Using the zmq notifications to avoid excessive mempool polling can be difficult
given the current notifications available. It announces all transactions
being added to mempool or included in blocks, but announces no evictions
and gives no indication if the transaction is in the mempool or a block.
Block notifications for zmq are also substandard, in that it only announces
block tips, while all block transactions are still announced.
This commit adds a unified stream which can be used to closely track mempool:
1) getrawmempool to fill out mempool knowledge
2) if txhash is announced, add or remove from set
based on add/remove flag
3) if blockhash is announced, get block txn list,
remove from those transactions local view of mempool
4) if we drop a sequence number, go to (1)
The mempool sequence number starts at the value 1, and
increments each time a transaction enters the mempool,
or is evicted from the mempool for any reason, including
block inclusion. The mempool sequence number is published
via ZMQ for any transaction-related notification.
These features allow for ZMQ/RPC consumer to track mempool
state in a more exacting way, without unnecesarily polling
getrawmempool. See interface_zmq.py::test_mempool_sync for
example usage.
zmqconfig.h is currently not really needed anywhere, except that
it declares zmqError (which is then defined in
zmqnotificationinterface.cpp). Note in particular that there is
no need to conditionally include zmq.h only if ZMQ is enabled, because
the place in the core code where the ZMQ library itself is included
(init.cpp) is conditional already on that.
This commit removes zmqconfig.h and replaces it by a much simpler
zmqutil.h library for zmqError. The definition of the function is
moved to the matching (newly created) zmqutil.cpp.
a4edb168b6 ZMQ: add options to configure outbound message high water mark, aka SNDHWM (mruddy)
Pull request description:
ZMQ: add options to configure outbound message high water mark, aka SNDHWM
This is my attempt at https://github.com/bitcoin/bitcoin/pull/13315
Tree-SHA512: a4cc3bcf179776899261a97c8c4f31f35d1d8950fd71a09a79c5c064879b38e600b26824c89c4091d941502ed5b0255390882f7d44baf9e6dc49d685a86e8edb
- removes mapBlockIndex find operation
- theoretically allows removing the cs_main lock during zqm notification while introducing a new file position lock
Continues Johnathan Corgan's work.
Publishing multipart messages
Bugfix: Add missing zmq header includes
Bugfix: Adjust build system to link ZeroMQ code for Qt binaries
