4 // Fraunhofer Institute for Open Communication Systems (FOKUS)
5 // Competence Center NETwork research (NET), St. Augustin, GERMANY
6 // Stefan Bund <g0dil@berlios.de>
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 2 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the
20 // Free Software Foundation, Inc.,
21 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 \brief PacketRegistry public header */
26 #ifndef HH_PacketRegistryImpl_
27 #define HH_PacketRegistryImpl_ 1
31 #include <boost/utility.hpp> // for boost::noncopyable
32 #include <boost/optional.hpp>
33 #include "../Utils/Exception.hh"
36 //#include "PacketRegistry.mpp"
37 ///////////////////////////////hh.p////////////////////////////////////////
41 /** \brief Registry entry
43 Value returned by a registry lookup
46 : public intrusive_refcount
48 virtual ~PkReg_Entry();
49 virtual Packet::factory_t factory() const = 0;
50 ///< Get factory of the registered packet type
51 virtual std::string name() const = 0;
54 namespace detail { template <class Key> class PacketRegistryImpl; }
56 /** \brief Packet registration facility
58 The PacketRegistry provides a generic facility to associate an arbitrary key with
59 Packets. Example keys are Ethertype or IP protocols.
61 Every PacketRegistry is identified by a type tag:
64 typedef some_key_type key_t;
67 The key type can be an arbitrary value type. The PacketRegistry for this Tag can then be
68 accessed using <code>senf::PacketRegistry<SomeTag>::</code>.
70 The PacketRegistry class has only static members and provides access to the packet
71 registry. It allows two-way lookup either by key or by packet type.
74 senf::Packet::factory_t factory (senf::PacketRegistry<SomeTag>::lookup(some_key).factory());
75 SomeTag::key_t key = PacketRegistry<SomeTag>::key<SomePacket>();
78 Packets can be registered either dynamically or statically. Dynamic:
80 // dynamic registration
81 senf::PacketRegistry<SomeTag>::registerPacket<SomePacket>(key_of_somePacket);
83 // static registration. 'registerSomePacket' is an arbitrary symbol name
84 senf::PacketRegistry<SomeTag>::RegistrationProxy<SomePacket>
85 registerSomePacket (key_of_somePacket);
88 This global variable declaration will register \a SomePacket with the \a SomeTag registry
89 under the key \a key_of_somePacket. The variable \a registerSomePacket is a dummy. It's only
90 function is to force the call of it's constructor during global construction time. This
91 static registration only works when the symbol is included into the final binary. To force
92 this inclusion, you should not put packet registrations into a library but into an object
95 \ingroup packet_module
101 /** \brief Statically register a packet type in a PacketRegistry
103 To use this class, define a global symbol in the following way:
106 senf::PacketRegistry<Tag>::RegistrationProxy<PacketType>
107 registerPacketType (key);
109 \endcode Here \a Tag is the type tag of the registry to register the packet in, \a
110 PacketType is the packet to register (this is the ConcretePacket of that packet) and \a
111 key is the key of type \c Tag::key_t under which the packet is to be registered. \a
112 registerPacketType is an arbitrary name for the global symbol.
114 template <class PacketType>
115 struct RegistrationProxy
117 RegistrationProxy(typename Tag::key_t key);
120 /** \brief Register new packet type
122 Register \a PacketType in the packet registry \a Tag under the given \a key.
124 \par Preconditions: The given \a key must be unique and not be assigned to any other
125 packet class in this registry. The Packet must not already be registered in the
128 \param PacketType ConcretePacket instantiation of packet to register
129 \param key The key of the packet
131 template <class PacketType>
132 static void registerPacket(typename Tag::key_t key);
134 /** \brief Find key of a packet type
136 Return the key of \a PacketType as registered in the \a Tag registry
138 \param PacketType packet of which the key is requested
139 \returns key of the packet
140 \throws PacketTypeNotRegistered if the packet type is not found in the registry.
142 template <class PacketType>
143 static typename Tag::key_t key();
145 /** \brief Find key of a packet type
147 Return the key of \a PacketType as registered in the \a Tag registry
149 \param PacketType packet of which the key is requested
150 \returns key of the packet wrapped in a <a
151 href="http://www.boost.org/libs/optional/doc/optional.html">boost::optional</a> or
152 an unbound optional, if the key is not found.
154 template <class PacketType>
155 static typename boost::optional<typename Tag::key_t> key(NoThrow_t);
157 /** \brief Find key of a packet
159 Return the key of \a packet, an arbitrary packet, as registered in the \a Tag registry.
161 \param packet The packet of which the key is requested
162 \returns key of the packet
163 \throws PacketTypeNotRegistered if the packet type is not found in the registry.
165 static typename Tag::key_t key(Packet packet);
167 /** \brief Find key of a packet
169 Return the key of \a packet, an arbitrary packet, as registered in the \a Tag registry.
172 packet of which the key is requested
173 \returns key of the packet wrapped in a <a
174 href="http://www.boost.org/libs/optional/doc/optional.html">boost::optional</a> or
175 an unbound optional, if the key is not found.
177 static typename boost::optional<typename Tag::key_t> key(Packet packet, NoThrow_t);
179 /** \brief Lookup a packet by it's key
181 \throws PacketTypeNotRegistered if the \a key is not found in the registry
182 \return Packet entry for given \a key
184 static PkReg_Entry const & lookup(typename Tag::key_t key);
186 /** \brief Lookup a packet by it's key
187 \return Pointer to packet entry for given \a key or 0, if the key is not found in the
190 static PkReg_Entry const * lookup(typename Tag::key_t key, NoThrow_t);
193 typedef detail::PacketRegistryImpl<typename Tag::key_t> Registry;
194 static Registry & registry();
197 /** \brief Statically add an entry to a packet registry
199 This macro will declare an anonymous global variable in such a way, that constructing this
200 variable will add a registration to the given packet registry.
204 # define SENF_PACKET_REGISTRY_REGISTER( registry, value, type ) \
206 senf::PacketRegistry< registry >::RegistrationProxy< type > \
207 packetRegistration_ ## __LINE__ ( value ); \
210 /** \brief Entry not found in registry
212 This exception is signaled whenever a throwing lookup operation fails.
214 struct PacketTypeNotRegisteredException : public std::exception
215 { virtual char const * what() const throw() { return "packet type not registered"; } };
219 ///////////////////////////////hh.e////////////////////////////////////////
221 #if !defined(HH_Packets__decls_) && !defined(HH_PacketRegistryImpl_i_)
222 #define HH_PacketRegistryImpl_i_
223 //#include "PacketRegistry.cci"
224 #include "PacketRegistry.ct"
225 #include "PacketRegistry.cti"
232 // c-file-style: "senf"
233 // indent-tabs-mode: nil
234 // ispell-local-dictionary: "american"
235 // compile-command: "scons -u test"
236 // comment-column: 40