chovy-sign/DiscUtils/Iso9660/CDReader.cs

207 lines
8.0 KiB
C#

//
// 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.Streams;
using DiscUtils.Vfs;
namespace DiscUtils.Iso9660
{
/// <summary>
/// Class for reading existing ISO images.
/// </summary>
public class CDReader : VfsFileSystemFacade, IClusterBasedFileSystem, IUnixFileSystem
{
/// <summary>
/// Initializes a new instance of the CDReader class.
/// </summary>
/// <param name="data">The stream to read the ISO image from.</param>
/// <param name="joliet">Whether to read Joliet extensions.</param>
public CDReader(Stream data, bool joliet)
: base(new VfsCDReader(data, joliet, false)) {}
/// <summary>
/// Initializes a new instance of the CDReader class.
/// </summary>
/// <param name="data">The stream to read the ISO image from.</param>
/// <param name="joliet">Whether to read Joliet extensions.</param>
/// <param name="hideVersions">Hides version numbers (e.g. ";1") from the end of files.</param>
public CDReader(Stream data, bool joliet, bool hideVersions)
: base(new VfsCDReader(data, joliet, hideVersions)) {}
/// <summary>
/// Gets which of the Iso9660 variants is being used.
/// </summary>
public Iso9660Variant ActiveVariant
{
get { return GetRealFileSystem<VfsCDReader>().ActiveVariant; }
}
/// <summary>
/// Gets the emulation requested of BIOS when the image is loaded.
/// </summary>
public BootDeviceEmulation BootEmulation
{
get { return GetRealFileSystem<VfsCDReader>().BootEmulation; }
}
/// <summary>
/// Gets the absolute start position (in bytes) of the boot image, or zero if not found.
/// </summary>
public long BootImageStart
{
get { return GetRealFileSystem<VfsCDReader>().BootImageStart; }
}
/// <summary>
/// Gets the memory segment the image should be loaded into (0 for default).
/// </summary>
public int BootLoadSegment
{
get { return GetRealFileSystem<VfsCDReader>().BootLoadSegment; }
}
/// <summary>
/// Gets a value indicating whether a boot image is present.
/// </summary>
public bool HasBootImage
{
get { return GetRealFileSystem<VfsCDReader>().HasBootImage; }
}
/// <summary>
/// Gets the size (in bytes) of each cluster.
/// </summary>
public long ClusterSize
{
get { return GetRealFileSystem<VfsCDReader>().ClusterSize; }
}
/// <summary>
/// Gets the total number of clusters managed by the file system.
/// </summary>
public long TotalClusters
{
get { return GetRealFileSystem<VfsCDReader>().TotalClusters; }
}
/// <summary>
/// Converts a cluster (index) into an absolute byte position in the underlying stream.
/// </summary>
/// <param name="cluster">The cluster to convert.</param>
/// <returns>The corresponding absolute byte position.</returns>
public long ClusterToOffset(long cluster)
{
return GetRealFileSystem<VfsCDReader>().ClusterToOffset(cluster);
}
/// <summary>
/// Converts an absolute byte position in the underlying stream to a cluster (index).
/// </summary>
/// <param name="offset">The byte position to convert.</param>
/// <returns>The cluster containing the specified byte.</returns>
public long OffsetToCluster(long offset)
{
return GetRealFileSystem<VfsCDReader>().OffsetToCluster(offset);
}
/// <summary>
/// Converts a file name to the list of clusters occupied by the file's data.
/// </summary>
/// <param name="path">The path to inspect.</param>
/// <returns>The clusters.</returns>
/// <remarks>Note that in some file systems, small files may not have dedicated
/// clusters. Only dedicated clusters will be returned.</remarks>
public Range<long, long>[] PathToClusters(string path)
{
return GetRealFileSystem<VfsCDReader>().PathToClusters(path);
}
/// <summary>
/// Converts a file name to the extents containing its data.
/// </summary>
/// <param name="path">The path to inspect.</param>
/// <returns>The file extents, as absolute byte positions in the underlying stream.</returns>
/// <remarks>Use this method with caution - not all file systems will store all bytes
/// directly in extents. Files may be compressed, sparse or encrypted. This method
/// merely indicates where file data is stored, not what's stored.</remarks>
public StreamExtent[] PathToExtents(string path)
{
return GetRealFileSystem<VfsCDReader>().PathToExtents(path);
}
/// <summary>
/// Gets an object that can convert between clusters and files.
/// </summary>
/// <returns>The cluster map.</returns>
public ClusterMap BuildClusterMap()
{
return GetRealFileSystem<VfsCDReader>().BuildClusterMap();
}
/// <summary>
/// Retrieves Unix-specific information about a file or directory.
/// </summary>
/// <param name="path">Path to the file or directory.</param>
/// <returns>Information about the owner, group, permissions and type of the
/// file or directory.</returns>
public UnixFileSystemInfo GetUnixFileInfo(string path)
{
return GetRealFileSystem<VfsCDReader>().GetUnixFileInfo(path);
}
/// <summary>
/// Detects if a stream contains a valid ISO file system.
/// </summary>
/// <param name="data">The stream to inspect.</param>
/// <returns><c>true</c> if the stream contains an ISO file system, else false.</returns>
public static bool Detect(Stream data)
{
byte[] buffer = new byte[IsoUtilities.SectorSize];
if (data.Length < 0x8000 + IsoUtilities.SectorSize)
{
return false;
}
data.Position = 0x8000;
int numRead = StreamUtilities.ReadMaximum(data, buffer, 0, IsoUtilities.SectorSize);
if (numRead != IsoUtilities.SectorSize)
{
return false;
}
BaseVolumeDescriptor bvd = new BaseVolumeDescriptor(buffer, 0);
return bvd.StandardIdentifier == BaseVolumeDescriptor.Iso9660StandardIdentifier;
}
/// <summary>
/// Opens a stream containing the boot image.
/// </summary>
/// <returns>The boot image as a stream.</returns>
public Stream OpenBootImage()
{
return GetRealFileSystem<VfsCDReader>().OpenBootImage();
}
}
}