LibHac/LibHac.Nand/DiscUtils.Streams/Builder/BuilderBufferExtent.cs

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2018-07-09 18:49:59 +02:00
//
// Copyright (c) 2008-2011, Kenneth Bell
//
// 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.
//
using System;
namespace DiscUtils.Streams
{
public class BuilderBufferExtent : BuilderExtent
{
private byte[] _buffer;
private readonly bool _fixedBuffer;
public BuilderBufferExtent(long start, long length)
: base(start, length) {}
public BuilderBufferExtent(long start, byte[] buffer)
: base(start, buffer.Length)
{
_fixedBuffer = true;
_buffer = buffer;
}
public override void Dispose() {}
public override void PrepareForRead()
{
if (!_fixedBuffer)
{
_buffer = GetBuffer();
}
}
public override int Read(long diskOffset, byte[] block, int offset, int count)
{
int startOffset = (int)(diskOffset - Start);
int numBytes = (int)Math.Min(Length - startOffset, count);
Array.Copy(_buffer, startOffset, block, offset, numBytes);
return numBytes;
}
public override void DisposeReadState()
{
if (!_fixedBuffer)
{
_buffer = null;
}
}
protected virtual byte[] GetBuffer()
{
throw new NotSupportedException("Derived class should implement");
}
}
}