rdb/src/main/java/org/apache/tuscany/das/rdb/graphbuilder/impl/MultiTableRegistry.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.tuscany.das.rdb.graphbuilder.impl;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.log4j.Logger;

import commonj.sdo.DataObject;

/**
 * 
 * Used to store and look up table objects based on primary key This could be a lot more 
 * efficient if we could use LinkedHashMap from JDK 1.4
 */
public class MultiTableRegistry implements TableRegistry {
    private static final Logger logger = Logger.getLogger(MultiTableRegistry.class);

    private Map tableNameMap;

    private Map tableValueMap;

    public MultiTableRegistry() {
        tableNameMap = new HashMap();
        tableValueMap = new HashMap();
    }

    /**
     * Get the table with the specified name and primary key
     * 
     * @param tableName
     * @param primaryKey
     * @return EDataObject
     */
    public DataObject get(String tableName, List primaryKey) {
        if (this.logger.isDebugEnabled()) {
            this.logger.debug("Looking for table " + tableName + " with PK " + primaryKey);
            this.logger.debug("\tReturning " + getPkMap(tableName).get(primaryKey));
        }
        return (DataObject) getPkMap(tableName).get(primaryKey);
    }

    /**
     * Add the table with the specified name and primary key
     * 
     * @param tableName
     * @param primaryKey
     * @param value
     */
    public void put(String tableName, List primaryKey, DataObject value) {
        if (getPkMap(tableName).put(primaryKey, value) == null) {
            getCreateValueList(tableName).add(value);
        }
    }

    /**
     * Get the HashMap that contains the primary key to table object mappings.
     * 
     * @param tableName
     * @return HashMap
     */
    private Map getPkMap(String tableName) {
        Map pkMap = (HashMap) tableNameMap.get(tableName);
        if (pkMap == null) {
            pkMap = new HashMap();
            tableNameMap.put(tableName, pkMap);
        }
        return pkMap;
    }

    private List getCreateValueList(String tableName) {
        List values = (List) tableValueMap.get(tableName);
        if (values == null) {
            values = new ArrayList();
            tableValueMap.put(tableName, values);
        }
        return values;
    }

    public boolean contains(String tableName, List primaryKey) {
        return get(tableName, primaryKey) == null ? false : true;

    }

    public void remove(String tableName, List primaryKey) {
    	getPkMap(tableName).get(primaryKey);
    	Map pkMap = (HashMap) tableNameMap.get(tableName);
    	
    	if(pkMap.get(primaryKey) != null) {
    		pkMap.remove(primaryKey);	
    	}
    	
    	if(pkMap.size() == 0) {
    		tableNameMap.remove(tableName);
    	}
    }    
}