[rbf] Implement directory operations.

Aaru.Filesystems/RBF/Dir.cs

@@ -0,0 +1,159 @@
+// /***************************************************************************
+// Aaru Data Preservation Suite
+// ----------------------------------------------------------------------------
+//
+// Filename       : Dir.cs
+// Author(s)      : Natalia Portillo <claunia@claunia.com>
+//
+// Component      : Random Block File 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 <http://www.gnu.org/licenses/>.
+//
+// ----------------------------------------------------------------------------
+// Copyright © 2011-2026 Natalia Portillo
+// ****************************************************************************/
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Aaru.CommonTypes.Enums;
+using Aaru.CommonTypes.Interfaces;
+
+namespace Aaru.Filesystems;
+
+/// <inheritdoc />
+public sealed partial class RBF
+{
+    /// <inheritdoc />
+    public ErrorNumber OpenDir(string path, out IDirNode node)
+    {
+        node = null;
+
+        if(!_mounted) return ErrorNumber.AccessDenied;
+
+        // Normalize the path
+        string normalizedPath = path ?? "/";
+
+        if(normalizedPath == "" || normalizedPath == ".") normalizedPath = "/";
+
+        // Root directory
+        if(normalizedPath == "/")
+        {
+            node = new RbfDirNode
+            {
+                Path           = "/",
+                Position       = 0,
+                DirectoryFdLsn = _rootDirLsn,
+                Contents       = _rootDirectoryCache.Keys.ToArray()
+            };
+
+            return ErrorNumber.NoError;
+        }
+
+        // Remove leading slash and split path
+        string pathWithoutLeadingSlash = normalizedPath.StartsWith("/", StringComparison.Ordinal)
+                                             ? normalizedPath[1..]
+                                             : normalizedPath;
+
+        string[] pathComponents = pathWithoutLeadingSlash.Split('/', StringSplitOptions.RemoveEmptyEntries);
+
+        if(pathComponents.Length == 0) return ErrorNumber.InvalidArgument;
+
+        // Start traversal from root directory cache
+        Dictionary<string, CachedDirectoryEntry> currentDirectory = _rootDirectoryCache;
+        CachedDirectoryEntry                     targetEntry      = null;
+
+        // Traverse all path components
+        for(var i = 0; i < pathComponents.Length; i++)
+        {
+            string component = pathComponents[i];
+
+            // Skip . and ..
+            if(component == "." || component == "..") continue;
+
+            // Find the component in current directory
+            if(!currentDirectory.TryGetValue(component, out CachedDirectoryEntry entry)) return ErrorNumber.NoSuchFile;
+
+            // If this is the last component, we found our target
+            if(i == pathComponents.Length - 1)
+            {
+                targetEntry = entry;
+
+                break;
+            }
+
+            // Not the last component - must be a directory to continue traversal
+            if(!entry.IsDirectory) return ErrorNumber.NotDirectory;
+
+            // Read the subdirectory contents
+            ErrorNumber errno = ReadDirectoryContents(entry.Fd, out Dictionary<string, CachedDirectoryEntry> subDir);
+
+            if(errno != ErrorNumber.NoError) return errno;
+
+            currentDirectory = subDir;
+        }
+
+        if(targetEntry == null) return ErrorNumber.NoSuchFile;
+
+        // Verify the target is a directory
+        if(!targetEntry.IsDirectory) return ErrorNumber.NotDirectory;
+
+        // Read the target directory contents
+        ErrorNumber readError = ReadDirectoryContents(targetEntry.Fd,
+                                                      out Dictionary<string, CachedDirectoryEntry> targetContents);
+
+        if(readError != ErrorNumber.NoError) return readError;
+
+        node = new RbfDirNode
+        {
+            Path           = normalizedPath,
+            Position       = 0,
+            DirectoryFdLsn = targetEntry.FdLsn,
+            Contents       = targetContents.Keys.ToArray()
+        };
+
+        return ErrorNumber.NoError;
+    }
+
+    /// <inheritdoc />
+    public ErrorNumber CloseDir(IDirNode node)
+    {
+        if(node is not RbfDirNode rbfNode) return ErrorNumber.InvalidArgument;
+
+        rbfNode.Position = -1;
+        rbfNode.Contents = null;
+
+        return ErrorNumber.NoError;
+    }
+
+    /// <inheritdoc />
+    public ErrorNumber ReadDir(IDirNode node, out string filename)
+    {
+        filename = null;
+
+        if(!_mounted) return ErrorNumber.AccessDenied;
+
+        if(node is not RbfDirNode rbfNode) return ErrorNumber.InvalidArgument;
+
+        if(rbfNode.Position < 0) return ErrorNumber.InvalidArgument;
+
+        if(rbfNode.Contents == null || rbfNode.Position >= rbfNode.Contents.Length) return ErrorNumber.NoError;
+
+        filename = rbfNode.Contents[rbfNode.Position++];
+
+        return ErrorNumber.NoError;
+    }
+}

Aaru.Filesystems/RBF/Unimplemented.cs

@@ -48,13 +48,4 @@ public sealed partial class RBF
     /// <inheritdoc />
     public ErrorNumber ReadFile(IFileNode node, long length, byte[] buffer, out long read) =>
         throw new NotImplementedException();
-
-    /// <inheritdoc />
-    public ErrorNumber OpenDir(string path, out IDirNode node) => throw new NotImplementedException();
-
-    /// <inheritdoc />
-    public ErrorNumber CloseDir(IDirNode node) => throw new NotImplementedException();
-
-    /// <inheritdoc />
-    public ErrorNumber ReadDir(IDirNode node, out string filename) => throw new NotImplementedException();
 }