diff --git a/Aaru.Filesystems/RT11/Analyze.cs b/Aaru.Filesystems/RT11/Analyze.cs new file mode 100644 index 000000000..3f14baef3 --- /dev/null +++ b/Aaru.Filesystems/RT11/Analyze.cs @@ -0,0 +1,172 @@ +// /*************************************************************************** +// Aaru Data Preservation Suite +// ---------------------------------------------------------------------------- +// +// Filename : Analyze.cs +// Author(s) : Natalia Portillo +// +// Component : RT-11 filesystem plugin. +// +// --[ License ] -------------------------------------------------------------- +// +// 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, see . +// +// ---------------------------------------------------------------------------- +// Copyright © 2011-2026 Natalia Portillo +// ****************************************************************************/ + +using System; +using System.Collections.Generic; +using System.Linq; +using Aaru.CommonTypes; +using Aaru.CommonTypes.Enums; +using Aaru.CommonTypes.Structs; + +namespace Aaru.Filesystems; + +// Information from http://www.trailing-edge.com/~shoppa/rt11fs/ +/// +public sealed partial class RT11 +{ +#region IReadOnlyFilesystem Members + + /// + public ErrorNumber GetFilesWithAffectedSectors(IEnumerable<(ulong Start, ulong End)> sectorExtents, + out List files, + InitProgressHandler initProgress = null, + UpdateProgressHandler updateProgress = null, + PulseProgressHandler pulseProgress = null, + EndProgressHandler endProgress = null) + { + files = []; + + if(!_mounted) return ErrorNumber.AccessDenied; + if(sectorExtents is null) return ErrorNumber.InvalidArgument; + + List<(ulong Start, ulong End)> normalizedExtents = NormalizeAnalyzeExtents(sectorExtents); + + if(normalizedExtents.Count == 0 || _rootDirectoryCache is null || _rootDirectoryCache.Count == 0) + return ErrorNumber.NoError; + + try + { + initProgress?.Invoke(); + pulseProgress?.Invoke("/"); + + string[] orderedEntries = _rootDirectoryCache.Keys.OrderBy(static entry => entry, + StringComparer.CurrentCultureIgnoreCase) + .ToArray(); + + long maximum = orderedEntries.Length > 0 ? orderedEntries.Length : 1; + + for(var i = 0; i < orderedEntries.Length; i++) + { + string entryPath = "/" + orderedEntries[i]; + + updateProgress?.Invoke(entryPath, i + 1, maximum); + + ErrorNumber errno = GetFileStartBlockAndLength(orderedEntries[i], + out uint startBlock, + out uint lengthInBlocks); + + if(errno == ErrorNumber.NoSuchFile) continue; + + if(errno != ErrorNumber.NoError) return errno; + + AddOverlappingFile(entryPath, startBlock, lengthInBlocks, normalizedExtents, files); + } + + return ErrorNumber.NoError; + } + finally + { + endProgress?.Invoke(); + } + } + +#endregion + + void AddOverlappingFile(string path, uint startBlock, uint lengthInBlocks, + IReadOnlyList<(ulong Start, ulong End)> sectorExtents, List files) + { + if(lengthInBlocks == 0) return; + + List<(ulong Start, ulong End)> overlaps = FindOverlappingExtents(startBlock, lengthInBlocks, sectorExtents); + + if(overlaps.Count == 0) return; + + files.Add(new FileSectorInfo + { + Path = path, + Inode = startBlock, + AffectedSectors = overlaps + }); + } + + List<(ulong Start, ulong End)> FindOverlappingExtents(uint startBlock, uint lengthInBlocks, + IReadOnlyList<(ulong Start, ulong End)> sectorExtents) + { + List<(ulong Start, ulong End)> overlaps = []; + + ulong startSector = _partition.Start + startBlock; + ulong endSector = startSector + lengthInBlocks - 1; + + AddExtentOverlaps(startSector, endSector, sectorExtents, overlaps); + + return NormalizeAnalyzeExtents(overlaps); + } + + static void AddExtentOverlaps(ulong startSector, ulong endSector, + IReadOnlyList<(ulong Start, ulong End)> sectorExtents, + List<(ulong Start, ulong End)> overlaps) + { + foreach((ulong Start, ulong End) requestedExtent in sectorExtents) + { + if(requestedExtent.End < startSector || requestedExtent.Start > endSector) continue; + + overlaps.Add((Math.Max(startSector, requestedExtent.Start), Math.Min(endSector, requestedExtent.End))); + } + } + + static List<(ulong Start, ulong End)> NormalizeAnalyzeExtents(IEnumerable<(ulong Start, ulong End)> extents) + { + var orderedExtents = extents.Where(static extent => extent.End >= extent.Start) + .OrderBy(static extent => extent.Start) + .ThenBy(static extent => extent.End) + .ToList(); + + List<(ulong Start, ulong End)> normalizedExtents = []; + + if(orderedExtents.Count == 0) return normalizedExtents; + + (ulong Start, ulong End) currentExtent = orderedExtents[0]; + + for(var i = 1; i < orderedExtents.Count; i++) + { + if(orderedExtents[i].Start <= currentExtent.End + 1) + { + currentExtent.End = Math.Max(currentExtent.End, orderedExtents[i].End); + + continue; + } + + normalizedExtents.Add(currentExtent); + currentExtent = orderedExtents[i]; + } + + normalizedExtents.Add(currentExtent); + + return normalizedExtents; + } +} \ No newline at end of file