ListSharedElement.java

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

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

import org.apache.log4j.Logger;

/**
 * һ�Զ�ڵ����
 * 
 * ����һ��һ�Զ��ӳ��map,���������ı��ڵ������еĹ�������
 * �Լ���������������Щ�ڵ��Ƿ���Ҫ��Ȼ����㲢����
 * 
 *
 */
public abstract class ListSharedElement extends SharedElement {

    protected static final Logger log = Logger.getLogger(ListSharedElement.class);

    public enum DEFAULT_LIST_RESULT_STRAGETY {
        /**
         * Ĭ��ȫ�Ӽ���ѯ
         */
        FULL_TABLE_SCAN,

        /**
         * Ĭ��һ������ѡ��
         */
        NONE
    }

    /**
     * Ĭ���ӽڵ��ѡ��ʽ��ȫ��
     */
    public DEFAULT_LIST_RESULT_STRAGETY            defaultListResultStragety;

    /**
     * ���û���ҵ�ָ����ListResult��ʱ��Ӧ��Ӧ�÷��صĽڵ����Ϣ
     */
    protected List<String>                         defaultListResult;

    /**
     * ���Ϊһ��list ����ļ���ʽ����һ�����������Ե͵��ߣ��������ȼ����ν���
     */
    //TODO:������
    protected RuleChain                            listResultRule;

    /**
     * �ӽڵ�Map
     * 		���ֱ����map��ʽָ����key����init�����б����õ��ӽڵ���Ϊ�ӽڵ��id
     * 
     * 		�����list��ʽָ�������±���Ϊ���map��key,����init�����б����õ��ӽڵ���Ϊid.
     */
    protected Map<String, ? extends SharedElement> subSharedElement = Collections.emptyMap();

    /**
     * ��LogicMapע���Լ��ĺ�����
     * 
     * ��ƽ��������������LogicTable����,������matcher�оͿ���֪�����й�������Ҫ�IJ����Ƿ񶼾߱��ˡ�
     * 
     * ��νmatcher���Ǹ��ݹ�������Ĺ�������Ҫ�IJ�����ȥsql����Ѱ����Ҫ�������ƥ�������+������
     *
     * ����һ��context���ڼ���ʱ���õ�
     * 
     * @param ruleSet
     */
    public void registeRule(Set<RuleChain> ruleSet) {

        registeSubSharedElement(ruleSet);

        registeCurrentSharedElement(ruleSet);
    }

    /** ע�ᵱǰ�ڵ�
     * @param ruleSet
     */
    private void registeCurrentSharedElement(Set<RuleChain> ruleSet) {
        if (this.listResultRule != null) {
            ruleSet.add(this.listResultRule);
        }
    }

    /**
     * ������ӽڵ���ע���ӽڵ�
     * 
     * @param ruleSet
     */
    private void registeSubSharedElement(Set<RuleChain> ruleSet) {
        for (SharedElement sharedElement : subSharedElement.values()) {
            if (sharedElement instanceof ListSharedElement) {
                ((ListSharedElement) sharedElement).registeRule(ruleSet);
            }
        }
    }

    public void setSubSharedElement(Map<String, ? extends SharedElement> subSharedElement) {
        this.subSharedElement = subSharedElement;
    }

    /** 
     * @see com.alipay.zdal.rule.ruleengine.entities.abstractentities.SharedElement#init()
     * �����databaseMapProvider =>��ʼ��databaseMap
     */
    public void init() {

        Map<String, ? extends SharedElement> subSharedElements = fillNullSubSharedElementWithEmptyList();

        initDefaultSubSharedElementsListRule();

        setChildIdByUsingMapKey(subSharedElements);

        super.init();

    }

    private void setChildIdByUsingMapKey(Map<String, ? extends SharedElement> subSharedElements) {
        for (Entry<String, ? extends SharedElement> sharedElement : subSharedElements.entrySet()) {
            //��map�е�key��Ϊid���ø��ӽڵ�
            sharedElement.getValue().setId(sharedElement.getKey());
            initOneSubSharedElement(sharedElement.getValue());
        }
    }

    protected Map<String, ? extends SharedElement> fillNullSubSharedElementWithEmptyList() {
        if (this.subSharedElement == null) {
            this.subSharedElement = Collections.emptyMap();
        }
        return subSharedElement;
    }

    protected void initOneSubSharedElement(SharedElement sharedElement) {
        sharedElement.init();
    }

    /**
     * ��ʼ��Ĭ�Ϲ���key���б�
     * 
     * �ᰴ�ռȶ����Գ�ʼ��������������������в��ܻ��target �ӹ���Ļ�
     * 
     * �ͻ�ʹ��Ĭ�Ϲ���
     * 
     */
    protected void initDefaultSubSharedElementsListRule() {
        if (defaultListResultStragety == null) {
            if (log.isDebugEnabled()) {
                log.debug("default stragety is null ,use none stragety .");
            }
            defaultListResultStragety = DEFAULT_LIST_RESULT_STRAGETY.NONE;
        }

        switch (defaultListResultStragety) {
            case FULL_TABLE_SCAN:
                buildFullTableKeysList();
                break;
            case NONE:
                //fix by shen: ��Ҫע����ǿձ����͵�ʱ��Ӧ�÷���Ψһ�Ľڵ�����ǿսڵ㡣
                if (listResultRule == null || listResultRule.getListResultRule() == null
                    || listResultRule.getListResultRule().isEmpty()) {
                    if (subSharedElement.size() == 1) {
                        log.warn("NONE stragety ,current element has only one SubElement,use "
                                 + "full table stragety! subElement is " + subSharedElement);
                        buildFullTableKeysList();
                    } else {
                        log
                            .warn("NONE stragety ,current element has more than one SubElement,use empty"
                                  + " default stragety! subElement is " + subSharedElement);
                        defaultListResult = Collections.emptyList();
                    }

                } else {
                    defaultListResult = Collections.emptyList();
                }
                break;
            default:
                throw new IllegalArgumentException("���ܴ��������");
        }
    }

    protected void buildFullTableKeysList() {
        int subSharedElementSize = 0;
        if (subSharedElement == null) {
            subSharedElement = Collections.emptyMap();
        }
        subSharedElementSize = subSharedElement.size();
        defaultListResult = new ArrayList<String>(subSharedElementSize);
        if (log.isDebugEnabled()) {
            log.debug("use full table stragety, default keys are :");
        }
        StringBuilder sb = new StringBuilder();
        for (String key : subSharedElement.keySet()) {
            sb.append(key).append("|");
            defaultListResult.add(key);
        }
        if (log.isDebugEnabled()) {
            log.debug(sb.toString());
        }
    }

    public Map<String, ? extends SharedElement> getSubSharedElements() {
        return subSharedElement;
    }

    public DEFAULT_LIST_RESULT_STRAGETY getDefaultListResultStragety() {
        return defaultListResultStragety;
    }

    public void setDefaultListResultStragety(DEFAULT_LIST_RESULT_STRAGETY defaultListResultStragety) {
        this.defaultListResultStragety = defaultListResultStragety;
    }

    @Override
    public String toString() {
        return "ListSharedElement [defaultListResult=" + defaultListResult
               + ", defaultListResultStragety=" + defaultListResultStragety + ", listResultRule="
               + listResultRule + ", subSharedElement=" + subSharedElement + "]";
    }

}