diff options
Diffstat (limited to 'portal-common/src/main/webapp/common/thirdparty/cometd/cometd/TimeSyncExtension.js')
| -rw-r--r-- | portal-common/src/main/webapp/common/thirdparty/cometd/cometd/TimeSyncExtension.js | 216 |
1 files changed, 0 insertions, 216 deletions
diff --git a/portal-common/src/main/webapp/common/thirdparty/cometd/cometd/TimeSyncExtension.js b/portal-common/src/main/webapp/common/thirdparty/cometd/cometd/TimeSyncExtension.js deleted file mode 100644 index 8eb11ad7..00000000 --- a/portal-common/src/main/webapp/common/thirdparty/cometd/cometd/TimeSyncExtension.js +++ /dev/null @@ -1,216 +0,0 @@ -/*
- * Copyright (c) 2010 the original author or authors.
- *
- * 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.
- */
-
-(function()
-{
- function bind(org_cometd)
- {
- /**
- * With each handshake or connect, the extension sends timestamps within the
- * ext field like: <code>{ext:{timesync:{tc:12345567890,l:23,o:4567},...},...}</code>
- * where:<ul>
- * <li>tc is the client timestamp in ms since 1970 of when the message was sent.
- * <li>l is the network lag that the client has calculated.
- * <li>o is the clock offset that the client has calculated.
- * </ul>
- *
- * <p>
- * A cometd server that supports timesync, can respond with an ext
- * field like: <code>{ext:{timesync:{tc:12345567890,ts:1234567900,p:123,a:3},...},...}</code>
- * where:<ul>
- * <li>tc is the client timestamp of when the message was sent,
- * <li>ts is the server timestamp of when the message was received
- * <li>p is the poll duration in ms - ie the time the server took before sending the response.
- * <li>a is the measured accuracy of the calculated offset and lag sent by the client
- * </ul>
- *
- * <p>
- * The relationship between tc, ts & l is given by <code>ts=tc+o+l</code> (the
- * time the server received the messsage is the client time plus the offset plus the
- * network lag). Thus the accuracy of the o and l settings can be determined with
- * <code>a=(tc+o+l)-ts</code>.
- * </p>
- * <p>
- * When the client has received the response, it can make a more accurate estimate
- * of the lag as <code>l2=(now-tc-p)/2</code> (assuming symmetric lag).
- * A new offset can then be calculated with the relationship on the client
- * that <code>ts=tc+o2+l2</code>, thus <code>o2=ts-tc-l2</code>.
- * </p>
- * <p>
- * Since the client also receives the a value calculated on the server, it
- * should be possible to analyse this and compensate for some asymmetry
- * in the lag. But the current client does not do this.
- * </p>
- *
- * @param configuration
- */
- return org_cometd.TimeSyncExtension = function(configuration)
- {
- var _cometd;
- var _maxSamples = configuration && configuration.maxSamples || 10;
- var _lags = [];
- var _offsets = [];
- var _lag = 0;
- var _offset = 0;
-
- function _debug(text, args)
- {
- _cometd._debug(text, args);
- }
-
- this.registered = function(name, cometd)
- {
- _cometd = cometd;
- _debug('TimeSyncExtension: executing registration callback');
- };
-
- this.unregistered = function()
- {
- _debug('TimeSyncExtension: executing unregistration callback');
- _cometd = null;
- _lags = [];
- _offsets = [];
- };
-
- this.incoming = function(message)
- {
- var channel = message.channel;
- if (channel && channel.indexOf('/meta/') === 0)
- {
- if (message.ext && message.ext.timesync)
- {
- var timesync = message.ext.timesync;
- _debug('TimeSyncExtension: server sent timesync', timesync);
-
- var now = new Date().getTime();
- var l2 = (now - timesync.tc - timesync.p) / 2;
- var o2 = timesync.ts - timesync.tc - l2;
-
- _lags.push(l2);
- _offsets.push(o2);
- if (_offsets.length > _maxSamples)
- {
- _offsets.shift();
- _lags.shift();
- }
-
- var samples = _offsets.length;
- var lagsSum = 0;
- var offsetsSum = 0;
- for (var i = 0; i < samples; ++i)
- {
- lagsSum += _lags[i];
- offsetsSum += _offsets[i];
- }
- _lag = parseInt((lagsSum / samples).toFixed());
- _offset = parseInt((offsetsSum / samples).toFixed());
- _debug('TimeSyncExtension: network lag', _lag, 'ms, time offset with server', _offset, 'ms', _lag, _offset);
- }
- }
- return message;
- };
-
- this.outgoing = function(message)
- {
- var channel = message.channel;
- if (channel && channel.indexOf('/meta/') === 0)
- {
- if (!message.ext)
- {
- message.ext = {};
- }
- message.ext.timesync = {
- tc: new Date().getTime(),
- l: _lag,
- o: _offset
- };
- _debug('TimeSyncExtension: client sending timesync', org_cometd.JSON.toJSON(message.ext.timesync));
- }
- return message;
- };
-
- /**
- * Get the estimated offset in ms from the clients clock to the
- * servers clock. The server time is the client time plus the offset.
- */
- this.getTimeOffset = function()
- {
- return _offset;
- };
-
- /**
- * Get an array of multiple offset samples used to calculate
- * the offset.
- */
- this.getTimeOffsetSamples = function()
- {
- return _offsets;
- };
-
- /**
- * Get the estimated network lag in ms from the client to the server.
- */
- this.getNetworkLag = function()
- {
- return _lag;
- };
-
- /**
- * Get the estimated server time in ms since the epoch.
- */
- this.getServerTime = function()
- {
- return new Date().getTime() + _offset;
- };
-
- /**
- *
- * Get the estimated server time as a Date object
- */
- this.getServerDate = function()
- {
- return new Date(this.getServerTime());
- };
-
- /**
- * Set a timeout to expire at given time on the server.
- * @param callback The function to call when the timer expires
- * @param atServerTimeOrDate a js Time or Date object representing the
- * server time at which the timeout should expire
- */
- this.setTimeout = function(callback, atServerTimeOrDate)
- {
- var ts = (atServerTimeOrDate instanceof Date) ? atServerTimeOrDate.getTime() : (0 + atServerTimeOrDate);
- var tc = ts - _offset;
- var interval = tc - new Date().getTime();
- if (interval <= 0)
- {
- interval = 1;
- }
- return org_cometd.Utils.setTimeout(_cometd, callback, interval);
- };
- };
- }
-
- if (typeof define === 'function' && define.amd)
- {
- define(['org/cometd'], bind);
- }
- else
- {
- bind(org.cometd);
- }
-})();
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