freenet.support

Class RandomGrabArray

java.lang.Object

freenet.support.RandomGrabArray

All Implemented Interfaces:

RequestSelectionTreeNode, RemoveRandom

Direct Known Subclasses:

RandomGrabArrayWithObject

public class RandomGrabArray
extends java.lang.Object
implements RemoveRandom, RequestSelectionTreeNode

An array which supports very fast remove-and-return-a-random-element. This is *NOT* persistent. The request selection structures are reconstructed on restart. However it used to be, and probably has a lot of cruft and inefficiency as a result. LOCKING: There is a single lock for the entire tree, the ClientRequestSelector. This must be taken before calling any methods on RGA or SRGA. See the javadocs there for deeper explanation. FIXME Simplify and improve performance. A lot of this is O(n), and this should probably be fixed. Memory usage was an issue but probably isn't now given that the individual items are now quite large (entire splitfiles or at least entire segments).

Nested Class Summary

Nested classes/interfaces inherited from interface freenet.support.RemoveRandom

RemoveRandom.RemoveRandomReturn

Field Summary

Fields

Modifier and Type	Field and Description
protected ClientRequestSelector	root

Constructor Summary

Constructors

Constructor and Description
RandomGrabArray(RemoveRandomParent parent, ClientRequestSelector root)

Method Summary

Modifier and Type	Method and Description
void	add(RandomGrabArrayItem req, ClientContext context)
void	clearWakeupTime(ClientContext context) When a request becomes fetchable, set all the wakeup times above it to 0.
boolean	contains(RandomGrabArrayItem item)
RandomGrabArrayItem	get(int idx)
RequestSelectionTreeNode	getParentGrabArray() Return the parent RequestSelectionTreeNode or null if it's not in the tree or is the root (e.g.
long	getWakeupTime(ClientContext context, long now) Unless this is a RandomGrabArrayItem, this will return the wakeup time for the subtree rooted at this node.
int	hashCode()
boolean	isEmpty()
void	moveElementsTo(RandomGrabArray existingGrabber, boolean canCommit)
boolean	reduceWakeupTime(long wakeupTime, ClientContext context) If the current cooldown time is larger than the parameter, reduce it and recurse up the tree.
void	remove(RandomGrabArrayItem it, ClientContext context)
RemoveRandom.RemoveRandomReturn	removeRandom(RandomGrabArrayItemExclusionList excluding, ClientContext context, long now) Return a random RandomGrabArrayItem, or a time at which there will be one, or null if the RGA is empty and should be removed by the parent.
void	setParent(RemoveRandomParent newParent)
int	size()

Methods inherited from class java.lang.Object

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

Field Detail

root

protected ClientRequestSelector root

Constructor Detail

RandomGrabArray

public RandomGrabArray(RemoveRandomParent parent,
                       ClientRequestSelector root)

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

add

public void add(RandomGrabArrayItem req,
                ClientContext context)

removeRandom

public RemoveRandom.RemoveRandomReturn removeRandom(RandomGrabArrayItemExclusionList excluding,
                                                    ClientContext context,
                                                    long now)

Description copied from interface: RemoveRandom

Return a random RandomGrabArrayItem, or a time at which there will be one, or null if the RGA is empty and should be removed by the parent.

Specified by:

removeRandom in interface RemoveRandom

remove

public void remove(RandomGrabArrayItem it,
                   ClientContext context)

isEmpty

public boolean isEmpty()

contains

public boolean contains(RandomGrabArrayItem item)

size

public int size()

get

public RandomGrabArrayItem get(int idx)

moveElementsTo

public void moveElementsTo(RandomGrabArray existingGrabber,
                           boolean canCommit)

setParent

public void setParent(RemoveRandomParent newParent)

Specified by:

setParent in interface RemoveRandom

getParentGrabArray

public RequestSelectionTreeNode getParentGrabArray()

Description copied from interface: RequestSelectionTreeNode

Return the parent RequestSelectionTreeNode or null if it's not in the tree or is the root (e.g. priority classes are kept in an array on ClientRequestSelector).

Specified by:

getParentGrabArray in interface RequestSelectionTreeNode

getWakeupTime

public long getWakeupTime(ClientContext context,
                          long now)

Description copied from interface: RequestSelectionTreeNode

Unless this is a RandomGrabArrayItem, this will return the wakeup time for the subtree rooted at this node. For a RandomGrabArrayItem it returns the wakeup time for just that single request.

Specified by:

getWakeupTime in interface RequestSelectionTreeNode

reduceWakeupTime

public boolean reduceWakeupTime(long wakeupTime,
                                ClientContext context)

Description copied from interface: RequestSelectionTreeNode

If the current cooldown time is larger than the parameter, reduce it and recurse up the tree. If we reach the root and wake it up, then wake up the scheduler. Returns true if anything changed.

Specified by:

reduceWakeupTime in interface RequestSelectionTreeNode

clearWakeupTime

public void clearWakeupTime(ClientContext context)

Description copied from interface: RequestSelectionTreeNode

When a request becomes fetchable, set all the wakeup times above it to 0. Will recurse up the tree.

Specified by:

clearWakeupTime in interface RequestSelectionTreeNode