X-Git-Url: http://g0dil.de/git?a=blobdiff_plain;f=Socket%2FMainpage.dox;h=643cee8408efabe30ca303e5e2ff2189d6bc4430;hb=3cde315703150449c967936e3f064fa5928a1cc2;hp=15993a6fe46a70ebe976bf3f40549d89e04fe356;hpb=62464586315edf52fbcc613acb4a8a7e919fd8e2;p=senf.git diff --git a/Socket/Mainpage.dox b/Socket/Mainpage.dox index 15993a6..643cee8 100644 --- a/Socket/Mainpage.dox +++ b/Socket/Mainpage.dox @@ -4,12 +4,13 @@ abstraction of the BSD socket API. The abstraction is based on several concepts: - \li The basic visible interface is a handle object - (senf::FileHandle and it's derived classes) - \li The socket interface relies on a policy framework to configure - it's functionality + \li The basic visible interface is a \link handle_group handle + object \endlink + \li The socket interface relies on a \link policy_group policy + framework \endlink to configure it's functionality \li The rest of the socket API is accessible using a classic - inheritance hierarchy of protocol classes + inheritance hierarchy of \link protocol_group protocol classes + \endlink The handle/body architecture provides automatic reference counted management of socket instances, the policy framework provides @@ -19,127 +20,137 @@ dependent options. \see \ref usage \n - \ref extend \n + \ref handle_group \n + \ref policy_group \n + \ref protocol_group \n + \ref extend \n \ref implementation */ /** \page usage Using the Socket Library - \section socket_handle The socket handle - Whenever you use the socket library, what you will be dealing with are senf::FileHandle derived instances. The socket library relies on reference counting to automatically manage the underlying socket representation. This frees you of having to manage the socket lifetime explicitly. - - \section socket_hierarchy The FileHandle hierarchy - - \image html FhHierarchy.png - - The senf::FileHandle class is the base of a hierarchy of socket - handle classes (realized as templates). These classes provide an - interface to the complete socket API. While going down the - inheritance hierarchy, the interface will be more and more - complete. - - The most complete interface is provided by - senf::ProtocolClientSocketHandle and - senf::ProtocolServerSocketHandle. The template Arguments specifies - the Protocol class of the underlying socket type. These are the - \e only classes having public constructors and are therefore the - only classes, which may be created by the library user. You will - normally use these classes by naming a specific socket typedef - (e.g. senf::TCPv4ClientSocketHandle). - - However, to aid writing flexible and generic code, the socket - library provides the senf::ClientSocketHandle and - senf::ServerSocketHandle class templates. These templates - implement a family of closely related classes based on the - specification of the socket policy. This policy specification may - be \e incomplete (see below). Instances of - senf::ClientSocketHandle/senf::ServerSocketHandle can be assigned - and converted to different ClientSocketHandle/ServerSocketHandle - types as long as the policy specifications are compatible. - - \attention It is very important, to (almost) always pass the socket - handle by value. The socket handle is a very lightweight - class and designed to be used like an ordinary built-in type. This - is very important in combination with the policy interface. - - \section policy_framework The policy framework - - \image html SocketPolicy.png - - The policy framework conceptually implements a list of parallel - inheritance hierarchies each covering a specific interface aspect - of the socket handle. The socket handle itself only provides - minimal functionality. All further functionality is relayed to a - policy class, or more precisely, to a group of policy classes, one - for each policy axis. The policy axis are - -
+ typedef senf::ProtocolClientSocketHandle MyProtocolClientSocketHandle;
+ typedef senf::ProtocolServerSocketHandle MyProtocolServerSocketHandle;
+
+
+ \section extend_policy Extending the policy framework
+
+ If you have to extend the policy framework, you will need to be
+ aware of some important limitations of the socket library:
+
+ \li When you define a new policy for some axis, this new policy
+ must not be derived from one of the existing concrete
+ policy classes (except of course the respective policy axis
+ base class). This is important since the policy type is \e not
+ polymorphic. The policy to be used is selected by the compiler
+ using the \e static type, which is exactly what is desired,
+ since this allows calls to be efficiently inlined.
+
+ \li Therefore, extending the policy framework will make the new
+ socket probably \e incompatible with generic code which relies
+ on the policy axis which is extended. Example: If you write a
+ new write policy because your protocol does not use ordinary
+ write() system calls but some protocol specific API, Then any
+ generic function relying on senf::WritablePolicy will \e not
+ work with the new socket, since the socket does \e not have
+ this policy, it has some other kind of write policy.
+
+ Therefore you need to be careful of what you are doing. The first
+ step is to find out, which policy you will have to implement. For
+ this, find the senf::ClientSocketHandle and/or
+ senf::ServerSocketHandle members you want to change (see \ref
+ senf::ClientSocketHandle and \ref senf::ServerSocketHandle). Not
+ all policy axis directly contribute to the SocketHandle
+ interface. However, some policy members additionally depend on
+ other policy axis (example: AddressingPolicy::connect is only
+ defined if the communication policy is
+ ConnectedCommunication).
+
+ \see policy_group
*/
/** \page implementation Implementation notes