mcs/class/Npgsql/Npgsql/NpgsqlRowDescription.cs

   1 // created on 12/6/2002 at 20:29
   2
   3 // Npgsql.NpgsqlRowDescription.cs
   4 //
   5 // Author:
   6 //      Francisco Jr. (fxjrlists@yahoo.com.br)
   7 //
   8 //      Copyright (C) 2002 The Npgsql Development Team
   9 //      npgsql-general@gborg.postgresql.org
  10 //      http://gborg.postgresql.org/project/npgsql/projdisplay.php
  11 //
  12 // This library is free software; you can redistribute it and/or
  13 // modify it under the terms of the GNU Lesser General Public
  14 // License as published by the Free Software Foundation; either
  15 // version 2.1 of the License, or (at your option) any later version.
  16 //
  17 // This library is distributed in the hope that it will be useful,
  18 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20 // Lesser General Public License for more details.
  21 //
  22 // You should have received a copy of the GNU Lesser General Public
  23 // License along with this library; if not, write to the Free Software
  24 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25
  26 using System;
  27 using System.Collections;
  28 using System.IO;
  29 using System.Text;
  30 using System.Net;
  31
  32 using NpgsqlTypes;
  33
  34 namespace Npgsql
  35 {
  36
  37
  38     /// <summary>
  39     /// This struct represents the internal data of the RowDescription message.
  40     /// </summary>
  41     ///
  42     // [FIXME] Is this name OK? Does it represent well the struct intent?
  43     // Should it be a struct or a class?
  44     internal struct NpgsqlRowDescriptionFieldData
  45     {
  46         public String                   name;                      // Protocol 2/3
  47         public Int32                    table_oid;                 // Protocol 3
  48         public Int16                    column_attribute_number;   // Protocol 3
  49         public Int32                    type_oid;                  // Protocol 2/3
  50         public Int16                    type_size;                 // Protocol 2/3
  51         public Int32                    type_modifier;                 // Protocol 2/3
  52         public FormatCode               format_code;               // Protocol 3. 0 text, 1 binary
  53         public NpgsqlBackendTypeInfo    type_info;                 // everything we know about this field type
  54     }
  55
  56     /// <summary>
  57     /// This class represents a RowDescription message sent from
  58     /// the PostgreSQL.
  59     /// </summary>
  60     ///
  61     internal sealed class NpgsqlRowDescription
  62     {
  63         // Logging related values
  64         private static readonly String CLASSNAME = "NpgsqlRowDescription";
  65
  66
  67         private ArrayList                fields_data = new ArrayList();
  68         private ArrayList                fields_index = new ArrayList();
  69
  70         private ProtocolVersion          protocol_version;
  71
  72         public NpgsqlRowDescription(ProtocolVersion protocolVersion)
  73         {
  74             protocol_version = protocolVersion;
  75         }
  76
  77         public void ReadFromStream(Stream input_stream, Encoding encoding, NpgsqlBackendTypeMapping type_mapping)
  78         {
  79             switch (protocol_version)
  80             {
  81             case ProtocolVersion.Version2 :
  82                 ReadFromStream_Ver_2(input_stream, encoding, type_mapping);
  83                 break;
  84
  85             case ProtocolVersion.Version3 :
  86                 ReadFromStream_Ver_3(input_stream, encoding, type_mapping);
  87                 break;
  88
  89             }
  90         }
  91
  92         private void ReadFromStream_Ver_2(Stream input_stream, Encoding encoding, NpgsqlBackendTypeMapping type_mapping)
  93         {
  94             NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ReadFromStream_Ver_2");
  95
  96             Byte[] input_buffer = new Byte[10]; // Max read will be 4 + 2 + 4
  97
  98             // Read the number of fields.
  99             input_stream.Read(input_buffer, 0, 2);
 100             Int16 num_fields = IPAddress.NetworkToHostOrder(BitConverter.ToInt16(input_buffer, 0));
 101
 102
 103             // Temporary FieldData object to get data from stream and put in array.
 104             NpgsqlRowDescriptionFieldData fd;
 105
 106             // Now, iterate through each field getting its data.
 107             for (Int16 i = 0; i < num_fields; i++)
 108             {
 109                 fd = new NpgsqlRowDescriptionFieldData();
 110
 111                 // Set field name.
 112                 fd.name = PGUtil.ReadString(input_stream, encoding);
 113
 114                 // Read type_oid(Int32), type_size(Int16), type_modifier(Int32)
 115                 input_stream.Read(input_buffer, 0, 4 + 2 + 4);
 116
 117                 fd.type_oid = IPAddress.NetworkToHostOrder(BitConverter.ToInt32(input_buffer, 0));
 118                 fd.type_info = type_mapping[fd.type_oid];
 119                 fd.type_size = IPAddress.NetworkToHostOrder(BitConverter.ToInt16(input_buffer, 4));
 120                 fd.type_modifier = IPAddress.NetworkToHostOrder(BitConverter.ToInt32(input_buffer, 6));
 121
 122                 // Add field data to array.
 123                 fields_data.Add(fd);
 124
 125                 fields_index.Add(fd.name);
 126             }
 127         }
 128
 129         private void ReadFromStream_Ver_3(Stream input_stream, Encoding encoding, NpgsqlBackendTypeMapping type_mapping)
 130         {
 131             NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ReadFromStream_Ver_3");
 132
 133             Byte[] input_buffer = new Byte[4]; // Max read will be 4 + 2 + 4 + 2 + 4 + 2
 134
 135             // Read the length of message.
 136             // [TODO] Any use for now?
 137             PGUtil.ReadInt32(input_stream, input_buffer);
 138             Int16 num_fields = PGUtil.ReadInt16(input_stream, input_buffer);
 139
 140             // Temporary FieldData object to get data from stream and put in array.
 141             NpgsqlRowDescriptionFieldData fd;
 142
 143             for (Int16 i = 0; i < num_fields; i++)
 144             {
 145                 fd = new NpgsqlRowDescriptionFieldData();
 146
 147                 fd.name = PGUtil.ReadString(input_stream, encoding);
 148                 fd.table_oid = PGUtil.ReadInt32(input_stream, input_buffer);
 149                 fd.column_attribute_number = PGUtil.ReadInt16(input_stream, input_buffer);
 150                 fd.type_oid = PGUtil.ReadInt32(input_stream, input_buffer);
 151                 fd.type_info = type_mapping[fd.type_oid];
 152                 fd.type_size = PGUtil.ReadInt16(input_stream, input_buffer);
 153                 fd.type_modifier = PGUtil.ReadInt32(input_stream, input_buffer);
 154                 fd.format_code = (FormatCode)PGUtil.ReadInt16(input_stream, input_buffer);
 155
 156                 fields_data.Add(fd);
 157                 fields_index.Add(fd.name);
 158             }
 159         }
 160
 161         public NpgsqlRowDescriptionFieldData this[Int32 index]
 162         {
 163             get
 164             {
 165                 return (NpgsqlRowDescriptionFieldData)fields_data[index];
 166             }
 167         }
 168
 169         public Int16 NumFields
 170         {
 171             get
 172             {
 173                 return (Int16)fields_data.Count;
 174             }
 175         }
 176
 177         public Int16 FieldIndex(String fieldName)
 178         {
 179             Int16 result = -1;
 180
 181             // First try to find the index with IndexOf (case-sensitive)
 182             result = (Int16)fields_index.IndexOf(fieldName);
 183
 184             if (result > -1)
 185             {
 186                 return result;
 187             }
 188             else
 189             {
 190
 191                 result = 0;
 192                 foreach (String name in fields_index)
 193                 {
 194
 195                     if (name.ToLower().Equals(fieldName.ToLower()))
 196                     {
 197                         return result;
 198                     }
 199                     result++;
 200                 }
 201
 202             }
 203
 204             throw new ArgumentOutOfRangeException("fieldName", fieldName, "Field name not found");
 205
 206         }
 207
 208     }
 209 }