1908720 - Add RTCStatsReport logging to verbose log level to assist with profiler based debugging

Status: RESOLVED WONTFIX

(Core :: WebRTC, enhancement, P2)

Description

[Nico Grunbaum [:ng, @chew:mozilla.org]]

This patch logs the results from calls to RTCPeerConnection::getStats(...). It does not however add a timer or other mechanism to drive those calls, instead relying on the assumption that WebRTC applications will generally be monitoring their stats. In Nightly, the stats history is enabled by default, and that will additionally drive these calls. The GenerateToJSON directive has been added to our internal representation of the RTCStatsReport which is not exposed to userland JS.

Comment 1

[Nico Grunbaum [:ng, @chew:mozilla.org]]

Attachment: WIP: Bug 1908720 - add WebRTC stats report logging at verbose level;r?bwc

Comment 2

[Nico Grunbaum [:ng, @chew:mozilla.org]]

(In reply to Nico Grunbaum [:ng, @chew:mozilla.org] from comment #0)

This patch logs the results from calls to RTCPeerConnection::getStats(...). It does not however add a timer or other mechanism to drive those calls, instead relying on the assumption that WebRTC applications will generally be monitoring their stats. In Nightly, the stats history is enabled by default, and that will additionally drive these calls. The GenerateToJSON directive has been added to our internal representation of the RTCStatsReport which is not exposed to userland JS.

This approach was flawed as: 1) there is a limit of just over 1000 characters that we are running into in the markers, 2) the RTCStatsReportInternal contains the SDP history and isn't structured the same as an RTCStatsReport, 3) by the spec calling JSON.stringify(aRTCStatsReport) returns "{}", 4) the translation from internal stats report to the spec stats report happens in JS.