@l5i/dashjs/build/es5/src/streaming/controllers/TimeSyncController.js

A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.

/**
 * The copyright in this software is being made available under the BSD License,
 * included below. This software may be subject to other third party and contributor
 * rights, including patent rights, and no such rights are granted under this license.
 *
 * Copyright (c) 2013, Dash Industry Forum.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *  * Redistributions of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation and/or
 *  other materials provided with the distribution.
 *  * Neither the name of Dash Industry Forum nor the names of its
 *  contributors may be used to endorse or promote products derived from this software
 *  without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY
 *  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */'use strict';Object.defineProperty(exports,'__esModule',{value:true});function _interopRequireDefault(obj){return obj && obj.__esModule?obj:{'default':obj};}var _constantsConstants=require('../constants/Constants');var _constantsConstants2=_interopRequireDefault(_constantsConstants);var _voDashJSError=require('./../vo/DashJSError');var _voDashJSError2=_interopRequireDefault(_voDashJSError);var _voMetricsHTTPRequest=require('./../vo/metrics/HTTPRequest');var _coreEventBus=require('./../../core/EventBus');var _coreEventBus2=_interopRequireDefault(_coreEventBus);var _coreEventsEvents=require('./../../core/events/Events');var _coreEventsEvents2=_interopRequireDefault(_coreEventsEvents);var _coreErrorsErrors=require('./../../core/errors/Errors');var _coreErrorsErrors2=_interopRequireDefault(_coreErrorsErrors);var _coreFactoryMaker=require('../../core/FactoryMaker');var _coreFactoryMaker2=_interopRequireDefault(_coreFactoryMaker);var _coreDebug=require('../../core/Debug');var _coreDebug2=_interopRequireDefault(_coreDebug);var _utilsURLUtils=require('../utils/URLUtils');var _utilsURLUtils2=_interopRequireDefault(_utilsURLUtils);var HTTP_TIMEOUT_MS=5000;function TimeSyncController(){var context=this.context;var eventBus=(0,_coreEventBus2['default'])(context).getInstance();var urlUtils=(0,_utilsURLUtils2['default'])(context).getInstance();var instance=undefined,logger=undefined,offsetToDeviceTimeMs=undefined,isSynchronizing=undefined,isInitialised=undefined,useManifestDateHeaderTimeSource=undefined,handlers=undefined,metricsModel=undefined,dashMetrics=undefined,baseURLController=undefined;function setup(){logger = (0,_coreDebug2['default'])(context).getInstance().getLogger(instance);}function initialize(timingSources,useManifestDateHeader){useManifestDateHeaderTimeSource = useManifestDateHeader;offsetToDeviceTimeMs = 0;isSynchronizing = false;isInitialised = false; // a list of known schemeIdUris and a method to call with @value
handlers = {'urn:mpeg:dash:utc:http-head:2014':httpHeadHandler,'urn:mpeg:dash:utc:http-xsdate:2014':httpHandler.bind(null,xsdatetimeDecoder),'urn:mpeg:dash:utc:http-iso:2014':httpHandler.bind(null,iso8601Decoder),'urn:mpeg:dash:utc:direct:2014':directHandler, // some specs referencing early ISO23009-1 drafts incorrectly use
// 2012 in the URI, rather than 2014. support these for now.
'urn:mpeg:dash:utc:http-head:2012':httpHeadHandler,'urn:mpeg:dash:utc:http-xsdate:2012':httpHandler.bind(null,xsdatetimeDecoder),'urn:mpeg:dash:utc:http-iso:2012':httpHandler.bind(null,iso8601Decoder),'urn:mpeg:dash:utc:direct:2012':directHandler, // it isn't clear how the data returned would be formatted, and
// no public examples available so http-ntp not supported for now.
// presumably you would do an arraybuffer type xhr and decode the
// binary data returned but I would want to see a sample first.
'urn:mpeg:dash:utc:http-ntp:2014':notSupportedHandler, // not clear how this would be supported in javascript (in browser)
'urn:mpeg:dash:utc:ntp:2014':notSupportedHandler,'urn:mpeg:dash:utc:sntp:2014':notSupportedHandler};if(!getIsSynchronizing()){attemptSync(timingSources);setIsInitialised(true);}}function setConfig(config){if(!config)return;if(config.metricsModel){metricsModel = config.metricsModel;}if(config.dashMetrics){dashMetrics = config.dashMetrics;}if(config.baseURLController){baseURLController = config.baseURLController;}}function getOffsetToDeviceTimeMs(){return getOffsetMs();}function setIsSynchronizing(value){isSynchronizing = value;}function getIsSynchronizing(){return isSynchronizing;}function setIsInitialised(value){isInitialised = value;}function setOffsetMs(value){offsetToDeviceTimeMs = value;}function getOffsetMs(){return offsetToDeviceTimeMs;} // takes xsdatetime and returns milliseconds since UNIX epoch
// may not be necessary as xsdatetime is very similar to ISO 8601
// which is natively understood by javascript Date parser
function alternateXsdatetimeDecoder(xsdatetimeStr){ // taken from DashParser - should probably refactor both uses
var SECONDS_IN_MIN=60;var MINUTES_IN_HOUR=60;var MILLISECONDS_IN_SECONDS=1000;var datetimeRegex=/^([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2})(?::([0-9]*)(\.[0-9]*)?)?(?:([+\-])([0-9]{2})([0-9]{2}))?/;var utcDate=undefined,timezoneOffset=undefined;var match=datetimeRegex.exec(xsdatetimeStr); // If the string does not contain a timezone offset different browsers can interpret it either
// as UTC or as a local time so we have to parse the string manually to normalize the given date value for
// all browsers
utcDate = Date.UTC(parseInt(match[1],10),parseInt(match[2],10) - 1, // months start from zero
parseInt(match[3],10),parseInt(match[4],10),parseInt(match[5],10),match[6] && (parseInt(match[6],10) || 0),match[7] && parseFloat(match[7]) * MILLISECONDS_IN_SECONDS || 0); // If the date has timezone offset take it into account as well
if(match[9] && match[10]){timezoneOffset = parseInt(match[9],10) * MINUTES_IN_HOUR + parseInt(match[10],10);utcDate += (match[8] === '+'?-1:+1) * timezoneOffset * SECONDS_IN_MIN * MILLISECONDS_IN_SECONDS;}return new Date(utcDate).getTime();} // try to use the built in parser, since xsdate is a constrained ISO8601
// which is supported natively by Date.parse. if that fails, try a
// regex-based version used elsewhere in this application.
function xsdatetimeDecoder(xsdatetimeStr){var parsedDate=Date.parse(xsdatetimeStr);if(isNaN(parsedDate)){parsedDate = alternateXsdatetimeDecoder(xsdatetimeStr);}return parsedDate;} // takes ISO 8601 timestamp and returns milliseconds since UNIX epoch
function iso8601Decoder(isoStr){return Date.parse(isoStr);} // takes RFC 1123 timestamp (which is same as ISO8601) and returns
// milliseconds since UNIX epoch
function rfc1123Decoder(dateStr){return Date.parse(dateStr);}function notSupportedHandler(url,onSuccessCB,onFailureCB){onFailureCB();}function directHandler(xsdatetimeStr,onSuccessCB,onFailureCB){var time=xsdatetimeDecoder(xsdatetimeStr);if(!isNaN(time)){onSuccessCB(time);return;}onFailureCB();}function httpHandler(decoder,url,onSuccessCB,onFailureCB,isHeadRequest){var oncomplete=undefined,onload=undefined;var complete=false;var req=new XMLHttpRequest();var verb=isHeadRequest?_voMetricsHTTPRequest.HTTPRequest.HEAD:_voMetricsHTTPRequest.HTTPRequest.GET;var urls=url.match(/\S+/g); // according to ISO 23009-1, url could be a white-space
// separated list of URLs. just handle one at a time.
url = urls.shift();oncomplete = function(){if(complete){return;} // we only want to pass through here once per xhr,
// regardless of whether the load was successful.
complete = true; // if there are more urls to try, call self.
if(urls.length){httpHandler(decoder,urls.join(' '),onSuccessCB,onFailureCB,isHeadRequest);}else {onFailureCB();}};onload = function(){var time=undefined,result=undefined;if(req.status === 200){time = isHeadRequest?req.getResponseHeader('Date'):req.response;result = decoder(time); // decoder returns NaN if non-standard input
if(!isNaN(result)){onSuccessCB(result);complete = true;}}};if(urlUtils.isRelative(url)){ // passing no path to resolve will return just MPD BaseURL/baseUri
var baseUrl=baseURLController.resolve();if(baseUrl){url = urlUtils.resolve(url,baseUrl.url);}}req.open(verb,url);req.timeout = HTTP_TIMEOUT_MS || 0;req.onload = onload;req.onloadend = oncomplete;req.send();}function httpHeadHandler(url,onSuccessCB,onFailureCB){httpHandler(rfc1123Decoder,url,onSuccessCB,onFailureCB,true);}function checkForDateHeader(){var metrics=metricsModel.getReadOnlyMetricsFor(_constantsConstants2['default'].STREAM);var dateHeaderValue=dashMetrics.getLatestMPDRequestHeaderValueByID(metrics,'Date');var dateHeaderTime=dateHeaderValue !== null?new Date(dateHeaderValue).getTime():Number.NaN;if(!isNaN(dateHeaderTime)){setOffsetMs(dateHeaderTime - new Date().getTime());completeTimeSyncSequence(false,dateHeaderTime / 1000,offsetToDeviceTimeMs);}else {completeTimeSyncSequence(true);}}function completeTimeSyncSequence(failed,time,offset){setIsSynchronizing(false);eventBus.trigger(_coreEventsEvents2['default'].TIME_SYNCHRONIZATION_COMPLETED,{time:time,offset:offset,error:failed?new _voDashJSError2['default'](_coreErrorsErrors2['default'].TIME_SYNC_FAILED_ERROR_CODE,_coreErrorsErrors2['default'].TIME_SYNC_FAILED_ERROR_MESSAGE):null});}function calculateTimeOffset(serverTime,deviceTime){var v=(serverTime - deviceTime) / 1000;var offset=undefined; // Math.trunc not implemented by IE11
if(Math.trunc){offset = Math.trunc(v);}else {offset = v - v % 1 || (!isFinite(v) || v === 0?v:v < 0?-0:0);}return offset * 1000;}function attemptSync(sources,sourceIndex){ // if called with no sourceIndex, use zero (highest priority)
var index=sourceIndex || 0; // the sources should be ordered in priority from the manifest.
// try each in turn, from the top, until either something
// sensible happens, or we run out of sources to try.
var source=sources[index]; // callback to emit event to listeners
var onComplete=function onComplete(time,offset){var failed=!time || !offset;if(failed && useManifestDateHeaderTimeSource){ //Before falling back to binary search , check if date header exists on MPD. if so, use for a time source.
checkForDateHeader();}else {completeTimeSyncSequence(failed,time,offset);}};setIsSynchronizing(true);if(source){ // check if there is a handler for this @schemeIdUri
if(handlers.hasOwnProperty(source.schemeIdUri)){ // if so, call it with its @value
handlers[source.schemeIdUri](source.value,function(serverTime){ // the timing source returned something useful
var deviceTime=new Date().getTime();var offset=calculateTimeOffset(serverTime,deviceTime);setOffsetMs(offset);logger.debug('Local time: ' + new Date(deviceTime));logger.debug('Server time: ' + new Date(serverTime));logger.info('Server Time - Local Time (ms): ' + offset);onComplete(serverTime,offset);},function(){ // the timing source was probably uncontactable
// or returned something we can't use - try again
// with the remaining sources
attemptSync(sources,index + 1);});}else { // an unknown schemeIdUri must have been found
// try again with the remaining sources
attemptSync(sources,index + 1);}}else { // no valid time source could be found, just use device time
setOffsetMs(0);onComplete();}}function reset(){setIsInitialised(false);setIsSynchronizing(false);}instance = {initialize:initialize,getOffsetToDeviceTimeMs:getOffsetToDeviceTimeMs,setConfig:setConfig,reset:reset};setup();return instance;}TimeSyncController.__dashjs_factory_name = 'TimeSyncController';var factory=_coreFactoryMaker2['default'].getSingletonFactory(TimeSyncController);factory.HTTP_TIMEOUT_MS = HTTP_TIMEOUT_MS;_coreFactoryMaker2['default'].updateSingletonFactory(TimeSyncController.__dashjs_factory_name,factory);exports['default'] = factory;module.exports = exports['default'];
//# sourceMappingURL=TimeSyncController.js.map