* Performance improvements for the event query API (#7319)
Rework the implementation of event query parsing and execution to
improve performance and reduce memory usage.
Previous memory and CPU profiles of the pubsub service showed query
processing as a significant hotspot. While we don't have evidence that
this is visibly hurting users, fixing it is fairly easy and self-contained.
Updates #6439.
Typical benchmark results comparing the original implementation (PEG) with the reworked implementation (Custom):
```
TEST TIME/OP BYTES/OP ALLOCS/OP SPEEDUP MEM SAVING
BenchmarkParsePEG-12 51716 ns 526832 27
BenchmarkParseCustom-12 2167 ns 4616 17 23.8x 99.1%
BenchmarkMatchPEG-12 3086 ns 1097 22
BenchmarkMatchCustom-12 294.2 ns 64 3 10.5x 94.1%
```
A workaround for #6729. Add parameters to control buffer sizes for
event subscription RPC clients. On some networks, buffering causes
clients to be dropped and/or events to be lost.
For additional context, see the discussion on #7188.
- Add experimental_subscription_buffer_size config parameter
- Add experimental_websocket_write_buffer_size config parameter
- Add experimental_close_on_slow_client config parameter
Co-authored-by: M. J. Fromberger <fromberger@interchain.io>
