mcs/class/ByteFX.Data/mysqlclient/Packet.cs

   1 using System;
   2 using System.IO;
   3 using System.Text;
   4
   5 namespace ByteFX.Data.MySqlClient
   6 {
   7         /// <summary>
   8         /// Summary description for Packet.
   9         /// </summary>
  10         internal class Packet : MemoryStream
  11         {
  12                 Encoding                encoding;
  13                 byte                    sequence;
  14                 int                             completeLen;
  15                 public static int   NULL_LEN=-1;
  16                 private int             shortLen = 2;
  17                 private int             intLen = 3;
  18                 private int             longLen = 4;
  19                 private bool    longInts = false;
  20
  21                 public Packet(bool longInts) : base()
  22                 {
  23                         LongInts = longInts;
  24                 }
  25
  26                 public Packet(byte[] bytes, bool longInts) : base(bytes.Length)
  27                 {
  28                         this.Write( bytes, 0, bytes.Length );
  29                         Position = 0;
  30                         LongInts = longInts;
  31                 }
  32
  33                 public bool LongInts
  34                 {
  35                         get { return longInts; }
  36                         set
  37                         {
  38                                 longInts = value;
  39                                 if (longInts)
  40                                 {
  41                                         intLen = 4;
  42                                         longLen = 8;
  43                                 }
  44                         }
  45                 }
  46
  47                 public int CompleteLength
  48                 {
  49                         get { return completeLen; }
  50                         set { completeLen = value; }
  51                 }
  52
  53                 public byte Sequence
  54                 {
  55                         get { return sequence; }
  56                         set { sequence = value; }
  57                 }
  58
  59                 public Encoding Encoding
  60                 {
  61                         set { encoding = value; }
  62                         get { return encoding; }
  63                 }
  64
  65                 public void Clear()
  66                 {
  67                         Position = 0;
  68                         this.SetLength(0);
  69                 }
  70
  71                 public byte this[int index]
  72                 {
  73                         get
  74                         {
  75                                 long pos = Position;
  76                                 Position = index;
  77                                 byte b = (byte)ReadByte();
  78                                 Position = pos;
  79                                 return b;
  80                         }
  81                 }
  82
  83                 public new int Length
  84                 {
  85                         get { return (int)base.Length; }
  86                 }
  87
  88                 public bool IsLastPacket()
  89                 {
  90                         return (Length == 1 && this[0] == 0xfe);
  91                 }
  92
  93                 public void Append( Packet p )
  94                 {
  95                         long oldPos = Position;
  96                         Position = Length;
  97                         this.Write( p.GetBuffer(), 0, p.Length );
  98                         Position = oldPos;
  99                 }
 100
 101                 public Packet ReadPacket()
 102                 {
 103                         if (! HasMoreData) return null;
 104
 105                         int len = this.ReadInteger(3);
 106                         byte seq = (byte)this.ReadByte();
 107                         byte[] buf = new byte[ len ];
 108                         this.Read( buf, 0, len );
 109                         Packet p = new Packet( buf, LongInts );
 110                         p.Sequence = seq;
 111                         p.Encoding = this.Encoding;
 112                         return p;
 113                 }
 114
 115                 public int ReadNBytes()
 116                 {
 117                         byte c = (byte)ReadByte();
 118                         if (c < 1 || c > 4) throw new MySqlException("Unexpected byte count received");
 119                         return ReadInteger((int)c);
 120                 }
 121
 122                 public string ReadLenString()
 123                 {
 124                         long len = ReadLenInteger();
 125
 126                         byte[] buffer = new Byte[len];
 127                         Read(buffer, 0, (int)len);
 128                         return encoding.GetString( buffer, 0, (int)len);
 129                 }
 130
 131
 132                 /// <summary>
 133                 /// WriteInteger
 134                 /// </summary>
 135                 /// <param name="v"></param>
 136                 /// <param name="numbytes"></param>
 137                 public void WriteInteger( int v, int numbytes )
 138                 {
 139                         int val = v;
 140
 141                         if (numbytes < 1 || numbytes > 4)
 142                                 throw new ArgumentOutOfRangeException("Wrong byte count for WriteInteger");
 143
 144                         for (int x=0; x < numbytes; x++)
 145                         {
 146                                 WriteByte( (byte)(val&0xff) );
 147                                 val >>= 8;
 148                         }
 149                 }
 150
 151                 /// <summary>
 152                 ///
 153                 /// </summary>
 154                 /// <param name="numbytes"></param>
 155                 /// <returns></returns>
 156                 public int ReadInteger(int numbytes)
 157                 {
 158                         int val = 0;
 159                         int raise = 1;
 160                         for (int x=0; x < numbytes; x++)
 161                         {
 162                                 int b = ReadByte();
 163                                 val += (b*raise);
 164                                 raise *= 256;
 165                         }
 166                         return val;
 167                 }
 168
 169                 /// <summary>
 170                 ///
 171                 /// </summary>
 172                 /// <returns></returns>
 173                 public long ReadLenInteger()
 174                 {
 175                         byte c  = (byte)ReadByte();
 176
 177                         switch(c)
 178                         {
 179                                 case 251 : return NULL_LEN;
 180                                 case 252 : return ReadInteger(shortLen);
 181                                 case 253 : return ReadInteger(intLen);
 182                                 case 254 : return ReadInteger(longLen);
 183                                 default  : return c;
 184                         }
 185                 }
 186
 187                 public bool HasMoreData
 188                 {
 189                         get { return Position < Length; }
 190                 }
 191
 192                 #region String Functions
 193                 public string ReadString()
 194                 {
 195                         System.Text.StringBuilder sb = new System.Text.StringBuilder();
 196
 197                         while ( HasMoreData )
 198                         {
 199                                 byte b = (byte)ReadByte();
 200                                 if (b == 0) break;
 201                                 sb.Append( Convert.ToChar( b ));
 202                         }
 203
 204                         return sb.ToString();
 205                 }
 206
 207                 public void WriteString(string v, Encoding encoding)
 208                 {
 209                         WriteStringNoNull(v, encoding);
 210                         WriteByte(0);
 211                 }
 212
 213                 public void WriteStringNoNull(string v, Encoding encoding)
 214                 {
 215                         byte[] bytes = encoding.GetBytes(v);
 216                         Write(bytes, 0, bytes.Length);
 217                 }
 218
 219                 #endregion
 220
 221
 222         }
 223 }