PartDiscontinousRangeEnumerator.java

/**
 * Alipay.com Inc.
 * Copyright (c) 2004-2012 All Rights Reserved.
 */
package com.alipay.zdal.rule.ruleengine.enumerator;

import java.util.Set;

import com.alipay.zdal.common.sqljep.function.Comparative;

public abstract class PartDiscontinousRangeEnumerator implements
                                                     CloseIntervalFieldsEnumeratorHandler {

    @SuppressWarnings("unchecked")
    protected abstract Comparable getOneStep(Comparable source, Comparable atomIncVal);

    /**
     * ���ݲ�ͬ���ݵ���С��λ��>��Ϊ>=
     * 
     * @param to
     * @return
     */
    protected abstract Comparative changeGreater2GreaterOrEq(Comparative from);

    /**
     * ���ݲ�ͬ���ݵ���С��λ��<��Ϊ<=
     * 
     * @param to
     * @return
     */
    protected abstract Comparative changeLess2LessOrEq(Comparative to);

    /**
     * �������ķ�Χ����range.size() * atomIncrementvalue��ֵ����ô�Ϳ�������·�Ż�
     * 
     * @param from
     *            ֻ��<=����µ�formֵ
     * @param to
     *            ֻ��>=����µ�to ֵ
     * @param range
     * @param atomIncrementValue
     * @return
     */
    @SuppressWarnings("unchecked")
    protected abstract boolean inputCloseRangeGreaterThanMaxFieldOfDifination(
                                                                              Comparable from,
                                                                              Comparable to,
                                                                              Integer cumulativeTimes,
                                                                              Comparable<?> atomIncrValue);

    /**
     *  ����ʼֵ��ʼ,������ֵ*�ۼӴ���+��ʼֵ�������ֵ��䶯һ�����ڵ����ж�����ֵ��ö�ٵ㡣
     * @param begin
     * @param cumulativeTimes
     * @param atomicIncreationValue
     * @return
     */
    protected abstract Set<Object> getAllPassableFields(Comparative begin, Integer cumulativeTimes,
                                                        Comparable<?> atomicIncreationValue);

    @SuppressWarnings("unchecked")
    public void mergeFeildOfDefinitionInCloseInterval(Comparative from, Comparative to,
                                                      Set<Object> retValue,
                                                      Integer cumulativeTimes,
                                                      Comparable<?> atomIncrValue) {
        if (cumulativeTimes == null || atomIncrValue == null) {
            throw new IllegalArgumentException("��ԭ������������Ӳ���Ϊ��ʱ����֧����sql��ʹ�÷�Χѡ����id>? and id<?");
        }
        from = changeGreater2GreaterOrEq(from);

        to = changeLess2LessOrEq(to);

        Comparable fromComparable = from.getValue();
        Comparable toComparable = to.getValue();

        if (inputCloseRangeGreaterThanMaxFieldOfDifination(fromComparable, toComparable,
            cumulativeTimes, atomIncrValue)) {
            //�����ȡ�÷�Χ���ڷ�����������һ���䶯���ڡ�ֱ�Ӷ�·��,����ȫȡ
            if (retValue != null) {
                retValue.addAll(getAllPassableFields(from, cumulativeTimes, atomIncrValue));
                return;
            } else {
                throw new IllegalArgumentException("��д��IJ���setΪnull");
            }
        }

        if (fromComparable.compareTo(toComparable) == 0) {
            //���ת��Ϊ>=��<=������£���ֵ����ˣ���ôֱ�ӷ��ء�
            retValue.add(fromComparable);
            return;
        }

        int rangeSize = cumulativeTimes;

        retValue.add(fromComparable);
        Comparable enumedFoD = fromComparable;
        for (int i = 0; i < rangeSize; i++) {
            enumedFoD = getOneStep(enumedFoD, atomIncrValue);
            int compareResult = enumedFoD.compareTo(toComparable);
            if (compareResult == 0) {
                //ö��ֵ����to��ֵ���򵥵İ�to��ֵ�ŵ�ö�����������
                retValue.add(toComparable);
                return;
            } else if (compareResult > 0) {
                //ö��ֵ����to��ֵ,���·ֿ�������Ҳ��Ҫ�����һ���¼��ϣ�������������һ����
                //�������������һ���ʱ����п��ܳ�������ֵ����һ��ֵ����from�������ֵ�ֵ���ڶ�������to������ֵ�������������һ�Σ���Ϊ�˱�֤��ȷ��ʱ������д
                retValue.add(toComparable);
                return;
            } else {
                //ö��С��to��ֵ,���ö�ٵ�������
                retValue.add(enumedFoD);

            }
        }

    }

}