Remove UndertowDataBuffer

This commit removes the UndertowDataBuffer, in favor of using regular
DataBuffers from the DataBufferFactory. During the development of the
DefaultPartHttpMessageReader, it was determined that invoking various
slicing and releasing operators on the UndertowDataBuffer resulted in
memory leaks. This commit fixes that.

Author: poutsma

spring-web/src/main/java/org/springframework/http/server/reactive/UndertowServerHttpRequest.java

@@ -21,7 +21,6 @@
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.ByteBuffer;
-import java.util.concurrent.atomic.AtomicInteger;
 
 import javax.net.ssl.SSLSession;
 
@@ -34,9 +33,6 @@
 
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferFactory;
-import org.springframework.core.io.buffer.DataBufferUtils;
-import org.springframework.core.io.buffer.DataBufferWrapper;
-import org.springframework.core.io.buffer.PooledDataBuffer;
 import org.springframework.http.HttpCookie;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -172,7 +168,6 @@ protected void readingPaused() {
 		@Nullable
 		protected DataBuffer read() throws IOException {
 			PooledByteBuffer pooledByteBuffer = this.byteBufferPool.allocate();
-			boolean release = true;
 			try {
 				ByteBuffer byteBuffer = pooledByteBuffer.getBuffer();
 				int read = this.channel.read(byteBuffer);
@@ -183,19 +178,17 @@ protected DataBuffer read() throws IOException {
 
 				if (read > 0) {
 					byteBuffer.flip();
-					DataBuffer dataBuffer = this.bufferFactory.wrap(byteBuffer);
-					release = false;
-					return new UndertowDataBuffer(dataBuffer, pooledByteBuffer);
+					DataBuffer dataBuffer = this.bufferFactory.allocateBuffer(read);
+					dataBuffer.write(byteBuffer);
+					return dataBuffer;
 				}
 				else if (read == -1) {
 					onAllDataRead();
 				}
 				return null;
 			}
 			finally {
-				if (release && pooledByteBuffer.isOpen()) {
-					pooledByteBuffer.close();
-				}
+				pooledByteBuffer.close();
 			}
 		}
 
@@ -205,59 +198,4 @@ protected void discardData() {
 		}
 	}
 
-
-	private static class UndertowDataBuffer extends DataBufferWrapper implements PooledDataBuffer {
-
-		private final PooledByteBuffer pooledByteBuffer;
-
-		private final AtomicInteger refCount;
-
-
-		public UndertowDataBuffer(DataBuffer dataBuffer, PooledByteBuffer pooledByteBuffer) {
-			super(dataBuffer);
-			this.pooledByteBuffer = pooledByteBuffer;
-			this.refCount = new AtomicInteger(1);
-		}
-
-		private UndertowDataBuffer(DataBuffer dataBuffer, PooledByteBuffer pooledByteBuffer,
-				AtomicInteger refCount) {
-			super(dataBuffer);
-			this.refCount = refCount;
-			this.pooledByteBuffer = pooledByteBuffer;
-		}
-
-		@Override
-		public boolean isAllocated() {
-			return this.refCount.get() > 0;
-		}
-
-		@Override
-		public PooledDataBuffer retain() {
-			this.refCount.incrementAndGet();
-			DataBufferUtils.retain(dataBuffer());
-			return this;
-		}
-
-		@Override
-		public boolean release() {
-			int refCount = this.refCount.decrementAndGet();
-			if (refCount == 0) {
-				try {
-					return DataBufferUtils.release(dataBuffer());
-				}
-				finally {
-					this.pooledByteBuffer.close();
-				}
-			}
-			return false;
-		}
-
-		@Override
-		public DataBuffer slice(int index, int length) {
-			DataBuffer slice = dataBuffer().slice(index, length);
-			return new UndertowDataBuffer(slice, this.pooledByteBuffer, this.refCount);
-		}
-
-	}
-
 }