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// Copyright 2006 The Closure Library Authors. 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.
/**
* @fileoverview tmpnetwork.js contains some temporary networking functions
* for browserchannel which will be moved at a later date.
*/
/**
* Namespace for BrowserChannel
*/
goog.provide('goog.net.tmpnetwork');
goog.require('goog.Uri');
goog.require('goog.net.ChannelDebug');
/**
* Default timeout to allow for google.com pings.
* @type {number}
*/
goog.net.tmpnetwork.GOOGLECOM_TIMEOUT = 10000;
goog.net.tmpnetwork.testGoogleCom = function(callback, opt_imageUri) {
// We need to add a 'rand' to make sure the response is not fulfilled
// by browser cache.
var uri = opt_imageUri;
if (!uri) {
uri = new goog.Uri('//www.google.com/images/cleardot.gif');
uri.makeUnique();
}
goog.net.tmpnetwork.testLoadImage(uri.toString(),
goog.net.tmpnetwork.GOOGLECOM_TIMEOUT, callback);
};
/**
* Test loading the given image, retrying if necessary.
* @param {string} url URL to the iamge.
* @param {number} timeout Milliseconds before giving up.
* @param {Function} callback Function to call with results.
* @param {number} retries The number of times to retry.
* @param {number=} opt_pauseBetweenRetriesMS Optional number of milliseconds
* between retries - defaults to 0.
*/
goog.net.tmpnetwork.testLoadImageWithRetries = function(url, timeout, callback,
retries, opt_pauseBetweenRetriesMS) {
var channelDebug = new goog.net.ChannelDebug();
channelDebug.debug('TestLoadImageWithRetries: ' + opt_pauseBetweenRetriesMS);
if (retries == 0) {
// no more retries, give up
callback(false);
return;
}
var pauseBetweenRetries = opt_pauseBetweenRetriesMS || 0;
retries--;
goog.net.tmpnetwork.testLoadImage(url, timeout, function(succeeded) {
if (succeeded) {
callback(true);
} else {
// try again
goog.global.setTimeout(function() {
goog.net.tmpnetwork.testLoadImageWithRetries(url, timeout, callback,
retries, pauseBetweenRetries);
}, pauseBetweenRetries);
}
});
};
/**
* Test loading the given image.
* @param {string} url URL to the iamge.
* @param {number} timeout Milliseconds before giving up.
* @param {Function} callback Function to call with results.
*/
goog.net.tmpnetwork.testLoadImage = function(url, timeout, callback) {
var channelDebug = new goog.net.ChannelDebug();
channelDebug.debug('TestLoadImage: loading ' + url);
var img = new Image();
img.onload = function() {
try {
channelDebug.debug('TestLoadImage: loaded');
goog.net.tmpnetwork.clearImageCallbacks_(img);
callback(true);
} catch (e) {
channelDebug.dumpException(e);
}
};
img.onerror = function() {
try {
channelDebug.debug('TestLoadImage: error');
goog.net.tmpnetwork.clearImageCallbacks_(img);
callback(false);
} catch (e) {
channelDebug.dumpException(e);
}
};
img.onabort = function() {
try {
channelDebug.debug('TestLoadImage: abort');
goog.net.tmpnetwork.clearImageCallbacks_(img);
callback(false);
} catch (e) {
channelDebug.dumpException(e);
}
};
img.ontimeout = function() {
try {
channelDebug.debug('TestLoadImage: timeout');
goog.net.tmpnetwork.clearImageCallbacks_(img);
callback(false);
} catch (e) {
channelDebug.dumpException(e);
}
};
goog.global.setTimeout(function() {
if (img.ontimeout) {
img.ontimeout();
}
}, timeout);
img.src = url;
};
/**
* Clear handlers to avoid memory leaks.
* @param {Image} img The image to clear handlers from.
* @private
*/
goog.net.tmpnetwork.clearImageCallbacks_ = function(img) {
// NOTE(user): Nullified individually to avoid compiler warnings
// (BUG 658126)
img.onload = null;
img.onerror = null;
img.onabort = null;
img.ontimeout = null;
};
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