//
// DecoderReplacementFallbackBuffer.cs
//
// Author:
// Atsushi Enomoto <atsushi@ximian.com>
//
//
// Copyright (C) 2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
namespace System.Text{
// This DecoderFallbackBuffer is simple. It ignores the input buffers.
// DecoderFallbackBuffer users could implement their own complex
// fallback buffers.
public sealed class DecoderReplacementFallbackBuffer
: DecoderFallbackBuffer
{
bool fallback_assigned;
int current;
string replacement;
public DecoderReplacementFallbackBuffer (
DecoderReplacementFallback fallback)
{
if (fallback == null)
throw new ArgumentNullException ("fallback");
replacement = fallback.DefaultString;
current = 0;
}
public override int Remaining {
get { return fallback_assigned ? replacement.Length - current : 0; }
}
public override bool Fallback (byte [] bytesUnknown, int index)
{
if (bytesUnknown == null)
throw new ArgumentNullException ("bytesUnknown");
if (fallback_assigned && Remaining != 0)
throw new ArgumentException ("Reentrant Fallback method invocation occured. It might be because either this FallbackBuffer is incorrectly shared by multiple threads, invoked inside Encoding recursively, or Reset invocation is forgotten.");
if (index < 0 || bytesUnknown.Length < index)
throw new ArgumentOutOfRangeException ("index");
fallback_assigned = true;
current = 0;
return replacement.Length > 0;
}
public override char GetNextChar ()
{
if (!fallback_assigned)
return '\0';
if (current >= replacement.Length)
return char.MinValue;
return replacement [current++];
}
public override bool MovePrevious ()
{
if (current == 0)
return false;
current--;
return true;
}
public override void Reset ()
{
fallback_assigned = false;
current = 0;
}
}
}
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