OpenSSL uses something like this to implement get/set access for
properties on its BIOs, so that it doesn't need to add a pair of
get/set functions to the vtable struct for every new abstract property
it provides an accessor for.
Doing this lets us make bufferevent_setfd abstract, and implement an
abstract bufferevent_getfd.
svn:r1284
This is a bit of an interface doozy, but it's really needed in order
to be able to document this stuff without apologizing it. This patch
does the following renamings:
evbuffercb -> bufferevent_data_cb
everrorcb -> bufferevent_event_cb
EVBUFFER_(READ,WRITE,...) -> BEV_EVENT_(...)
EVBUFFER_(INPUT,OUTPUT) -> bufferevent_get_(input,output)
All the old names are available in event2/bufferevent_compat.h
svn:r1283
This way we don't expose more of a bufferevent than we need to. One
motivation is to make it easier to automatically get deferred callbacks
with a bufferevent without exposing the deferred_cb structure.
svn:r1169
The new bufferevent_pair abstraction works like a set of buferevent_sockets
connected by a socketpair, except that it doesn't require a socketpair,
and therefore doesn't need to get the kernel involved.
It's also a good way to make sure that deferred callbacks work. It's a good
use case for deferred callbacks: before I implemented them, the recursive
relationship between the evbuffer callback and the read callback would
make the unit tests overflow the stack.
svn:r1152
