Merge pull request #66 from netty/panama-fixups

Remove hacks related to the now lifted ByteBuffer/MemorySegment restrictions

src/main/java/io/netty/buffer/api/adaptor/ByteBufAdaptor.java

@@ -1244,23 +1244,7 @@ public final class ByteBufAdaptor extends ByteBuf {
             return true;
         });
 
-        int read;
+        int read = (int) in.read(components);
-        if (isDirect()) {
-            // TODO we cannot use off-heap buffers here, until the JDK allows direct byte buffers based on native
-            //  memory segments to be used in IO operations.
-            ByteBuffer[] copies = new ByteBuffer[components.length];
-            for (int i = 0; i < copies.length; i++) {
-                copies[i] = ByteBuffer.allocateDirect(components[i].remaining());
-            }
-            read = (int) in.read(copies);
-            for (int i = 0; i < copies.length; i++) {
-                ByteBuffer copy = copies[i];
-                ByteBuffer component = components[i];
-                component.put(copy.flip()).flip();
-            }
-        } else {
-            read = (int) in.read(components);
-        }
 
         if (read > 0) {
             writerIndex(read + writerIndex());

src/main/java/io/netty/buffer/api/memseg/MemSegBuffer.java

@@ -237,16 +237,9 @@ class MemSegBuffer extends RcSupport<Buffer, MemSegBuffer> implements Buffer, Re
     @Override
     public ByteBuffer readableBuffer() {
         var buffer = seg.asByteBuffer();
-        if (buffer.isDirect()) {
-            // TODO Remove this when the slicing of shared, native segments JDK bug is fixed.
-            //  See https://mail.openjdk.java.net/pipermail/panama-dev/2021-January/011810.html
-            ByteBuffer tmp = ByteBuffer.allocateDirect(buffer.capacity());
-            tmp.put(buffer);
-            buffer = tmp.position(0);
-        }
         buffer = buffer.asReadOnlyBuffer();
-        // TODO avoid slicing and just set position+limit when JDK bug is fixed.
+        buffer = buffer.position(readerOffset()).limit(readerOffset() + readableBytes());
-        return buffer.slice(readerOffset(), readableBytes()).order(order);
+        return buffer.order(order);
     }
 
     @Override
@@ -277,24 +270,17 @@ class MemSegBuffer extends RcSupport<Buffer, MemSegBuffer> implements Buffer, Re
     @Override
     public ByteBuffer writableBuffer() {
         var buffer = wseg.asByteBuffer();
-
+        buffer = buffer.position(writerOffset()).limit(writerOffset() + writableBytes());
-        if (buffer.isDirect()) {
-            buffer = buffer.position(writerOffset()).limit(writerOffset() + writableBytes());
-        } else {
-            // TODO avoid slicing and just set position when JDK bug is fixed.
-            buffer = buffer.slice(writerOffset(), writableBytes());
-        }
         return buffer.order(order);
     }
     // </editor-fold>
 
     @Override
     public long nativeAddress() {
-        try {
+        if (seg.isNative()) {
             return seg.address().toRawLongValue();
-        } catch (UnsupportedOperationException e) {
-            return 0; // This is a heap segment.
         }
+        return 0; // This is a heap segment.
     }
 
     @Override