forked from npgsql/npgsql
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathNpgsqlCopyIn.cs
More file actions
224 lines (209 loc) · 8.55 KB
/
NpgsqlCopyIn.cs
File metadata and controls
224 lines (209 loc) · 8.55 KB
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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
// Npgsql.NpgsqlCopyIn.cs
//
// Author:
// Kalle Hallivuori <kato@iki.fi>
//
// Copyright (C) 2007 The Npgsql Development Team
// npgsql-general@gborg.postgresql.org
// http://gborg.postgresql.org/project/npgsql/projdisplay.php
//
// Copyright (c) 2002-2007, The Npgsql Development Team
//
// Permission to use, copy, modify, and distribute this software and its
// documentation for any purpose, without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph and the following two paragraphs appear in all copies.
//
// IN NO EVENT SHALL THE NPGSQL DEVELOPMENT TEAM BE LIABLE TO ANY PARTY
// FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
// INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
// DOCUMENTATION, EVEN IF THE NPGSQL DEVELOPMENT TEAM HAS BEEN ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
//
// THE NPGSQL DEVELOPMENT TEAM SPECIFICALLY DISCLAIMS ANY WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
// ON AN "AS IS" BASIS, AND THE NPGSQL DEVELOPMENT TEAM HAS NO OBLIGATIONS
// TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
using System.IO;
namespace Npgsql
{
/// <summary>
/// Represents a PostgreSQL COPY FROM STDIN operation with a corresponding SQL statement
/// to execute against a PostgreSQL database
/// and an associated stream used to read data from (if provided by user)
/// or for writing it (when generated by driver).
/// Eg. new NpgsqlCopyIn("COPY mytable FROM STDIN", connection, streamToRead).Start();
/// </summary>
public class NpgsqlCopyIn
{
private readonly NpgsqlConnector _context;
private readonly NpgsqlCommand _cmd;
private Stream _copyStream;
private bool _disposeCopyStream; // user did not provide stream, so reset it after use
/// <summary>
/// Creates NpgsqlCommand to run given query upon Start(). Data for the requested COPY IN operation can then be written to CopyData stream followed by a call to End() or Cancel().
/// </summary>
public NpgsqlCopyIn(string copyInQuery, NpgsqlConnection conn)
: this(new NpgsqlCommand(copyInQuery, conn), conn)
{
}
/// <summary>
/// Given command is run upon Start(). Data for the requested COPY IN operation can then be written to CopyData stream followed by a call to End() or Cancel().
/// </summary>
public NpgsqlCopyIn(NpgsqlCommand cmd, NpgsqlConnection conn)
: this(cmd, conn, null)
{
}
/// <summary>
/// Given command is executed upon Start() and all data from fromStream is passed to it as copy data.
/// </summary>
public NpgsqlCopyIn(NpgsqlCommand cmd, NpgsqlConnection conn, Stream fromStream)
{
_context = conn.Connector;
_cmd = cmd;
_copyStream = fromStream;
}
/// <summary>
/// Returns true if the connection is currently reserved for this operation.
/// </summary>
public bool IsActive
{
get { return _context != null && _context.CurrentState is NpgsqlCopyInState && _context.Mediator.CopyStream == _copyStream; }
}
/// <summary>
/// The stream provided by user or generated upon Start().
/// User may provide a stream to constructor; it is used to pass to server all data read from it.
/// Otherwise, call to Start() sets this to a writable NpgsqlCopyInStream that passes all data written to it to server.
/// In latter case this is only available while the copy operation is active and null otherwise.
/// </summary>
public Stream CopyStream
{
get { return _copyStream; }
}
/// <summary>
/// Returns true if this operation is currently active and in binary format.
/// </summary>
public bool IsBinary
{
get { return IsActive && _context.CurrentState.CopyFormat.IsBinary; }
}
/// <summary>
/// Returns true if this operation is currently active and field at given location is in binary format.
/// </summary>
public bool FieldIsBinary(int fieldNumber)
{
return IsActive && _context.CurrentState.CopyFormat.FieldIsBinary(fieldNumber);
}
/// <summary>
/// Returns number of fields expected on each input row if this operation is currently active, otherwise -1
/// </summary>
public int FieldCount
{
get { return IsActive ? _context.CurrentState.CopyFormat.FieldCount : -1; }
}
/// <summary>
/// The Command used to execute this copy operation.
/// </summary>
public NpgsqlCommand NpgsqlCommand
{
get { return _cmd; }
}
/// <summary>
/// Set before a COPY IN query to define size of internal buffer for reading from given CopyStream.
/// </summary>
public int CopyBufferSize
{
get { return _context.Mediator.CopyBufferSize; }
set { _context.Mediator.CopyBufferSize = value; }
}
/// <summary>
/// Command specified upon creation is executed as a non-query.
/// If CopyStream is set upon creation, it will be flushed to server as copy data, and operation will be finished immediately.
/// Otherwise the CopyStream member can be used for writing copy data to server and operation finished with a call to End() or Cancel().
/// </summary>
public void Start()
{
if (_context.CurrentState is NpgsqlReadyState)
{
_context.Mediator.CopyStream = _copyStream;
_cmd.ExecuteBlind();
_disposeCopyStream = _copyStream == null;
_copyStream = _context.Mediator.CopyStream;
if (_copyStream == null && ! (_context.CurrentState is NpgsqlReadyState))
{
throw new NpgsqlException("Not a COPY IN query: " + _cmd.CommandText);
}
}
else
{
throw new NpgsqlException("Copy can only start in Ready state, not in " + _context.CurrentState);
}
}
/// <summary>
/// Called after writing all data to CopyStream to successfully complete this copy operation.
/// </summary>
public void End()
{
if (_context != null)
{
try
{
if (IsActive)
{
// Stop Notification thread so we can process this message.
// See bug 1010796
using (_context.BlockNotificationThread())
{
_context.CurrentState.SendCopyDone(_context);
}
}
}
finally
{
if (_context.Mediator.CopyStream == _copyStream)
{
_context.Mediator.CopyStream = null;
}
if (_disposeCopyStream)
{
_copyStream = null;
}
}
}
}
/// <summary>
/// Withdraws an already started copy operation. The operation will fail with given error message.
/// Will do nothing if current operation is not active.
/// </summary>
public void Cancel(string message)
{
if (_context != null)
{
try
{
if (IsActive)
{
// Stop Notification thread so we can process this message.
// See bug 1010796
using (_context.BlockNotificationThread())
{
_context.CurrentState.SendCopyFail(_context, message);
}
}
}
finally
{
if (_context.Mediator.CopyStream == _copyStream)
{
_context.Mediator.CopyStream = null;
}
if (_disposeCopyStream)
{
_copyStream = null;
}
}
}
}
}
}