NFC: simplify C# FFI definitions

crates/bindings-csharp/Codegen.Tests/fixtures/server/snapshots/Module#FFI.verified.cs

@@ -1149,7 +1149,7 @@ public static void __describe_module__(SpacetimeDB.Internal.BytesSink d) =>
 
     [UnmanagedCallersOnly(EntryPoint = "__call_reducer__")]
     public static SpacetimeDB.Internal.Errno __call_reducer__(
-        uint id,
+        int id,
         ulong sender_0,
         ulong sender_1,
         ulong sender_2,

crates/bindings-csharp/Codegen/Module.cs

@@ -876,7 +876,7 @@ public static void Main() {
 
                         [UnmanagedCallersOnly(EntryPoint = "__call_reducer__")]
                         public static SpacetimeDB.Internal.Errno __call_reducer__(
-                            uint id,
+                            int id,
                             ulong sender_0,
                             ulong sender_1,
                             ulong sender_2,

crates/bindings-csharp/Runtime/Internal/FFI.cs

@@ -128,15 +128,15 @@ public readonly record struct RowIter(uint Handle)
 
     [LibraryImport(StdbNamespace)]
     public static partial CheckedStatus table_id_from_name(
-        [In] byte[] name,
-        uint name_len,
+        ReadOnlySpan<byte> name,
+        int name_len,
         out TableId out_
     );
 
     [LibraryImport(StdbNamespace)]
     public static partial CheckedStatus index_id_from_name(
-        [In] byte[] name,
-        uint name_len,
+        ReadOnlySpan<byte> name,
+        int name_len,
         out IndexId out_
     );
 
@@ -153,20 +153,20 @@ out RowIter out_
     public static partial CheckedStatus datastore_btree_scan_bsatn(
         IndexId index_id,
         ReadOnlySpan<byte> prefix,
-        uint prefix_len,
+        int prefix_len,
         ColId prefix_elems,
         ReadOnlySpan<byte> rstart,
-        uint rstart_len,
+        int rstart_len,
         ReadOnlySpan<byte> rend,
-        uint rend_len,
+        int rend_len,
         out RowIter out_
     );
 
     [LibraryImport(StdbNamespace)]
     public static partial Errno row_iter_bsatn_advance(
         RowIter iter_handle,
-        [MarshalUsing(CountElementName = nameof(buffer_len))] [Out] byte[] buffer,
-        ref uint buffer_len
+        Span<byte> buffer,
+        ref int buffer_len
     );
 
     [LibraryImport(StdbNamespace)]
@@ -176,42 +176,42 @@ ref uint buffer_len
     public static partial CheckedStatus datastore_insert_bsatn(
         TableId table_id,
         Span<byte> row,
-        ref uint row_len
+        ref int row_len
     );
 
     [LibraryImport(StdbNamespace)]
     public static partial CheckedStatus datastore_delete_by_btree_scan_bsatn(
         IndexId index_id,
         ReadOnlySpan<byte> prefix,
-        uint prefix_len,
+        int prefix_len,
         ColId prefix_elems,
         ReadOnlySpan<byte> rstart,
-        uint rstart_len,
+        int rstart_len,
         ReadOnlySpan<byte> rend,
-        uint rend_len,
+        int rend_len,
         out uint out_
     );
 
     [LibraryImport(StdbNamespace)]
     public static partial CheckedStatus datastore_delete_all_by_eq_bsatn(
         TableId table_id,
-        [In] byte[] relation,
-        uint relation_len,
+        ReadOnlySpan<byte> relation,
+        int relation_len,
         out uint out_
     );
 
     [LibraryImport(StdbNamespace)]
     public static partial Errno bytes_source_read(
         BytesSource source,
         Span<byte> buffer,
-        ref uint buffer_len
+        ref int buffer_len
     );
 
     [LibraryImport(StdbNamespace)]
     public static partial CheckedStatus bytes_sink_write(
         BytesSink sink,
         ReadOnlySpan<byte> buffer,
-        ref uint buffer_len
+        ref int buffer_len
     );
 
     public enum LogLevel : byte
@@ -227,13 +227,13 @@ public enum LogLevel : byte
     [LibraryImport(StdbNamespace)]
     public static partial void console_log(
         LogLevel level,
-        [In] byte[] target,
-        uint target_len,
-        [In] byte[] filename,
-        uint filename_len,
+        ReadOnlySpan<byte> target,
+        int target_len,
+        ReadOnlySpan<byte> filename,
+        int filename_len,
         uint line_number,
-        [In] byte[] message,
-        uint message_len
+        ReadOnlySpan<byte> message,
+        int message_len
     );
 
     [NativeMarshalling(typeof(ConsoleTimerIdMarshaller))]
@@ -262,17 +262,17 @@ internal static class ConsoleTimerIdMarshaller
     }
 
     [LibraryImport(StdbNamespace)]
-    public static partial ConsoleTimerId console_timer_start([In] byte[] name, uint name_len);
+    public static partial ConsoleTimerId console_timer_start(ReadOnlySpan<byte> name, int name_len);
 
     [LibraryImport(StdbNamespace)]
     public static partial CheckedStatus console_timer_end(ConsoleTimerId stopwatch_id);
 
     [LibraryImport(StdbNamespace)]
     public static partial void volatile_nonatomic_schedule_immediate(
-        [In] byte[] name,
-        uint name_len,
-        [In] byte[] args,
-        uint args_len
+        ReadOnlySpan<byte> name,
+        int name_len,
+        ReadOnlySpan<byte> args,
+        int args_len
     );
 
     // Note #1: our Identity type has the same layout as a fixed-size 32-byte little-endian buffer,

crates/bindings-csharp/Runtime/Internal/IIndex.cs

@@ -11,7 +11,7 @@ public abstract class IndexBase<Row>
     public IndexBase(string name)
     {
         var name_bytes = System.Text.Encoding.UTF8.GetBytes(name);
-        FFI.index_id_from_name(name_bytes, (uint)name_bytes.Length, out indexId);
+        FFI.index_id_from_name(name_bytes, name_bytes.Length, out indexId);
     }
 
     private static void ToParams<Bounds>(
@@ -50,12 +50,12 @@ protected uint DoDelete<Bounds>(Bounds bounds)
         FFI.datastore_delete_by_btree_scan_bsatn(
             indexId,
             prefix,
-            (uint)prefix.Length,
+            prefix.Length,
             prefixElems,
             rstart,
-            (uint)rstart.Length,
+            rstart.Length,
             rend,
-            (uint)rend.Length,
+            rend.Length,
             out var out_
         );
         return out_;
@@ -70,12 +70,12 @@ protected override void IterStart(out FFI.RowIter handle)
             FFI.datastore_btree_scan_bsatn(
                 indexId,
                 prefix,
-                (uint)prefix.Length,
+                prefix.Length,
                 prefixElems,
                 rstart,
-                (uint)rstart.Length,
+                rstart.Length,
                 rend,
-                (uint)rend.Length,
+                rend.Length,
                 out handle
             );
         }

crates/bindings-csharp/Runtime/Internal/IReducer.cs

@@ -26,9 +26,9 @@ public static void VolatileNonatomicScheduleImmediate(string name, MemoryStream
 
         FFI.volatile_nonatomic_schedule_immediate(
             name_bytes,
-            (uint)name_bytes.Length,
+            name_bytes.Length,
             args_bytes,
-            (uint)args_bytes.Length
+            args_bytes.Length
         );
     }
 }

crates/bindings-csharp/Runtime/Internal/ITable.cs

@@ -17,10 +17,9 @@ public bool MoveNext()
                 return false;
             }
 
-            uint buffer_len;
             while (true)
             {
-                buffer_len = (uint)buffer.Length;
+                var buffer_len = buffer.Length;
                 var ret = FFI.row_iter_bsatn_advance(handle, buffer, ref buffer_len);
                 if (ret == Errno.EXHAUSTED)
                 {
@@ -116,7 +115,7 @@ protected override void IterStart(out FFI.RowIter handle) =>
         new(() =>
         {
             var name_bytes = System.Text.Encoding.UTF8.GetBytes(tableName);
-            FFI.table_id_from_name(name_bytes, (uint)name_bytes.Length, out var out_);
+            FFI.table_id_from_name(name_bytes, name_bytes.Length, out var out_);
             return out_;
         });
 
@@ -142,19 +141,19 @@ protected static T DoInsert(T row)
     {
         // Insert the row.
         var bytes = IStructuralReadWrite.ToBytes(row);
-        var bytes_len = (uint)bytes.Length;
+        var bytes_len = bytes.Length;
         FFI.datastore_insert_bsatn(tableId, bytes, ref bytes_len);
 
         // Write back any generated column values.
-        using var stream = new MemoryStream(bytes, 0, (int)bytes_len);
+        using var stream = new MemoryStream(bytes, 0, bytes_len);
         using var reader = new BinaryReader(stream);
         return View.ReadGenFields(reader, row);
     }
 
     protected static bool DoDelete(T row)
     {
         var bytes = IStructuralReadWrite.ToBytes(row);
-        FFI.datastore_delete_all_by_eq_bsatn(tableId, bytes, (uint)bytes.Length, out var out_);
+        FFI.datastore_delete_all_by_eq_bsatn(tableId, bytes, bytes.Length, out var out_);
         return out_ > 0;
     }
 

crates/bindings-csharp/Runtime/Internal/Module.cs

@@ -102,12 +102,12 @@ private static byte[] Consume(this BytesSource source)
             return [];
         }
         var buffer = new byte[0x20_000];
-        var written = 0U;
+        var written = 0;
         while (true)
         {
             // Write into the spare capacity of the buffer.
-            var spare = buffer.AsSpan((int)written);
-            var buf_len = (uint)spare.Length;
+            var spare = buffer.AsSpan(written);
+            var buf_len = spare.Length;
             var ret = FFI.bytes_source_read(source, spare, ref buf_len);
             written += buf_len;
             switch (ret)
@@ -135,15 +135,13 @@ private static byte[] Consume(this BytesSource source)
         }
     }
 
-    private static void Write(this BytesSink sink, byte[] bytes)
+    private static void Write(this BytesSink sink, Span<byte> bytes)
     {
-        var start = 0U;
-        while (start != bytes.Length)
+        while (!bytes.IsEmpty)
         {
-            var written = (uint)bytes.Length;
-            var buffer = bytes.AsSpan((int)start);
-            FFI.bytes_sink_write(sink, buffer, ref written);
-            start += written;
+            var written = bytes.Length;
+            FFI.bytes_sink_write(sink, bytes, ref written);
+            bytes = bytes[written..];
         }
     }
 
@@ -165,7 +163,7 @@ public static void __describe_module__(BytesSink description)
     }
 
     public static Errno __call_reducer__(
-        uint id,
+        int id,
         ulong sender_0,
         ulong sender_1,
         ulong sender_2,
@@ -180,19 +178,17 @@ BytesSink error
         try
         {
             var senderIdentity = Identity.From(
-                MemoryMarshal.AsBytes([sender_0, sender_1, sender_2, sender_3]).ToArray()
-            );
-            var senderAddress = Address.From(
-                MemoryMarshal.AsBytes([address_0, address_1]).ToArray()
+                MemoryMarshal.AsBytes([sender_0, sender_1, sender_2, sender_3])
             );
+            var senderAddress = Address.From(MemoryMarshal.AsBytes([address_0, address_1]));
             var random = new Random((int)timestamp.MicrosecondsSinceEpoch);
             var time = timestamp.ToStd();
 
             var ctx = newContext!(senderIdentity, senderAddress, random, time);
 
             using var stream = new MemoryStream(args.Consume());
             using var reader = new BinaryReader(stream);
-            reducers[(int)id].Invoke(reader, ctx);
+            reducers[id].Invoke(reader, ctx);
             if (stream.Position != stream.Length)
             {
                 throw new Exception("Unrecognised extra bytes in the reducer arguments");

crates/bindings-csharp/Runtime/Log.cs

@@ -168,12 +168,12 @@ uint lineNumber
         FFI.console_log(
             level,
             target_bytes,
-            (uint)target_bytes.Length,
+            target_bytes.Length,
             filename_bytes,
-            (uint)filename_bytes.Length,
+            filename_bytes.Length,
             lineNumber,
             text_bytes,
-            (uint)text_bytes.Length
+            text_bytes.Length
         );
     }
 }

crates/bindings-csharp/Runtime/LogStopwatch.cs

@@ -11,7 +11,7 @@ public sealed class LogStopwatch : IDisposable
     public LogStopwatch(string name)
     {
         var name_bytes = Encoding.UTF8.GetBytes(name);
-        StopwatchId = FFI.console_timer_start(name_bytes, (uint)name_bytes.Length);
+        StopwatchId = FFI.console_timer_start(name_bytes, name_bytes.Length);
     }
 
     void IDisposable.Dispose()