simpledb.materialize
Class RecordComparator

java.lang.Object
  simpledb.materialize.RecordComparator

All Implemented Interfaces:

Comparator<Scan>

public class RecordComparator
extends Object
implements Comparator<Scan>

A comparator for scans.

Author:

Edward Sciore

Constructor Summary

RecordComparator(List<String> fields)
Creates a comparator using the specified fields, using the ordering implied by its iterator.

Method Summary

int	compare(Scan s1, Scan s2) Compares the current records of the two specified scans.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

RecordComparator

public RecordComparator(List<String> fields)

Creates a comparator using the specified fields, using the ordering implied by its iterator.

Parameters:

fields - a list of field names

Method Detail

compare

public int compare(Scan s1,
                   Scan s2)

Compares the current records of the two specified scans. The sort fields are considered in turn. When a field is encountered for which the records have different values, those values are used as the result of the comparison. If the two records have the same values for all sort fields, then the method returns 0.

Specified by:

compare in interface Comparator<Scan>

Parameters:

s1 - the first scan

s2 - the second scan

Returns:

the result of comparing each scan's current record according to the field list