Bug 624 - Separate netty and exi specific classes from netconf-util.

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

diff --git a/opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfEXIToMessageDecoder.java b/opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfEXIToMessageDecoder.java
new file mode 100644 (file)
index 0000000..57134af
--- /dev/null
+++ b/opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/NetconfEXIToMessageDecoder.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.netconf.nettyutil.handler;
+
+import java.io.InputStream;
+import java.util.List;
+
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMResult;
+import javax.xml.transform.sax.SAXTransformerFactory;
+import javax.xml.transform.sax.TransformerHandler;
+
+import org.opendaylight.controller.netconf.api.NetconfMessage;
+import org.openexi.sax.EXIReader;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.w3c.dom.Document;
+import org.xml.sax.InputSource;
+
+import com.google.common.base.Preconditions;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufInputStream;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.ByteToMessageDecoder;
+
+public final class NetconfEXIToMessageDecoder extends ByteToMessageDecoder {
+
+    private static final Logger LOG = LoggerFactory.getLogger(NetconfEXIToMessageDecoder.class);
+
+    private final NetconfEXICodec codec;
+
+    public NetconfEXIToMessageDecoder(final NetconfEXICodec codec) {
+        this.codec = Preconditions.checkNotNull(codec);
+    }
+
+    @Override
+    protected void decode(final ChannelHandlerContext ctx, final ByteBuf in, final List<Object> out) throws Exception {
+        /*
+         * Note that we could loop here and process all the messages, but we can't do that.
+         * The reason is <stop-exi> operation, which has the contract of immediately stopping
+         * the use of EXI, which means the next message needs to be decoded not by us, but rather
+         * by the XML decoder.
+         */
+
+        // If empty Byte buffer is passed to r.parse, EOFException is thrown
+        if (in.isReadable() == false) {
+            LOG.debug("No more content in incoming buffer.");
+            return;
+        }
+
+        LOG.trace("Received to decode: {}", ByteBufUtil.hexDump(in));
+
+        final EXIReader r = codec.getReader();
+
+        final SAXTransformerFactory transformerFactory
+                = (SAXTransformerFactory) TransformerFactory.newInstance();
+        final TransformerHandler handler = transformerFactory.newTransformerHandler();
+        r.setContentHandler(handler);
+
+        final DOMResult domResult = new DOMResult();
+        handler.setResult(domResult);
+
+        try (final InputStream is = new ByteBufInputStream(in)) {
+            r.parse(new InputSource(is));
+        }
+
+        out.add(new NetconfMessage((Document) domResult.getNode()));
+    }
+}