LibHac/LibHac.Nand/DiscUtils.Core/ApplePartitionMap/PartitionMapFactory.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;
using DiscUtils.Partitions;
using DiscUtils.Streams;

namespace DiscUtils.ApplePartitionMap
{
    [PartitionTableFactory]
    internal sealed class PartitionMapFactory : PartitionTableFactory
    {
        public override bool DetectIsPartitioned(Stream s)
        {
            if (s.Length < 1024)
            {
                return false;
            }

            s.Position = 0;

            byte[] initialBytes = StreamUtilities.ReadExact(s, 1024);

            BlockZero b0 = new BlockZero();
            b0.ReadFrom(initialBytes, 0);
            if (b0.Signature != 0x4552)
            {
                return false;
            }

            PartitionMapEntry initialPart = new PartitionMapEntry(s);
            initialPart.ReadFrom(initialBytes, 512);

            return initialPart.Signature == 0x504d;
        }

        public override PartitionTable DetectPartitionTable(VirtualDisk disk)
        {
            if (!DetectIsPartitioned(disk.Content))
            {
                return null;
            }

            return new PartitionMap(disk.Content);
        }
    }
}