An alternative to UBB.threads
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// Copyright (c) 2004-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as published by
// the Free Software Foundation
//
// There are special exceptions to the terms and conditions of the GPL
// as it is applied to this software. View the full text of the
// exception in file EXCEPTIONS in the directory of this software
// distribution.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
using System;
using System.Diagnostics;
using System.Text;
using System.IO;
using MySql.Data.Common;
using MySql.Data.MySqlClient.Properties;
namespace MySql.Data.MySqlClient
{
class MySqlPacket
{
private byte[] tempBuffer = new byte[256];
private Encoding encoding;
private MemoryStream buffer = new MemoryStream(5);
private DBVersion version;
private MySqlPacket()
{
Clear();
}
public MySqlPacket(Encoding enc) : this()
{
Encoding = enc;
}
public MySqlPacket(MemoryStream stream)
: this()
{
buffer = stream;
}
#region Properties
public Encoding Encoding
{
get { return encoding; }
set
{
Debug.Assert(value != null);
encoding = value;
}
}
public bool HasMoreData
{
get { return buffer.Position < buffer.Length; }
}
public int Position
{
get { return (int)buffer.Position; }
set { buffer.Position = (long)value; }
}
public int Length
{
get { return (int)buffer.Length; }
set { buffer.SetLength(value); }
}
public bool IsLastPacket
{
get
{
byte[] bits = buffer.GetBuffer();
return bits[0] == 0xfe && Length <= 5;
}
}
public byte[] Buffer
{
get { return buffer.GetBuffer(); }
}
public DBVersion Version
{
get { return version; }
set { version = value; }
}
#endregion
public void Clear()
{
Position = 4;
}
#region Byte methods
public byte ReadByte()
{
return (byte)buffer.ReadByte();
}
public int Read(byte[] byteBuffer, int offset, int count)
{
return buffer.Read(byteBuffer, offset, count);
}
public void WriteByte(byte b)
{
buffer.WriteByte(b);
}
public void Write(byte[] bytesToWrite)
{
Write(bytesToWrite, 0, bytesToWrite.Length);
}
public void Write(byte[] bytesToWrite, int offset, int countToWrite)
{
buffer.Write(bytesToWrite, offset, countToWrite);
}
public int ReadNBytes()
{
byte c = ReadByte();
if (c < 1 || c > 4)
throw new MySqlException(Resources.IncorrectTransmission);
return ReadInteger(c);
}
#endregion
#region Integer methods
public int ReadFieldLength()
{
byte c = ReadByte();
switch (c)
{
case 251: return -1;
case 252: return ReadInteger(2);
case 253: return ReadInteger(3);
case 254: return ReadInteger(8);
default: return c;
}
}
public ulong ReadBitValue(int numbytes)
{
ulong value = 0;
int pos = (int)buffer.Position;
byte[] bits = buffer.GetBuffer();
int shift = 0;
for (int i = 0; i < numbytes; i++)
{
value <<= shift;
value |= bits[pos++];
shift = 8;
}
buffer.Position += numbytes;
return value;
}
public long ReadLong(int numbytes)
{
Debug.Assert((buffer.Position + numbytes) <= buffer.Length);
byte[] bytes = buffer.GetBuffer();
int pos = (int)buffer.Position;
buffer.Position += numbytes;
switch (numbytes)
{
case 2: return BitConverter.ToUInt16(bytes, pos);
case 4: return BitConverter.ToUInt32(bytes, pos);
case 8: return BitConverter.ToInt64(bytes, pos);
}
throw new NotSupportedException("Only byte lengths of 2, 4, or 8 are supported");
}
public ulong ReadULong(int numbytes)
{
Debug.Assert((buffer.Position + numbytes) <= buffer.Length);
byte[] bytes = buffer.GetBuffer();
int pos = (int)buffer.Position;
buffer.Position += numbytes;
switch (numbytes)
{
case 2: return BitConverter.ToUInt16(bytes, pos);
case 4: return BitConverter.ToUInt32(bytes, pos);
case 8: return BitConverter.ToUInt64(bytes, pos);
}
throw new NotSupportedException("Only byte lengths of 2, 4, or 8 are supported");
}
public int Read3ByteInt()
{
int value = 0;
int pos = (int)buffer.Position;
byte[] bits = buffer.GetBuffer();
int shift = 0;
for (int i = 0; i < 3; i++)
{
value |= (int)(bits[pos++] << shift);
shift += 8;
}
buffer.Position += 3;
return value;
}
public int ReadInteger(int numbytes)
{
if (numbytes == 3)
return Read3ByteInt();
Debug.Assert(numbytes <= 4);
return (int)ReadLong(numbytes);
}
/// <summary>
/// WriteInteger
/// </summary>
/// <param name="v"></param>
/// <param name="numbytes"></param>
public void WriteInteger(long v, int numbytes)
{
long val = v;
Debug.Assert(numbytes > 0 && numbytes < 9);
for (int x = 0; x < numbytes; x++)
{
tempBuffer[x] = (byte)(val & 0xff);
val >>= 8;
}
Write(tempBuffer, 0, numbytes);
}
public int ReadPackedInteger()
{
byte c = ReadByte();
switch (c)
{
case 251: return -1;
case 252: return ReadInteger(2);
case 253: return ReadInteger(3);
case 254: return ReadInteger(4);
default: return c;
}
}
public void WriteLength(long length)
{
if (length < 251)
WriteByte((byte)length);
else if (length < 65536L)
{
WriteByte(252);
WriteInteger(length, 2);
}
else if (length < 16777216L)
{
WriteByte(253);
WriteInteger(length, 3);
}
else
{
WriteByte(254);
WriteInteger(length, 4);
}
}
#endregion
#region String methods
public void WriteLenString(string s)
{
byte[] bytes = encoding.GetBytes(s);
WriteLength(bytes.Length);
Write(bytes, 0, bytes.Length);
}
public void WriteStringNoNull(string v)
{
byte[] bytes = encoding.GetBytes(v);
Write(bytes, 0, bytes.Length);
}
public void WriteString(string v)
{
WriteStringNoNull(v);
WriteByte(0);
}
public string ReadLenString()
{
long len = ReadPackedInteger();
return ReadString(len);
}
public string ReadAsciiString(long length)
{
if (length == 0)
return String.Empty;
// byte[] buf = new byte[length];
Read(tempBuffer, 0, (int)length);
return ASCIIEncoding.ASCII.GetString(tempBuffer, 0, (int)length);
//return encoding.GetString(tempBuffer, 0, (int)length); //buf.Length);
}
public string ReadString(long length)
{
if (length == 0)
return String.Empty;
if (tempBuffer == null || length > tempBuffer.Length)
tempBuffer = new byte[length];
Read(tempBuffer, 0, (int)length);
return encoding.GetString(tempBuffer, 0, (int)length);
}
public string ReadString()
{
byte[] bits = buffer.GetBuffer();
int end = (int)buffer.Position;
while (end < (int)buffer.Length &&
bits[end] != 0 && (int)bits[end] != -1)
end++;
string s = encoding.GetString(bits,
(int)buffer.Position, end - (int)buffer.Position);
buffer.Position = end + 1;
return s;
}
#endregion
}
}