#region License

// The PostgreSQL License

//

// Copyright (C) 2016 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.

#endregion

using System;

using System.Collections.Generic;

using System.Diagnostics.Contracts;

using System.Linq;

using System.Text;

namespace Npgsql.FrontendMessages

{

/// <summary>

/// A simple query message.

/// </summary>

class QueryMessage : FrontendMessage

{

string _query;

char[] _queryChars;

int _charPos;

internal const byte Code = (byte)'Q';

internal QueryMessage Populate(string query)

{

Contract.Requires(query != null);

_query = query;

_charPos = -1;

return this;

}

internal override bool Write(WriteBuffer buf)

{

if (_charPos == -1)

{

// Start new query

if (buf.WriteSpaceLeft < 1 + 4)

return false;

_charPos = 0;

var queryByteLen = PGUtil.UTF8Encoding.GetByteCount(_query);

_queryChars = _query.ToCharArray();

buf.WriteByte(Code);

buf.WriteInt32(4 + // Message length (including self excluding code)

queryByteLen + // Query byte length

1); // Null terminator

}

if (_charPos < _queryChars.Length)

{

int charsUsed;

bool completed;

buf.WriteStringChunked(_queryChars, _charPos, _queryChars.Length - _charPos, true,

out charsUsed, out completed);

_charPos += charsUsed;

if (!completed)

return false;

}

if (buf.WriteSpaceLeft < 1)

return false;

buf.WriteByte(0);

_charPos = -1;

return true;

}

public override string ToString()

{

return $"[Query={_query}]";

}

}

}