LibHac/libhac.Nand/DiscUtils.Streams/Builder/BuilderStreamExtent.cs

//
// 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.IO;

namespace DiscUtils.Streams
{
    public class BuilderStreamExtent : BuilderExtent
    {
        private readonly Ownership _ownership;
        private Stream _source;

        public BuilderStreamExtent(long start, Stream source)
            : this(start, source, Ownership.None) {}

        public BuilderStreamExtent(long start, Stream source, Ownership ownership)
            : base(start, source.Length)
        {
            _source = source;
            _ownership = ownership;
        }

        public override void Dispose()
        {
            if (_source != null && _ownership == Ownership.Dispose)
            {
                _source.Dispose();
                _source = null;
            }
        }

        public override void PrepareForRead() {}

        public override int Read(long diskOffset, byte[] block, int offset, int count)
        {
            _source.Position = diskOffset - Start;
            return _source.Read(block, offset, count);
        }

        public override void DisposeReadState() {}
    }
}