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/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.util.comparator;
import com.tangosol.util.QueryMap;
import java.util.Comparator;
/**
* This interface is used by Comparator implementations that can use value
* extraction optimization exposed by the
* {@link com.tangosol.util.QueryMap.Entry} interface.
*
* @author cp/gg 2002.12.13, 2006.06.12
*/
public interface QueryMapComparator
extends Comparator
{
/**
* Compare two entries based on the rules specified by {@link Comparator}.
*
* If possible, use the {@link com.tangosol.util.QueryMap.Entry#extract
* extract} method to optimize the value extraction process.
*
* This method is expected to be implemented by Comparator wrappers,
* such as {@link ChainedComparator} and {@link InverseComparator},
* which simply pass on this invocation to the wrapped Comparator objects
* if they too implement this interface, or to invoke their default
* compare method passing the actual objects (not the extracted values)
* obtained from the extractor using the passed entries.
*
* This interface is also expected to be implemented by ValueExtractor
* implementations that implement the Comparator interface. It is expected
* that in most cases, the Comparator wrappers will eventually terminate
* at (i.e. delegate to) ValueExtractors that also implement this
* interface.
*
* @param entry1 the first entry to compare values from; read-only
* @param entry2 the second entry to compare values from; read-only
*
* @return a negative integer, zero, or a positive integer as the first
* entry denotes a value that is is less than, equal to, or
* greater than the value denoted by the second entry
*
* @throws ClassCastException if the arguments' types prevent them from
* being compared by this Comparator.
* @throws com.tangosol.util.WrapperException if the extractor encounters
* an exception in the course of extracting the value
* @throws IllegalArgumentException if the extractor cannot handle
* the passed objects for any other reason; an implementor should
* include a descriptive message
* @since Coherence 3.2
*/
public int compareEntries(QueryMap.Entry entry1, QueryMap.Entry entry2);
}