[GDFX] Implement analysis.

Aaru.Filesystems/GDFX/Analyze.cs

@@ -0,0 +1,163 @@
+// /***************************************************************************
+// Aaru Data Preservation Suite
+// ----------------------------------------------------------------------------
+//
+// Filename       : Analyze.cs
+// Author(s)      : Natalia Portillo <claunia@claunia.com>
+//
+// Component      : Microsoft Xbox DVD File System 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 <http://www.gnu.org/licenses/>.
+//
+// ----------------------------------------------------------------------------
+// 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;
+
+public sealed partial class GDFX
+{
+#region IReadOnlyFilesystem Members
+
+    /// <inheritdoc />
+    public ErrorNumber GetFilesWithAffectedSectors(IEnumerable<(ulong Start, ulong End)> sectorExtents,
+                                                   out List<FileSectorInfo>              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) return ErrorNumber.NoError;
+
+        try
+        {
+            initProgress?.Invoke();
+
+            return TraverseDirectoryForAffectedSectors("/", normalizedExtents, files, updateProgress, pulseProgress);
+        }
+        finally
+        {
+            endProgress?.Invoke();
+        }
+    }
+
+#endregion
+
+    ErrorNumber TraverseDirectoryForAffectedSectors(string path, List<(ulong Start, ulong End)> sectorExtents,
+                                                    List<FileSectorInfo> files, UpdateProgressHandler updateProgress,
+                                                    PulseProgressHandler pulseProgress)
+    {
+        pulseProgress?.Invoke(path);
+
+        if(!_directoryCache.TryGetValue(path, out List<DecodedEntry> entries)) return ErrorNumber.NoSuchFile;
+
+        DecodedEntry[] ordered = entries.OrderBy(static e => e.Name, StringComparer.OrdinalIgnoreCase).ToArray();
+
+        long maximum = ordered.Length > 0 ? ordered.Length : 1;
+
+        for(var i = 0; i < ordered.Length; i++)
+        {
+            DecodedEntry entry     = ordered[i];
+            string       entryPath = path == "/" ? "/" + entry.Name : path + "/" + entry.Name;
+
+            updateProgress?.Invoke(entryPath, i + 1, maximum);
+
+            if(entry.IsDirectory)
+            {
+                ErrorNumber errno = TraverseDirectoryForAffectedSectors(entryPath,
+                                                                        sectorExtents,
+                                                                        files,
+                                                                        updateProgress,
+                                                                        pulseProgress);
+
+                if(errno != ErrorNumber.NoError) return errno;
+
+                continue;
+            }
+
+            if(entry.DataSize == 0) continue;
+
+            ulong absoluteStart = _partitionBaseOffset / SECTOR_SIZE + entry.DataSector + _partition.Start;
+            ulong sectorCount   = (entry.DataSize + SECTOR_SIZE - 1) / SECTOR_SIZE;
+            ulong absoluteEnd   = absoluteStart + sectorCount - 1;
+
+            List<(ulong Start, ulong End)> overlaps = [];
+
+            foreach((ulong Start, ulong End) extent in sectorExtents)
+            {
+                if(extent.End < absoluteStart || extent.Start > absoluteEnd) continue;
+
+                overlaps.Add((Math.Max(absoluteStart, extent.Start), Math.Min(absoluteEnd, extent.End)));
+            }
+
+            if(overlaps.Count == 0) continue;
+
+            files.Add(new FileSectorInfo
+            {
+                Path            = entryPath,
+                Inode           = entry.DataSector,
+                AffectedSectors = NormalizeAnalyzeExtents(overlaps)
+            });
+        }
+
+        return ErrorNumber.NoError;
+    }
+
+    static List<(ulong Start, ulong End)> NormalizeAnalyzeExtents(IEnumerable<(ulong Start, ulong End)> extents)
+    {
+        var orderedExtents = extents.Where(static e => e.End >= e.Start)
+                                    .OrderBy(static e => e.Start)
+                                    .ThenBy(static e => e.End)
+                                    .ToList();
+
+        List<(ulong Start, ulong End)> normalized = [];
+
+        if(orderedExtents.Count == 0) return normalized;
+
+        (ulong Start, ulong End) current = orderedExtents[0];
+
+        for(var i = 1; i < orderedExtents.Count; i++)
+        {
+            if(orderedExtents[i].Start <= current.End + 1)
+            {
+                current.End = Math.Max(current.End, orderedExtents[i].End);
+
+                continue;
+            }
+
+            normalized.Add(current);
+            current = orderedExtents[i];
+        }
+
+        normalized.Add(current);
+
+        return normalized;
+    }
+}