Changes GetStatsReport to a callback-based function. Stats collection
is dispatched to three different stats collecting methods, being
invoked asynchronously on the signaling, worker and network threads.
The three resulting stats reports are merged into one before returned.
The only current stats being collected is on the signaling thread, but
a FakeRTCStatsCollector is able to test the multi-threaded and
stats-merging behaviors. Future CLs simply have to put their stats
collecting code in the appropriate ProducePartialResultsOnFooThread
method.
BUG=chromium:627816
Review-Url: https://codereview.webrtc.org/2270033004
Cr-Commit-Position: refs/heads/master@{#14064}
Using a timestamp based on a timer that is monotonically increasing for
the cache, so that cache's freshness can be checked regardless of if
system clock is modified.
Using a system clock for the stats' timestamp, which needs to be
relative to UNIX epoch (Jan 1, 1970, UTC).
This CL removes the dependency on faketiming.h.
BUG=chromium:627816
NOTRY=True
Review-Url: https://codereview.webrtc.org/2299643002
Cr-Commit-Position: refs/heads/master@{#13997}
This is the stats collector for the new stats types, RTCStats[1] and
RTCStatsReport[2]. It so far only produces RTCPeerConnectionStats[3] as
an example of how it would collect stats. Each RTCStats subclass will
get a corresponding RTCStatsCollector::ProduceFooStats().
Stats reports are cached and returned as const references (ref
counting). This allows stats to be inspected by multiple observers and
across multiple threads. No copies will have to be made when surfacing
this to Blink or other places.
The current implementation of ProducePeerConnectionStats() only look at
existing DataChannels. This might be incorret if data channels can be
removed? Will investigate in a follow-up, crbug.com/636818.
[1] https://www.w3.org/TR/2016/WD-webrtc-20160531/#idl-def-rtcstats
[2] https://www.w3.org/TR/2016/WD-webrtc-20160531/#rtcstatsreport-object
[3] https://w3c.github.io/webrtc-stats/archives/20160526/webrtc-stats.html#pcstats-dict*
BUG=chromium:627816, chromium:636818
Review-Url: https://codereview.webrtc.org/2242043002
Cr-Commit-Position: refs/heads/master@{#13979}
