Module org.eclipse.persistence.core

Package org.eclipse.persistence.internal.sessions

Class CommitOrderCalculator

java.lang.Object

org.eclipse.persistence.internal.sessions.CommitOrderCalculator

public class CommitOrderCalculator
extends Object

This class calculates a commit order for a series of classes based on the dependencies between them. It builds up a graph of dependencies (CommitOrderDependencyNodes) then applies topological sort to them to get an ordering. This is a throwaway class, which exists only for the lifetime of the calculation. The algorithm is described in the method comment for orderCommits(). This class also includes static methods for quicksort, copied from the standard libraries and adapted for these objects, since that seemed like the easiest way to sort.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	currentTime
protected Vector<CommitOrderDependencyNode>	nodes
protected Vector	orderedDescriptors
protected AbstractSession	session

Constructor Summary

Constructors

Constructor	Description
CommitOrderCalculator(AbstractSession session)

Method Summary

Modifier and Type	Method	Description
protected void	addNode(ClassDescriptor d)
void	addNodes(Vector descriptors)
void	calculateMappingDependencies()	Add to each node the dependent nodes
void	calculateSpecifiedDependencies()	Add to each node the dependent nodes
void	depthFirstSearch()
int	getNextTime()
Vector<CommitOrderDependencyNode>	getNodes()
Vector	getOrderedClasses()	Return the constraint ordered classes.
Vector	getOrderedDescriptors()	Return the constraint ordered descriptors.
CommitOrderDependencyNode	nodeFor(Class<?> c)
CommitOrderDependencyNode	nodeFor(ClassDescriptor d)
void	orderCommits()	Calculate the commit order.

Methods inherited from class java.lang.Object

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

Field Details

currentTime

protected int currentTime

nodes

protected Vector<CommitOrderDependencyNode> nodes

orderedDescriptors

protected Vector orderedDescriptors

session

protected AbstractSession session

Constructor Details

CommitOrderCalculator

public CommitOrderCalculator(AbstractSession session)

Method Details

addNode

protected void addNode(ClassDescriptor d)

addNodes

public void addNodes(Vector descriptors)

calculateMappingDependencies

public void calculateMappingDependencies()

Add to each node the dependent nodes

calculateSpecifiedDependencies

public void calculateSpecifiedDependencies()

Add to each node the dependent nodes

depthFirstSearch

public void depthFirstSearch()

getNextTime

public int getNextTime()

getNodes

public Vector<CommitOrderDependencyNode> getNodes()

getOrderedClasses

public Vector getOrderedClasses()

Return the constraint ordered classes.

getOrderedDescriptors

public Vector getOrderedDescriptors()

Return the constraint ordered descriptors.

nodeFor

public CommitOrderDependencyNode nodeFor(Class<?> c)

nodeFor

public CommitOrderDependencyNode nodeFor(ClassDescriptor d)

orderCommits

public void orderCommits()

Calculate the commit order. Do a depth first search on the graph, skipping nodes that we have already visited or are in the process of visiting. Keep a counter and note when we first encounter a node and when we finish visiting it. Once we've visited everything, sort nodes by finishing time