# FastSeek WPF

A Windows-only WPF port of the FastSeek instant file search tool.

## Requirements

- Windows 10/11
- .NET 8 SDK or later
- Administrator privileges (required for NTFS MFT and USN journal access)

## Build

```powershell
cd FastSeekWpf
dotnet publish -c Release -r win-x64 --self-contained false
```

Or just run from source:

```powershell
cd FastSeekWpf
dotnet run
```

**Must run as Administrator.** Right-click → Run as Administrator, or launch from an elevated PowerShell.

## Usage

- **Alt+Space** — toggle the search window
- **Esc** — hide
- **Up/Down** — navigate results
- **Enter** — open selected file/folder
- **Ctrl+Enter** — open containing folder
- **Type** — search as you type (results update instantly)

## Architecture

The app reads the NTFS Master File Table (MFT) directly via `FSCTL_ENUM_USN_DATA` / direct `$MFT` read, builds an in-memory index, and keeps it in sync via the USN Change Journal. Search is name-only with fuzzy matching and type-based ranking.

## Performance Fixes Applied

- **Zero-CPU hotkey thread**: Switched from `PeekMessageW` polling (`Thread.Sleep(10)`) to blocking `GetMessageW` with a manual reset event for clean shutdown. Idle CPU is now 0%.
- **Allocation-free search**: `SearchEngine` uses cached lowercase string arrays (`IndexStore.NameCache` / `NameLowerCache`) instead of calling `Encoding.UTF8.GetString` in the hot loop. Uses `Span<char>` for matching, stack-allocated candidate arrays, and `[ThreadStatic]` reusable `StringBuilder` for path building.
- **Debounced search**: TextChanged no longer blocks the UI thread. Searches run on a background thread with 25ms debounce and a `CancellationTokenSource` to cancel stale queries.
- **DWM rounded corners**: Added `DwmSetWindowAttribute` with `DWMWA_WINDOW_CORNER_PREFERENCE=DWMWCP_ROUND` for native Windows 11 rounded window corners, plus `DWMWA_USE_IMMERSIVE_DARK_MODE`.
- **Arena-based inserts**: `IndexStore` keeps `List<byte>` for arenas (O(1) append instead of `Array.Resize` on every insert). Live updates no longer copy the entire arena array.
- **Lock isolation**: Search result building (path resolution, exclusion filtering, ranking) happens outside the `lock(_indexLock)` — only the candidate matching is inside. Deadlocks eliminated.

## Known Issues / TODO

- [x] DWM rounded corners — fixed via `DwmSetWindowAttribute` P/Invoke
- [x] Zero-CPU hotkey thread — fixed via `GetMessageW` + manual reset event
- [x] Arena allocation churn — fixed via `List<byte>.AddRange`
- [x] Search blocking UI — fixed via debounced background search
- [ ] Search results could use a virtualized `ListView` with container recycling for >10k visible items
- [ ] No system tray icon — app runs hidden with hotkey toggle only
- [ ] No settings UI for exclusions