X-Git-Url: http://g0dil.de/git?a=blobdiff_plain;f=Packets%2FPacket.hh;h=bb2ac904cf3bd0c0e24d422c74cbb71cbb4d8422;hb=e4526bf485cbf7f35d26264cb2ede91efdd5c54f;hp=af45ff2b5c53b5a6ba394892a50893bdafdc1246;hpb=078c34233b7d5ca7f9fd9dfb77568f840ad41915;p=senf.git diff --git a/Packets/Packet.hh b/Packets/Packet.hh index af45ff2..bb2ac90 100644 --- a/Packets/Packet.hh +++ b/Packets/Packet.hh @@ -314,6 +314,66 @@ namespace senf { ///@} + ///\name Annotations + ///@{ + + template + Annotation & annotation(); ///< Get packet annotation + /**< This member will retrieve an arbitrary packet + annotation. Every annotation is identified by a unique + \a Annotation type. This type should \e always be a \c + struct. + + \code + struct MyAnnotation { + int value; + }; + + senf::Packet p (...); + + p.annotation().value = 1; + \endcode + + Annotations are shared by all headers / interpreters + within a single packet chain. + + If an annotation is \e not a POD type (more + specifically, if it's constructor or destructor is not + trivial including base classes and members), the \a + Annotation type \e must inherit from + senf::ComplexAnnotation. Failing to follow this rule + will result in undefined behavior and will probably + lead to a program crash. + + \code + struct MyStringAnnotation : senf::ComplexAnnotation { + std::string value; + }; + \endcode + (This type is not POD since \c std::string is not POD) + + \implementation The annotation system is implemented + quite efficiently since annotations are stored + within a packet embedded vector of fixed size (the + size is determined automatically at runtime by the + number of different annotations + used). Additionally, non-complex small annotations + require no additional memory management (\c new / + \c delete). + + \idea Pool the annotation vectors: In the destructor + swap the vector into a vector graveyard (swapping + two vectors is an O(1) no allocation operation). In + the constructor, if there is a vector in the + graveyard, swap it in from there. Of course, it + would be better to do away with the vector and just + allocate the space together with the packet but + that looks quite complicated to do ... especially + considering that the packetimpl itself uses a pool. + */ + + ///@} + ///\name Other methods ///@{ @@ -331,11 +391,12 @@ namespace senf { when using a packet in a boolean context. */ void finalizeThis(); ///< Update calculated fields - /**< This call will update all calculated fields of the - packet. This includes checksums, payload size fields or - other fields, which can be set from other information - in the packet. Each concrete packet type should - document, which fields are set by finalize(). + /**< The finalize() fammily of members will update + calculated packet fields: checksums, size fields and so + on. This includes any field, which can be set from + other information in the packet. Each concrete packet + type should document, which fields are set by + finalize(). finalizeThis() will \e only process the current header. Even if only changing fields in this protocol, @@ -345,37 +406,56 @@ namespace senf { template void finalizeTo(); ///< Update calculated fields - /**< This call will update all calculated fields of the - packet. This includes checksums, payload size fields or - other fields, which can be set from other information - in the packet. Each concrete packet type should - document, which fields are set by finalize(). + /**< The finalize() fammily of members will update + calculated packet fields: checksums, size fields and so + on. This includes any field, which can be set from + other information in the packet. Each concrete packet + type should document, which fields are set by + finalize(). finalizeTo() will automatically process all - packets/headers/interpreters from the first occurrence - of packet type \a Other backwards up to \c this. */ + packets/headers/interpreters from the \e first + occurrence of packet type \a Other (beginning at \c + this packet searching forward towards deeper nested + packets) backwards up to \c this. + + This call is equivalent to + \code + p.finalizeTo(p.next()) + \endcode */ void finalizeTo(Packet other); ///< Update calculated fields - /**< This call will update all calculated fields of the - packet. This includes checksums, payload size fields or - other fields, which can be set from other information - in the packet. Each concrete packet type should - document, which fields are set by finalize(). + /**< The finalize() fammily of members will update + calculated packet fields: checksums, size fields and so + on. This includes any field, which can be set from + other information in the packet. Each concrete packet + type should document, which fields are set by + finalize(). - finalizeAll(other) will automatically process all - packets/headers/interpreters from \a other backwards up - to \c this. */ + finalizeTo(other) will automatically process all + packets/headers/interpreters beginning at \a other + backwards towards outer packets up to \c this. */ void finalizeAll(); ///< Update calculated fields - /**< This call will update all calculated fields of the - packet. This includes checksums, payload size fields or - other fields, which can be set from other information - in the packet. Each concrete packet type should - document, which fields are set by finalize(). + /**< The finalize() fammily of members will update + calculated packet fields: checksums, size fields and so + on. This includes any field, which can be set from + other information in the packet. Each concrete packet + type should document, which fields are set by + finalize(). finalizeAll() will automatically process all packets/headers/interpreters from the end of the chain - backwards up to \c this. */ + (the most inner packet) backwards up to \c this. + + This call is equivalent to + \code + p.finalizeTo(p.last()) + \endcode + + Beware, that finalizeAll() will \e not finalize any + headers before \c this, it will \e only process inner + headers. */ void dump(std::ostream & os) const; ///< Write out a printable packet representation /**< This method is provided mostly to help debugging packet