
        return;
      }
      results = [];
      rejectAll(reason);
    }
    for (var i = 0, ii = promises.length; i < ii; ++i) {
      var promise = promises[i];
      var resolve = (function(i) {
        return function(value) {
          if (deferred._status === STATUS_REJECTED) {
            return;
          }
          results[i] = value;
          unresolved--;
          if (unresolved === 0) {
            resolveAll(results);
          }
        };
      })(i);
      if (Promise.isPromise(promise)) {
        promise.then(resolve, reject);
      } else {
        resolve(promise);
      }
    }
    return deferred;
  };

  /**
   * Checks if the value is likely a promise (has a 'then' function).
   * @return {boolean} true if value is thenable
   */
  Promise.isPromise = function Promise_isPromise(value) {
    return value && typeof value.then === 'function';
  };

  /**
   * Creates resolved promise
   * @param value resolve value
   * @returns {Promise}
   */
  Promise.resolve = function Promise_resolve(value) {
    return new Promise(function (resolve) { resolve(value); });
  };

  /**
   * Creates rejected promise
   * @param reason rejection value
   * @returns {Promise}
   */
  Promise.reject = function Promise_reject(reason) {
    return new Promise(function (resolve, reject) { reject(reason); });
  };

  Promise.prototype = {
    _status: null,
    _value: null,
    _handlers: null,
    _unhandledRejection: null,

    _updateStatus: function Promise__updateStatus(status, value) {
      if (this._status === STATUS_RESOLVED ||
          this._status === STATUS_REJECTED) {
        return;
      }

      if (status === STATUS_RESOLVED &&
          Promise.isPromise(value)) {
        value.then(this._updateStatus.bind(this, STATUS_RESOLVED),
                   this._updateStatus.bind(this, STATUS_REJECTED));
        return;
      }

      this._status = status;
      this._value = value;

      if (status === STATUS_REJECTED && this._handlers.length === 0) {
        this._unhandledRejection = true;
        HandlerManager.addUnhandledRejection(this);
      }

      HandlerManager.scheduleHandlers(this);
    },

    _resolve: function Promise_resolve(value) {
      this._updateStatus(STATUS_RESOLVED, value);
    },

    _reject: function Promise_reject(reason) {
      this._updateStatus(STATUS_REJECTED, reason);
    },

    then: function Promise_then(onResolve, onReject) {
      var nextPromise = new Promise(function (resolve, reject) {
        this.resolve = resolve;
        this.reject = reject;
      });
      this._handlers.push({
        thisPromise: this,
        onResolve: onResolve,
        onReject: onReject,
        nextPromise: nextPromise
      });
      HandlerManager.scheduleHandlers(this);
      return nextPromise;
    },

    catch: function Promise_catch(onReject) {
      return this.then(undefined, onReject);
    }
  };

  globalScope.Promise = Promise;
//#else
//throw new Error('DOM Promise is not present');
//#endif
})();

var StatTimer = (function StatTimerClosure() {
  function rpad(str, pad, length) {
    while (str.length < length) {
      str += pad;
    }
    return str;
  }
  function StatTimer() {
    this.started = {};
    this.times = [];
    this.enabled = true;
  }
  StatTimer.prototype = {
    time: function StatTimer_time(name) {
      if (!this.enabled) {
        return;
      }
      if (name in this.started) {
        warn('Timer is already running for ' + name);
      }
      this.started[name] = Date.now();
    },
    timeEnd: function StatTimer_timeEnd(name) {
      if (!this.enabled) {
        return;
      }
      if (!(name in this.started)) {
        warn('Timer has not been started for ' + name);
      }
      this.times.push({
        'name': name,
        'start': this.started[name],
        'end': Date.now()
      });
      // Remove timer from started so it can be called again.
      delete this.started[name];
    },
    toString: function StatTimer_toString() {
      var i, ii;
      var times = this.times;
      var out = '';
      // Find the longest name for padding purposes.
      var longest = 0;
      for (i = 0, ii = times.length; i < ii; ++i) {
        var name = times[i]['name'];
        if (name.length > longest) {
          longest = name.length;
        }
      }
      for (i = 0, ii = times.length; i < ii; ++i) {
        var span = times[i];
        var duration = span.end - span.start;
        out += rpad(span['name'], ' ', longest) + ' ' + duration + 'ms\n';
      }
      return out;
    }
  };
  return StatTimer;
})();

PDFJS.createBlob = function createBlob(data, contentType) {
  if (typeof Blob !== 'undefined') {
    return new Blob([data], { type: contentType });
  }
  // Blob builder is deprecated in FF14 and removed in FF18.
  var bb = new MozBlobBuilder();
  bb.append(data);
  return bb.getBlob(contentType);
};

PDFJS.createObjectURL = (function createObjectURLClosure() {
  // Blob/createObjectURL is not available, falling back to data schema.
  var digits =
    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';

  return function createObjectURL(data, contentType) {
    if (!PDFJS.disableCreateObjectURL &&
        typeof URL !== 'undefined' && URL.createObjectURL) {
      var blob = PDFJS.createBlob(data, contentType);
      return URL.createObjectURL(blob);
    }

    var buffer = 'data:' + contentType + ';base64,';
    for (var i = 0, ii = data.length; i < ii; i += 3) {
      var b1 = data[i] & 0xFF;
      var b2 = data[i + 1] & 0xFF;
      var b3 = data[i + 2] & 0xFF;
      var d1 = b1 >> 2, d2 = ((b1 & 3) << 4) | (b2 >> 4);
      var d3 = i + 1 < ii ? ((b2 & 0xF) << 2) | (b3 >> 6) : 64;
      var d4 = i + 2 < ii ? (b3 & 0x3F) : 64;
      buffer += digits[d1] + digits[d2] + digits[d3] + digits[d4];
    }
    return buffer;
  };
})();

function MessageHandler(sourceName, targetName, comObj) {
  this.sourceName = sourceName;
  this.targetName = targetName;
  this.comObj = comObj;
  this.callbackIndex = 1;
  this.postMessageTransfers = true;
  var callbacksCapabilities = this.callbacksCapabilities = {};
  var ah = this.actionHandler = {};

  this._onComObjOnMessage = function messageHandlerComObjOnMessage(event) {
    var data = event.data;
    if (data.targetName !== this.sourceName) {
      return;
    }
    if (data.isReply) {
      var callbackId = data.callbackId;
      if (data.callbackId in callbacksCapabilities) {
        var callback = callbacksCapabilities[callbackId];
        delete callbacksCapabilities[callbackId];
        if ('error' in data) {
          callback.reject(data.error);
        } else {
          callback.resolve(data.data);
        }
      } else {
        error('Cannot resolve callback ' + callbackId);
      }
    } else if (data.action in ah) {
      var action = ah[data.action];
      if (data.callbackId) {
        var sourceName = this.sourceName;
        var targetName = data.sourceName;
        Promise.resolve().then(function () {
          return action[0].call(action[1], data.data);
        }).then(function (result) {
          comObj.postMessage({
            sourceName: sourceName,
            targetName: targetName,
            isReply: true,
            callbackId: data.callbackId,
            data: result
          });
        }, function (reason) {
          if (reason instanceof Error) {
            // Serialize error to avoid "DataCloneError"
            reason = reason + '';
          }
          comObj.postMessage({
            sourceName: sourceName,
            targetName: targetName,
            isReply: true,
            callbackId: data.callbackId,
            error: reason
          });
        });
      } else {
        action[0].call(action[1], data.data);
      }
    } else {
      error('Unknown action from worker: ' + data.action);
    }
  }.bind(this);
  comObj.addEventListener('message', this._onComObjOnMessage);
}

MessageHandler.prototype = {
  on: function messageHandlerOn(actionName, handler, scope) {
    var ah = this.actionHandler;
    if (ah[actionName]) {
      error('There is already an actionName called "' + actionName + '"');
    }
    ah[actionName] = [handler, scope];
  },
  /**
   * Sends a message to the comObj to invoke the action with the supplied data.
   * @param {String} actionName Action to call.
   * @param {JSON} data JSON data to send.
   * @param {Array} [transfers] Optional list of transfers/ArrayBuffers
   */
  send: function messageHandlerSend(actionName, data, transfers) {
    var message = {
      sourceName: this.sourceName,
      targetName: this.targetName,
      action: actionName,
      data: data
    };
    this.postMessage(message, transfers);
  },
  /**
   * Sends a message to the comObj to invoke the action with the supplied data.
   * Expects that other side will callback with the response.
   * @param {String} actionName Action to call.
   * @param {JSON} data JSON data to send.
   * @param {Array} [transfers] Optional list of transfers/ArrayBuffers.
   * @returns {Promise} Promise to be resolved with response data.
   */
  sendWithPromise:
    function messageHandlerSendWithPromise(actionName, data, transfers) {
    var callbackId = this.callbackIndex++;
    var message = {
      sourceName: this.sourceName,
      targetName: this.targetName,
      action: actionName,
      data: data,
      callbackId: callbackId
    };
    var capability = createPromiseCapability();
    this.callbacksCapabilities[callbackId] = capability;
    try {
      this.postMessage(message, transfers);
    } catch (e) {
      capability.reject(e);
    }
    return capability.promise;
  },
  /**
   * Sends raw message to the comObj.
   * @private
   * @param message {Object} Raw message.
   * @param transfers List of transfers/ArrayBuffers, or undefined.
   */
  postMessage: function (message, transfers) {
    if (transfers && this.postMessageTransfers) {
      this.comObj.postMessage(message, transfers);
    } else {
      this.comObj.postMessage(message);
    }
  },

  destroy: function () {
    this.comObj.removeEventListener('message', this._onComObjOnMessage);
  }
};

function loadJpegStream(id, imageUrl, objs) {
  var img = new Image();
  img.onload = (function loadJpegStream_onloadClosure() {
    objs.resolve(id, img);
  });
  img.onerror = (function loadJpegStream_onerrorClosure() {
    objs.resolve(id, null);
    warn('Error during JPEG image loading');
  });
  img.src = imageUrl;
}

exports.FONT_IDENTITY_MATRIX = FONT_IDENTITY_MATRIX;
exports.IDENTITY_MATRIX = IDENTITY_MATRIX;
exports.OPS = OPS;
exports.UNSUPPORTED_FEATURES = UNSUPPORTED_FEATURES;
exports.AnnotationBorderStyleType = AnnotationBorderStyleType;
exports.AnnotationFlag = AnnotationFlag;
exports.AnnotationType = AnnotationType;
exports.FontType = FontType;
exports.ImageKind = ImageKind;
exports.InvalidPDFException = InvalidPDFException;
exports.LinkTarget = LinkTarget;
exports.LinkTargetStringMap = LinkTargetStringMap;
exports.MessageHandler = MessageHandler;
exports.MissingDataException = MissingDataException;
exports.MissingPDFException = MissingPDFException;
exports.NotImplementedException = NotImplementedException;
exports.PasswordException = PasswordException;
exports.PasswordResponses = PasswordResponses;
exports.StatTimer = StatTimer;
exports.StreamType = StreamType;
exports.TextRenderingMode = TextRenderingMode;
exports.UnexpectedResponseException = UnexpectedResponseException;
exports.UnknownErrorException = UnknownErrorException;
exports.Util = Util;
exports.XRefParseException = XRefParseException;
exports.assert = assert;
exports.bytesToString = bytesToString;
exports.combineUrl = combineUrl;
exports.createPromiseCapability = createPromiseCapability;
exports.deprecated = deprecated;
exports.error = error;
exports.info = info;
exports.isArray = isArray;
exports.isArrayBuffer = isArrayBuffer;
exports.isBool = isBool;
exports.isEmptyObj = isEmptyObj;
exports.isExternalLinkTargetSet = isExternalLinkTargetSet;
exports.isInt = isInt;
exports.isNum = isNum;
exports.isString = isString;
exports.isValidUrl = isValidUrl;
exports.loadJpegStream = loadJpegStream;
exports.log2 = log2;
exports.readInt8 = readInt8;
exports.readUint16 = readUint16;
exports.readUint32 = readUint32;
exports.shadow = shadow;
exports.string32 = string32;
exports.stringToBytes = stringToBytes;
exports.stringToPDFString = stringToPDFString;
exports.stringToUTF8String = stringToUTF8String;
exports.utf8StringToString = utf8StringToString;
exports.warn = warn;
}));

/* Copyright 2012 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* globals NetworkManager */

'use strict';

(function (root, factory) {
  //if (typeof define === 'function' && define.amd) {
  //  define('pdfjs/core/chunked_stream', ['exports', 'pdfjs/shared/util'],
  //    factory);
  // } else if (typeof exports !== 'undefined') {
  //   factory(exports, require('../shared/util.js'));
  //} else {
    factory((root.pdfjsCoreChunkedStream = {}), root.pdfjsSharedUtil);
  //}
}(window, function (exports, sharedUtil) {

var MissingDataException = sharedUtil.MissingDataException;
var assert = sharedUtil.assert;
var createPromiseCapability = sharedUtil.createPromiseCapability;
var isInt = sharedUtil.isInt;
var isEmptyObj = sharedUtil.isEmptyObj;

var ChunkedStream = (function ChunkedStreamClosure() {
  function ChunkedStream(length, chunkSize, manager) {
    this.bytes = new Uint8Array(length);
    this.start = 0;
    this.pos = 0;
    this.end = length;
    this.chunkSize = chunkSize;
    this.loadedChunks = [];
    this.numChunksLoaded = 0;
    this.numChunks = Math.ceil(length / chunkSize);
    this.manager = manager;
    this.progressiveDataLength = 0;
    this.lastSuccessfulEnsureByteChunk = -1;  // a single-entry cache
  }

  // required methods for a stream. if a particular stream does not
  // implement these, an error should be thrown
  ChunkedStream.prototype = {

    getMissingChunks: function ChunkedStream_getMissingChunks() {
      var chunks = [];
      for (var chunk = 0, n = this.numChunks; chunk < n; ++chunk) {
        if (!this.loadedChunks[chunk]) {
          chunks.push(chunk);
        }
      }
      return chunks;
    },

    getBaseStreams: function ChunkedStream_getBaseStreams() {
      return [this];
    },

    allChunksLoaded: function ChunkedStream_allChunksLoaded() {
      return this.numChunksLoaded === this.numChunks;
    },

    onReceiveData: function ChunkedStream_onReceiveData(begin, chunk) {
      var end = begin + chunk.byteLength;

      assert(begin % this.chunkSize === 0, 'Bad begin offset: ' + begin);
      // Using this.length is inaccurate here since this.start can be moved
      // See ChunkedStream.moveStart()
      var length = this.bytes.length;
      assert(end % this.chunkSize === 0 || end === length,
             'Bad end offset: ' + end);

      this.bytes.set(new Uint8Array(chunk), begin);
      var chunkSize = this.chunkSize;
      var beginChunk = Math.floor(begin / chunkSize);
      var endChunk = Math.floor((end - 1) / chunkSize) + 1;
      var curChunk;

      for (curChunk = beginChunk; curChunk < endChunk; ++curChunk) {
        if (!this.loadedChunks[curChunk]) {
          this.loadedChunks[curChunk] = true;
          ++this.numChunksLoaded;
        }
      }
    },

    onReceiveProgressiveData:
        function ChunkedStream_onReceiveProgressiveData(data) {
      var position = this.progressiveDataLength;
      var beginChunk = Math.floor(position / this.chunkSize);

      this.bytes.set(new Uint8Array(data), position);
      position += data.byteLength;
      this.progressiveDataLength = position;
      var endChunk = position >= this.end ? this.numChunks :
                     Math.floor(position / this.chunkSize);
      var curChunk;
      for (curChunk = beginChunk; curChunk < endChunk; ++curChunk) {
        if (!this.loadedChunks[curChunk]) {
          this.loadedChunks[curChunk] = true;
          ++this.numChunksLoaded;
        }
      }
    },

    ensureByte: function ChunkedStream_ensureByte(pos) {
      var chunk = Math.floor(pos / this.chunkSize);
      if (chunk === this.lastSuccessfulEnsureByteChunk) {
        return;
      }

      if (!this.loadedChunks[chunk]) {
        throw new MissingDataException(pos, pos + 1);
      }
      this.lastSuccessfulEnsureByteChunk = chunk;
    },

    ensureRange: function ChunkedStream_ensureRange(begin, end) {
      if (begin >= end) {
        return;
      }

      if (end <= this.progressiveDataLength) {
        return;
      }

      var chunkSize = this.chunkSize;
      var beginChunk = Math.floor(begin / chunkSize);
      var endChunk = Math.floor((end - 1) / chunkSize) + 1;
      for (var chunk = beginChunk; chunk < endChunk; ++chunk) {
        if (!this.loadedChunks[chunk]) {
          throw new MissingDataException(begin, end);
        }
      }
    },

    nextEmptyChunk: function ChunkedStream_nextEmptyChunk(beginChunk) {
      var chunk, numChunks = this.numChunks;
      for (var i = 0; i < numChunks; ++i) {
        chunk = (beginChunk + i) % numChunks; // Wrap around to beginning
        if (!this.loadedChunks[chunk]) {
          return chunk;
        }
      }
      return null;
    },

    hasChunk: function ChunkedStream_hasChunk(chunk) {
      return !!this.loadedChunks[chunk];
    },

    get length() {
      return this.end - this.start;
    },

    get isEmpty() {
      return this.length === 0;
    },

    getByte: function ChunkedStream_getByte() {
      var pos = this.pos;
      if (pos >= this.end) {
        return -1;
      }
      this.ensureByte(pos);
      return this.bytes[this.pos++];
    },

    getUint16: function ChunkedStream_getUint16() {
      var b0 = this.getByte();
      var b1 = this.getByte();
      if (b0 === -1 || b1 === -1) {
        return -1;
      }
      return (b0 << 8) + b1;
    },

    getInt32: function ChunkedStream_getInt32() {
      var b0 = this.getByte();
      var b1 = this.getByte();
      var b2 = this.getByte();
      var b3 = this.getByte();
      return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
    },

    // returns subarray of original buffer
    // should only be read
    getBytes: function ChunkedStream_getBytes(length) {
      var bytes = this.bytes;
      var pos = this.pos;
      var strEnd = this.end;

      if (!length) {
        this.ensureRange(pos, strEnd);
        return bytes.subarray(pos, strEnd);
      }

      var end = pos + length;
      if (end > strEnd) {
        end = strEnd;
      }
      this.ensureRange(pos, end);

      this.pos = end;
      return bytes.subarray(pos, end);
    },

    peekByte: function ChunkedStream_peekByte() {
      var peekedByte = this.getByte();
      this.pos--;
      return peekedByte;
    },

    peekBytes: function ChunkedStream_peekBytes(length) {
      var bytes = this.getBytes(length);
      this.pos -= bytes.length;
      return bytes;
    },

    getByteRange: function ChunkedStream_getBytes(begin, end) {
      this.ensureRange(begin, end);
      return this.bytes.subarray(begin, end);
    },

    skip: function ChunkedStream_skip(n) {
      if (!n) {
        n = 1;
      }
      this.pos += n;
    },

    reset: function ChunkedStream_reset() {
      this.pos = this.start;
    },

    moveStart: function ChunkedStream_moveStart() {
      this.start = this.pos;
    },

    makeSubStream: function ChunkedStream_makeSubStream(start, length, dict) {
      this.ensureRange(start, start + length);