BUG-2459: reuse EXI Transmogrifier

[controller.git] / opendaylight / netconf / netconf-netty-util / src / main / java / org / opendaylight / controller / netconf / nettyutil / handler / NetconfMessageToEXIEncoder.java

diff --git a/opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfMessageToEXIEncoder.java b/opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfMessageToEXIEncoder.java
index 0a866fffaa082c346cb726b1d815b170e9b77a0e..aceb6ac520f5568120c8538fb320f72f2c8418e4 100644 (file)
--- a/opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfMessageToEXIEncoder.java
+++ b/opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfMessageToEXIEncoder.java
@@ -12,38 +12,51 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufOutputStream;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
+import java.io.IOException;
 import java.io.OutputStream;
 import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.sax.SAXResult;
-import javax.xml.transform.sax.SAXTransformerFactory;
 import org.opendaylight.controller.netconf.api.NetconfMessage;
-import org.opendaylight.controller.netconf.util.xml.XmlUtil;
+import org.openexi.proc.common.EXIOptionsException;
 import org.openexi.sax.Transmogrifier;
+import org.openexi.sax.TransmogrifierException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.xml.sax.ContentHandler;
 
 public final class NetconfMessageToEXIEncoder extends MessageToByteEncoder<NetconfMessage> {
-
     private static final Logger LOG = LoggerFactory.getLogger(NetconfMessageToEXIEncoder.class);
+    /**
+     * This class is not marked as shared, so it can be attached to only a single channel,
+     * which means that {@link #encode(ChannelHandlerContext, NetconfMessage, ByteBuf)}
+     * cannot be invoked concurrently. Hence we can reuse the transmogrifier.
+     */
+    private final Transmogrifier transmogrifier;
+
+    private NetconfMessageToEXIEncoder(final Transmogrifier transmogrifier) {
+        this.transmogrifier = Preconditions.checkNotNull(transmogrifier);
+    }
 
-    private static final SAXTransformerFactory saxTransformerFactory = (SAXTransformerFactory)SAXTransformerFactory.newInstance();
-    private final NetconfEXICodec codec;
-
-    public NetconfMessageToEXIEncoder(final NetconfEXICodec codec) {
-        this.codec = Preconditions.checkNotNull(codec);
+    public static NetconfMessageToEXIEncoder create(final NetconfEXICodec codec) throws EXIOptionsException, TransmogrifierException {
+        return new NetconfMessageToEXIEncoder(codec.getTransmogrifier());
     }
 
     @Override
-    protected void encode(final ChannelHandlerContext ctx, final NetconfMessage msg, final ByteBuf out) throws Exception {
-        LOG.trace("Sent to encode : {}", XmlUtil.toString(msg.getDocument()));
+    protected void encode(final ChannelHandlerContext ctx, final NetconfMessage msg, final ByteBuf out) throws EXIOptionsException, IOException, TransformerException, TransmogrifierException {
+        LOG.trace("Sent to encode : {}", msg);
 
         try (final OutputStream os = new ByteBufOutputStream(out)) {
-            final Transmogrifier transmogrifier = codec.getTransmogrifier();
             transmogrifier.setOutputStream(os);
-
-            final Transformer transformer = saxTransformerFactory.newTransformer();
-            transformer.transform(new DOMSource(msg.getDocument()), new SAXResult(transmogrifier.getSAXTransmogrifier()));
+            final ContentHandler handler = transmogrifier.getSAXTransmogrifier();
+            final Transformer transformer = ThreadLocalTransformers.getDefaultTransformer();
+            transformer.transform(new DOMSource(msg.getDocument()), new SAXResult(handler));
+        } finally {
+            // Make sure we do not retain any reference to state by removing
+            // the output stream reference and resetting internal state.
+            transmogrifier.setOutputStream(null);
+            transmogrifier.getSAXTransmogrifier();
         }
     }
 }