// created on 30/7/2002 at 00:31
// Npgsql.NpgsqlMediator.cs
//
// Author:
// Francisco Jr. (fxjrlists@yahoo.com.br)
//
// Copyright (C) 2002 The Npgsql Development Team
// npgsql-general@gborg.postgresql.org
// http://gborg.postgresql.org/project/npgsql/projdisplay.php
//
// 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;
using System.IO;
using System.Text;
namespace Npgsql
{
///
/// This class is responsible for serving as bridge between the backend
/// protocol handling and the core classes. It is used as the mediator for
/// exchanging data generated/sent from/to backend.
///
///
internal sealed class NpgsqlMediator
{
public enum SQLSentType
{
None,
Simple,
Parse,
Execute
}
// Stream for user to exchange COPY data
private Stream _copyStream;
// Size of data chunks read from user stream and written to server in COPY IN
private int _copyBufferSize = 8192;
// Very temporary holder of data received during COPY OUT
private byte[] _receivedCopyData;
// Last command sent. This is saved for possible later use by NpgsqlException if an error occurs.
private byte[] _sqlSent = null;
private SQLSentType _sqlSentType = SQLSentType.None;
// The current command timeout on the backend. This is set via "SET statement_timeout = ".
private Int32 _backendCommandTimeout = -1; // -1 means unknown - we have no way to know it until we set it.
public String GetSqlSent()
{
switch (_sqlSentType)
{
case SQLSentType.None :
return "";
case SQLSentType.Parse:
return string.Format("{{PARSE}} {0}", BackendEncoding.UTF8Encoding.GetString(_sqlSent));
case SQLSentType.Execute :
return string.Format("{{EXECUTE}} {0}", BackendEncoding.UTF8Encoding.GetString(_sqlSent));
default :
return BackendEncoding.UTF8Encoding.GetString(_sqlSent);
}
}
public void SetSqlSent(byte[] sqlSent, SQLSentType sqlSentType)
{//We only use this if there is an error, so let's only get the string when that happens.
_sqlSent = sqlSent;
_sqlSentType = sqlSentType;
}
///
/// The current command timeout on the backend. This is set via "SET statement_timeout = (milliseconds)".
/// A value of -1 means the backend's timeout value is unknown because it has not yet been set.
///
public Int32 BackendCommandTimeout
{
get { return _backendCommandTimeout; }
set { _backendCommandTimeout = value; }
}
public Stream CopyStream
{
get { return _copyStream; }
set { _copyStream = value; }
}
public int CopyBufferSize
{
get { return _copyBufferSize; }
set { _copyBufferSize = value; }
}
public byte[] ReceivedCopyData
{
get
{
byte[] result = _receivedCopyData;
_receivedCopyData = null;
return result;
}
set { _receivedCopyData = value; }
}
}
}