jextract/jni: Add initial Foundation.Data support

.gitignore

@@ -49,3 +49,5 @@ Package.resolved
 */**/*.swiftdeps~
 */**/.docc-build/
 
+
+BuildLogic/.kotlin/

Samples/SwiftJavaExtractFFMSampleApp/Sources/MySwiftLibrary/Data.swift

@@ -0,0 +1,35 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2026 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#if canImport(FoundationEssentials)
+import FoundationEssentials
+#else
+import Foundation
+#endif
+
+public func echoData(_ data: Data) -> Data {
+  return data
+}
+
+public func makeData() -> Data {
+  return Data([0x01, 0x02, 0x03, 0x04])
+}
+
+public func getDataCount(_ data: Data) -> Int {
+  return data.count
+}
+
+public func compareData(_ data1: Data, _ data2: Data) -> Bool {
+  return data1 == data2
+}

Samples/SwiftJavaExtractFFMSampleApp/src/jmh/java/org/swift/swiftkit/ffm/FFMDataBenchmark.java

@@ -0,0 +1,125 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2026 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+package org.swift.swiftkit.ffm;
+
+import com.example.swift.Data;
+import com.example.swift.MySwiftLibrary;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.nio.ByteBuffer;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.AverageTime)
+@Warmup(iterations = 5, time = 200, timeUnit = TimeUnit.MILLISECONDS)
+@Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Benchmark)
+@Fork(value = 2, jvmArgsAppend = { "--enable-native-access=ALL-UNNAMED" })
+public class FFMDataBenchmark {
+
+    private static class Holder<T> {
+        T value;
+    }
+
+    @Param({"4", "100", "1000"})
+    public int dataSize;
+
+    ClosableAllocatingSwiftArena arena;
+    Data data;
+
+    @Setup(Level.Trial)
+    public void beforeAll() {
+        arena = AllocatingSwiftArena.ofConfined();
+        data = Data.init(makeBytes(dataSize), arena);
+    }
+
+    @TearDown(Level.Trial)
+    public void afterAll() {
+        arena.close();
+    }
+
+    private static byte[] makeBytes(int size) {
+        byte[] bytes = new byte[size];
+        for (int i = 0; i < size; i++) {
+            bytes[i] = (byte) (i % 256);
+        }
+        return bytes;
+    }
+
+    @Benchmark
+    public long ffm_baseline_globalMakeInt() {
+        return MySwiftLibrary.globalMakeInt();
+    }
+
+    @Benchmark
+    public long ffm_passDataToSwift() {
+        return MySwiftLibrary.getDataCount(data);
+    }
+
+    @Benchmark
+    public ByteBuffer ffm_data_withUnsafeBytes_asByteBuffer() {
+      Holder<ByteBuffer> buf = new Holder<>();
+      data.withUnsafeBytes((bytes) -> {
+        buf.value = bytes.asByteBuffer();
+      });
+      return buf.value;
+    }
+
+    @Benchmark
+    public byte[] ffm_data_withUnsafeBytes_toArray() {
+      Holder<byte[]> buf = new Holder<>();
+      data.withUnsafeBytes((bytes) -> {
+        buf.value = bytes.toArray(ValueLayout.JAVA_BYTE);
+      });
+      return buf.value;
+    }
+
+    @Benchmark
+    public byte[] ffm_data_toByteArray() {
+      return data.toByteArray();
+    }
+
+    @Benchmark
+    public byte[] ffm_data_toByteArray_withArena() {
+      return data.toByteArray(arena);
+    }
+
+    @Benchmark
+    public MemorySegment ffm_data_toMemorySegment() {
+      return data.toMemorySegment(arena);
+    }
+
+    @Benchmark
+    public ByteBuffer ffm_data_toByteBuffer() {
+      return data.toByteBuffer(arena);
+    }
+
+    @Benchmark
+    public Data ffm_receiveDataFromSwift(Blackhole bh) {
+        Data result = MySwiftLibrary.makeData(arena);
+        bh.consume(result.getCount());
+        return result;
+    }
+
+    @Benchmark
+    public Data ffm_echoData(Blackhole bh) {
+        Data echoed = MySwiftLibrary.echoData(data, arena);
+        bh.consume(echoed.getCount());
+        return echoed;
+    }
+}

Samples/SwiftJavaExtractFFMSampleApp/src/test/java/com/example/swift/DataImportTest.java

@@ -17,6 +17,8 @@
 import org.junit.jupiter.api.Test;
 import org.swift.swiftkit.ffm.AllocatingSwiftArena;
 
+import java.lang.foreign.ValueLayout;
+
 import static org.junit.jupiter.api.Assertions.*;
 
 public class DataImportTest {
@@ -46,4 +48,95 @@ void test_DataProtocol_receive() {
             assertEquals(6, result);
         }
     }
+
+    @Test
+    void test_Data_toByteArray() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[] { 10, 20, 30, 40 };
+            var data = Data.fromByteArray(original, arena);
+            byte[] result = data.toByteArray();
+            assertEquals(original.length, result.length);
+            assertArrayEquals(original, result);
+        }
+    }
+
+    @Test
+    void test_Data_toByteArray_withArena() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[] { 10, 20, 30, 40 };
+            var data = Data.fromByteArray(original, arena);
+            byte[] result = data.toByteArray(arena);
+            assertEquals(original.length, result.length);
+            assertArrayEquals(original, result);
+        }
+    }
+
+    @Test
+    void test_Data_toByteArray_emptyData() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[0];
+            var data = Data.fromByteArray(original, arena);
+            byte[] result = data.toByteArray();
+            assertEquals(0, result.length);
+        }
+    }
+
+    @Test
+    void test_Data_fromByteArray() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[] { 1, 2, 3, 4, 5 };
+            var data = Data.fromByteArray(original, arena);
+            assertEquals(5, data.getCount());
+        }
+    }
+
+    @Test
+    void test_Data_toMemorySegment() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[] { 10, 20, 30, 40 };
+            var data = Data.fromByteArray(original, arena);
+            var segment = data.toMemorySegment(arena);
+
+            assertEquals(original.length, segment.byteSize());
+            for (int i = 0; i < original.length; i++) {
+                assertEquals(original[i], segment.get(ValueLayout.JAVA_BYTE, i));
+            }
+        }
+    }
+
+    @Test
+    void test_Data_toByteBuffer() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[] { 10, 20, 30, 40 };
+            var data = Data.fromByteArray(original, arena);
+            var buffer = data.toByteBuffer(arena);
+
+            assertEquals(original.length, buffer.capacity());
+            for (int i = 0; i < original.length; i++) {
+                assertEquals(original[i], buffer.get(i));
+            }
+        }
+    }
+
+    @Test
+    void test_Data_toMemorySegment_emptyData() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[0];
+            var data = Data.fromByteArray(original, arena);
+            var segment = data.toMemorySegment(arena);
+            assertEquals(0, segment.byteSize());
+        }
+    }
+
+    @Test
+    void test_Data_toByteBuffer_emptyData() {
+        try (var arena = AllocatingSwiftArena.ofConfined()) {
+            byte[] original = new byte[0];
+            var data = Data.fromByteArray(original, arena);
+            var buffer = data.toByteBuffer(arena);
+
+            assertEquals(0, buffer.capacity());
+        }
+    }
+
 }

Samples/SwiftJavaExtractJNISampleApp/Sources/MySwiftLibrary/Data.swift

@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2026 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#if canImport(FoundationEssentials)
+import FoundationEssentials
+#else
+import Foundation
+#endif
+import SwiftJava
+
+public func echoData(_ data: Data) -> Data {
+  return data
+}
+
+public func makeData() -> Data {
+  return Data([0x01, 0x02, 0x03, 0x04])
+}
+
+public func getDataCount(_ data: Data) -> Int {
+  return data.count
+}
+
+public func compareData(_ data1: Data, _ data2: Data) -> Bool {
+  return data1 == data2
+}

Samples/SwiftJavaExtractJNISampleApp/Sources/MySwiftLibrary/MySwiftLibrary.swift

@@ -35,6 +35,10 @@ public func globalTakeInt(i: Int64) {
   p("i:\(i)")
 }
 
+public func globalEchoInt(i: Int64) -> Int64{
+  i
+}
+
 public func globalMakeInt() -> Int64 {
   return 42
 }