Background ​When optimizing the write performance of GreptimeDB v0.7, we discovered through flame graphs that the CPU time spent parsing Prometheus write requests accounted for about 12% of the total. In comparison, the CPU time spent on protocol parsing by VictoriaMetrics, which is implemented in Go, is only around 5%. This forced us to start considering optimizing the overhead of the protocol conversion layer.To simplify the discussion, all the test code is stored in the GitHub repository http...