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 using System.Globalization;
  32
  33 using NpgsqlTypes;
  34
  35 namespace Npgsql
  36 {
  37
  38
  39     /// <summary>
  40     /// This struct represents the internal data of the RowDescription message.
  41     /// </summary>
  42     ///
  43     // [FIXME] Is this name OK? Does it represent well the struct intent?
  44     // Should it be a struct or a class?
  45     internal struct NpgsqlRowDescriptionFieldData
  46     {
  47         public String                   name;                      // Protocol 2/3
  48         public Int32                    table_oid;                 // Protocol 3
  49         public Int16                    column_attribute_number;   // Protocol 3
  50         public Int32                    type_oid;                  // Protocol 2/3
  51         public Int16                    type_size;                 // Protocol 2/3
  52         public Int32                    type_modifier;                 // Protocol 2/3
  53         public FormatCode               format_code;               // Protocol 3. 0 text, 1 binary
  54         public NpgsqlBackendTypeInfo    type_info;                 // everything we know about this field type
  55     }
  56
  57     /// <summary>
  58     /// This class represents a RowDescription message sent from
  59     /// the PostgreSQL.
  60     /// </summary>
  61     ///
  62     internal sealed class NpgsqlRowDescription
  63     {
  64         // Logging related values
  65         private static readonly String CLASSNAME = "NpgsqlRowDescription";
  66
  67
  68         private NpgsqlRowDescriptionFieldData[]  fields_data;
  69         private string[]                fields_index;
  70         private Hashtable               field_name_index_table;
  71
  72         private ProtocolVersion          protocol_version;
  73
  74         public NpgsqlRowDescription(ProtocolVersion protocolVersion)
  75         {
  76             protocol_version = protocolVersion;
  77         }
  78
  79         public void ReadFromStream(Stream input_stream, Encoding encoding, NpgsqlBackendTypeMapping type_mapping)
  80         {
  81             switch (protocol_version)
  82             {
  83             case ProtocolVersion.Version2 :
  84                 ReadFromStream_Ver_2(input_stream, encoding, type_mapping);
  85                 break;
  86
  87             case ProtocolVersion.Version3 :
  88                 ReadFromStream_Ver_3(input_stream, encoding, type_mapping);
  89                 break;
  90
  91             }
  92         }
  93
  94         private void ReadFromStream_Ver_2(Stream input_stream, Encoding encoding, NpgsqlBackendTypeMapping type_mapping)
  95         {
  96             NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ReadFromStream_Ver_2");
  97
  98             Byte[] input_buffer = new Byte[10]; // Max read will be 4 + 2 + 4
  99
 100             // Read the number of fields.
 101             input_stream.Read(input_buffer, 0, 2);
 102             Int16 num_fields = IPAddress.NetworkToHostOrder(BitConverter.ToInt16(input_buffer, 0));
 103
 104
 105             // Temporary FieldData object to get data from stream and put in array.
 106             NpgsqlRowDescriptionFieldData fd;
 107
 108             fields_data = new NpgsqlRowDescriptionFieldData[num_fields];
 109             fields_index = new string[num_fields];
 110
 111             field_name_index_table = new Hashtable(num_fields);
 112
 113
 114             // Now, iterate through each field getting its data.
 115             for (Int16 i = 0; i < num_fields; i++)
 116             {
 117                 fd = new NpgsqlRowDescriptionFieldData();
 118
 119                 // Set field name.
 120                 fd.name = PGUtil.ReadString(input_stream, encoding);
 121
 122                 // Read type_oid(Int32), type_size(Int16), type_modifier(Int32)
 123                 input_stream.Read(input_buffer, 0, 4 + 2 + 4);
 124
 125                 fd.type_oid = IPAddress.NetworkToHostOrder(BitConverter.ToInt32(input_buffer, 0));
 126                 fd.type_info = type_mapping[fd.type_oid];
 127                 fd.type_size = IPAddress.NetworkToHostOrder(BitConverter.ToInt16(input_buffer, 4));
 128                 fd.type_modifier = IPAddress.NetworkToHostOrder(BitConverter.ToInt32(input_buffer, 6));
 129
 130                 // Add field data to array.
 131                 fields_data[i] = fd;
 132
 133                 fields_index[i] = fd.name;
 134
 135                 if (!field_name_index_table.ContainsKey(fd.name))
 136                     field_name_index_table.Add(fd.name, i);
 137             }
 138         }
 139
 140         private void ReadFromStream_Ver_3(Stream input_stream, Encoding encoding, NpgsqlBackendTypeMapping type_mapping)
 141         {
 142             NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ReadFromStream_Ver_3");
 143
 144             Byte[] input_buffer = new Byte[4]; // Max read will be 4 + 2 + 4 + 2 + 4 + 2
 145
 146             // Read the length of message.
 147             // [TODO] Any use for now?
 148             PGUtil.ReadInt32(input_stream, input_buffer);
 149             Int16 num_fields = PGUtil.ReadInt16(input_stream, input_buffer);
 150
 151             // Temporary FieldData object to get data from stream and put in array.
 152             NpgsqlRowDescriptionFieldData fd;
 153
 154             fields_data = new NpgsqlRowDescriptionFieldData[num_fields];
 155             fields_index = new string[num_fields];
 156             field_name_index_table = new Hashtable(num_fields);
 157
 158             for (Int16 i = 0; i < num_fields; i++)
 159             {
 160                 fd = new NpgsqlRowDescriptionFieldData();
 161
 162                 fd.name = PGUtil.ReadString(input_stream, encoding);
 163                 fd.table_oid = PGUtil.ReadInt32(input_stream, input_buffer);
 164                 fd.column_attribute_number = PGUtil.ReadInt16(input_stream, input_buffer);
 165                 fd.type_oid = PGUtil.ReadInt32(input_stream, input_buffer);
 166                 fd.type_info = type_mapping[fd.type_oid];
 167                 fd.type_size = PGUtil.ReadInt16(input_stream, input_buffer);
 168                 fd.type_modifier = PGUtil.ReadInt32(input_stream, input_buffer);
 169                 fd.format_code = (FormatCode)PGUtil.ReadInt16(input_stream, input_buffer);
 170
 171                 fields_data[i] = fd;
 172                 fields_index[i] = fd.name;
 173
 174                 if (!field_name_index_table.ContainsKey(fd.name))
 175                     field_name_index_table.Add(fd.name, i);
 176             }
 177         }
 178
 179         public NpgsqlRowDescriptionFieldData this[Int32 index]
 180         {
 181             get
 182             {
 183                 return fields_data[index];
 184             }
 185         }
 186
 187         public Int16 NumFields
 188         {
 189             get
 190             {
 191                 return (Int16)fields_data.Length;
 192             }
 193         }
 194
 195         public Int16 FieldIndex(String fieldName)
 196         {
 197
 198
 199             // First try to find with hashtable, case sensitive.
 200
 201             Object result1 = field_name_index_table[fieldName];
 202
 203             if (result1 != null)
 204                 return (Int16)result1;
 205
 206
 207             result1 = field_name_index_table[fieldName.ToLower(CultureInfo.InvariantCulture)];
 208
 209             if (result1 != null)
 210                 return (Int16)result1;
 211
 212             // Then the index with IndexOf (case-sensitive)
 213
 214
 215             Int16 result = (Int16)Array.IndexOf(fields_index, fieldName, 0, fields_index.Length);
 216
 217             if (result != -1)
 218             {
 219                 return result;
 220             }
 221             else
 222             {
 223
 224                 foreach(string name in fields_index)
 225                 {
 226                     ++result;
 227                     if (string.Compare(name, fieldName, true, CultureInfo.InvariantCulture) == 0)
 228                         return result;
 229                 }
 230             }
 231
 232             return -1;
 233
 234
 235         }
 236
 237     }
 238 }