Bug 1518609 - Add telemetry to legacy maxRetransmitTime DataChannel param r=jib,janerik

Adds telemetry to the DataChannel init param maxRetransmitTime.

Differential Revision: https://phabricator.services.mozilla.com/D15999

--HG--
extra : moz-landing-system : lando

dom/media/PeerConnection.jsm

@@ -36,8 +36,6 @@ const PC_TRANSCEIVER_CID = Components.ID("{09475754-103a-41f5-a2d0-e1f27eb0b537}
 const PC_COREQUEST_CID = Components.ID("{74b2122d-65a8-4824-aa9e-3d664cb75dc2}");
 const PC_DTMF_SENDER_CID = Components.ID("{3610C242-654E-11E6-8EC0-6D1BE389A607}");
 
-const TELEMETRY_PC_CONNECTED = "webrtc.peerconnection.connected";
-const TELEMETRY_PC_PROMISE_GETSTATS = "webrtc.peerconnection.promise_stats_used";
 function logMsg(msg, file, line, flag, winID) {
   let scriptErrorClass = Cc["@mozilla.org/scripterror;1"];
   let scriptError = scriptErrorClass.createInstance(Ci.nsIScriptError);
@@ -313,18 +311,55 @@ setupPrototype(RTCStatsReport, {
   QueryInterface: ChromeUtils.generateQI([]),
 });
 
-// This is its own class so that it does not need to be exposed to the client.
+// Records PC related telemetry
 class PeerConnectionTelemetry {
   // Record which style(s) of invocation for getStats are used
   recordGetStats() {
-    Services.telemetry.scalarAdd(TELEMETRY_PC_PROMISE_GETSTATS, 1);
+    Services.telemetry.scalarAdd("webrtc.peerconnection.promise_stats_used",
+                                 1);
     this.recordGetStats = () => {};
   }
   // ICE connection state enters connected or completed.
   recordConnected() {
-    Services.telemetry.scalarAdd(TELEMETRY_PC_CONNECTED, 1);
+    Services.telemetry.scalarAdd("webrtc.peerconnection.connected", 1);
     this.recordConnected = () => {};
   }
+  // DataChannel is created
+  _recordDataChannelCreated() {
+    Services.telemetry.scalarAdd("webrtc.peerconnection.datachannel_created",
+                                 1);
+    this._recordDataChannelCreated = () => {};
+  }
+  // DataChannel initialized with maxRetransmitTime
+  _recordMaxRetransmitTime(maxRetransmitTime) {
+    if (maxRetransmitTime === undefined) {
+      return false;
+    }
+    Services.telemetry.scalarAdd(
+      "webrtc.peerconnection.datachannel_max_retx_used", 1);
+    this._recordMaxRetransmitTime = () => true;
+    return true;
+  }
+  // DataChannel initialized with maxPacketLifeTime
+  _recordMaxPacketLifeTime(maxPacketLifeTime) {
+    if (maxPacketLifeTime === undefined) {
+      return false;
+    }
+    Services.telemetry.scalarAdd(
+      "webrtc.peerconnection.datachannel_max_life_used", 1);
+    this._recordMaxPacketLifeTime = () => true;
+    return true;
+  }
+  // DataChannel initialized
+  recordDataChannelInit(maxRetransmitTime, maxPacketLifeTime) {
+    const retxUsed = this._recordMaxRetransmitTime(maxRetransmitTime);
+    if (this._recordMaxPacketLifeTime(maxPacketLifeTime) && retxUsed) {
+      Services.telemetry.scalarAdd(
+        "webrtc.peerconnection.datachannel_max_retx_and_life_used", 1);
+      this.recordDataChannelInit = () => {};
+    }
+    this._recordDataChannelCreated();
+  }
 }
 
 // Cache for RTPSourceEntries
@@ -1571,10 +1606,15 @@ class RTCPeerConnection {
 
   createDataChannel(label, {
                       maxRetransmits, ordered, negotiated, id = 0xFFFF,
-                      maxRetransmitTime, maxPacketLifeTime = maxRetransmitTime,
+                      maxRetransmitTime, maxPacketLifeTime,
                       protocol,
                     } = {}) {
     this._checkClosed();
+    this._pcTelemetry.recordDataChannelInit(maxRetransmitTime, maxPacketLifeTime);
+
+    if (maxPacketLifeTime === undefined) {
+      maxPacketLifeTime = maxRetransmitTime;
+    }
 
     if (maxRetransmitTime !== undefined) {
       this.logWarning("Use maxPacketLifeTime instead of deprecated maxRetransmitTime which will stop working soon in createDataChannel!");

toolkit/components/telemetry/Scalars.yaml

@@ -771,7 +771,73 @@ webrtc.peerconnection:
     record_in_processes:
       - 'main'
       - 'content'
-
+  datachannel_created:
+    bug_numbers:
+      - 1518609
+    description: >
+      The number of RTCPeerConnection objects in which a RTCDataChannel was
+      created. This is recorded once for each RTCPeerConnection after the first
+      RTCDataChannel is created.
+    expires: "70"
+    kind: uint
+    notification_emails:
+      - ngrunbaum@mozilla.com
+    release_channel_collection: opt-out
+    record_in_processes:
+      - 'main'
+      - 'content'
+  datachannel_max_retx_used:
+    bug_numbers:
+      - 1518609
+    description: >
+      The number of RTCPeerConnection objects in which one or more
+      RTCDataChannels were created with the legacy maxRetransmitTime option
+      instead of the new, synonymous maxPacketLifeTime option. This is recorded
+      once for each RTCPeerConnection after a RTCDataChannel is created with
+      the maxRetransmitTime option.
+    expires: "70"
+    kind: uint
+    notification_emails:
+      - ngrunbaum@mozilla.com
+    release_channel_collection: opt-out
+    record_in_processes:
+      - 'main'
+      - 'content'
+  datachannel_max_life_used:
+    bug_numbers:
+      - 1518609
+    description: >
+      The number of RTCPeerConnection objects in which one or more RTCDataChannels
+      were created with the maxPacketLifeTime option instead of the deprecated,
+      synonymous maxRetransmitTime option. This is recorded once for each
+      RTCPeerConnection after a RTCDataChannel is created with the
+      maxPacketLifeTime option.
+    expires: "70"
+    kind: uint
+    notification_emails:
+      - ngrunbaum@mozilla.com
+    release_channel_collection: opt-out
+    record_in_processes:
+      - 'main'
+      - 'content'
+  datachannel_max_retx_and_life_used:
+    bug_numbers:
+      - 1518609
+    description: >
+      The number of RTCPeerConnection objects in which one or more RTCDataChannels
+      were created with both maxPacketLifeTime and the deprecated, synonymous
+      maxRetransmitTime option. This is recorded once for each
+      RTCPeerConnection after RTCDataChannels have been created with the
+      maxPacketLifeTime and the maxRetransmitTime options, either together
+      or in seperate invocations.
+    expires: "70"
+    kind: uint
+    notification_emails:
+      - ngrunbaum@mozilla.com
+    release_channel_collection: opt-out
+    record_in_processes:
+      - 'main'
+      - 'content'
 # The following section contains WebRTC nICEr scalars
 # For more info on ICE, see https://tools.ietf.org/html/rfc5245
 # For more info on STUN, see https://tools.ietf.org/html/rfc5389