Files
wickra/bindings/csharp/Wickra/WickraNative.cs
T
kingchenc 91f6f67257 Add C# (.NET) binding over the C ABI hub (#226)
The first language stecker on the C ABI hub: a .NET binding exposing all 514
indicators as idiomatic `IDisposable` classes, generated from `wickra.h`.

## What's here

- **`bindings/csharp/`** — the `Wickra` .NET 8 package. `[LibraryImport]`
  source-generated P/Invoke (`NativeMethods.g.cs`) plus idiomatic wrappers
  (`Indicators.g.cs`), both generated from the committed `bindings/c/include/wickra.h`.
  The binding owns no indicator maths — it only marshals types across the C ABI.
- **Marshalling, verified end-to-end against the native library.** Opaque handles
  cross as `nint` kept alive per call via a `SafeHandle`; `bool` as
  `[MarshalAs(U1)]` (Rust `bool` is one byte); a self-correcting
  `DllImportResolver` validates the loaded library actually exports the Wickra
  ABI. Tests cover one representative per FFI archetype (scalar, candle, pairwise,
  multi-output, bars, profile, values-profile, order-book / array-input) plus
  exact Sma reference values.
- **NuGet packaging** — `dotnet pack` produces `Wickra.<version>.nupkg`; the
  release pipeline stages prebuilt native libraries under `runtimes/<rid>/native/`
  for six target triples (win/linux/osx × x64/arm64).
- **`examples/csharp/`** — nine examples mirroring `examples/c/`: streaming,
  backtest, multi_timeframe, parallel_assets, three strategies, and
  fetch_btcusdt + live_binance.
- **CI** — a `csharp` job on the three OSes builds the C ABI, tests the binding,
  and runs the offline examples. **Release** — a gated `csharp-publish` job packs
  and pushes to NuGet (gated on `NUGET_API_KEY`, independent of the GitHub-release
  job so a C# hiccup never blocks the C/C++ asset release).
- **Docs consistency wave** — README, CONTRIBUTING, CHANGELOG, examples/README,
  the issue / PR templates, `sync-about.yml`, and `.gitattributes`.

The native Python / Node / WASM bindings and the C ABI are untouched; this is
additive. Publishing to NuGet stays gated behind the release tag and the secret.
2026-06-09 14:32:05 +02:00

88 lines
3.0 KiB
C#

using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
namespace Wickra;
/// <summary>
/// Native library resolution for the Wickra C ABI.
/// </summary>
/// <remarks>
/// When consumed as a NuGet package the native library ships under
/// <c>runtimes/&lt;rid&gt;/native/</c> and the default runtime resolver finds it
/// automatically. For local development (project reference against a cargo build)
/// the resolver additionally walks up the directory tree to locate
/// <c>target/release</c> or <c>target/debug</c>. Every candidate is validated to
/// actually export the Wickra ABI before it is accepted, so an unrelated library
/// of the same name cannot shadow the real one.
/// </remarks>
internal static class WickraNative
{
/// <summary>The library name passed to <c>[LibraryImport]</c>.</summary>
internal const string LibraryName = "wickra";
// Any exported symbol works as a fingerprint; sma_new exists in every build.
private const string SentinelSymbol = "wickra_sma_new";
[ModuleInitializer]
internal static void Register()
{
NativeLibrary.SetDllImportResolver(typeof(WickraNative).Assembly, Resolve);
}
private static nint Resolve(string libraryName, System.Reflection.Assembly assembly, DllImportSearchPath? searchPath)
{
if (libraryName != LibraryName)
{
return nint.Zero;
}
// 1. Default resolution (NuGet runtimes/ layout, app-local copies). Accept
// only if it is genuinely the Wickra ABI; otherwise discard and fall through.
if (NativeLibrary.TryLoad(libraryName, assembly, searchPath, out var handle))
{
if (Exports(handle))
{
return handle;
}
NativeLibrary.Free(handle);
}
// 2. Development fallback: locate the cargo build output.
var fileName = NativeFileName();
var dir = AppContext.BaseDirectory;
for (var i = 0; i < 16 && dir is not null; i++)
{
foreach (var profile in new[] { "release", "debug" })
{
var candidate = Path.Combine(dir, "target", profile, fileName);
if (File.Exists(candidate) && NativeLibrary.TryLoad(candidate, out var devHandle))
{
if (Exports(devHandle))
{
return devHandle;
}
NativeLibrary.Free(devHandle);
}
}
dir = Path.GetDirectoryName(dir.TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar));
}
return nint.Zero;
}
private static bool Exports(nint handle) => NativeLibrary.TryGetExport(handle, SentinelSymbol, out _);
private static string NativeFileName()
{
if (OperatingSystem.IsWindows())
{
return "wickra.dll";
}
return OperatingSystem.IsMacOS() ? "libwickra.dylib" : "libwickra.so";
}
}