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%
```
Components:
* Add a basic parsing benchmark.
* Move the original query implementation to a subdirectory.
* Add lexical scanner for Query expressions.
* Add a parser for Query expressions.
* Implement query compiler.
* Add test cases based on OpenAPI examples.
* Add MustCompile to replace the original MustParse, and update usage.
## Issue:
This PR adds an "EXISTS" condition to the event query grammar. It enables querying for the occurrence of an event without having to provide a condition for one of its attributes.
As an example, someone interested in all slashing events might currently catch them with a query such as slash.power > 0.
With this PR the event can be captured with slash.power EXISTS or just slash EXISTS to catch by event type.
## Examples:
`slash EXISTS`
## Commits:
* Add EXISTS condition to query grammar
* Gofmt files
* Move PEG instructions out of auto-generated file to prevent overwrite
* Update libs/pubsub/query/query.go
Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>
* Update changelog and add test case
* Merge with other changes in PR #4070
* Add EXISTS to Conditions() func
* Apply gofmt
* Addressing PR comments
Currently the top level directory contains basically all of the code
for the crypto package. This PR moves the crypto code into submodules
in a similar manner to what `golang/x/crypto` does. This improves code
organization.
Ref discussion: https://github.com/tendermint/tendermint/pull/1966Closes#1956
M. J. Fromberger
Henrik Aasted Sørensen
ValarDragon
Anton Kaliaev
Zach Ramsay
Liamsi