Key Locks

[bbengfort]

Scope of changes

Implements a fixed memory key lock mutex that balances keys across a fixed number of locks. The more locks, the better concurrency, but without unbounded growth. This data structure will be used to ensure concurrent accesses on a single node are safe.

Benchmarks:

goos: darwin
goarch: arm64
pkg: github.com/rotationalio/honu/pkg/store/locks
cpu: Apple M1 Max
BenchmarkLocks/Mutex-10         	      19	  59030469 ns/op	   62458 B/op	    1074 allocs/op
BenchmarkLocks/KeyLock-10       	      42	  29340972 ns/op	   49993 B/op	    1033 allocs/op

Under a lot of contention, the key lock allows more concurrent access to the lock space than a single mutex, doubling the concurrent performance with the same safety guarantees.

Type of change

• new feature
• bug fix
• documentation
• testing
• technical debt
• other (describe)

Acceptance criteria

This PR will be merged without review.

Definition of Done

• I have manually tested the change running it locally (having rebuilt all containers) or via unit tests
• I have added unit and/or integration tests that cover my changes
• I have added new test fixtures as needed to support added tests
• I have updated the dependencies list if necessary (including updating yarn.lock and/or go.sum)