2019/harness/xhr.js

/**
 * @license
 * Copyright 2018 Google Inc. All rights reserved.
 *
 * 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() {

var BYPASS_CACHE = false;

// Hook the onload event for request that is finished successfully
var Request = function(manager, logger, file, onload, postLength,
                       start, length) {
  var self = this;

  this.open = function() {
    this.xhr = new XMLHttpRequest();

    this.onload = onload;
    this.type = util.isValidArgument(postLength) ? 'POST' : 'GET';

    this.xhr.open(this.type,
                  file + (BYPASS_CACHE ? '?' + (new Date()).getTime() : ''));
    this.xhr.responseType = 'arraybuffer';

    this.startTime = new Date().getTime();
    this.lastUpdate = this.startTime;

    if (start != null && length != null)
      this.xhr.setRequestHeader(
          'Range', 'bytes=' + start + '-' + (start + length - 1));

    this.xhr.addEventListener('error', function(e) {
      if (self.xhr.status === 404)
        alert('Failed to find "' + file +
              '" with error 404. Is it on the server?');
      manager.requestFinished(self);
      logger.log('XHR error with code', self.xhr.status);
      self.open();
      self.send();
    });

    this.xhr.addEventListener('timeout', function(e) {
      manager.requestFinished(self);
      logger.log('XHR timeout');
      self.open();
      self.send();
    });

    this.xhr.addEventListener('load', function(e) {
      manager.requestFinished(self);
      return self.onload(e);
    });

    this.xhr.addEventListener('progress', function onProgress(e) {
      if (e.lengthComputable && (e.loaded === e.total)) {
        self.xhr.removeEventListener('progress', onProgress);
      }
      self.lastUpdate = new Date().getTime();
    });
  };

  this.getRawResponse = function() {
    if (this.xhr.status === 404)
      alert('Failed to find "' + file +
            '" with error 404. Is it on the server?');
    logger.assert(this.xhr.status >= 200 && this.xhr.status < 300,
                  'XHR bad status: ' + this.xhr.status);
    return this.xhr.response;
  };

  this.getResponseData = function() {
    if (this.xhr.status === 404)
      alert('Failed to find "' + file +
            '" with error 404. Is it on the server?');
    logger.assert(this.xhr.status >= 200 && this.xhr.status < 300,
                  'XHR bad status: ' + this.xhr.status);
    var result = new Uint8Array(this.xhr.response);
    if (length != null) {
      logger.checkEq(result.length, length, 'XHR length', true);
    }
    return result;
  };

  this.send = function(postData) {
    manager.addRequest(this);
    if (postData) {
      logger.checkEq(this.type, 'POST', 'XHR requestType', true);
      this.xhr.send(postData);
    } else {
      logger.checkEq(this.type, 'GET', 'XHR requestType', true);
      this.xhr.send();
    }
  };

  this.abort = function() {
    this.xhr.abort();
  };

  this.open();
};

var XHRManager = function(logger) {
  var requests = [];
  this.totalRequestDuration = 0;

  this.addRequest = function(request) {
    logger.checkEq(requests.indexOf(request), -1, 'request index', true);
    requests.push(request);
  };

  this.requestFinished = function(request) {
    var currentTime = new Date().getTime();
    this.totalRequestDuration += currentTime - request.startTime;
    logger.checkNE(requests.indexOf(request), -1, 'request index', true);
    requests.splice(requests.indexOf(request), 1);
  };

  this.abortAll = function() {
    for (var i = 0; i < requests.length; ++i)
      requests[i].abort();
    requests = [];
  };

  this.createRequest = function(file, onload, start, length) {
    return new Request(this, logger, file, onload, null, start, length);
  };

  this.createPostRequest = function(file, onload, postLength, start, length) {
    return new Request(this, logger, file, onload, postLength, start, length);
  };

  this.hasActiveRequests = function() {
    if (requests.length > 0) {
      return true;
    }
    return false;
  }

  this.getLastUpdate = function() {
    if (requests.length == 0) {
      return null;
    }

    var latestUpdate = 0;
    for (var i in requests) {
      latestUpdate = Math.max(requests[i].lastUpdate, latestUpdate);
    }
    return latestUpdate;
  };
};

window.createXHRManager = function(logger) {
  return new XHRManager(logger);
};

})();