* Summary: new Frame type to replace AMQFrame. Instead of holding

	  a shared_ptr to a heap-allocated AMQBody subclass, it holds the
	  body in-line in a boost::variant of all the concrete AMQBody
	  subclasses. Actually there are nested variants, the compiler
	  does not cope well with a single variant of 130-some types.

	  Creating, encoding and decoding a local Frame doess 0 heap
	  allocation apart from that done by the concrete
	  AMQBody::encode/decode - e.g. method bodies with std::string
	  fields.  for method bodies

	  All variants contain type boost::blank. This guarantees 0 heap
	  alloocation by the variant and represents the "uninitialized"
	  state. variant.h provides NoBlankVisitor to help write visitors
	  for variants containing blank. 
	
	* src/qpid/framing/MethodHolder.h, .cpp: Holds a variant
	  containing a method body. 

	* src/qpid/framing/Frame.h, .cpp: New Frame holds body in a
	  variant rather than via heap allocation.

	* src/qpid/framing/variant.h: Utilities for using boost::variant.

	* src/qpid/framing/amqp_types.h: Added FrameType typedef.

	* src/qpid/framing/AMQMethodBody.h: Friends with MethodHolder.

	* src/Makefile.am:
	 - Improved ruby generation rule.
	 - Run method_variants template.
	 - Added new source files
	 - Pre-compiled header rule for method_variants.h

	* rubygen/templates/method_variants.rb: Generate variants
	  to hold methods of each class, and MethodVariant to hold all
	  the class variants.

	* rubygen/cppgen.rb: variant, tuple methods.

	* MethodBodyClass.h.tmpl: Added default constructor to method bodies.

	* amqpgen.rb (AmqpRoot::merge): fix bug in merge.


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@563683 13f79535-47bb-0310-9956-ffa450edef68

14 files changed, 653 insertions, 13 deletions

diff --git a/cpp/gentools/templ.cpp/MethodBodyClass.h.tmpl b/cpp/gentools/templ.cpp/MethodBodyClass.h.tmpl
index aeabd8a256..605b09ac94 100644
--- a/cpp/gentools/templ.cpp/MethodBodyClass.h.tmpl
+++ b/cpp/gentools/templ.cpp/MethodBodyClass.h.tmpl
@@ -63,7 +63,7 @@ public:
 
 ${mb_constructor_with_initializers}
 
-    ${CLASS}${METHOD}Body(ProtocolVersion version): ${mb_base_class}(version) {}
+    ${CLASS}${METHOD}Body(ProtocolVersion version=ProtocolVersion()	): ${mb_base_class}(version) {}
     virtual ~${CLASS}${METHOD}Body() {}
     
     // Attribute get methods
diff --git a/cpp/rubygen/amqpgen.rb b/cpp/rubygen/amqpgen.rb
index 0da1bfe824..31f7544011 100755
--- a/cpp/rubygen/amqpgen.rb
+++ b/cpp/rubygen/amqpgen.rb
@@ -155,7 +155,7 @@ class AmqpRoot < AmqpElement
     from.elements.each { |from_child|
       tag,name = from_child.name, from_child.attributes["name"]
       to_child=to.elements["./#{tag}[@name='#{name}']"]
-      to_child ? merge(to_child, from_child) : to.add(from_child.clone) }
+      to_child ? merge(to_child, from_child) : to.add(from_child.deep_clone) }
   end
 
   private :merge
diff --git a/cpp/rubygen/cppgen.rb b/cpp/rubygen/cppgen.rb
index d369d23da1..371cc7cd05 100755
--- a/cpp/rubygen/cppgen.rb
+++ b/cpp/rubygen/cppgen.rb
@@ -128,6 +128,7 @@ class CppGen < Generator
 
   # Write a .cpp file.
   def cpp_file(path)
+    path = (/\.cpp$/ === path ? path : path+".cpp")
     file(path) do
       gen Copyright
       yield
@@ -157,14 +158,18 @@ class CppGen < Generator
     genl
     gen "#{type} #{name}"
     gen ": #{bases.join(', ')}" unless bases.empty?
-    genl "{"
-    yield
-    genl "};"
-    genl
+    scope(" {","};", &block)
   end
 
   def struct(name, *bases, &block) struct_class("struct", name, bases, &block); end
   def class_(name, *bases, &block) struct_class("class", name, bases, &block); end
-  def typedef(type, name) genl "typedef #{type} #{name};" end
+
+  def typedef(type, name) genl "typedef #{type} #{name};\n" end
+
+  def variant(types) "boost::variant<#{types.join(", ")}>"; end
+  def variantl(types) "boost::variant<#{types.join(", \n")}>"; end
+  def blank_variant(types) variant(["boost::blank"]+types); end
+  def tuple(types) "boost::tuple<#{types.join(', ')}>"; end
+  
 end
 
diff --git a/cpp/rubygen/templates/method_variants.rb b/cpp/rubygen/templates/method_variants.rb
new file mode 100755
index 0000000000..0787657089
--- /dev/null
+++ b/cpp/rubygen/templates/method_variants.rb
@@ -0,0 +1,72 @@
+#!/usr/bin/env ruby
+$: << ".."                      # Include .. in load path
+require 'cppgen'
+
+# Generate the full AMQP class/method model as C++ types.
+class AmqpCppModelGen < CppGen
+  
+  def initialize(outdir, amqp)
+    super(outdir, amqp)
+  end
+
+  def gen_set_variant(varname, idtype, pairs, errmsg)
+    pairs.sort!
+    scope("inline void setVariant(#{varname}& var, #{idtype} id) {") {
+      scope("switch (id) {") {
+        pairs.each { |i,t| 
+          genl "case #{i}: var=#{t}(); break;";
+        }
+        genl "default: THROW_QPID_ERROR(FRAMING_ERROR, (boost::format(\"#{errmsg}\")%id).str());"
+      }
+    }
+    genl
+  end
+
+  def gen_class(c)
+    varname="#{c.name.caps}Variant"
+    mtypes=c.methods.map { |m| m.body_name }
+    typedef(blank_variant(mtypes), varname)
+    genl
+    pairs=c.methods.map { |m| [m.index.to_i,m.body_name] }
+    gen_set_variant(varname, "MethodId", pairs,
+                    "%d is not a valid method index in class #{c.name}")
+    mtypes.each { |t|
+      genl "template<> struct ClassVariant<#{t}> { typedef #{varname} value; };"
+    }
+    genl
+  end
+
+  def gen_all()
+    varname="MethodVariant"
+    types=@amqp.classes.map { |c| "#{c.name.caps}Variant" }
+    pairs=@amqp.classes.map { |c| [c.index.to_i,"#{c.name.caps}Variant"] }
+    typedef(blank_variant(types), varname) 
+    genl
+    gen_set_variant(varname, "ClassId", pairs,
+                    "%d is not a valid class index.")
+  end
+
+  def generate()
+    h_file("qpid/framing/method_variants.h") {
+      @amqp.methods.each { |m| include "qpid/framing/#{m.body_name}.h"}
+      include "qpid/framing/amqp_types.h"
+      include "qpid/QpidError.h"
+      include "qpid/framing/variant.h"
+      include "<boost/format.hpp>"
+      genl
+      namespace("qpid::framing") {
+        genl "// Metafunction returns class variant containing method T."
+        genl "template <class T> struct ClassVariant {};"
+        genl
+        @amqp.classes.each { |c| gen_class c }
+      }
+      namespace("qpid::framing") {
+        gen_all
+        genl
+      }
+    }
+  end
+end
+
+AmqpCppModelGen.new(Outdir, Amqp).generate();
+
diff --git a/cpp/src/Makefile.am b/cpp/src/Makefile.am
index ad720754c1..c74c27d42a 100644
--- a/cpp/src/Makefile.am
+++ b/cpp/src/Makefile.am
@@ -43,13 +43,15 @@ maintainer-clean-local:
 
 rgen_dir=$(top_srcdir)/rubygen
 rgen_tdir=$(rgen_dir)/templates
-rgen_script=$(rgen_dir)/generate
-rgen_cmd=ruby -I $(rgen_dir) $(rgen_script)
+rgen_generator=$(rgen_dir)/generate $(rgen_dir)/amqpgen.rb $(rgen_dir)/cppgen.rb
 
-rgen_templates=$(rgen_tdir)/frame_body_lists.rb $(rgen_tdir)/Session.rb
+rgen_cmd=ruby -I $(rgen_dir) $(rgen_dir)/generate
+rgen_templates=$(rgen_tdir)/method_variants.rb $(rgen_tdir)/frame_body_lists.rb  $(rgen_tdir)/Session.rb
 
-rubygen.mk: $(rgen_script) $(specs) $(rgen_templates)
-	gen=`$(rgen_cmd) . $(specs) $(rgen_templates)` ; echo Generated $$gen; echo rgen_srcs=$$gen > $@
+rubygen.mk: $(rgen_generator) $(specs) $(rgen_templates)
+	{ echo "rgen_srcs= \\"; \
+	for f in `$(rgen_cmd) . $(specs) $(rgen_templates) `; do echo "	$$f \\"; done; \
+	echo; } > $@
 
 $(rgen_srcs): rubygen.mk
 
@@ -172,7 +174,11 @@ libqpidcommon_la_SOURCES = \
   qpid/log/Selector.h \
   qpid/log/Statement.cpp \
   qpid/log/Statement.h \
-  qpid/memory.h
+  qpid/memory.h \
+  qpid/framing/Frame.cpp qpid/framing/Frame.h \
+  qpid/framing/method_variants.h \
+  qpid/framing/MethodHolder.cpp qpid/framing/MethodHolder.h
+
 
 libqpidbroker_la_LIBADD = libqpidcommon.la -lboost_iostreams
 libqpidbroker_la_SOURCES = \
@@ -410,3 +416,16 @@ nobase_include_HEADERS = \
 
 # Force build of qpidd during dist phase so help2man will work.
 dist-hook: qpidd
+
+# FIXME aconway 2007-08-06: Use of gch should be conditional on gcc version.
+
+# Pre compiled headers - use BUILT_SOURCES to get them built first.
+BUILT_SOURCES=qpid/framing/method_variants.h.gch
+sinclude qpid/framing/method_variants.h.gch.deps
+CLEANFILES=qpid/framing/method_variants.h.gch qpid/framing/method_variants.h.gch.deps
+
+SUFFIXES=.h.gch
+.h.h.gch:
+	rm -f $@
+	$(CXXCOMPILE) -MT $@ -MD -MP -MF $@.deps -fPIC -DPIC -x c++-header -c -o $@ $<
+
diff --git a/cpp/src/qpid/framing/AMQMethodBody.h b/cpp/src/qpid/framing/AMQMethodBody.h
index 2b46c6ea00..cbfd438b48 100644
--- a/cpp/src/qpid/framing/AMQMethodBody.h
+++ b/cpp/src/qpid/framing/AMQMethodBody.h
@@ -80,6 +80,7 @@ class AMQMethodBody : public AMQBody
 
     virtual void printPrefix(std::ostream&) const {}
 
+  friend class MethodHolder;
 };
 
 
diff --git a/cpp/src/qpid/framing/Frame.cpp b/cpp/src/qpid/framing/Frame.cpp
new file mode 100644
index 0000000000..7bdc0adf00
--- /dev/null
+++ b/cpp/src/qpid/framing/Frame.cpp
@@ -0,0 +1,119 @@
+/*
+ *
+ * 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 <boost/format.hpp>
+
+#include "Frame.h"
+#include "qpid/QpidError.h"
+#include "AMQRequestBody.h"
+#include "AMQResponseBody.h"
+
+
+namespace qpid {
+namespace framing {
+
+namespace {
+struct GetBodyVisitor : public NoBlankVisitor<AMQBody*> {
+    QPID_USING_NOBLANK(AMQBody*);
+    AMQBody* operator()(MethodHolder& h) const { return h.getMethod(); }
+    template <class T> AMQBody* operator()(T& t) const { return &t; }
+};
+}
+
+AMQBody* Frame::getBody() {
+    return boost::apply_visitor(GetBodyVisitor(), body);
+}
+
+const AMQBody* Frame::getBody() const {
+    return boost::apply_visitor(GetBodyVisitor(), const_cast<Variant&>(body));
+}
+
+void Frame::encode(Buffer& buffer)
+{
+    buffer.putOctet(getBody()->type());
+    buffer.putShort(channel);    
+    buffer.putLong(getBody()->size());
+    getBody()->encode(buffer);
+    buffer.putOctet(0xCE);
+}
+
+uint32_t Frame::size() const{
+    return 1/*type*/ + 2/*channel*/ + 4/*body size*/ + getBody()->size()
+        + 1/*0xCE*/;
+}
+
+bool Frame::decode(Buffer& buffer)
+{    
+    if(buffer.available() < 7)
+        return false;
+    buffer.record();
+    uint32_t frameSize = decodeHead(buffer);
+    if(buffer.available() < frameSize + 1){
+        buffer.restore();
+        return false;
+    }
+    decodeBody(buffer, frameSize);
+    uint8_t end = buffer.getOctet();
+    if(end != 0xCE) THROW_QPID_ERROR(FRAMING_ERROR, "Frame end not found");
+    return true;
+}
+
+uint32_t Frame::decodeHead(Buffer& buffer){    
+    type = buffer.getOctet();
+    channel = buffer.getShort();
+    return buffer.getLong();
+}
+
+void Frame::decodeBody(Buffer& buffer, uint32_t size)
+{    
+    switch(type)
+    {
+      case METHOD_BODY:
+      case REQUEST_BODY:
+      case RESPONSE_BODY: {
+        ClassId c=buffer.getShort();
+        MethodId m=buffer.getShort();
+        body = MethodHolder(c,m);
+        break;
+      }
+      case HEADER_BODY: 
+	body = AMQHeaderBody();
+	break;
+      case CONTENT_BODY: 
+	body = AMQContentBody();
+	break;
+      case HEARTBEAT_BODY: 
+	body = AMQHeartbeatBody();
+	break;
+      default:
+	THROW_QPID_ERROR(
+            FRAMING_ERROR,
+            boost::format("Unknown frame type %d") % type);
+    }
+    getBody()->decode(buffer, size);
+}
+
+std::ostream& operator<<(std::ostream& out, const Frame& f)
+{
+    return out << "Frame[channel=" << f.getChannel() << "; " << f.body << "]";
+}
+
+
+}} // namespace qpid::framing
diff --git a/cpp/src/qpid/framing/Frame.h b/cpp/src/qpid/framing/Frame.h
new file mode 100644
index 0000000000..4a504a6b41
--- /dev/null
+++ b/cpp/src/qpid/framing/Frame.h
@@ -0,0 +1,72 @@
+#ifndef _AMQFrame_
+#define _AMQFrame_
+
+/*
+ *
+ * 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 "AMQDataBlock.h"
+#include "AMQHeaderBody.h"
+#include "AMQContentBody.h"
+#include "AMQHeartbeatBody.h"
+#include "MethodHolder.h"
+
+namespace qpid {
+namespace framing {
+
+class Frame : public AMQDataBlock {
+  public:
+    typedef boost::variant<boost::blank,
+                           AMQHeaderBody,
+                           AMQContentBody,
+                           AMQHeartbeatBody,
+                           MethodHolder> Variant;
+
+    Frame(ChannelId channel_=0, const Variant& body_=Variant())
+        : body(body_), channel(channel_) {}
+
+    void encode(Buffer& buffer);
+    bool decode(Buffer& buffer); 
+    uint32_t size() const;
+
+    uint16_t getChannel() const { return channel; }
+
+    AMQBody* getBody();
+    const AMQBody* getBody() const;
+
+    template <class T> T* castBody() {
+        return boost::polymorphic_downcast<T*>(getBody());
+    }
+
+    Variant body;
+
+  private:
+    uint32_t decodeHead(Buffer& buffer); 
+    void decodeBody(Buffer& buffer, uint32_t size); 
+
+    uint8_t type;
+    uint16_t channel;
+};
+
+std::ostream& operator<<(std::ostream&, const Frame&);
+
+}} // namespace qpid::framing
+
+
+#endif
diff --git a/cpp/src/qpid/framing/MethodHolder.cpp b/cpp/src/qpid/framing/MethodHolder.cpp
new file mode 100644
index 0000000000..27046af43c
--- /dev/null
+++ b/cpp/src/qpid/framing/MethodHolder.cpp
@@ -0,0 +1,93 @@
+/*
+ *
+ * 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 "MethodHolder.h"
+#include "amqp_types.h"
+#include "qpid/framing/Buffer.h"
+#include "qpid/framing/variant.h"
+
+using namespace boost;
+
+namespace qpid {
+namespace framing {
+
+struct SetVariantVisitor : public NoBlankVisitor<> {
+    QPID_USING_NOBLANK();
+    MethodId id;
+    SetVariantVisitor(MethodId m) : id(m) {}
+    template <class T> void operator()(T& t) const { setVariant(t, id); }
+};
+
+inline void setVariant(MethodVariant& var, ClassId c, MethodId m) {
+    setVariant(var,c);
+    boost::apply_visitor(SetVariantVisitor(m), var);
+}
+
+void MethodHolder::setMethod(ClassId c, MethodId m) {
+    setVariant(method, c, m);
+}
+
+MethodHolder::MethodHolder(ClassId c, MethodId m) {
+    setMethod(c,m);
+}
+
+struct GetClassId : public NoBlankVisitor<ClassId> {
+    QPID_USING_NOBLANK(ClassId);
+    template <class T> ClassId operator()(const T&) const {
+        return T::CLASS_ID;
+    }
+};
+
+struct GetMethodId : public NoBlankVisitor<MethodId> {
+    QPID_USING_NOBLANK(ClassId);
+    template <class T> MethodId operator()(const T&) const {
+        return T::METHOD_ID;
+    }
+};
+
+void MethodHolder::encode(Buffer& b) const {
+    const AMQMethodBody* body = getMethod();
+    b.putShort(body->amqpClassId());
+    b.putShort(body->amqpMethodId());
+    body->encodeContent(b);
+}
+
+void MethodHolder::decode(Buffer& b) {
+    ClassId classId = b.getShort();
+    ClassId methodId = b.getShort();
+    setVariant(method, classId, methodId);
+    getMethod()->decodeContent(b);
+}
+
+uint32_t  MethodHolder::size() const {
+    return sizeof(ClassId)+sizeof(MethodId)+getMethod()->size();
+}
+
+
+AMQMethodBody* MethodHolder::getMethod() {
+    return applyApplyVisitor(AddressVisitor<AMQMethodBody*>(), method);
+}
+
+const AMQMethodBody* MethodHolder::getMethod() const {
+    return const_cast<MethodHolder*>(this)->getMethod();
+}
+
+}} // namespace qpid::framing
diff --git a/cpp/src/qpid/framing/MethodHolder.h b/cpp/src/qpid/framing/MethodHolder.h
new file mode 100644
index 0000000000..b93c6b83b1
--- /dev/null
+++ b/cpp/src/qpid/framing/MethodHolder.h
@@ -0,0 +1,80 @@
+#ifndef QPID_FRAMING_METHODBODYHOLDER_H
+#define QPID_FRAMING_METHODBODYHOLDER_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/framing/method_variants.h"
+
+#include <boost/type_traits/has_nothrow_copy.hpp>
+
+namespace qpid {
+namespace framing {
+
+class AMQMethodBody;
+
+/**
+ * Holder for arbitrary method body.
+ */
+class MethodHolder
+{
+  public:
+    MethodHolder() {}
+    MethodHolder(const MethodVariant& mv) : method(mv) {}
+
+    /** Construct from a concrete method body type.
+     * ClassVariant<T>::value is the containing class variant.
+     */
+    template <class T>
+    MethodHolder(const T& t)
+        : method(typename ClassVariant<T>::value(t)) {}
+
+    /** Construct from class/method ID, set the method accordingly. */
+    MethodHolder(ClassId, MethodId);
+
+    /** Set the method to the type corresponding to ClassId, MethodId */
+    void setMethod(ClassId, MethodId);
+    
+    AMQMethodBody* getMethod();
+    const AMQMethodBody* getMethod() const;
+    
+    MethodVariant method;
+
+    void encode(Buffer&) const;
+    void decode(Buffer&);
+    uint32_t size() const;
+};
+
+inline std::ostream& operator<<(std::ostream& out, const MethodHolder& h) {
+    return out << h.method;
+}
+
+
+}} // namespace qpid::framing
+
+namespace boost {
+template<> struct has_nothrow_copy<qpid::framing::MethodHolder> 
+    : public boost::true_type {};
+}
+
+
+
+#endif  /*!QPID_FRAMING_METHODBODYHOLDER_H*/
diff --git a/cpp/src/qpid/framing/amqp_types.h b/cpp/src/qpid/framing/amqp_types.h
index ff75b28468..5ea08a69af 100644
--- a/cpp/src/qpid/framing/amqp_types.h
+++ b/cpp/src/qpid/framing/amqp_types.h
@@ -42,6 +42,7 @@ namespace qpid {
 namespace framing {
 
 using std::string;
+typedef uint8_t FrameType;
 typedef uint16_t ChannelId;
 typedef uint64_t RequestId;
 typedef uint64_t ResponseId;
diff --git a/cpp/src/qpid/framing/variant.h b/cpp/src/qpid/framing/variant.h
new file mode 100644
index 0000000000..3cb8aece5d
--- /dev/null
+++ b/cpp/src/qpid/framing/variant.h
@@ -0,0 +1,92 @@
+#ifndef QPID_FRAMING_VARIANT_H
+#define QPID_FRAMING_VARIANT_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.
+ *
+ */
+
+/**@file Tools for using boost::variant */
+
+#include "qpid/QpidError.h"
+
+#include <boost/variant.hpp>
+
+namespace qpid {
+namespace framing {
+class Buffer;
+
+/** boost::static_visitor that throws exception if variant contains blank.
+ * Sublclasses need to have a using() declaration, can be generated
+ * with QPID_USING_BLANK_THROW(R)
+ */
+template <class R=void>
+struct NoBlankVisitor : public boost::static_visitor<R> {
+    R foundBlank() const {
+        assert(0);
+        THROW_QPID_ERROR(INTERNAL_ERROR, "Invalid variant value.");
+    }
+    R operator()(const boost::blank&) const { return foundBlank(); }
+    R operator()(boost::blank&) const { return foundBlank(); }
+};
+
+
+}} // qpid::framing
+
+
+/** Generate using statement needed in visitors inheriting NoBlankVisitor
+ *  @param R return type.
+ */
+#define QPID_USING_NOBLANK(R) using ::qpid::framing::NoBlankVisitor<R>::operator()
+
+namespace qpid {
+namespace framing {
+
+/** Convert the variant value to type R. */
+template <class R> struct ConvertVisitor : public NoBlankVisitor<R> {
+    QPID_USING_NOBLANK(R);
+    template <class T> R operator()(T& t) const { return t; }
+};
+
+/** Convert address of variant value to type R. */
+template <class R> struct AddressVisitor : public NoBlankVisitor<R> {
+    QPID_USING_NOBLANK(R);
+    template <class T> R operator()(T& t) const { return &t; }
+};
+
+/** Apply a visitor to the nested variant in a variant of variants */
+template<class V>
+struct ApplyVisitor : public NoBlankVisitor<typename V::result_type> {
+    QPID_USING_NOBLANK(typename V::result_type);
+    const V& visitor;
+    ApplyVisitor(const V& v) : visitor(v) {}
+    template <class T> typename V::result_type operator()(T& t) const {
+        return boost::apply_visitor(visitor, t);
+    }
+};
+
+/** Convenience function to construct and apply an ApplyVisitor */
+template <class Visitor, class Visitable>
+typename Visitor::result_type applyApplyVisitor(const Visitor& visitor, Visitable& visitable) {
+    return boost::apply_visitor(ApplyVisitor<Visitor>(visitor), visitable);
+}
+
+}} // namespace qpid::framing
+
+    
+#endif  /*!QPID_FRAMING_VARIANT_H*/
diff --git a/cpp/src/tests/Frame.cpp b/cpp/src/tests/Frame.cpp
new file mode 100644
index 0000000000..f02564f5da
--- /dev/null
+++ b/cpp/src/tests/Frame.cpp
@@ -0,0 +1,77 @@
+/*
+ *
+ * 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/framing/Frame.h"
+
+#define BOOST_AUTO_TEST_MAIN    // Must come before #include<boost/test/*>
+#include <boost/test/auto_unit_test.hpp>
+#include <boost/lexical_cast.hpp>
+
+using namespace std;
+using namespace qpid::framing;
+using namespace boost;
+
+BOOST_AUTO_TEST_CASE(testContentBody) {
+    Frame f(42, AMQContentBody("foobar"));
+    AMQBody* body=f.getBody();
+    BOOST_CHECK(dynamic_cast<AMQContentBody*>(body));
+    Buffer b(f.size());
+    f.encode(b);
+    b.flip();
+    Frame g;
+    g.decode(b);
+    AMQContentBody* content=dynamic_cast<AMQContentBody*>(g.getBody());
+    BOOST_REQUIRE(content);
+    BOOST_CHECK_EQUAL(content->getData(), "foobar");
+}
+
+BOOST_AUTO_TEST_CASE(testMethodBody) {
+    FieldTable args;
+    args.setString("foo", "bar");
+    Frame f(
+        42, QueueDeclareBody(ProtocolVersion(), 1, "q", "altex",
+                             true, false, true, false, true, args));
+    BOOST_CHECK_EQUAL(f.getChannel(), 42);
+    Buffer b(f.size());
+    f.encode(b);
+    b.flip();
+    Frame g;
+    g.decode(b);
+    BOOST_CHECK_EQUAL(f.getChannel(), g.getChannel());
+    QueueDeclareBody* declare=dynamic_cast<QueueDeclareBody*>(g.getBody());
+    BOOST_REQUIRE(declare);
+    BOOST_CHECK_EQUAL(declare->getAlternateExchange(), "altex");
+    BOOST_CHECK_EQUAL(lexical_cast<string>(*f.getBody()), lexical_cast<string>(*g.getBody()));
+}
+
+BOOST_AUTO_TEST_CASE(testLoop) {
+    // Run in a loop so heap profiler can spot any allocations.
+    Buffer b(1024);
+    for (int i = 0; i < 100; ++i) {
+        Frame ctor(2, AccessRequestOkBody(ProtocolVersion(), 42));
+        Frame assign(3);
+        assign.body = AccessRequestOkBody(ProtocolVersion(), 42);
+        assign.encode(b);
+        b.flip();
+        Frame g;
+        g.decode(b);
+        BOOST_REQUIRE(dynamic_cast<AccessRequestOkBody*>(g.getBody())->getTicket() == 42);
+    }
+}
diff --git a/cpp/src/tests/Makefile.am b/cpp/src/tests/Makefile.am
index bc173d61d6..503083af21 100644
--- a/cpp/src/tests/Makefile.am
+++ b/cpp/src/tests/Makefile.am
@@ -43,6 +43,15 @@ check_PROGRAMS+=Shlib
 Shlib_SOURCES=Shlib.cpp
 Shlib_LDADD=-lboost_unit_test_framework $(lib_common)
 
+TESTS+=Frame
+check_PROGRAMS+=Frame
+Frame_SOURCES=Frame.cpp
+Frame_LDADD=-lboost_unit_test_framework $(lib_common)
+
+
+
+# TODO aconway 2007-08-07: Why aren't these tests run automatically?
+
 check_PROGRAMS+=ConcurrentQueue
 ConcurrentQueue_SOURCES=ConcurrentQueue.cpp
 ConcurrentQueue_LDADD=-lboost_test_exec_monitor $(lib_common)