From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 9 Oct 2016 13:53:23 +0000 (+0300)
Subject: Massive overhaul of the Protocol class
X-Git-Url: http://git.tdb.fi/?p=libs%2Fnet.git;a=commitdiff_plain;h=3c2a877580e234df5fcbe06bf2850cd29f875e28

Massive overhaul of the Protocol class

Makes the serialization machinery more flexible and reduces the number of
virtual function calls when de/serializing packets.
---

diff --git a/source/net/communicator.cpp b/source/net/communicator.cpp
index 618e8b4..b30a8e9 100644
--- a/source/net/communicator.cpp
+++ b/source/net/communicator.cpp
@@ -133,7 +133,7 @@ bool Communicator::receive_packet(const Protocol &proto, ReceiverBase &recv)
 	{
 		char *pkt = in_begin;
 		in_begin += psz;
-		proto.disassemble(recv, pkt, psz);
+		proto.dispatch(recv, pkt, psz);
 		return true;
 	}
 	else
@@ -155,7 +155,7 @@ void Communicator::send_handshake()
 	shake.hash = protocol.get_hash();
 
 	HandshakeProtocol hsproto;
-	unsigned size = hsproto.assemble(shake, out_buf, buf_size);
+	unsigned size = hsproto.serialize(shake, out_buf, buf_size);
 	socket.write(out_buf, size);
 }
 
diff --git a/source/net/communicator.h b/source/net/communicator.h
index cd465a5..5921767 100644
--- a/source/net/communicator.h
+++ b/source/net/communicator.h
@@ -47,7 +47,7 @@ public:
 			throw sequence_error("connection aborted");
 		if(handshake_status!=2)
 			throw sequence_error("handshaking not done");
-		unsigned size = protocol.assemble(pkt, out_buf, buf_size);
+		unsigned size = protocol.serialize(pkt, out_buf, buf_size);
 		try
 		{
 			socket.write(out_buf, size);
diff --git a/source/net/protocol.cpp b/source/net/protocol.cpp
index d56ac77..d862ed8 100644
--- a/source/net/protocol.cpp
+++ b/source/net/protocol.cpp
@@ -6,108 +6,17 @@
 
 using namespace std;
 
-namespace {
-
-using Msp::Net::buffer_error;
-
-template<typename T>
-class Assembler
-{
-public:
-	static char *assemble(const T &v, char *, char *);
-	static const char *disassemble(T &, const char *, const char *);
-};
-
-template<typename T>
-class Assembler<vector<T> >
-{
-public:
-	static char *assemble(const vector<T> &v, char *, char *);
-	static const char *disassemble(vector<T> &, const char *, const char *);
-};
-
-template<typename T>
-char *Assembler<T>::assemble(const T &v, char *data, char *end)
-{
-	// XXX Assumes little-endian
-	const char *ptr = reinterpret_cast<const char *>(&v)+sizeof(T);
-	for(unsigned i=0; i<sizeof(T); ++i)
-	{
-		if(data==end)
-			throw buffer_error("overflow");
-		*data++ = *--ptr;
-	}
-	return data;
-}
-
-template<>
-char *Assembler<string>::assemble(const string &v, char *data, char *end)
-{
-	data = Assembler<unsigned short>::assemble(v.size(), data, end);
-	if(end-data<static_cast<int>(v.size()))
-		throw buffer_error("overflow");
-	memcpy(data, v.data(), v.size());
-	return data+v.size();
-}
-
-template<typename T>
-char *Assembler<vector<T> >::assemble(const vector<T> &v, char *data, char *end)
-{
-	data = Assembler<unsigned short>::assemble(v.size(), data, end);
-	for(typename vector<T>::const_iterator i=v.begin(); i!=v.end(); ++i)
-		data = Assembler<T>::assemble(*i, data, end);
-	return data;
-}
-
-template<typename T>
-const char *Assembler<T>::disassemble(T &v, const char *data, const char *end)
-{
-	char *ptr = reinterpret_cast<char *>(&v)+sizeof(T);
-	for(unsigned i=0; i<sizeof(T); ++i)
-	{
-		if(data==end)
-			throw buffer_error("underflow");
-		*--ptr = *data++;
-	}
-	return data;
-}
-
-template<>
-const char *Assembler<string>::disassemble(string &v, const char *data, const char *end)
-{
-	unsigned short size;
-	data = Assembler<unsigned short>::disassemble(size, data, end);
-	if(end-data<size)
-		throw buffer_error("underflow");
-	v.assign(data, data+size);
-	return data+size;
-}
-
-template<typename T>
-const char *Assembler<vector<T> >::disassemble(vector<T> &v, const char *data, const char *end)
-{
-	/* We assume that the vector is in pristine state - this holds because the
-	only code path leading here is from PacketDef<P>::disassemble, which creates
-	a new packet. */
-	unsigned short size;
-	data = Assembler<unsigned short>::disassemble(size, data, end);
-	for(unsigned i=0; i<size; ++i)
-	{
-		T u;
-		data = Assembler<T>::disassemble(u, data, end);
-		v.push_back(u);
-	}
-	return data;
-}
-
-}
 
 namespace Msp {
 namespace Net {
 
 Protocol::Protocol(unsigned npi):
+	header_def(0),
 	next_packet_id(npi)
-{ }
+{
+	PacketDefBuilder<PacketHeader, NullSerializer<PacketHeader> >(*this, header_def, NullSerializer<PacketHeader>())
+		(&PacketHeader::type)(&PacketHeader::length);
+}
 
 Protocol::~Protocol()
 {
@@ -115,16 +24,16 @@ Protocol::~Protocol()
 		delete i->second;
 }
 
-void Protocol::add_packet(PacketDefBase &pdef)
+void Protocol::add_packet(PacketDefBase *pdef)
 {
-	PacketDefBase *&ptr = packet_class_defs[pdef.get_class_id()];
+	PacketDefBase *&ptr = packet_class_defs[pdef->get_class_id()];
 	if(ptr)
 		delete ptr;
-	ptr = &pdef;
-	packet_id_defs[pdef.get_id()] = &pdef;
+	ptr = pdef;
+	packet_id_defs[pdef->get_id()] = pdef;
 }
 
-const Protocol::PacketDefBase &Protocol::get_packet_by_class(unsigned id) const
+const Protocol::PacketDefBase &Protocol::get_packet_by_class_id(unsigned id) const
 {
 	return *get_item(packet_class_defs, id);
 }
@@ -134,24 +43,24 @@ const Protocol::PacketDefBase &Protocol::get_packet_by_id(unsigned id) const
 	return *get_item(packet_id_defs, id);
 }
 
-unsigned Protocol::disassemble(ReceiverBase &rcv, const char *data, unsigned size) const
+unsigned Protocol::dispatch(ReceiverBase &rcv, const char *buf, unsigned size) const
 {
-	const unsigned char *udata = reinterpret_cast<const unsigned char *>(data);
-	unsigned id = (udata[0]<<8)+udata[1];
-	unsigned psz = (udata[2]<<8)+udata[3];
-	if(psz>size)
+	PacketHeader header;
+	buf = header_def.deserialize(header, buf, buf+size);
+	if(header.length>size)
 		throw bad_packet("truncated");
-	const PacketDefBase &pdef = get_packet_by_id(id);
-	const char *ptr = pdef.disassemble(rcv, data+4, data+psz);
-	return ptr-data;
+	const PacketDefBase &pdef = get_packet_by_id(header.type);
+	const char *ptr = pdef.dispatch(rcv, buf, buf+header.length);
+	return ptr-buf;
 }
 
-unsigned Protocol::get_packet_size(const char *data, unsigned size) const
+unsigned Protocol::get_packet_size(const char *buf, unsigned size) const
 {
 	if(size<4)
 		return 0;
-	const unsigned char *udata = reinterpret_cast<const unsigned char *>(data);
-	return (udata[2]<<8)+udata[3];
+	PacketHeader header;
+	header_def.deserialize(header, buf, buf+size);
+	return header.length;
 }
 
 unsigned Protocol::get_hash() const
@@ -160,73 +69,97 @@ unsigned Protocol::get_hash() const
 	return 123;
 }
 
-void Protocol::assemble_header(char *buf, unsigned id, unsigned size)
+
+/* TODO These assumes the machine is little-endian; are there any relevant
+big-endian platforms these days? */
+template<typename T>
+char *Protocol::BasicSerializer<T>::serialize(const T &value, char *buf, char *end) const
 {
-	buf[0] = (id>>8)&0xFF;
-	buf[1] = id&0xFF;
-	buf[2] = (size>>8)&0xFF;
-	buf[3] = size&0xFF;
+	if(end-buf<static_cast<int>(sizeof(T)))
+		throw buffer_error("overflow");
+
+	const char *ptr = reinterpret_cast<const char *>(&value)+sizeof(T);
+	for(unsigned i=0; i<sizeof(T); ++i)
+		*buf++ = *--ptr;
+
+	return buf;
 }
 
 template<typename T>
-char *Protocol::assemble_field(const T &v, char *d, char *e)
-{ return Assembler<T>::assemble(v, d, e); }
-
-template char *Protocol::assemble_field<>(const char &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const signed char &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const unsigned char &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const short &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const unsigned short &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const int &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const unsigned &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const long &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const unsigned long &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const float &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const double &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const string &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<char> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<signed char> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<unsigned char> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<short> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<unsigned short> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<int> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<unsigned> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<long> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<unsigned long> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<float> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<double> &v, char *d, char *e);
-template char *Protocol::assemble_field<>(const vector<string> &v, char *d, char *e);
+const char *Protocol::BasicSerializer<T>::deserialize(T &value, const char *buf, const char *end) const
+{
+	if(end-buf<static_cast<int>(sizeof(T)))
+		throw buffer_error("underflow");
+
+	char *ptr = reinterpret_cast<char *>(&value)+sizeof(T);
+	for(unsigned i=0; i<sizeof(T); ++i)
+		*--ptr = *buf++;
+
+	return buf;
+}
+
+template char *Protocol::BasicSerializer<Int8>::serialize(const Int8 &, char *, char *) const;
+template char *Protocol::BasicSerializer<Int16>::serialize(const Int16 &, char *, char *) const;
+template char *Protocol::BasicSerializer<Int32>::serialize(const Int32 &, char *, char *) const;
+template char *Protocol::BasicSerializer<Int64>::serialize(const Int64 &, char *, char *) const;
+template char *Protocol::BasicSerializer<UInt8>::serialize(const UInt8 &, char *, char *) const;
+template char *Protocol::BasicSerializer<UInt16>::serialize(const UInt16 &, char *, char *) const;
+template char *Protocol::BasicSerializer<UInt32>::serialize(const UInt32 &, char *, char *) const;
+template char *Protocol::BasicSerializer<UInt64>::serialize(const UInt64 &, char *, char *) const;
+template char *Protocol::BasicSerializer<float>::serialize(const float &, char *, char *) const;
+template char *Protocol::BasicSerializer<double>::serialize(const double &, char *, char *) const;
+template const char *Protocol::BasicSerializer<Int8>::deserialize(Int8 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<Int16>::deserialize(Int16 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<Int32>::deserialize(Int32 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<Int64>::deserialize(Int64 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<UInt8>::deserialize(UInt8 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<UInt16>::deserialize(UInt16 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<UInt32>::deserialize(UInt32 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<UInt64>::deserialize(UInt64 &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<float>::deserialize(float &, const char *, const char *) const;
+template const char *Protocol::BasicSerializer<double>::deserialize(double &, const char *, const char *) const;
+
+
+Protocol::StringSerializer::StringSerializer(const Protocol &p):
+	length_serializer(p)
+{ }
+
+char *Protocol::StringSerializer::serialize(const string &str, char *buf, char *end) const
+{
+	buf = length_serializer.serialize(str.size(), buf, end);
+	if(end-buf<static_cast<int>(str.size()))
+		throw buffer_error("overflow");
+	copy(str.begin(), str.end(), buf);
+	return buf+str.size();
+}
+
+const char *Protocol::StringSerializer::deserialize(string &str, const char *buf, const char *end) const
+{
+	UInt16 length;
+	buf = length_serializer.deserialize(length, buf, end);
+	if(end-buf<static_cast<int>(length))
+		throw buffer_error("underflow");
+	str.assign(buf, buf+length);
+	return buf+length;
+}
 
-template<typename T>
-const char *Protocol::disassemble_field(T &v, const char *d, const char *e)
-{ return Assembler<T>::disassemble(v, d, e); }
-
-template const char *Protocol::disassemble_field<>(char &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(signed char &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(unsigned char &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(short &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(unsigned short &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(int &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(unsigned &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(long &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(unsigned long &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(float &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(double &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(string &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<char> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<signed char> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<unsigned char> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<short> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<unsigned short> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<int> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<unsigned> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<long> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<unsigned long> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<float> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<double> &v, const char *d, const char *e);
-template const char *Protocol::disassemble_field<>(vector<string> &v, const char *d, const char *e);
 
 unsigned Protocol::PacketDefBase::next_class_id = 1;
 
+Protocol::PacketDefBase::PacketDefBase(unsigned i):
+	id(i)
+{ }
+
+
+Protocol::PacketHeader::PacketHeader():
+	type(0),
+	length(0)
+{ }
+
+Protocol::PacketHeader::PacketHeader(UInt16 t, UInt16 l):
+	type(t),
+	length(l)
+{ }
+
 } // namespace Net
 } // namespace Msp
diff --git a/source/net/protocol.h b/source/net/protocol.h
index 75b3514..f6c382c 100644
--- a/source/net/protocol.h
+++ b/source/net/protocol.h
@@ -4,6 +4,7 @@
 #include <map>
 #include <stdexcept>
 #include <vector>
+#include <msp/core/inttypes.h>
 #include "receiver.h"
 
 namespace Msp {
@@ -28,147 +29,409 @@ public:
 class Protocol
 {
 private:
-	class PacketDefBase
+	template<typename T, UInt8 K>
+	struct BasicTraits;
+
+	template<typename T>
+	struct Traits;
+
+	template<typename C>
+	struct CompoundTypeDef
 	{
-	protected:
-		unsigned id;
+		virtual ~CompoundTypeDef() { }
 
-		PacketDefBase(unsigned i): id(i) { }
-	public:
-		virtual ~PacketDefBase() { }
-		virtual unsigned get_class_id() const = 0;
-		unsigned get_id() const { return id; }
-		virtual const char *disassemble(ReceiverBase &, const char *, const char *) const = 0;
+		virtual char *serialize(const C &, char *, char *) const = 0;
+		virtual const char *deserialize(C &, const char *, const char *) const = 0;
+	};
 
-		static unsigned next_class_id;
+	template<typename C, typename S>
+	struct CompoundDef: public CompoundTypeDef<C>
+	{
+		S *serializer;
+
+		CompoundDef(const S &);
+		virtual ~CompoundDef();
+
+		virtual char *serialize(const C &, char *, char *) const;
+		virtual const char *deserialize(C &, const char *, const char *) const;
 	};
 
-	template<typename P>
-	class FieldBase
+	template<typename T>
+	class BasicSerializer
 	{
-	protected:
-		FieldBase() { }
 	public:
-		virtual ~FieldBase() { }
-		virtual char *assemble(const P &, char *, char *) const = 0;
-		virtual const char *disassemble(P &, const char *, const char *) const = 0;
+		typedef T ValueType;
+
+		BasicSerializer(const Protocol &) { }
+
+		char *serialize(const T &, char *, char *) const;
+		const char *deserialize(T &, const char *, const char *) const;
 	};
 
-	template<typename P, typename T>
-	class Field: public FieldBase<P>
+	class StringSerializer
 	{
+	public:
+		typedef std::string ValueType;
+
 	private:
-		T P::*ptr;
+		BasicSerializer<UInt16> length_serializer;
 
 	public:
-		Field(T P::*p): ptr(p) { }
-
-		virtual char *assemble(const P &p, char *d, char *e) const
-		{ return assemble_field(p.*ptr, d, e); }
+		StringSerializer(const Protocol &);
 
-		virtual const char *disassemble(P &p, const char *d, const char *e) const
-		{ return disassemble_field(p.*ptr, d, e); }
+		char *serialize(const std::string &, char *, char *) const;
+		const char *deserialize(std::string &, const char *, const char *) const;
 	};
 
-protected:
-	template<typename P>
-	class PacketDef: public PacketDefBase
+	template<typename A>
+	class ArraySerializer
 	{
+	public:
+		typedef A ValueType;
+
 	private:
-		std::vector<FieldBase<P> *> fields;
+		BasicSerializer<UInt16> length_serializer;
+		typename Traits<typename A::value_type>::Serializer element_serializer;
 
 	public:
-		PacketDef(unsigned i): PacketDefBase(i)
-		{ if(!class_id) class_id = next_class_id++; }
+		ArraySerializer(const Protocol &);
 
-		~PacketDef()
+		char *serialize(const A &, char *, char *) const;
+		const char *deserialize(A &, const char *, const char *) const;
+	};
+
+	template<typename P, typename Head, typename S>
+	class Serializer: public Head
+	{
+	public:
+		template<typename N>
+		struct Next
 		{
-			for(typename std::vector<FieldBase<P> *>::const_iterator i=fields.begin(); i!=fields.end(); ++i)
-				delete *i;
-		}
+			typedef Serializer<P, Serializer<P, Head, S>, typename Traits<N>::Serializer> Type;
+		};
 
-		virtual unsigned get_class_id() const { return class_id; }
+	private:
+		typedef typename S::ValueType P::*Pointer;
 
-		template<typename T>
-		PacketDef &operator()(T P::*p)
-		{ fields.push_back(new Field<P, T>(p)); return *this; }
+		Pointer ptr;
+		S ser;
 
-		char *assemble(const P &p, char *d, char *e) const
-		{
-			for(typename std::vector<FieldBase<P> *>::const_iterator i=fields.begin(); i!=fields.end(); ++i)
-				d = (*i)->assemble(p, d, e);
-			return d;
-		}
+	public:
+		Serializer(const Head &, Pointer, const Protocol &);
 
-		const char *disassemble(ReceiverBase &r, const char *d, const char *e) const
+		char *serialize(const P &, char *, char *) const;
+		const char *deserialize(P &, const char *, const char *) const;
+	};
+
+	template<typename P>
+	class NullSerializer
+	{
+	public:
+		template<typename N>
+		struct Next
 		{
-			PacketReceiver<P> *prcv = dynamic_cast<PacketReceiver<P> *>(&r);
-			if(!prcv)
-				throw bad_packet("unsupported");
-			P pkt;
-			for(typename std::vector<FieldBase<P> *>::const_iterator i=fields.begin(); i!=fields.end(); ++i)
-				d = (*i)->disassemble(pkt, d, e);
-			prcv->receive(pkt);
-			return d;
-		}
+			typedef Serializer<P, NullSerializer, typename Traits<N>::Serializer> Type;
+		};
+
+		char *serialize(const P &, char *b, char *) const { return b; }
+		const char *deserialize(P &, const char *b, const char *) const { return b; }
+	};
+
+	class PacketDefBase
+	{
+	protected:
+		unsigned id;
+
+		static unsigned next_class_id;
+
+		PacketDefBase(unsigned);
+	public:
+		virtual ~PacketDefBase() { }
+		virtual unsigned get_class_id() const = 0;
+		unsigned get_id() const { return id; }
+		virtual const char *dispatch(ReceiverBase &, const char *, const char *) const = 0;
+	};
+
+	template<typename P>
+	class PacketTypeDef: public PacketDefBase
+	{
+	private:
+		CompoundTypeDef<P> *compound;
 
 		static unsigned class_id;
+
+	public:
+		PacketTypeDef(unsigned);
+		~PacketTypeDef();
+
+		static unsigned get_static_class_id() { return class_id; }
+		virtual unsigned get_class_id() const { return class_id; }
+
+		template<typename S>
+		void set_serializer(const S &);
+
+		const CompoundTypeDef<P> &get_compound() const { return *compound; }
+
+		char *serialize(const P &, char *, char *) const;
+		const char *deserialize(P &, const char *, const char *) const;
+		virtual const char *dispatch(ReceiverBase &, const char *, const char *) const;
+	};
+
+	template<typename P, typename S>
+	class PacketDefBuilder
+	{
+	private:
+		const Protocol &protocol;
+		PacketTypeDef<P> &pktdef;
+		S serializer;
+
+	public:
+		PacketDefBuilder(const Protocol &, PacketTypeDef<P> &, const S &);
+		
+		template<typename T>
+		PacketDefBuilder<P, typename S::template Next<T>::Type> operator()(T P::*);
+	};
+
+	struct PacketHeader
+	{
+		UInt16 type;
+		UInt16 length;
+
+		PacketHeader();
+		PacketHeader(UInt16, UInt16);
 	};
 
 	typedef std::map<unsigned, PacketDefBase *> PacketMap;
 
+	PacketTypeDef<PacketHeader> header_def;
 	unsigned next_packet_id;
 	PacketMap packet_class_defs;
 	PacketMap packet_id_defs;
 
+protected:
 	Protocol(unsigned = 1);
 public:
 	~Protocol();
 
 private:
-	void add_packet(PacketDefBase &);
+	void add_packet(PacketDefBase *);
 
 protected:
 	template<typename P>
-	PacketDef<P> &add()
-	{
-		PacketDef<P> *pdef = new PacketDef<P>(next_packet_id++);
-		add_packet(*pdef);
-		return *pdef;
-	}
+	PacketDefBuilder<P, NullSerializer<P> > add();
 
-	const PacketDefBase &get_packet_by_class(unsigned) const;
+	const PacketDefBase &get_packet_by_class_id(unsigned) const;
 	const PacketDefBase &get_packet_by_id(unsigned) const;
 
-public:
 	template<typename P>
-	unsigned assemble(const P &pkt, char *buf, unsigned size) const
-	{
-		unsigned id = PacketDef<P>::class_id;
-		const PacketDef<P> &pdef = static_cast<const PacketDef<P> &>(get_packet_by_class(id));
-		char *ptr = pdef.assemble(pkt, buf+4, buf+size);
-		assemble_header(buf, pdef.get_id(), (size = ptr-buf));
-		return size;
-	}
+	const PacketTypeDef<P> &get_packet_by_class() const;
 
-	unsigned disassemble(ReceiverBase &, const char *, unsigned) const;
+public:
+	template<typename P>
+	unsigned serialize(const P &, char *, unsigned) const;
 
 	unsigned get_packet_size(const char *, unsigned) const;
+	unsigned dispatch(ReceiverBase &, const char *, unsigned) const;
 
 	unsigned get_hash() const;
+};
 
-private:
-	static void assemble_header(char *, unsigned, unsigned);
 
-	template<typename T>
-	static char *assemble_field(const T &, char *, char *);
+template<typename P>
+Protocol::PacketDefBuilder<P, Protocol::NullSerializer<P> > Protocol::add()
+{
+	PacketTypeDef<P> *pdef = new PacketTypeDef<P>(next_packet_id++);
+	add_packet(pdef);
+	return PacketDefBuilder<P, NullSerializer<P> >(*this, *pdef, NullSerializer<P>());
+}
 
-	template<typename T>
-	static const char *disassemble_field(T &, const char *, const char *);
+template<typename P>
+const Protocol::PacketTypeDef<P> &Protocol::get_packet_by_class() const
+{
+	const PacketDefBase &pdef = get_packet_by_class_id(PacketTypeDef<P>::get_static_class_id());
+	return static_cast<const PacketTypeDef<P> &>(pdef);
+}
+
+template<typename P>
+unsigned Protocol::serialize(const P &pkt, char *buf, unsigned size) const
+{
+	const PacketTypeDef<P> &pdef = get_packet_by_class<P>();
+	char *ptr = pdef.serialize(pkt, buf+4, buf+size);
+	size = ptr-buf;
+	header_def.serialize(PacketHeader(pdef.get_id(), size), buf, buf+4);
+	return size;
+}
+
+
+template<typename T, UInt8 K>
+struct Protocol::BasicTraits
+{
+	typedef BasicSerializer<T> Serializer;
 };
 
+template<> struct Protocol::Traits<Int8>: BasicTraits<Int8> { };
+template<> struct Protocol::Traits<UInt8>: BasicTraits<UInt8> { };
+template<> struct Protocol::Traits<Int16>: BasicTraits<Int16> { };
+template<> struct Protocol::Traits<UInt16>: BasicTraits<UInt16> { };
+template<> struct Protocol::Traits<Int32>: BasicTraits<Int32> { };
+template<> struct Protocol::Traits<UInt32>: BasicTraits<UInt32> { };
+template<> struct Protocol::Traits<Int64>: BasicTraits<Int64> { };
+template<> struct Protocol::Traits<UInt64>: BasicTraits<UInt64> { };
+template<> struct Protocol::Traits<float>: BasicTraits<float> { };
+template<> struct Protocol::Traits<double>: BasicTraits<double> { };
+
+template<> struct Protocol::Traits<std::string>
+{
+	typedef StringSerializer Serializer;
+};
+
+template<typename T>
+struct Protocol::Traits<std::vector<T> >
+{
+	typedef ArraySerializer<std::vector<T> > Serializer;
+};
+
+
+
+template<typename C, typename S>
+Protocol::CompoundDef<C, S>::CompoundDef(const S &s):
+	serializer(new S(s))
+{ }
+
+template<typename C, typename S>
+Protocol::CompoundDef<C, S>::~CompoundDef()
+{
+	delete serializer;
+}
+
+template<typename C, typename S>
+char *Protocol::CompoundDef<C, S>::serialize(const C &com, char *buf, char *end) const
+{
+	return serializer->serialize(com, buf, end);
+}
+
+template<typename C, typename S>
+const char *Protocol::CompoundDef<C, S>::deserialize(C &com, const char *buf, const char *end) const
+{
+	return serializer->deserialize(com, buf, end);
+}
+
+
+template<typename A>
+Protocol::ArraySerializer<A>::ArraySerializer(const Protocol &proto):
+	length_serializer(proto),
+	element_serializer(proto)
+{ }
+
+template<typename A>
+char *Protocol::ArraySerializer<A>::serialize(const A &array, char *buf, char *end) const
+{
+	buf = length_serializer.serialize(array.size(), buf, end);
+	for(typename A::const_iterator i=array.begin(); i!=array.end(); ++i)
+		buf = element_serializer.serialize(*i, buf, end);
+	return buf;
+}
+
+template<typename A>
+const char *Protocol::ArraySerializer<A>::deserialize(A &array, const char *buf, const char *end) const
+{
+	UInt16 length;
+	buf = length_serializer.deserialize(length, buf, end);
+	array.resize(length);
+	for(unsigned i=0; i<length; ++i)
+		buf = element_serializer.deserialize(array[i], buf, end);
+	return buf;
+}
+
+
+template<typename P, typename Head, typename S>
+Protocol::Serializer<P, Head, S>::Serializer(const Head &h, Pointer p, const Protocol &proto):
+	Head(h),
+	ptr(p),
+	ser(proto)
+{ }
+
+template<typename P, typename Head, typename S>
+char * Protocol::Serializer<P, Head, S>::serialize(const P &pkt, char *buf, char *end) const
+{
+	buf = Head::serialize(pkt, buf, end);
+	return ser.serialize(pkt.*ptr, buf, end);
+}
+
+template<typename P, typename Head, typename S>
+const char * Protocol::Serializer<P, Head, S>::deserialize(P &pkt, const char *buf, const char *end) const
+{
+	buf = Head::deserialize(pkt, buf, end);
+	return ser.deserialize(pkt.*ptr, buf, end);
+}
+
+
+template<typename P>
+unsigned Protocol::PacketTypeDef<P>::class_id = 0;
+
 template<typename P>
-unsigned Protocol::PacketDef<P>::class_id = 0;
+Protocol::PacketTypeDef<P>::PacketTypeDef(unsigned i):
+	PacketDefBase(i),
+	compound(new CompoundDef<P, NullSerializer<P> >(NullSerializer<P>()))
+{
+	if(!class_id)
+		class_id = next_class_id++;
+}
+
+template<typename P>
+Protocol::PacketTypeDef<P>::~PacketTypeDef()
+{
+	delete compound;
+}
+
+template<typename P>
+template<typename S>
+void Protocol::PacketTypeDef<P>::set_serializer(const S &ser)
+{
+	delete compound;
+	compound = new CompoundDef<P, S>(ser);
+}
+
+template<typename P>
+char *Protocol::PacketTypeDef<P>::serialize(const P &pkt, char *buf, char *end) const
+{
+	return compound->serialize(pkt, buf, end);
+}
+
+template<typename P>
+const char *Protocol::PacketTypeDef<P>::deserialize(P &pkt, const char *buf, const char *end) const
+{
+	return compound->deserialize(pkt, buf, end);
+}
+
+template<typename P>
+const char *Protocol::PacketTypeDef<P>::dispatch(ReceiverBase &rcv, const char *buf, const char *end) const
+{
+	PacketReceiver<P> *prcv = dynamic_cast<PacketReceiver<P> *>(&rcv);
+	if(!prcv)
+		throw bad_packet("unsupported");
+	P pkt;
+	buf = deserialize(pkt, buf, end);
+	prcv->receive(pkt);
+	return buf;
+}
+
+
+template<typename P, typename S>
+Protocol::PacketDefBuilder<P, S>::PacketDefBuilder(const Protocol &p, PacketTypeDef<P> &k, const S &s):
+	protocol(p),
+	pktdef(k),
+	serializer(s)
+{ }
+
+template<typename P, typename S>
+template<typename T>
+Protocol::PacketDefBuilder<P, typename S::template Next<T>::Type> Protocol::PacketDefBuilder<P, S>::operator()(T P::*ptr)
+{
+	typename S::template Next<T>::Type next_ser(serializer, ptr, protocol);
+	pktdef.set_serializer(next_ser);
+	return PacketDefBuilder<P, typename S::template Next<T>::Type>(protocol, pktdef, next_ser);
+}
 
 } // namespace Net
 } // namespace Msp