Upload FastSeekWpf/Core/IndexStore.cs

FastSeekWpf/Core/IndexStore.cs

@@ -12,13 +12,14 @@ public class CachedEntry
     public ulong ParentRef { get; set; }
     public string Name { get; set; } = string.Empty;
     public FileKind Kind { get; set; }
+    public byte DriveIdx { get; set; }
 }
 
 [Serializable]
 public class CacheData
 {
     public List<CachedEntry> Entries { get; set; } = new();
-    public string DriveRoot { get; set; } = string.Empty;
+    public List<string> DriveRoots { get; set; } = new();
     public List<JournalCheckpoint> Checkpoints { get; set; } = new();
 }
 
@@ -31,6 +32,7 @@ public struct IndexEntry
     public ushort NameLen;
     public ushort NameLowerLen;
     public byte Flags;
+    public byte DriveIdx; // index into IndexStore.DriveRoots
 
     public readonly bool IsDir => (Flags & 1) != 0;
     public readonly FileKind Kind => IsDir ? FileKind.Directory : FileKind.File;
@@ -41,6 +43,7 @@ public struct IndexEntry
 /// - Arena-backed name storage (List&lt;byte&gt; for O(1) append)
 /// - Parallel cached lowercase strings for zero-allocation search
 /// - Sorted ref_lookup for O(log n) parent lookups
+/// - Multi-drive support via per-entry DriveIdx
 /// </summary>
 public class IndexStore
 {
@@ -53,7 +56,8 @@ public class IndexStore
     public List<string> NameLowerCache = new();
     // Sorted by file_ref for binary search
     public List<(ulong fileRef, int idx)> RefLookup = new();
-    public string DriveRoot = string.Empty;
+    // One root per drive — entries reference via DriveIdx
+    public List<string> DriveRoots = new();
     public List<JournalCheckpoint> Checkpoints = new();
 
     public int Count => Entries.Count;
@@ -62,6 +66,7 @@ public class IndexStore
 
     public string NameAt(int i) => NameCache[i];
     public string NameLowerAt(int i) => NameLowerCache[i];
+    public string DriveRootAt(int i) => DriveRoots[Entries[i].DriveIdx];
 
     public uint? LookupIdx(ulong fileRef)
     {
@@ -88,18 +93,25 @@ public class IndexStore
 
     public void PopulateFromScan(ScanResult scan, string driveRoot)
     {
-        DriveRoot = driveRoot;
+        // Find or add drive root
+        byte driveIdx = 0;
+        int existing = DriveRoots.IndexOf(driveRoot);
+        if (existing >= 0)
+        {
+            driveIdx = (byte)existing;
+        }
+        else
+        {
+            driveIdx = (byte)DriveRoots.Count;
+            DriveRoots.Add(driveRoot);
+        }
+
         int count = scan.Records.Count;
-        Entries.Clear();
-        Entries.Capacity = count;
-        NameArena.Clear();
-        NameArena.Capacity = count * 30;
-        NameLowerArena.Clear();
-        NameLowerArena.Capacity = count * 30;
-        NameCache.Clear();
-        NameCache.Capacity = count;
-        NameLowerCache.Clear();
-        NameLowerCache.Capacity = count;
+        Entries.Capacity = Math.Max(Entries.Capacity, Entries.Count + count);
+        NameArena.Capacity = Math.Max(NameArena.Capacity, NameArena.Count + count * 30);
+        NameLowerArena.Capacity = Math.Max(NameLowerArena.Capacity, NameLowerArena.Count + count * 30);
+        NameCache.Capacity = Math.Max(NameCache.Capacity, NameCache.Count + count);
+        NameLowerCache.Capacity = Math.Max(NameLowerCache.Capacity, NameLowerCache.Count + count);
 
         foreach (var r in scan.Records)
         {
@@ -130,7 +142,8 @@ public class IndexStore
                 NameLowerOff = nlOff,
                 NameLen = nLen,
                 NameLowerLen = nlLen,
-                Flags = r.IsDir ? (byte)1 : (byte)0
+                Flags = r.IsDir ? (byte)1 : (byte)0,
+                DriveIdx = driveIdx
             });
 
             NameCache.Add(name);
@@ -140,7 +153,6 @@ public class IndexStore
 
     /// <summary>
     /// Sort entries by lowercase name and rebuild lookup tables.
-    /// (Renamed from Finalize to avoid CS0465 warning — object.Finalize is the destructor.)
     /// </summary>
     public void CompleteIndex()
     {
@@ -174,9 +186,10 @@ public class IndexStore
                 FileRef = e.FileRef,
                 ParentRef = e.ParentRef,
                 Name = NameAt(i),
-                Kind = e.Kind
+                Kind = e.Kind,
+                DriveIdx = e.DriveIdx
             }).ToList(),
-            DriveRoot = DriveRoot,
+            DriveRoots = new List<string>(DriveRoots),
             Checkpoints = new List<JournalCheckpoint>(Checkpoints)
         };
     }
@@ -186,7 +199,7 @@ public class IndexStore
         int count = cache.Entries.Count;
         var store = new IndexStore
         {
-            DriveRoot = cache.DriveRoot,
+            DriveRoots = new List<string>(cache.DriveRoots),
             Checkpoints = new List<JournalCheckpoint>(cache.Checkpoints)
         };
         store.Entries.Capacity = count;
@@ -216,7 +229,8 @@ public class IndexStore
                 NameLowerOff = nlOff,
                 NameLen = nLen,
                 NameLowerLen = nlLen,
-                Flags = c.Kind == FileKind.Directory ? (byte)1 : (byte)0
+                Flags = c.Kind == FileKind.Directory ? (byte)1 : (byte)0,
+                DriveIdx = c.DriveIdx
             });
 
             store.NameCache.Add(c.Name);
@@ -242,6 +256,11 @@ public class IndexStore
         ushort nlLen = (ushort)lowerBytes.Length;
         NameLowerArena.AddRange(lowerBytes);
 
+        // Default to first drive if unknown
+        byte driveIdx = 0;
+        if (DriveRoots.Count == 0)
+            DriveRoots.Add("C:\\");
+
         var entry = new IndexEntry
         {
             FileRef = record.FileRef,
@@ -250,7 +269,8 @@ public class IndexStore
             NameLowerOff = nlOff,
             NameLen = nLen,
             NameLowerLen = nlLen,
-            Flags = record.Kind == FileKind.Directory ? (byte)1 : (byte)0
+            Flags = record.Kind == FileKind.Directory ? (byte)1 : (byte)0,
+            DriveIdx = driveIdx
         };
 
         // Insert in sorted position by lowercase name
@@ -307,24 +327,27 @@ public class IndexStore
 
     public string BuildPath(ulong fileRef)
     {
-        // string is a managed type, can't stackalloc it. Use small heap array.
         string[] components = new string[64];
         int compCount = 0;
         ulong current = fileRef;
+        byte driveIdx = 0;
 
         for (int i = 0; i < 64; i++)
         {
             var idx = LookupIdx(current);
             if (idx == null) break;
 
-            var entry = Entries[(int)idx];
-            components[compCount++] = NameAt((int)idx);
+            int eIdx = (int)idx;
+            components[compCount++] = NameAt(eIdx);
+            var entry = Entries[eIdx];
+            driveIdx = entry.DriveIdx;
             if (entry.ParentRef == current) break;
             current = entry.ParentRef;
         }
 
-        var sb = new StringBuilder(DriveRoot.Length + compCount * 32);
-        sb.Append(DriveRoot);
+        string driveRoot = driveIdx < DriveRoots.Count ? DriveRoots[driveIdx] : "C:\\";
+        var sb = new StringBuilder(driveRoot.Length + compCount * 32);
+        sb.Append(driveRoot);
         for (int i = compCount - 1; i >= 0; i--)
         {
             if (sb.Length > 0 && sb[sb.Length - 1] != '\\' && sb[sb.Length - 1] != '/')