peersim.edsim
Class Heap

java.lang.Object
  peersim.edsim.Heap

All Implemented Interfaces:

PriorityQ

public class Heap
extends java.lang.Object
implements PriorityQ

The Heap data structure used to maintain events "sorted" by scheduled time and to obtain the next event to be executed.

Nested Class Summary

Nested classes/interfaces inherited from interface peersim.edsim.PriorityQ

PriorityQ.Event

Parameter Summary

pbits
This parameter specifies how many bits are used to order events that occur at the same time.

size
Specifies the initial capacity of the heap.

Constructor Summary

Heap()
Initializes a new heap using defaults.

Heap(java.lang.String prefix)
Initializes a new heap using the configuration.

Method Summary

void	add(long time, java.lang.Object event, Node node, byte pid) Add a new event, to be scheduled at the specified time.
void	add(long time, java.lang.Object event, Node node, byte pid, long priority) Add a new event, to be scheduled at the specified time.
long	maxPriority() Maximal value of priority this interpretation can deal with.
long	maxTime() Maximal value of time this interpretation can represent.
PriorityQ.Event	removeFirst() Removes the first event in the heap and returns it.
int	size() Returns the current number of events in the system.
java.lang.String	toString() Prints the time values contained in the heap.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Parameter Detail

pbits

This parameter specifies how many bits are used to order events that occur at the same time. Defaults to 8. A value smaller than 8 causes an IllegalParameterException. Higher values allow for a better discrimination, but reduce the maximal time steps that can be simulated.

size

Specifies the initial capacity of the heap. Defaults to 65536.

Constructor Detail

Heap

public Heap()

Initializes a new heap using defaults.

Heap

public Heap(java.lang.String prefix)

Initializes a new heap using the configuration.

Method Detail

size

public int size()

Returns the current number of events in the system.

Specified by:

size in interface PriorityQ

add

public void add(long time,
                java.lang.Object event,
                Node node,
                byte pid)

Add a new event, to be scheduled at the specified time.

Specified by:

add in interface PriorityQ

Parameters:

time - the time at which this event should be scheduled

event - the object describing the event

node - the node at which the event has to be delivered

pid - the protocol that handles the event

add

public void add(long time,
                java.lang.Object event,
                Node node,
                byte pid,
                long priority)

Add a new event, to be scheduled at the specified time.

Specified by:

add in interface PriorityQ

Parameters:

time - the time at which this event should be scheduled

event - the object describing the event

node - the node at which the event has to be delivered

pid - the protocol that handles the event

priority - if for two events the "time" value is the same, this value should be used to order them. Lower value means higher priority. Like with time, non-negativity as assumed.

removeFirst

public PriorityQ.Event removeFirst()

Removes the first event in the heap and returns it. Note that, to avoid garbage collection, a singleton instance of the Event class is used. This means that data contained in the returned event are overwritten when a new invocation of this method is performed.

Specified by:

removeFirst in interface PriorityQ

Returns:

first event or null if size is zero

maxTime

public long maxTime()

Description copied from interface: PriorityQ

Maximal value of time this interpretation can represent.

Specified by:

maxTime in interface PriorityQ

maxPriority

public long maxPriority()

Description copied from interface: PriorityQ

Maximal value of priority this interpretation can deal with. That is, the number of different priority levels is maxPriority()+1 because 0 is also a valid level.

Specified by:

maxPriority in interface PriorityQ

See Also:

PriorityQ.add(long,Object,Node,byte,long)

toString

public java.lang.String toString()

Prints the time values contained in the heap.

Overrides:

toString in class java.lang.Object