/*
 * Copyright 1999-2012 Alibaba Group.
 *  
 * Licensed 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 com.alibaba.cobar.jdbc.packet;

import java.util.ArrayList;
import java.util.List;

import com.alibaba.cobar.jdbc.util.MySQLMessage;

/**
 * From server to client. One packet for each row in the result set.
 * 
 * <pre>
 * Bytes                   Name
 * -----                   ----
 * n (Length Coded String) (column value)
 * ...
 * 
 * (column value):         The data in the column, as a character string.
 *                         If a column is defined as non-character, the
 *                         server converts the value into a character
 *                         before sending it. Since the value is a Length
 *                         Coded String, a NULL can be represented with a
 *                         single byte containing 251(see the description
 *                         of Length Coded Strings in section "Elements" above).
 * 
 * @see http://forge.mysql.com/wiki/MySQL_Internals_ClientServer_Protocol#Row_Data_Packet
 * </pre>
 * 
 * @author xianmao.hexm 2010-7-23 上午01:05:55
 */
public class RowDataPacket extends MySQLPacket {

    public final int fieldCount;
    public final List<byte[]> fieldValues;

    public RowDataPacket(int fieldCount) {
        this.fieldCount = fieldCount;
        this.fieldValues = new ArrayList<byte[]>(fieldCount);
    }

    public void read(BinaryPacket data) {
        packetLength = data.packetLength;
        packetId = data.packetId;
        MySQLMessage mm = new MySQLMessage(data.value);
        for (int i = 0; i < fieldCount; i++) {
            fieldValues.add(mm.readBytesWithLength());
        }
    }

    @Override
    protected String packetInfo() {
        return "MySQL RowData Packet";
    }

}