Move the PeerConnection's usage pattern concept to its own file.

This makes it easier to use it from multiple other modules.

Bug: webrtc:11995
Change-Id: Id23843ae4600ebe46aed7465e873d107089fd50b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/187347
Reviewed-by: Mirko Bonadei <[email protected]>
Commit-Queue: Harald Alvestrand <[email protected]>
Cr-Commit-Position: refs/heads/master@{#32361}

Author: Harald Alvestrand

pc/BUILD.gn

@@ -230,6 +230,7 @@ rtc_library("peerconnection") {
     ":rtp_sender",
     ":rtp_transceiver",
     ":stats_collector_interface",
+    ":usage_pattern",
     ":video_track_source",
     "../api:array_view",
     "../api:audio_options_api",
@@ -305,6 +306,18 @@ rtc_library("peer_connection_message_handler") {
   ]
 }
 
+rtc_library("usage_pattern") {
+  sources = [
+    "usage_pattern.cc",
+    "usage_pattern.h",
+  ]
+  deps = [
+    "../api:libjingle_peerconnection_api",
+    "../rtc_base:logging",
+    "../system_wrappers:metrics",
+  ]
+}
+
 rtc_library("rtp_transceiver") {
   sources = [
     "rtp_transceiver.cc",
@@ -745,6 +758,7 @@ if (rtc_include_tests) {
       ":rtp_receiver",
       ":rtp_sender",
       ":rtp_transceiver",
+      ":usage_pattern",
       ":video_track_source",
       "../api:array_view",
       "../api:audio_options_api",

pc/peer_connection.cc

@@ -3066,33 +3066,11 @@ void PeerConnection::ReportIceCandidateCollected(
 
 void PeerConnection::NoteUsageEvent(UsageEvent event) {
   RTC_DCHECK_RUN_ON(signaling_thread());
-  usage_event_accumulator_ |= static_cast<int>(event);
+  usage_pattern_.NoteUsageEvent(event);
 }
 
 void PeerConnection::ReportUsagePattern() const {
-  RTC_DLOG(LS_INFO) << "Usage signature is " << usage_event_accumulator_;
-  RTC_HISTOGRAM_ENUMERATION_SPARSE("WebRTC.PeerConnection.UsagePattern",
-                                   usage_event_accumulator_,
-                                   static_cast<int>(UsageEvent::MAX_VALUE));
-  const int bad_bits =
-      static_cast<int>(UsageEvent::SET_LOCAL_DESCRIPTION_SUCCEEDED) |
-      static_cast<int>(UsageEvent::CANDIDATE_COLLECTED);
-  const int good_bits =
-      static_cast<int>(UsageEvent::SET_REMOTE_DESCRIPTION_SUCCEEDED) |
-      static_cast<int>(UsageEvent::REMOTE_CANDIDATE_ADDED) |
-      static_cast<int>(UsageEvent::ICE_STATE_CONNECTED);
-  if ((usage_event_accumulator_ & bad_bits) == bad_bits &&
-      (usage_event_accumulator_ & good_bits) == 0) {
-    // If called after close(), we can't report, because observer may have
-    // been deallocated, and therefore pointer is null. Write to log instead.
-    if (observer_) {
-      Observer()->OnInterestingUsage(usage_event_accumulator_);
-    } else {
-      RTC_LOG(LS_INFO) << "Interesting usage signature "
-                       << usage_event_accumulator_
-                       << " observed after observer shutdown";
-    }
-  }
+  usage_pattern_.ReportUsagePattern(observer_);
 }
 
 bool PeerConnection::SrtpRequired() const {

pc/peer_connection.h

@@ -36,6 +36,7 @@
 #include "pc/stats_collector.h"
 #include "pc/stream_collection.h"
 #include "pc/transceiver_list.h"
+#include "pc/usage_pattern.h"
 #include "pc/webrtc_session_description_factory.h"
 #include "rtc_base/experiments/field_trial_parser.h"
 #include "rtc_base/operations_chain.h"
@@ -70,53 +71,6 @@ class PeerConnection : public PeerConnectionInternal,
                        public RtpSenderBase::SetStreamsObserver,
                        public sigslot::has_slots<> {
  public:
-  // A bit in the usage pattern is registered when its defining event occurs at
-  // least once.
-  enum class UsageEvent : int {
-    TURN_SERVER_ADDED = 0x01,
-    STUN_SERVER_ADDED = 0x02,
-    DATA_ADDED = 0x04,
-    AUDIO_ADDED = 0x08,
-    VIDEO_ADDED = 0x10,
-    // |SetLocalDescription| returns successfully.
-    SET_LOCAL_DESCRIPTION_SUCCEEDED = 0x20,
-    // |SetRemoteDescription| returns successfully.
-    SET_REMOTE_DESCRIPTION_SUCCEEDED = 0x40,
-    // A local candidate (with type host, server-reflexive, or relay) is
-    // collected.
-    CANDIDATE_COLLECTED = 0x80,
-    // A remote candidate is successfully added via |AddIceCandidate|.
-    ADD_ICE_CANDIDATE_SUCCEEDED = 0x100,
-    ICE_STATE_CONNECTED = 0x200,
-    CLOSE_CALLED = 0x400,
-    // A local candidate with private IP is collected.
-    PRIVATE_CANDIDATE_COLLECTED = 0x800,
-    // A remote candidate with private IP is added, either via AddiceCandidate
-    // or from the remote description.
-    REMOTE_PRIVATE_CANDIDATE_ADDED = 0x1000,
-    // A local mDNS candidate is collected.
-    MDNS_CANDIDATE_COLLECTED = 0x2000,
-    // A remote mDNS candidate is added, either via AddIceCandidate or from the
-    // remote description.
-    REMOTE_MDNS_CANDIDATE_ADDED = 0x4000,
-    // A local candidate with IPv6 address is collected.
-    IPV6_CANDIDATE_COLLECTED = 0x8000,
-    // A remote candidate with IPv6 address is added, either via AddIceCandidate
-    // or from the remote description.
-    REMOTE_IPV6_CANDIDATE_ADDED = 0x10000,
-    // A remote candidate (with type host, server-reflexive, or relay) is
-    // successfully added, either via AddIceCandidate or from the remote
-    // description.
-    REMOTE_CANDIDATE_ADDED = 0x20000,
-    // An explicit host-host candidate pair is selected, i.e. both the local and
-    // the remote candidates have the host type. This does not include candidate
-    // pairs formed with equivalent prflx remote candidates, e.g. a host-prflx
-    // pair where the prflx candidate has the same base as a host candidate of
-    // the remote peer.
-    DIRECT_CONNECTION_SELECTED = 0x40000,
-    MAX_VALUE = 0x80000,
-  };
-
   explicit PeerConnection(PeerConnectionFactory* factory,
                           std::unique_ptr<RtcEventLog> event_log,
                           std::unique_ptr<Call> call);
@@ -873,7 +827,7 @@ class PeerConnection : public PeerConnectionInternal,
   cricket::AudioOptions audio_options_ RTC_GUARDED_BY(signaling_thread());
   cricket::VideoOptions video_options_ RTC_GUARDED_BY(signaling_thread());
 
-  int usage_event_accumulator_ RTC_GUARDED_BY(signaling_thread()) = 0;
+  UsagePattern usage_pattern_ RTC_GUARDED_BY(signaling_thread());
   bool return_histogram_very_quickly_ RTC_GUARDED_BY(signaling_thread()) =
       false;