Instead of several levels of functions, just have two functions
(one for routes, the other for end-of-rib), this allows to create
messages in a simple linear fashion.
Also reduce three duplicite functions to construct BGP header for
BMP messages to just one.
This commit is quite a substantial rework of the underlying layers in
BMP TX:
- several unnecessary layers of indirection dropped, including most of
the original BMP's buffer machinery
- all messages are now written directly into one protocol's buffer
allocated for the whole time big enough to fit every possible message
- output blocks are allocated by pages and immediately returned when
used, improving the overall memory footprint
- no intermediary allocation is done from the heap altogether
- there is a documented and configurable limit on the TX queue size
There were some nasty problems with deferred protocol state updates and
race conditions on BGP startup, shutdown, and also with referencing the
cached states.
Now it looks fixed.
The original algorithm assumed principles not consistent with the RFC
and could have lead to false invalids.
Also added filter tests showing also how the ASPA literals are used in
the static protocol.
This reverts commit d01a7c2bda.
It seems that the performance penalty in global ea cache is actually
very high so returning back to local attribute caches in every BGP.
closes#86
The uncork events are running from mainloop so these should just
dispatch the right event to the right loop. Doing anything long there
is bad for performance and latency as the uncork list may be huge.
Channel is now just subscribing to yet another journal announcing
digested tries from the ROA table.
Creating tries in every channel on-the-fly was too slow to handle
and it ate obnoxious amounts of memory. Instead, the tries are
constructed directly in the table and the channels are notified
with the completed tries.
The delayed export-release mechanism is used to keep the tries allocated
until routes get reloaded.
Originally, this mechanism required to check whether there's enough time to work
and then to send an event. This macro combines all the logic and goes more straightforwardly
to the _end_ of the export processing loop.
One should note that there were two cases where the export processing loop
was deferred at the _beginning_, which led to ignoring some routes on
reimports. This wasn't easily noticeable in the tests until the one-task
limit got a ceiling on 300 ms to keep reasonable latency.
In future, this and rtable's data structures should be probably merged
but it isn't a good idea to do now. The used data structure is similar
to rtable -- an array of pointers to linked lists.
Feed is lockless, as with all tables.
Full export (receiving updates) is not supported yet but we don't have
any method how to use it anyway. Gonna implement it later.
There is no real need for storing bucket attributes locally and we may
save some memory by caching the attributes in one central place.
If this becomes a contention problem, we should reduce the lock load
of the central attribute cache.
Introducing a new omnipotent internal API to just pass route updates
from whatever point wherever we want.
From now on, all the exports should be processed by RT_WALK_EXPORTS
macro, and you can also issue a separate feed-only request to just get a
feed and finish.
The exporters can now also stop and the readers must expect that to
happen and recover. Main tables don't stop, though.
