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AMPS Java client by 60East Technologies, Inc.
////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2010-2022 60East Technologies Inc., All Rights Reserved.
//
// This computer software is owned by 60East Technologies Inc. and is
// protected by U.S. copyright laws and other laws and by international
// treaties. This computer software is furnished by 60East Technologies
// Inc. pursuant to a written license agreement and may be used, copied,
// transmitted, and stored only in accordance with the terms of such
// license agreement and with the inclusion of the above copyright notice.
// This computer software or any other copies thereof may not be provided
// or otherwise made available to any other person.
//
// U.S. Government Restricted Rights. This computer software: (a) was
// developed at private expense and is in all respects the proprietary
// information of 60East Technologies Inc.; (b) was not developed with
// government funds; (c) is a trade secret of 60East Technologies Inc.
// for all purposes of the Freedom of Information Act; and (d) is a
// commercial item and thus, pursuant to Section 12.212 of the Federal
// Acquisition Regulations (FAR) and DFAR Supplement Section 227.7202,
// Government's use, duplication or disclosure of the computer software
// is subject to the restrictions set forth by 60East Technologies Inc..
//
////////////////////////////////////////////////////////////////////////////
package com.crankuptheamps.client;
import com.crankuptheamps.client.exception.*;
/**
* FixedDelayStrategy is an implementation that delays for a fixed time
* period, as specified in the constructor, when reconnecting to the same
* server as we were previously connected to, or if we are invoked again
* for the first server we ever tried.
*/
public class FixedDelayStrategy implements ReconnectDelayStrategy
{
/**
* A specialized exception type thrown by ExponentialDelayStrategy
* to indicate that the client should "give up" on attempting to
* reconnect to a server.
*/
public static class MaximumRetryExceeded extends AMPSException
{
private static final long serialVersionUID = 1L;
}
/**
* The default delay when reconnecting to a server, in milliseconds.
*/
public static final int DEFAULT_DELAY = 200;
/**
* Construct a FixedDelayStrategy with the default delay (200ms).
*/
public FixedDelayStrategy()
{
this._delay = DEFAULT_DELAY;
this._maximum = 0;
}
/**
* Construct a FixedDelayStrategy with a specified delay.
*
* @param delay_ The delay (milliseconds) to be used between reconnect
* attempts to the same server.
*/
public FixedDelayStrategy(int delay_)
{
this._maximum = 0;
if(delay_ < 0)
{
this._delay = DEFAULT_DELAY;
}
else
{
this._delay = delay_;
}
}
/**
* Construct a FixedDelayStrategy with a specified delay and maximum.
*
* @param delay_ The delay (milliseconds) to be used between reconnect
* attempts to the same server.
* @param maximum_ The maximum time (milliseconds) to try connecting
* to servers before "giving up."
*/
public FixedDelayStrategy(int delay_, int maximum_)
{
this._maximum = maximum_;
if(delay_ < 0)
{
this._delay = DEFAULT_DELAY;
}
else
{
this._delay = delay_;
}
}
/**
* Returns the time (in milliseconds) that the client should wait before connecting to the given server URI.
* @param uri_ The URI to which the client intends to connect.
* @return Returns the time in milliseconds the client should delay before connecting to uri_.
* @throws Exception Any exception thrown indicates no connection should be attempted.
*/
public int getConnectWaitDuration(String uri_) throws Exception
{
int delay = 0;
if(_lastUri == null || !_lastUri.equals(uri_))
{
// Do not wait to fail over; reconnect immediately.
_lastUri = uri_;
if(_firstUri != null && _firstUri.equals(uri_))
{
// We have wrapped around the "list" of servers. Delay.
delay = _delay;
}
else if(_firstUri == null)
{
// This is the first time through. Mark uri_ as the first
// of the assumed "list" of servers.
_firstUri = uri_;
}
}
else
{
// retrying the "same" server
delay = _delay;
}
if(_maximum > 0)
{
long now = System.currentTimeMillis();
if(_start > 0)
{
if (now-_start > _maximum+delay)
{
throw new MaximumRetryExceeded();
}
}
else
{
_start = now;
}
}
return delay;
}
/**
* Resets the state of this delay. AMPS calls this method when a connection is successfully established.
*/
public void reset()
{
_lastUri = null;
_firstUri = null;
_start = 0;
}
protected int _delay;
protected int _maximum;
protected long _start;
protected String _lastUri;
protected String _firstUri;
}