// Npgsql.NpgsqlCopyOutState.cs
//
// Author:
// Kalle Hallivuori
//
// Copyright (C) 2007 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;
namespace Npgsql
{
///
/// Represents an ongoing COPY TO STDOUT operation.
/// Provides methods to read data from server or end the operation.
///
internal sealed class NpgsqlCopyOutState : NpgsqlState
{
public static readonly NpgsqlCopyOutState Instance = new NpgsqlCopyOutState();
//private readonly String CLASSNAME = MethodBase.GetCurrentMethod().DeclaringType.Name;
private NpgsqlCopyFormat _copyFormat = null;
private NpgsqlCopyOutState()
: base()
{
}
///
/// Copy format information returned from server.
///
public override NpgsqlCopyFormat CopyFormat
{
get { return _copyFormat; }
}
///
/// Called from NpgsqlState.ProcessBackendResponses upon CopyOutResponse.
/// If CopyStream is already set, it is used to write data received from server, after which the copy ends.
/// Otherwise CopyStream is set to a readable NpgsqlCopyOutStream that receives data from server.
///
protected override void StartCopy(NpgsqlConnector context, NpgsqlCopyFormat copyFormat)
{
_copyFormat = copyFormat;
Stream userFeed = context.Mediator.CopyStream;
if (userFeed == null)
{
context.Mediator.CopyStream = new NpgsqlCopyOutStream(context);
}
else
{
byte[] buf;
while ((buf = GetCopyData(context)) != null)
{
userFeed.Write(buf, 0, buf.Length);
}
userFeed.Close();
}
}
///
/// Called from NpgsqlOutStream.Read to read copy data from server.
///
public override byte[] GetCopyData(NpgsqlConnector context)
{
// polling in COPY would take seconds on Windows
foreach (IServerResponseObject obj in ProcessBackendResponses(context))
{
if (obj is IDisposable)
{
(obj as IDisposable).Dispose();
}
}
return context.Mediator.ReceivedCopyData;
}
}
}