From https://issues.apache.org/jira/browse/QPID-879 contributed by Jonathan Robie.

XML exchange allowing messages to be routed base on XQuery expressions.


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@653854 13f79535-47bb-0310-9956-ffa450edef68

7 files changed, 366 insertions, 1 deletions

diff --git a/cpp/src/qpid/broker/Deliverable.h b/cpp/src/qpid/broker/Deliverable.h
index e46d2024bf..c40780c4ae 100644
--- a/cpp/src/qpid/broker/Deliverable.h
+++ b/cpp/src/qpid/broker/Deliverable.h
@@ -22,6 +22,7 @@
 #define _Deliverable_
 
 #include "Queue.h"
+#include "Message.h"
 
 namespace qpid {
     namespace broker {
@@ -29,6 +30,9 @@ namespace qpid {
         public:
             bool delivered;
             Deliverable() : delivered(false) {}
+
+	    virtual Message& getMessage() = 0;
+	    
             virtual void deliverTo(Queue::shared_ptr& queue) = 0;
             virtual uint64_t contentSize() { return 0; }
             virtual ~Deliverable(){}
diff --git a/cpp/src/qpid/broker/ExchangeRegistry.cpp b/cpp/src/qpid/broker/ExchangeRegistry.cpp
index 58d9d5efb8..c1eb5ff5a3 100644
--- a/cpp/src/qpid/broker/ExchangeRegistry.cpp
+++ b/cpp/src/qpid/broker/ExchangeRegistry.cpp
@@ -18,11 +18,16 @@
  * under the License.
  *
  */
+
+#include "config.h"
 #include "ExchangeRegistry.h"
 #include "DirectExchange.h"
 #include "FanOutExchange.h"
 #include "HeadersExchange.h"
 #include "TopicExchange.h"
+#ifdef HAVE_XML
+#include "XmlExchange.h"
+#endif
 #include "qpid/management/ManagementExchange.h"
 #include "qpid/framing/reply_exceptions.h"
 
@@ -55,7 +60,13 @@ pair<Exchange::shared_ptr, bool> ExchangeRegistry::declare(const string& name, c
             exchange = Exchange::shared_ptr(new HeadersExchange(name, durable, args, parent));
         }else if (type == ManagementExchange::typeName) {
             exchange = Exchange::shared_ptr(new ManagementExchange(name, durable, args, parent));
-        }else{
+        }
+#ifdef HAVE_XML
+	else if (type == XmlExchange::typeName) {
+            exchange = Exchange::shared_ptr(new XmlExchange(name, durable, args, parent));
+        }
+#endif
+	else{
             throw UnknownExchangeTypeException();    
         }
         exchanges[name] = exchange;
diff --git a/cpp/src/qpid/broker/TxPublish.h b/cpp/src/qpid/broker/TxPublish.h
index 680e0c7546..d2590debfb 100644
--- a/cpp/src/qpid/broker/TxPublish.h
+++ b/cpp/src/qpid/broker/TxPublish.h
@@ -69,6 +69,8 @@ namespace qpid {
             virtual bool prepare(TransactionContext* ctxt) throw();
             virtual void commit() throw();
             virtual void rollback() throw();
+
+	    virtual Message& getMessage() { return *msg; };
             
             virtual void deliverTo(Queue::shared_ptr& queue);
 
diff --git a/cpp/src/qpid/broker/XmlExchange.cpp b/cpp/src/qpid/broker/XmlExchange.cpp
new file mode 100644
index 0000000000..8577e9211c
--- /dev/null
+++ b/cpp/src/qpid/broker/XmlExchange.cpp
@@ -0,0 +1,249 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+#include "config.h"
+#include "XmlExchange.h"
+
+#include "DeliverableMessage.h"
+
+#include "qpid/log/Statement.h"
+#include "qpid/framing/FieldTable.h"
+#include "qpid/framing/FieldValue.h"
+#include "qpid/framing/reply_exceptions.h"
+
+#include <xercesc/framework/MemBufInputSource.hpp>
+
+#include <xqilla/context/ItemFactory.hpp>
+#include <xqilla/xqilla-simple.hpp>
+
+#include <iostream>
+#include <sstream>
+
+using namespace qpid::framing;
+using namespace qpid::sys;
+using qpid::management::Manageable;
+
+namespace qpid {
+namespace broker {
+
+XmlExchange::XmlExchange(const string& _name, Manageable* _parent) : Exchange(_name, _parent)
+{
+    if (mgmtExchange.get() != 0)
+        mgmtExchange->set_type (typeName);
+}
+
+XmlExchange::XmlExchange(const std::string& _name, bool _durable,
+                         const FieldTable& _args, Manageable* _parent) :
+    Exchange(_name, _durable, _args, _parent)
+{
+    if (mgmtExchange.get() != 0)
+        mgmtExchange->set_type (typeName);
+}
+
+/*
+ *  Use the name of the query as the binding key.
+ *
+ *  The first time a given name is used in a binding, the query body
+ *  must be provided.After that, no query body should be present.
+ *  
+ *  To modify an installed query, the user must first unbind the
+ *  existing query, then replace it by binding again with the same
+ *  name.
+ *
+ */
+
+      // #### TODO: The Binding should take the query text
+      // #### only. Consider encapsulating the entire block, including
+      // #### the if condition.
+      
+
+bool XmlExchange::bind(Queue::shared_ptr queue, const string& routingKey, const FieldTable* bindingArguments)
+{
+    RWlock::ScopedWlock l(lock);
+    XmlBinding::vector& bindings(bindingsMap[routingKey]);
+    XmlBinding::vector::iterator i;
+
+    string queryText = bindingArguments->getString("xquery");
+
+    for (i = bindings.begin(); i != bindings.end(); i++)
+        if ((*i)->queue == queue)
+            break;
+
+    if (i == bindings.end()) {
+
+        try {
+            Query query(xqilla.parse(X(queryText.c_str())));
+            XmlBinding::shared_ptr binding(new XmlBinding (routingKey, queue, this, query));
+            XmlBinding::vector bindings(1, binding);
+            bindingsMap[routingKey] = bindings; 
+        }
+        catch (XQException& e) {
+            throw InternalErrorException(QPID_MSG("Could not parse xquery:"+ queryText));
+        }
+
+        if (mgmtExchange.get() != 0) {
+            mgmtExchange->inc_bindings ();
+        }
+        return true;
+    } else{
+        return false;
+    }
+}
+
+bool XmlExchange::unbind(Queue::shared_ptr queue, const string& routingKey, const FieldTable* /*args*/)
+{
+    RWlock::ScopedWlock l(lock);
+    XmlBinding::vector& bindings(bindingsMap[routingKey]);
+    XmlBinding::vector::iterator i;
+
+    for (i = bindings.begin(); i != bindings.end(); i++)
+        if ((*i)->queue == queue)
+            break;
+
+    if (i < bindings.end()) {
+        bindings.erase(i);
+        if (bindings.empty()) {
+            bindingsMap.erase(routingKey);
+        }
+        if (mgmtExchange.get() != 0) {
+            mgmtExchange->dec_bindings ();
+        }
+        return true;
+    } else {
+        return false;
+    }
+}
+
+bool XmlExchange::matches(Query& query, Deliverable& msg, const qpid::framing::FieldTable* args) 
+{
+  // ### TODO: Need istream for frameset
+  // Hack alert - the following code does not work for really large messages
+
+  string msgContent;
+  msg.getMessage().getFrames().getContent(msgContent);
+
+  boost::scoped_ptr<DynamicContext> context(query->createDynamicContext());
+
+  try {
+    XERCES_CPP_NAMESPACE::MemBufInputSource xml((XMLByte*)msgContent.c_str(), msgContent.length(), "input" );
+    Sequence seq(context->parseDocument(xml));
+
+    FieldTable::ValueMap::const_iterator v = args->begin();
+    for(; v != args->end(); ++v) {
+      // ### TODO: Do types properly
+      if (v->second->convertsTo<std::string>()) {
+        QPID_LOG(trace, "XmlExchange, external variable: " << v->first << " = " << v->second->getData().getString().c_str());
+        Item::Ptr value = context->getItemFactory()->createString(X(v->second->getData().getString().c_str()), context.get());
+        context->setExternalVariable(X(v->first.c_str()), value);
+      }
+    }
+
+    if(!seq.isEmpty() && seq.first()->isNode()) {
+      context->setContextItem(seq.first());
+      context->setContextPosition(1);
+      context->setContextSize(1);
+    }
+    Result result = query->execute(context.get());
+    return result->getEffectiveBooleanValue(context.get(), 0);
+  }
+  catch (XQException& e) {
+    QPID_LOG(warning, "Could not parse XML content (or message headers):" << msgContent);
+  }
+  return 0;
+}
+
+void XmlExchange::route(Deliverable& msg, const string& routingKey, const FieldTable* args)
+{
+    RWlock::ScopedRlock l(lock);
+    XmlBinding::vector& bindings(bindingsMap[routingKey]);
+    XmlBinding::vector::iterator i;
+    int count(0);
+
+    for (i = bindings.begin(); i != bindings.end(); i++, count++) {
+
+      if (matches((*i)->xquery, msg, args)) {
+	msg.deliverTo((*i)->queue);
+
+	if ((*i)->mgmtBinding.get() != 0)
+	  (*i)->mgmtBinding->inc_msgMatched ();
+      }
+    }
+
+    if(!count){
+      QPID_LOG(warning, "XMLExchange " << getName() << " could not route message with query " << routingKey);
+      if (mgmtExchange.get() != 0) {
+	mgmtExchange->inc_msgDrops  ();
+	mgmtExchange->inc_byteDrops (msg.contentSize ());
+      }
+    }
+    else {
+      if (mgmtExchange.get() != 0) {
+	mgmtExchange->inc_msgRoutes  (count);
+	mgmtExchange->inc_byteRoutes (count * msg.contentSize ());
+      }
+    }
+
+    if (mgmtExchange.get() != 0) {
+      mgmtExchange->inc_msgReceives  ();
+      mgmtExchange->inc_byteReceives (msg.contentSize ());
+    }
+
+}
+
+
+bool XmlExchange::isBound(Queue::shared_ptr queue, const string* const routingKey, const FieldTable* const) 
+{
+    XmlBinding::vector::iterator j;
+
+    if (routingKey) {
+      XmlBindingsMap::iterator i = bindingsMap.find(*routingKey);
+
+      if (i == bindingsMap.end())
+	return false;
+      if (!queue)
+	return true;
+      for (j = i->second.begin(); j != i->second.end(); j++)
+	if ((*j)->queue == queue)
+	  return true;
+    } else if (!queue) {
+      //if no queue or routing key is specified, just report whether any bindings exist
+      return bindingsMap.size() > 0;
+    } else {
+      for (XmlBindingsMap::iterator i = bindingsMap.begin(); i != bindingsMap.end(); i++)
+	for (j = i->second.begin(); j != i->second.end(); j++)
+	  if ((*j)->queue == queue)
+	    return true;
+      return false;
+    }
+
+    return false;
+}
+
+
+XmlExchange::~XmlExchange() 
+{
+    bindingsMap.clear();
+}
+
+const std::string XmlExchange::typeName("xml");
+ 
+}
+}
diff --git a/cpp/src/qpid/broker/XmlExchange.h b/cpp/src/qpid/broker/XmlExchange.h
new file mode 100644
index 0000000000..883bfceaca
--- /dev/null
+++ b/cpp/src/qpid/broker/XmlExchange.h
@@ -0,0 +1,87 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+#ifndef _XmlExchange_
+#define _XmlExchange_
+
+#include "Exchange.h"
+#include "qpid/framing/FieldTable.h"
+#include "qpid/sys/Monitor.h"
+#include "Queue.h"
+
+#include <xqilla/xqilla-simple.hpp>
+
+#include <boost/scoped_ptr.hpp>
+
+#include <map>
+#include <vector>
+
+namespace qpid {
+namespace broker {
+
+class XmlExchange : public virtual Exchange {
+
+    typedef boost::shared_ptr<XQQuery> Query;
+
+    struct XmlBinding : public Exchange::Binding {
+        typedef boost::shared_ptr<XmlBinding> shared_ptr;
+        typedef std::vector<XmlBinding::shared_ptr> vector;
+
+        boost::shared_ptr<XQQuery> xquery;
+
+        XmlBinding(const std::string& key, const Queue::shared_ptr queue, Exchange* parent, Query query):
+            Binding(key, queue, parent), xquery(query) {}
+    };
+
+        
+    typedef std::map<string, XmlBinding::vector > XmlBindingsMap;
+
+    XmlBindingsMap bindingsMap;
+    XQilla xqilla;
+    qpid::sys::RWlock lock;
+
+    bool matches(Query& query, Deliverable& msg, const qpid::framing::FieldTable* args);
+
+  public:
+    static const std::string typeName;
+        
+    XmlExchange(const std::string& name, management::Manageable* parent = 0);
+    XmlExchange(const string& _name, bool _durable,
+		const qpid::framing::FieldTable& _args, management::Manageable* parent = 0);
+
+    virtual std::string getType() const { return typeName; }
+        
+    virtual bool bind(Queue::shared_ptr queue, const std::string& routingKey, const qpid::framing::FieldTable* args);
+
+    virtual bool unbind(Queue::shared_ptr queue, const std::string& routingKey, const qpid::framing::FieldTable* args);
+
+    virtual void route(Deliverable& msg, const std::string& routingKey, const qpid::framing::FieldTable* args);
+
+    virtual bool isBound(Queue::shared_ptr queue, const string* const routingKey, const qpid::framing::FieldTable* const args);
+
+    virtual ~XmlExchange();
+};
+
+
+}
+}
+
+
+#endif
diff --git a/cpp/src/qpid/client/Exchange.h b/cpp/src/qpid/client/Exchange.h
index 239c131658..f30881c94b 100644
--- a/cpp/src/qpid/client/Exchange.h
+++ b/cpp/src/qpid/client/Exchange.h
@@ -69,6 +69,13 @@ namespace client {
          * match zero or more words.
          */
 	static const std::string TOPIC_EXCHANGE;
+
+	/**
+	 *
+	 */
+
+	static const std::string XML_EXCHANGE;
+
         /**
          * The headers exchange routes messages based on whether their
          * headers match the binding arguments specified when
diff --git a/cpp/src/qpid/framing/FieldTable.h b/cpp/src/qpid/framing/FieldTable.h
index 707496a861..3c65d31aee 100644
--- a/cpp/src/qpid/framing/FieldTable.h
+++ b/cpp/src/qpid/framing/FieldTable.h
@@ -48,6 +48,7 @@ class FieldTable
   public:
     typedef boost::shared_ptr<FieldValue> ValuePtr;
     typedef std::map<std::string, ValuePtr> ValueMap;
+    typedef ValueMap::iterator iterator;
 
     ~FieldTable();
     uint32_t size() const;
@@ -79,6 +80,10 @@ class FieldTable
     ValueMap::const_iterator begin() const { return values.begin(); }
     ValueMap::const_iterator end() const { return values.end(); }
     ValueMap::const_iterator find(const std::string& s) const { return values.find(s); }
+
+    // ### Hack Alert
+
+    ValueMap::iterator getValues() { return values.begin(); }
     
   private:
     ValueMap values;