/*
* 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.net.mysql;
import java.nio.ByteBuffer;
import com.alibaba.cobar.mysql.BufferUtil;
import com.alibaba.cobar.mysql.MySQLMessage;
import com.alibaba.cobar.net.FrontendConnection;
/**
* From Server To Client, part of Result Set Packets. One for each column in the
* result set. Thus, if the value of field_columns in the Result Set Header
* Packet is 3, then the Field Packet occurs 3 times.
*
* <pre>
* Bytes Name
* ----- ----
* n (Length Coded String) catalog
* n (Length Coded String) db
* n (Length Coded String) table
* n (Length Coded String) org_table
* n (Length Coded String) name
* n (Length Coded String) org_name
* 1 (filler)
* 2 charsetNumber
* 4 length
* 1 type
* 2 flags
* 1 decimals
* 2 (filler), always 0x00
* n (Length Coded Binary) default
*
* @see http://forge.mysql.com/wiki/MySQL_Internals_ClientServer_Protocol#Field_Packet
* </pre>
*
* @author xianmao.hexm 2010-7-22 下午05:43:34
*/
public class FieldPacket extends MySQLPacket {
private static final byte[] DEFAULT_CATALOG = "def".getBytes();
private static final byte[] FILLER = new byte[2];
public byte[] catalog = DEFAULT_CATALOG;
public byte[] db;
public byte[] table;
public byte[] orgTable;
public byte[] name;
public byte[] orgName;
public int charsetIndex;
public long length;
public int type;
public int flags;
public byte decimals;
public byte[] definition;
/**
* 把字节数组转变成FieldPacket
*/
public void read(byte[] data) {
MySQLMessage mm = new MySQLMessage(data);
this.packetLength = mm.readUB3();
this.packetId = mm.read();
readBody(mm);
}
/**
* 把BinaryPacket转变成FieldPacket
*/
public void read(BinaryPacket bin) {
this.packetLength = bin.packetLength;
this.packetId = bin.packetId;
readBody(new MySQLMessage(bin.data));
}
@Override
public ByteBuffer write(ByteBuffer buffer, FrontendConnection c) {
int size = calcPacketSize();
buffer = c.checkWriteBuffer(buffer, c.getPacketHeaderSize() + size);
BufferUtil.writeUB3(buffer, size);
buffer.put(packetId);
writeBody(buffer);
return buffer;
}
@Override
public int calcPacketSize() {
int size = (catalog == null ? 1 : BufferUtil.getLength(catalog));
size += (db == null ? 1 : BufferUtil.getLength(db));
size += (table == null ? 1 : BufferUtil.getLength(table));
size += (orgTable == null ? 1 : BufferUtil.getLength(orgTable));
size += (name == null ? 1 : BufferUtil.getLength(name));
size += (orgName == null ? 1 : BufferUtil.getLength(orgName));
size += 13;// 1+2+4+1+2+1+2
if (definition != null) {
size += BufferUtil.getLength(definition);
}
return size;
}
@Override
protected String getPacketInfo() {
return "MySQL Field Packet";
}
private void readBody(MySQLMessage mm) {
this.catalog = mm.readBytesWithLength();
this.db = mm.readBytesWithLength();
this.table = mm.readBytesWithLength();
this.orgTable = mm.readBytesWithLength();
this.name = mm.readBytesWithLength();
this.orgName = mm.readBytesWithLength();
mm.move(1);
this.charsetIndex = mm.readUB2();
this.length = mm.readUB4();
this.type = mm.read() & 0xff;
this.flags = mm.readUB2();
this.decimals = mm.read();
mm.move(FILLER.length);
if (mm.hasRemaining()) {
this.definition = mm.readBytesWithLength();
}
}
private void writeBody(ByteBuffer buffer) {
byte nullVal = 0;
BufferUtil.writeWithLength(buffer, catalog, nullVal);
BufferUtil.writeWithLength(buffer, db, nullVal);
BufferUtil.writeWithLength(buffer, table, nullVal);
BufferUtil.writeWithLength(buffer, orgTable, nullVal);
BufferUtil.writeWithLength(buffer, name, nullVal);
BufferUtil.writeWithLength(buffer, orgName, nullVal);
buffer.put((byte) 0x0C);
BufferUtil.writeUB2(buffer, charsetIndex);
BufferUtil.writeUB4(buffer, length);
buffer.put((byte) (type & 0xff));
BufferUtil.writeUB2(buffer, flags);
buffer.put(decimals);
buffer.position(buffer.position() + FILLER.length);
if (definition != null) {
BufferUtil.writeWithLength(buffer, definition);
}
}
}