1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/*-------------------------------------------------------------------------
LargeObjectManager.cs
This class is a port of the class LargeObjectManager.java implemented by
PostgreSQL Global Development Group
Copyright (c) 2004, Emiliano Necciari
Original Code: Copyright (c) 2003, PostgreSQL Global Development Group
Note: (Francisco Figueiredo Jr.)
Changed case of method names to conform to .Net names standard.
Also changed type names to their true names. i.e. int -> Int32
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-------------------------------------------------------------------------
*/
using System;
using System.Data;
using Npgsql;
namespace NpgsqlTypes
{
/// <summary>
/// Summary description for LargeObjectManager.
/// </summary>
public class LargeObjectManager
{
// the fastpath api for this connection
private Fastpath fp;
/*
* This mode indicates we want to write to an object
*/
public const Int32 WRITE = 0x00020000;
/*
* This mode indicates we want to read an object
*/
public static Int32 READ = 0x00040000;
/*
* This mode is the default. It indicates we want read and write access to
* a large object
*/
public static Int32 READWRITE = READ | WRITE;
/*
* This prevents us being created by mere mortals
*/
private LargeObjectManager()
{}
/*
* Constructs the LargeObject API.
*
* <p><b>Important Notice</b>
* <br>This method should only be called by org.postgresql.Connection
*
* <p>There should only be one LargeObjectManager per Connection. The
* org.postgresql.Connection class keeps track of the various extension API's
* and it's advised you use those to gain access, and not going direct.
*/
public LargeObjectManager(NpgsqlConnection conn)
{
// We need Fastpath to do anything
// Now get the function oid's for the api
//
// This is an example of Fastpath.addFunctions();
//
String sql;
if (conn.ServerVersion > new ServerVersion(7,3,0) )
{
sql = "SELECT p.proname,p.oid "+
" FROM pg_catalog.pg_proc p, pg_catalog.pg_namespace n "+
" WHERE p.pronamespace=n.oid AND n.nspname='pg_catalog' AND (";
}
else
{
sql = "SELECT proname,oid FROM pg_proc WHERE ";
}
sql += " proname = 'lo_open'" +
" or proname = 'lo_close'" +
" or proname = 'lo_creat'" +
" or proname = 'lo_unlink'" +
" or proname = 'lo_lseek'" +
" or proname = 'lo_tell'" +
" or proname = 'loread'" +
" or proname = 'lowrite'";
if (conn.ServerVersion > new ServerVersion(7,3,0) )
{
sql += ")";
}
IDbCommand cmd = new NpgsqlCommand(sql);
cmd.Connection = conn;
this.fp = new Fastpath(conn,conn.Connector.Stream);
IDataReader res = cmd.ExecuteReader(CommandBehavior.CloseConnection);
if (res == null)
throw new NpgsqlException("postgresql.lo.init");
fp.AddFunctions(res);
}
/*
* This opens an existing large object, based on its OID. This method
* assumes that READ and WRITE access is required (the default).
*
* @param oid of large object
* @return LargeObject instance providing access to the object
* @exception NpgsqlException on error
*/
public LargeObject Open(Int32 oid)
{
return new LargeObject(fp, oid, READWRITE);
}
/*
* This opens an existing large object, based on its OID
*
* @param oid of large object
* @param mode mode of open
* @return LargeObject instance providing access to the object
* @exception NpgsqlException on error
*/
public LargeObject Open(Int32 oid, Int32 mode)
{
return new LargeObject(fp, oid, mode);
}
/*
* This creates a large object, returning its OID.
*
* <p>It defaults to READWRITE for the new object's attributes.
*
* @return oid of new object
* @exception NpgsqlException on error
*/
public Int32 Create()
{
FastpathArg[] args = new FastpathArg[1];
args[0] = new FastpathArg(READWRITE);
return fp.GetInteger("lo_creat", args);
}
/*
* This creates a large object, returning its OID
*
* @param mode a bitmask describing different attributes of the new object
* @return oid of new object
* @exception NpgsqlException on error
*/
public Int32 Create(Int32 mode)
{
FastpathArg[] args = new FastpathArg[1];
args[0] = new FastpathArg(mode);
return fp.GetInteger("lo_creat", args);
}
/*
* This deletes a large object.
*
* @param oid describing object to delete
* @exception NpgsqlException on error
*/
public void Delete(Int32 oid)
{
FastpathArg[] args = new FastpathArg[1];
args[0] = new FastpathArg(oid);
fp.FastpathCall("lo_unlink", false, args);
}
/*
* This deletes a large object.
*
* <p>It is identical to the delete method, and is supplied as the C API uses
* unlink.
*
* @param oid describing object to delete
* @exception NpgsqlException on error
*/
public void Unlink(Int32 oid)
{
Delete(oid);
}
}
}
|
