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package com.peterphi.std.threading;
import org.joda.time.Duration;
import java.io.Serializable;
import java.util.concurrent.TimeUnit;
/**
* Represents an immutable Timeout (ie. a duration). Timeouts are distinct from Deadlines in that they do not have a start
* time.
* This class can be used to represent a duration without needing a dependency on Joda time
*/
public final class Timeout implements Comparable, Serializable
{
/**
*
*/
private static final long serialVersionUID = 1L;
/**
* A zero-length timeout
*/
public static final Timeout ZERO = new Timeout(0, TimeUnit.MILLISECONDS);
/**
* 0.25 seconds (250 milliseconds)
*/
public static final Timeout ONE_QUARTER_SECOND = new Timeout(250, TimeUnit.MILLISECONDS);
/**
* One second
*/
public static final Timeout ONE_SECOND = new Timeout(1, TimeUnit.SECONDS);
/**
* Ten seconds
*/
public static final Timeout TEN_SECONDS = new Timeout(10, TimeUnit.SECONDS);
/**
* Thirty seconds
*/
public static final Timeout THIRTY_SECONDS = new Timeout(30, TimeUnit.SECONDS);
/**
* One minute
*/
public static final Timeout ONE_MINUTE = new Timeout(1, TimeUnit.MINUTES);
/**
* Five minutes
*/
public static final Timeout FIVE_MINUTES = new Timeout(5, TimeUnit.MINUTES);
/**
* 30 minutes
*/
public static final Timeout THIRTY_MINUTES = new Timeout(30, TimeUnit.MINUTES);
/**
* The maximum possible timeout
*/
public static final Timeout MAX_VALUE = new Timeout(Long.MAX_VALUE);
private final long period;
private final TimeUnit unit;
public Timeout(Duration duration)
{
this(duration.getMillis());
}
/**
* Constructs a deadline using a given period of time
*
* @param milliseconds
* period in milliseconds
*/
public Timeout(final long milliseconds)
{
this(milliseconds, TimeUnit.MILLISECONDS);
}
/**
* Constructs a deadline using a given period of time
*
* @param period
* the number of units
* @param unit
* the unit of time being used
*/
public Timeout(final long period, final TimeUnit unit)
{
if (unit == null)
throw new IllegalArgumentException("Must supply a unit");
if (period < 0)
throw new IllegalArgumentException("Timeouts must be positive!");
this.period = period;
this.unit = unit;
}
/**
* Create a new deadline which is the given period of time in the future
*
* @return a deadline the given period of time in the future
*/
public Deadline start()
{
return new Deadline(this);
}
/**
* Create a new deadline within a given maximum timeframe; this prevents
*
* @param max
* the maximum deadline
*
* @return a new deadline which is at most the provided maximum
*/
public Deadline start(final Deadline max)
{
return Deadline.soonest(max, start());
}
/**
* Get the number of milliseconds this timeout represents
*
* @return
*/
public long getMilliseconds()
{
return unit.toMillis(period);
}
/**
* Get this timeout represented in a different unit
*
* @param toUnit
*
* @return
*/
public long get(final TimeUnit toUnit)
{
if (this.unit == toUnit)
return period;
else
return toUnit.convert(period, this.unit);
}
@Override
public int hashCode()
{
return (int) (period ^ (period >>> 32)) ^ unit.hashCode();
}
@Override
public boolean equals(final Object o)
{
if (this == o)
return true;
else if (o == null)
return false;
else if (o.getClass().equals(Timeout.class))
{
final Timeout that = (Timeout) o;
return this.getMilliseconds() == that.getMilliseconds();
}
else
{
return false;
}
}
/**
* Create a new Timeout which is equal to this timeout multiplied by some value
*
* @param by
* the amount to multiply the current timeout by
*
* @return a new Timeout which is equal to this timeout multiplied by some value
*/
public Timeout multiply(final long by)
{
return new Timeout(period * by, this.unit);
}
/**
* Create a new Timeout which is equal to this timeout multiplied by some value
* The resulting Timeout will be in milliseconds to maximise precision.
*
* @param by
* the amount to multiply the current timeout by
*
* @return a new Timeout which is equal to this timeout multiplied by some value (with the unit now set to Milliseconds)
*/
public Timeout multiply(final double by)
{
final double newMillis = getMilliseconds() * by;
final long rounded = Math.round(newMillis);
return new Timeout(rounded, TimeUnit.MILLISECONDS);
}
@Override
public String toString()
{
return "[Timeout: " + toEnglishString() + "]";
}
public String toEnglishString()
{
return Long.toString(period) + " " + unit.toString().toLowerCase();
}
@Override
public int compareTo(final Timeout that)
{
final Long thisPeriod = new Long(this.period);
final long thatPeriod = that.get(this.unit);
return thisPeriod.compareTo(thatPeriod);
}
/**
* Sleep for the duration of this timeout (or until the thread is interrupted)
*/
public void sleep()
{
try
{
Thread.sleep(getMilliseconds());
}
catch (InterruptedException e)
{
// ignore but return
}
}
/**
* Sleep for the duration of this timeout (or until the thread is interrupted, or until the provided deadline expires)
*/
public void sleep(Deadline deadline)
{
final long millis = Math.min(deadline.getTimeLeft(), getMilliseconds());
if (millis > 0)
{
try
{
Thread.sleep(millis);
}
catch (InterruptedException e)
{
// ignore but return
}
}
}
public Duration toDuration()
{
return new Duration(getMilliseconds());
}
/**
* Filter through a number of timeouts to find the one with the longest period
*
* @param timeouts
* a list of timeouts (nulls are ignored)
*
* @return the timeout with the longest period
*
* @throws IllegalArgumentException
* if no non-null timeouts are presented
*/
public static Timeout max(Timeout... timeouts)
{
Timeout max = null;
for (Timeout timeout : timeouts)
{
if (timeout != null)
if (max == null || max.getMilliseconds() < timeout.getMilliseconds())
max = timeout;
}
if (max != null)
return max;
else
throw new IllegalArgumentException("Must specify at least one non-null timeout!");
}
/**
* Filter through a number of timeouts to find the one with the shortest period
*
* @param timeouts
* a list of timeouts (nulls are ignored)
*
* @return the timeout with the shortest period
*
* @throws IllegalArgumentException
* if no non-null timeouts are presented
*/
public static Timeout min(Timeout... timeouts)
{
Timeout min = null;
for (Timeout timeout : timeouts)
{
if (timeout != null)
if (min == null || min.getMilliseconds() > timeout.getMilliseconds())
min = timeout;
}
if (min != null)
return min;
else
throw new IllegalArgumentException("Must specify at least one non-null timeout!");
}
/**
* Adds together all the supplied timeouts
*
* @param timeouts
* a list of timeouts (nulls are ignored)
*
* @return the sum of all the timeouts specified
*/
public static Timeout sum(Timeout... timeouts)
{
long sum = 0;
for (Timeout timeout : timeouts)
if (timeout != null)
sum += timeout.getMilliseconds();
if (sum != 0)
return new Timeout(sum);
else
return Timeout.ZERO;
}
}