org.qbroker.common

Class CollectibleCells

java.lang.Object

org.qbroker.common.CollectibleCells

public class CollectibleCells
extends java.lang.Object

CollectibleCells are a fixed numner of indexed cells that are collectible with the associated unigue IDs. All the collectible (TAKEN) cells are always kept in their natural order.

A cell is always in one of the two different status, EMPTY, and TAKEN. All cells line up in a circular array. The cells in the same status always stay together in a group. Therefore the circle is divided into two segments of arcs. There are two marks separating those two arcs, ie, the two different groups of cells. Tail divieds empty cells and taken cells. Head separates taken cells and empty cells.

There are two methods to change the status of a cell. The method of take() is to take an empty cell and toggles its status from EMPTY to TAKEN. The method of collect() is to collect a taken cell and switches it from TAKEN to EMPTY.

capacity -- maximum number of cells in the list
size -- number of taken cells
status -- status of a cell
id -- the fixed id of a cell

This is MT-Safe.

Author:

yannanlu@yahoo.com

Constructor Summary

Constructors

Constructor and Description
CollectibleCells(java.lang.String name, int capacity) initialzes the list with capacity of cells

Method Summary

Modifier and Type	Method and Description
void	acknowledge(long[] state) acknowledges the request msgs only
void	clear() clear all cells and reset all marks
int	collect(long milliSec) collects the next collectible cell and returns its id upon success or -1 otherwise.
int	collect(long milliSec, int id) collects the id-th cell and returns the id upon success or -1 otherwise.
protected void	finalize()
int	getCapacity()
int	getCellStatus(int id) returns the status of the cell with the id if it is not out of bound or -1 otherwise
java.lang.String	getName()
int	queryIDs(int[] ids, int type) loads the ids of the type of cells in the natual order to the given array
int	size() returns the number of taken cells in the list
int	take(int id) takes the empty cell with the id and returns the size upon success or -1 otherwise.

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectibleCells

public CollectibleCells(java.lang.String name,
                        int capacity)

initialzes the list with capacity of cells

Method Detail

getName

public java.lang.String getName()

size

public int size()

returns the number of taken cells in the list

getCapacity

public int getCapacity()

getCellStatus

public int getCellStatus(int id)

returns the status of the cell with the id if it is not out of bound or -1 otherwise

collect

public int collect(long milliSec,
                   int id)

collects the id-th cell and returns the id upon success or -1 otherwise. If milliSec is less than 0, there is no wait.

collect

public int collect(long milliSec)

collects the next collectible cell and returns its id upon success or -1 otherwise.

take

public int take(int id)

takes the empty cell with the id and returns the size upon success or -1 otherwise.

queryIDs

public int queryIDs(int[] ids,
                    int type)

loads the ids of the type of cells in the natual order to the given array

acknowledge

public void acknowledge(long[] state)

acknowledges the request msgs only

clear

public void clear()

clear all cells and reset all marks

finalize

protected void finalize()

Overrides:

finalize in class java.lang.Object