Files
duplicati/Duplicati/Library/Snapshots/WindowsSnapshot.cs
T
2020-08-21 07:38:12 -07:00

329 lines
13 KiB
C#

#region Disclaimer / License
// Copyright (C) 2015, The Duplicati Team
// http://www.duplicati.com, info@duplicati.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//
#endregion
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Duplicati.Library.Common.IO;
namespace Duplicati.Library.Snapshots
{
/// <summary>
/// This class encapsulates all access to the Windows Volume Shadow copy Services,
/// implementing the disposable patterns to ensure correct release of resources.
///
/// The class presents all files and folders with their regular filenames to the caller,
/// and internally handles the conversion to the shadow path.
/// </summary>
public sealed class WindowsSnapshot : SnapshotBase
{
/// <summary>
/// The tag used for logging messages
/// </summary>
public static readonly string LOGTAG = Logging.Log.LogTagFromType<WindowsSnapshot>();
/// <summary>
/// The main reference to the backup controller
/// </summary>
private readonly VssBackupComponents _vssBackupComponents;
/// <summary>
/// Constructs a new backup snapshot, using all the required disks
/// </summary>
/// <param name="sources">Sources to determine which volumes to include in snapshot</param>
/// <param name="options">A set of commandline options</param>
public WindowsSnapshot(IEnumerable<string> sources, IDictionary<string, string> options)
{
// For Windows, ensure we don't store paths with UNC prefix
sources = sources.Select(SystemIOWindows.StripUNCPrefix);
try
{
_vssBackupComponents = new VssBackupComponents();
// Default to exclude the System State writer
var excludedWriters = new Guid[] { new Guid("{e8132975-6f93-4464-a53e-1050253ae220}") };
if (options.ContainsKey("vss-exclude-writers"))
{
excludedWriters = options["vss-exclude-writers"]
.Split(';')
.Where(x => !string.IsNullOrWhiteSpace(x) && x.Trim().Length > 0)
.Select(x => new Guid(x))
.ToArray();
}
_vssBackupComponents.SetupWriters(null, excludedWriters);
_vssBackupComponents.InitShadowVolumes(sources);
_vssBackupComponents.MapVolumesToSnapShots();
//If we should map the drives, we do that now and update the volumeMap
if (Utility.Utility.ParseBoolOption(options, "vss-use-mapping"))
{
_vssBackupComponents.MapDrives();
}
}
catch (Exception ex1)
{
Logging.Log.WriteVerboseMessage(LOGTAG, "WindowsSnapshotCreation", ex1, "Failed to initialize windows snapshot instance");
//In case we fail in the constructor, we do not want a snapshot to be active
try
{
Dispose();
}
catch(Exception ex2)
{
Logging.Log.WriteVerboseMessage(LOGTAG, "VSSCleanupOnError", ex2, "Failed during VSS error cleanup");
}
throw;
}
}
#region Private functions
/// <summary>
/// A callback function that takes a non-shadow path to a folder,
/// and returns all folders found in a non-shadow path format.
/// </summary>
/// <param name="localFolderPath">The non-shadow path of the folder to list</param>
/// <returns>A list of non-shadow paths</returns>
protected override string[] ListFolders(string localFolderPath)
{
string[] tmp = null;
var spath = ConvertToSnapshotPath(localFolderPath);
tmp = SystemIO.IO_WIN.GetDirectories(spath);
var root = Util.AppendDirSeparator(SystemIO.IO_WIN.GetPathRoot(localFolderPath));
var volumePath = Util.AppendDirSeparator(ConvertToSnapshotPath(root));
volumePath = SystemIOWindows.PrefixWithUNC(volumePath);
for (var i = 0; i < tmp.Length; i++)
{
tmp[i] = root + SystemIOWindows.PrefixWithUNC(tmp[i]).Substring(volumePath.Length);
}
return tmp;
}
/// <summary>
/// A callback function that takes a non-shadow path to a folder,
/// and returns all files found in a non-shadow path format.
/// </summary>
/// <param name="localFolderPath">The non-shadow path of the folder to list</param>
/// <returns>A list of non-shadow paths</returns>
protected override string[] ListFiles(string localFolderPath)
{
string[] files = null;
var spath = ConvertToSnapshotPath(localFolderPath);
files = SystemIO.IO_WIN.GetFiles(spath);
// convert back to non-shadow, i.e., non-vss version
var root = Util.AppendDirSeparator(SystemIO.IO_WIN.GetPathRoot(localFolderPath));
var volumePath = Util.AppendDirSeparator(ConvertToSnapshotPath(root));
volumePath = SystemIOWindows.PrefixWithUNC(volumePath);
for (var i = 0; i < files.Length; i++)
{
files[i] = root + SystemIOWindows.PrefixWithUNC(files[i]).Substring(volumePath.Length);
}
return files;
}
#endregion
#region ISnapshotService Members
/// <summary>
/// Enumerates all files and folders in the snapshot, restricted to sources
/// </summary>
/// <param name="sources">Sources to enumerate</param>
/// <param name="callback">The callback to invoke with each found path</param>
/// <param name="errorCallback">The callback used to report errors</param>
public override IEnumerable<string> EnumerateFilesAndFolders(IEnumerable<string> sources, Utility.Utility.EnumerationFilterDelegate callback, Utility.Utility.ReportAccessError errorCallback)
{
// For Windows, ensure we don't store paths with UNC prefix
return base.EnumerateFilesAndFolders(sources.Select(SystemIOWindows.StripUNCPrefix), callback, errorCallback);
}
/// <summary>
/// Gets the last write time of a given file in UTC
/// </summary>
/// <param name="localPath">The full path to the file in non-shadow format</param>
/// <returns>The last write time of the file</returns>
public override DateTime GetLastWriteTimeUtc(string localPath)
{
var spath = ConvertToSnapshotPath(localPath);
return SystemIO.IO_WIN.GetLastWriteTimeUtc(SystemIOWindows.PrefixWithUNC(spath));
}
/// <summary>
/// Gets the creation of a given file in UTC
/// </summary>
/// <param name="localPath">The full path to the file in non-shadow format</param>
/// <returns>The last write time of the file</returns>
public override DateTime GetCreationTimeUtc(string localPath)
{
var spath = ConvertToSnapshotPath(localPath);
return SystemIO.IO_WIN.GetCreationTimeUtc(SystemIOWindows.PrefixWithUNC(spath));
}
/// <summary>
/// Opens a file for reading
/// </summary>
/// <param name="localPath">The full path to the file in non-shadow format</param>
/// <returns>An open filestream that can be read</returns>
public override Stream OpenRead(string localPath)
{
return SystemIO.IO_WIN.FileOpenRead(ConvertToSnapshotPath(localPath));
}
/// <summary>
/// Returns the size of a file
/// </summary>
/// <param name="localPath">The full path to the file in non-snapshot format</param>
/// <returns>The length of the file</returns>
public override long GetFileSize(string localPath)
{
return SystemIO.IO_WIN.FileLength(ConvertToSnapshotPath(localPath));
}
/// <summary>
/// Gets the attributes for the given file or folder
/// </summary>
/// <returns>The file attributes</returns>
/// <param name="localPath">The file or folder to examine</param>
public override FileAttributes GetAttributes(string localPath)
{
return SystemIO.IO_WIN.GetFileAttributes(ConvertToSnapshotPath(localPath));
}
/// <summary>
/// Returns the symlink target if the entry is a symlink, and null otherwise
/// </summary>
/// <param name="localPath">The file or folder to examine</param>
/// <returns>The symlink target</returns>
public override string GetSymlinkTarget(string localPath)
{
var spath = ConvertToSnapshotPath(localPath);
return SystemIO.IO_WIN.GetSymlinkTarget(spath);
}
/// <summary>
/// Gets the metadata for the given file or folder
/// </summary>
/// <returns>The metadata for the given file or folder</returns>
/// <param name="localPath">The file or folder to examine</param>
/// <param name="isSymlink">A flag indicating if the target is a symlink</param>
/// <param name="followSymlink">A flag indicating if a symlink should be followed</param>
public override Dictionary<string, string> GetMetadata(string localPath, bool isSymlink, bool followSymlink)
{
return SystemIO.IO_WIN.GetMetadata(ConvertToSnapshotPath(localPath), isSymlink, followSymlink);
}
/// <inheritdoc />
public override bool IsBlockDevice(string localPath)
{
return false;
}
/// <inheritdoc />
public override string HardlinkTargetID(string localPath)
{
return null;
}
/// <inheritdoc />
public override string ConvertToLocalPath(string snapshotPath)
{
if (!Path.IsPathRooted(snapshotPath))
throw new InvalidOperationException();
foreach (var kvp in _vssBackupComponents.SnapshotDeviceAndVolumes)
{
if (snapshotPath.StartsWith(kvp.Key, Utility.Utility.ClientFilenameStringComparison))
return SystemIO.IO_WIN.PathCombine(kvp.Value, snapshotPath.Substring(kvp.Key.Length));
}
throw new InvalidOperationException();
}
/// <inheritdoc />
public override string ConvertToSnapshotPath(string localPath)
{
// For Windows, ensure we don't store paths with UNC prefix
localPath = SystemIOWindows.StripUNCPrefix(localPath);
if (!Path.IsPathRooted(localPath))
throw new InvalidOperationException();
var root = SystemIO.IO_WIN.GetPathRoot(localPath);
var volumePath = _vssBackupComponents.GetVolumeFromCache(root);
// Note that using a simple Path.Combine() for the following code
// can result in invalid snapshot paths; e.g., if localPath is
// @"C:\", mappedPath would not have the required trailing
// directory separator.
var subPath = localPath.Substring(root.Length);
if (!subPath.StartsWith(Util.DirectorySeparatorString, StringComparison.Ordinal))
{
volumePath = Util.AppendDirSeparator(volumePath, Util.DirectorySeparatorString);
}
var mappedPath = volumePath + subPath;
return mappedPath;
}
/// <inheritdoc />
public override bool FileExists(string localFilePath)
{
return SystemIO.IO_WIN.FileExists(ConvertToSnapshotPath(localFilePath));
}
/// <inheritdoc />
public override bool DirectoryExists(string localFolderPath)
{
return SystemIO.IO_WIN.DirectoryExists(ConvertToSnapshotPath(localFolderPath));
}
/// <inheritdoc />
public override bool IsSnapshot => true;
#endregion
/// <inheritdoc />
protected override void Dispose(bool disposing)
{
if (disposing)
{
_vssBackupComponents.Dispose();
}
base.Dispose(disposing);
}
}
}