5 files changed, 173 insertions, 8 deletions
diff --git a/cpp/src/Makefile.am b/cpp/src/Makefile.am
index 47e714955c..8c904f6aff 100644
--- a/cpp/src/Makefile.am
+++ b/cpp/src/Makefile.am
@@ -150,6 +150,8 @@ libqpidcommon_la_SOURCES = \
   qpid/framing/Correlator.cpp \
   qpid/framing/Value.cpp \
   qpid/framing/Proxy.cpp \
+  qpid/framing/Handler.h \
+  qpid/framing/FrameHandler.h \
   gen/qpid/framing/AMQP_ClientProxy.cpp \
   gen/qpid/framing/AMQP_HighestVersion.h \
   gen/qpid/framing/AMQP_MethodVersionMap.cpp \
diff --git a/cpp/src/qpid/framing/FrameHandler.h b/cpp/src/qpid/framing/FrameHandler.h
index 817c569119..c552fbb9df 100644
--- a/cpp/src/qpid/framing/FrameHandler.h
+++ b/cpp/src/qpid/framing/FrameHandler.h
@@ -21,18 +21,12 @@
  *
  */
 
-#include <boost/noncopyable.hpp>
+#include "Handler.h"
 
 namespace qpid {
 namespace framing {
 class AMQFrame;
-
-class FrameHandler : private boost::noncopyable {
-  public:
-    virtual ~FrameHandler() {}
-    virtual void handle(AMQFrame& frame) = 0;
-};
-
+typedef Handler<AMQFrame&> FrameHandler;
 }}
 
 
diff --git a/cpp/src/qpid/framing/Handler.h b/cpp/src/qpid/framing/Handler.h
new file mode 100644
index 0000000000..05a02a30b1
--- /dev/null
+++ b/cpp/src/qpid/framing/Handler.h
@@ -0,0 +1,98 @@
+#ifndef QPID_FRAMING_HANDLER_H
+#define QPID_FRAMING_HANDLER_H
+
+/*
+ *
+ * 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 "qpid/shared_ptr.h"
+#include <vector>
+#include <assert.h>
+
+namespace qpid {
+namespace framing {
+
+/** Handler for objects of type T. */
+template <class T> struct Handler {
+    typedef T Type;
+    typedef shared_ptr<Handler> Ptr;
+
+    virtual ~Handler() {}
+    virtual void handle(T) = 0;
+    virtual void link(Ptr next_) { next=next_; }
+  protected:
+    void nextHandler(T data) { if (next) next->handle(data); }
+  private:
+    Ptr next;
+};
+
+
+/** Factory interface that takes a context of type C */
+template <class T, class C> struct HandlerFactory {
+    virtual ~HandlerFactory() {}
+    typedef typename Handler<T>::Ptr Ptr;
+
+    /** Create a handler */
+    virtual Ptr create(C context) = 0;
+
+    /** Create a handler and link it to next */
+    Ptr create(C context, Ptr next) {
+        Ptr h=create(context);
+        h->link(next);
+    }
+};
+
+/** Factory implementation template */
+template <class FH, class C>
+struct HandlerFactoryImpl : public HandlerFactory<typename FH::Type, C> {
+    shared_ptr<Handler<typename FH::Type> > create(C context) {
+        return typename FH::Ptr(new FH(context));
+    }
+};
+
+/** A factory chain is a vector of handler factories used to create
+ * handler chains. The chain does not own the factories.
+ */
+template <class T, class C>
+struct HandlerFactoryChain : public std::vector<HandlerFactory<T,C>* > {
+    typedef typename Handler<T>::Ptr Ptr;
+    
+    /** Create a handler chain, return the first handler.
+     *@param context - passed to each factory.
+     */
+    Ptr create(C context) {
+        return this->create(context, this->begin());
+    }
+
+  private:
+    typedef typename std::vector<HandlerFactory<T,C>*>::iterator iterator;
+    Ptr create(C context, iterator i) {
+        if (i != this->end()) {
+            Ptr h=(*i)->create(context);
+            h->link(create(context, i+1));
+            return h;
+        }
+        return Ptr();
+    }
+};
+
+}}
+
+
+#endif  /*!QPID_FRAMING_HANDLER_H*/
diff --git a/cpp/src/tests/Handler.cpp b/cpp/src/tests/Handler.cpp
new file mode 100644
index 0000000000..6725394be8
--- /dev/null
+++ b/cpp/src/tests/Handler.cpp
@@ -0,0 +1,67 @@
+/*
+ *
+ * Copyright (c) 2006 The Apache Software Foundation
+ *
+ * Licensed 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.
+ *
+ */
+
+#define BOOST_AUTO_TEST_MAIN    // Must come before #include<boost/test/*>
+#include <boost/test/auto_unit_test.hpp>
+
+#include "qpid/framing/AMQFrame.h"
+#include "qpid/framing/FrameHandler.h"
+#include "test_tools.h"
+#include <boost/assign.hpp>
+
+using namespace std;
+using namespace qpid;
+using namespace qpid::framing;
+using namespace boost::assign;
+
+typedef int DummyFrame;
+typedef int DummyContext;
+vector<int> handledBy;
+
+/** Both a link and a terminal handler. */
+template <int N>
+struct TestHandler : public Handler<DummyFrame> {
+    TestHandler(DummyContext c) : context(c) {}
+    
+    void handle(DummyFrame frame) {
+        handledBy.push_back(N+context);
+        nextHandler(frame);
+    }
+
+    typedef HandlerFactoryImpl<TestHandler<N>, DummyContext> Factory;
+    DummyContext context;
+};
+
+
+
+BOOST_AUTO_TEST_CASE(handlerChains) {
+    TestHandler<1>::Factory a;
+    TestHandler<2>::Factory b;
+    TestHandler<3>::Factory c;
+    HandlerFactoryChain<DummyFrame, DummyContext> factory;
+    factory.push_back(&a);
+    factory.push_back(&b);
+    factory.push_back(&c);
+    factory.create(10)->handle(1);
+
+    vector<int> expect;
+    expect = list_of(11)(12)(13);
+    BOOST_CHECK_EQUAL(expect, handledBy);
+}
+
+
diff --git a/cpp/src/tests/Makefile.am b/cpp/src/tests/Makefile.am
index ab772ea744..60290ee2da 100644
--- a/cpp/src/tests/Makefile.am
+++ b/cpp/src/tests/Makefile.am
@@ -25,6 +25,10 @@ unit_progs+=Url
 Url_SOURCES=Url.cpp test_tools.h
 Url_LDADD=-lboost_unit_test_framework $(lib_common) 
 
+unit_progs+=Handler
+Handler_SOURCES=Handler.cpp test_tools.h
+Handler_LDADD=-lboost_unit_test_framework $(lib_common) 
+
 include cluster.mk
 
 # NB: CppUnit test libraries below will be migrated to boost test programs.