High-performance JSON parsing in Go

CockroachDB's exploration into optimizing JSON parser performance in Go reveals significant speed improvements by transitioning from the standard Go `encoding/json` library to the `jsoniter` library, and ultimately, a customized fork of the high-performance `pkg/json` library. The initial inefficiency of the ParseJSON function, which used a two-phase parsing approach, prompted benchmarking to understand its shortcomings, particularly in memory allocation. The switch to `jsoniter` resulted in substantial speed gains but revealed suboptimal allocation behavior with escaped characters. Further enhancement was achieved by adopting and modifying `pkg/json`, achieving over 1GB/s throughput and improved allocation efficiency. This project underscores the importance of careful library selection and API design in achieving high performance, while also benefiting from Cockroach Labs' "Flex Friday" policy, allowing engineers to explore such optimizations.