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com.tangosol.net.partition
Class SimpleAssignmentStrategy.AnalysisContext.LoadComparator

java.lang.Object
com.tangosol.net.partition.SimpleAssignmentStrategy.AnalysisContext.LoadComparator

All Implemented Interfaces:

java.util.Comparator

Enclosing class:

SimpleAssignmentStrategy.AnalysisContext

public class SimpleAssignmentStrategy.AnalysisContext.LoadComparator

extends java.lang.Object

implements java.util.Comparator

LoadComparator is a Comparator that can be used to compare two Member objects based on their partition load (as defined by the LoadCalculator).

A member is ordered "lower" than another member if it has a lower member load (as determined by the LoadCalculator). Members with equivalent loads are ordered equivalently.

Note: This comparator does not define an ordering that is "consistent with equals". If used in a context requiring such a natural ordering, it should be chained with comparator that does provide a natural ordering.

Field Summary

protected int	m_cFairShare The cached fair-share load.
protected boolean	m_fPrimary Flag for primary or backup load comparison.

Constructor Summary

SimpleAssignmentStrategy.AnalysisContext.LoadComparator(boolean fPrimary)
Construct a LoadComparator.

Method Summary

int	compare(java.lang.Object o1, java.lang.Object o2) Compares its two arguments for order.
int	getFairShare() Return the fair-share load.
boolean	isPrimary() Return true iff the comparator should use the primary load.

Methods inherited from interface java.util.Comparator

equals

Field Detail

m_cFairShare

protected int m_cFairShare

The cached fair-share load.

m_fPrimary

protected boolean m_fPrimary

Flag for primary or backup load comparison.

Constructor Detail

SimpleAssignmentStrategy.AnalysisContext.LoadComparator

public SimpleAssignmentStrategy.AnalysisContext.LoadComparator(boolean fPrimary)

Construct a LoadComparator.

Parameters:

fPrimary - true if the comparator should use the primary load, or false for backup load

Method Detail

getFairShare

public int getFairShare()

Return the fair-share load.

Returns:

the fair-share load

isPrimary

public boolean isPrimary()

Return true iff the comparator should use the primary load.

Returns:

true iff the comparator should use the primary load

compare

public int compare(java.lang.Object o1,
                   java.lang.Object o2)

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

The implementor must ensure that sgn(compare(x, y)) == -sgn(compare(y, x)) for all x and y. (This implies that compare(x, y) must throw an exception if and only if compare(y, x) throws an exception.)

The implementor must also ensure that the relation is transitive: ((compare(x, y)>0) && (compare(y, z)>0)) implies compare(x, z)>0.

Finally, the implementer must ensure that compare(x, y)==0 implies that sgn(compare(x, z))==sgn(compare(y, z)) for all z.

It is generally the case, but not strictly required that (compare(x, y)==0) == (x.equals(y)). Generally speaking, any comparator that violates this condition should clearly indicate this fact. The recommended language is "Note: this comparator imposes orderings that are inconsistent with equals."

Specified by:

compare in interface java.util.Comparator

Parameters:

o1 - the first object to be compared.

o2 - the second object to be compared.

Returns:

a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

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