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

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