org.colomoto.mddlib.operators

Class AbstractOperator

java.lang.Object

org.colomoto.mddlib.operators.AbstractOperator

All Implemented Interfaces:

MDDOperator

Direct Known Subclasses:

AbstractFlexibleOperator

public abstract class AbstractOperator
extends Object
implements MDDOperator

Common (boring) part of a MDDOperator implementation. This provides a helper method for a simple recursion on two nodes and support for merging a list of nodes, either by falling back on two-way merges and by performing real multiple-nodes recursion.

The main method for two-way merge is not implemented here and is the only requirement for implementors.

To properly support multiple merge, implementors are encouraged to override multiple_leaves(MDDManager, int[]) and recurse_multiple(MDDManager, int[], int, int).

Author:

Aurelien Naldi

See Also:

MDDBaseOperators, AbstractFlexibleOperator

Constructor Summary

Constructors

Constructor and Description
AbstractOperator() Create an operator which does not support multiple merge.
AbstractOperator(boolean multipleMerge) Create an operator.

Method Summary

Modifier and Type	Method and Description
int	combine(MDDManager ddmanager, int[] nodes) Apply this operation to a set of nodes.
protected int	multiple_leaves(MDDManager ddmanager, int[] leaves) Get the result of a multiple merge when only leaves are left.
protected int	recurse_multiple(MDDManager ddmanager, int[] nodes, int leafcount, MDDVariable bestVar) The recursive part of the multiple merge.
int	recurse(MDDManager ddmanager, NodeRelation status, int first, int other) Common logic for recursive operation.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.colomoto.mddlib.MDDOperator

combine

Constructor Detail

AbstractOperator

public AbstractOperator()

Create an operator which does not support multiple merge.

AbstractOperator

public AbstractOperator(boolean multipleMerge)

Create an operator.

Parameters:

multipleMerge - if true, optimised multiple merge will be used instead of the fallback

Method Detail

recurse

public int recurse(MDDManager ddmanager,
                   NodeRelation status,
                   int first,
                   int other)

Common logic for recursive operation. This method is a helper for specialised implementations of combine(MDDManager, int, int).

Parameters:

ddmanager -

status -

first -

other -

Returns:

the resulting node index

combine

public int combine(MDDManager ddmanager,
                   int[] nodes)

Apply this operation to a set of nodes. This method falls back to applying it multiple times to pairs of nodes unless multiple merge is marked as supported.

Specified by:

combine in interface MDDOperator

Parameters:

ddmanager - the MDD manager in which the nodes are stored

nodes - the roots of the MDDs to combine

Returns:

the root node of the combined MDD. It can be a new or an existing node.

multiple_leaves

protected int multiple_leaves(MDDManager ddmanager,
                              int[] leaves)

Get the result of a multiple merge when only leaves are left. If your operator supports multiple merge, it SHOULD override this method.

A series of two-nodes merges is performed as fallback.

Parameters:

ddmanager -

leaves -

Returns:

the resulting node index

recurse_multiple

protected int recurse_multiple(MDDManager ddmanager,
                               int[] nodes,
                               int leafcount,
                               MDDVariable bestVar)

The recursive part of the multiple merge.

Parameters:

ddmanager -

nodes -

leafcount -

bestVar -

Returns:

the resulting node index