response_latency_ms definition

[joewilliams]

In the docs response_latency_ms is defined as:

This measurement reflects the time-to-first-byte (TTFB) by recording the elapsed time between the proxy processing a request's headers and the first data frame of the response.

Looking at report.rs it defines response_latency_ms as:

Elapsed times between a request's headers being received and its response stream completing

The way I read each of these they seem to be suggesting two different things. The former timing ends at the beginning of the response and the latter the timing ends at the end of the response.

I am not super familiar with rust but I found where I think the latency being recorded here which I think suggests that the metric is timing to the end of the response and the docs are a bit misleading.

Can anyone shed some light please?