/* * Copyright 2012-2015 org.opencloudb. * * 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 org.opencloudb.net.mysql; import java.nio.ByteBuffer; import java.util.ArrayList; import java.util.List; import org.opencloudb.mysql.BufferUtil; import org.opencloudb.mysql.MySQLMessage; import org.opencloudb.net.FrontendConnection; /** * 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 mycat */ public class RowDataPacket extends MySQLPacket { private static final byte NULL_MARK = (byte) 251; public final int fieldCount; public final List<byte[]> fieldValues; public RowDataPacket(int fieldCount) { this.fieldCount = fieldCount; this.fieldValues = new ArrayList<byte[]>(fieldCount); } public void add(byte[] value) { fieldValues.add(value); } public void read(byte[] data) { MySQLMessage mm = new MySQLMessage(data); packetLength = mm.readUB3(); packetId = mm.read(); for (int i = 0; i < fieldCount; i++) { fieldValues.add(mm.readBytesWithLength()); } } @Override public ByteBuffer write(ByteBuffer bb, FrontendConnection c) { bb = c.checkWriteBuffer(bb, c.getPacketHeaderSize()); BufferUtil.writeUB3(bb, calcPacketSize()); bb.put(packetId); for (int i = 0; i < fieldCount; i++) { byte[] fv = fieldValues.get(i); if (fv == null || fv.length == 0) { bb = c.checkWriteBuffer(bb, 1); bb.put(RowDataPacket.NULL_MARK); } else { bb = c.checkWriteBuffer(bb, BufferUtil.getLength(fv.length)); BufferUtil.writeLength(bb, fv.length); bb = c.writeToBuffer(fv, bb); } } return bb; } @Override public int calcPacketSize() { int size = 0; for (int i = 0; i < fieldCount; i++) { byte[] v = fieldValues.get(i); size += (v == null || v.length == 0) ? 1 : BufferUtil.getLength(v); } return size; } @Override protected String getPacketInfo() { return "MySQL RowData Packet"; } }