#region License
// The PostgreSQL License
//
// Copyright (C) 2015 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.Data;
using System.Diagnostics.Contracts;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using NpgsqlTypes;
namespace Npgsql
{
abstract class CachedValue
{
internal bool IsSet { get; set; }
internal bool IsProviderSpecificValue { get; set; }
}
internal class CachedValue : CachedValue
{
T _value;
internal T Value
{
get
{
Contract.Requires(IsSet);
return _value;
}
set
{
IsSet = true;
_value = value;
}
}
}
// TODO: CachedValue instances need to be pooled
internal class RowCache
{
readonly List _values = new List(10);
internal CachedValue Get(int column)
{
CachedValue result;
if (column < _values.Count)
{
var c = _values[column];
if (c == null)
{
result = new CachedValue();
_values[column] = result;
return result;
}
result = c as CachedValue;
if (result == null)
{
// TODO: Return c to pool
result = new CachedValue();
_values[column] = result;
}
return result;
}
for (var i = _values.Count; i < column; i++) {
_values.Add(null);
}
result = new CachedValue();
_values.Add(result);
return result;
}
internal void Clear()
{
foreach (var c in _values)
{
if (c != null) {
c.IsSet = false;
}
}
}
}
}