mirror of https://github.com/status-im/metro.git
54 lines
1.3 KiB
JavaScript
54 lines
1.3 KiB
JavaScript
/**
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* Copyright (c) 2015-present, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*
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* @providesModule Channel
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*/
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var XHR = require('XHR');
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/**
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* Client implementation of a server-push channel.
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*
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* @see Channel.js for full documentation
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*/
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var channel = null, at = null, delay = 0;
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var Channel = {};
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Channel.connect = function() {
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var url = '/pull';
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if (channel) {
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url += '?channel=' + channel + '&at=' + at;
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}
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XHR.get(url, function(err, xhr) {
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if (err) {
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delay = Math.min(Math.max(1000, delay * 2), 30000);
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} else {
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var res = xhr.responseText;
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res = JSON.parse(res);
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delay = 0;
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// Cache channel state
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channel = res.channel;
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at = res.at;
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var messages = res.messages;
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messages.forEach(function(message) {
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var ev = document.createEvent('CustomEvent');
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ev.initCustomEvent(message.event, true, true, message.detail);
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window.dispatchEvent(ev);
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});
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}
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// Reconnect
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setTimeout(Channel.connect, delay);
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});
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};
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module.exports = Channel;
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