duplicati/Duplicati/Library/Snapshots/NoSnapshotLinux.cs

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using System.Collections.Generic;
using System.Runtime.Versioning;
using Duplicati.Library.Common.IO;

namespace Duplicati.Library.Snapshots
{
    /// <summary>
    /// Handler for providing a snapshot like access to files and folders
    /// </summary>
    [SupportedOSPlatform("linux")]
    [SupportedOSPlatform("macOS")]
    public sealed class NoSnapshotLinux : SnapshotBase
    {
        /// <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)
        {
            return SystemIO.IO_SYS.GetSymlinkTarget(localPath);
        }
        
        /// <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_SYS.GetMetadata(localPath, isSymlink, followSymlink);
        }
        
        /// <summary>
        /// Gets a value indicating if the path points to a block device
        /// </summary>
        /// <returns><c>true</c> if this instance is a block device; otherwise, <c>false</c>.</returns>
        /// <param name="localPath">The file or folder to examine</param>
        public override bool IsBlockDevice(string localPath)
        {
            var n = PosixFile.GetFileType(SystemIOLinux.NormalizePath(localPath));
            switch (n)
            {
                case PosixFile.FileType.Directory:
                case PosixFile.FileType.Symlink:
                case PosixFile.FileType.File:
                    return false;
                default:
                    return true;
            }
        }
        
        /// <summary>
        /// Gets a unique hardlink target ID
        /// </summary>
        /// <returns>The hardlink ID</returns>
        /// <param name="localPath">The file or folder to examine</param>
        public override string HardlinkTargetID(string localPath)
        {
            var normalizePath = SystemIOLinux.NormalizePath(localPath);
            return PosixFile.GetHardlinkCount(normalizePath) <= 1
                ? null
                : PosixFile.GetInodeTargetID(normalizePath);
        }

        /// <inheritdoc />
        public override string ConvertToLocalPath(string snapshotPath)
        {
            return snapshotPath;
        }

        /// <inheritdoc />
        public override string ConvertToSnapshotPath(string localPath)
        {
            return SystemIOLinux.NormalizePath(localPath);
        }
    }
}