Bug 1745707 - Put id-rewriting into the id generator. r=ng

As the id generator is already a shared resource, this seems like a natural fit.

Differential Revision: https://phabricator.services.mozilla.com/D133636

dom/media/webrtc/jsapi/PeerConnectionImpl.cpp

@@ -2869,37 +2869,6 @@ void PeerConnectionImpl::CollectConduitTelemetryData() {
   }
 }
 
-template <class T>
-void AssignWithOpaqueIds(dom::Sequence<T>& aSource, dom::Sequence<T>& aDest,
-                         RefPtr<RTCStatsIdGenerator>& aGenerator) {
-  for (auto& stat : aSource) {
-    stat.mId.Value() = aGenerator->Id(stat.mId.Value());
-  }
-  if (!aDest.AppendElements(aSource, fallible)) {
-    mozalloc_handle_oom(0);
-  }
-}
-
-template <class T>
-void RewriteRemoteIds(dom::Sequence<T>& aList,
-                      RefPtr<RTCStatsIdGenerator>& aGenerator) {
-  for (auto& stat : aList) {
-    if (stat.mRemoteId.WasPassed()) {
-      stat.mRemoteId.Value() = aGenerator->Id(stat.mRemoteId.Value());
-    }
-  }
-}
-
-template <class T>
-void RewriteLocalIds(dom::Sequence<T>& aList,
-                     RefPtr<RTCStatsIdGenerator>& aGenerator) {
-  for (auto& stat : aList) {
-    if (stat.mLocalId.WasPassed()) {
-      stat.mLocalId.Value() = aGenerator->Id(stat.mLocalId.Value());
-    }
-  }
-}
-
 RefPtr<dom::RTCStatsReportPromise> PeerConnectionImpl::GetStats(
     dom::MediaStreamTrack* aSelector, bool aInternalStats) {
   MOZ_ASSERT(NS_IsMainThread());
@@ -3006,63 +2975,7 @@ RefPtr<dom::RTCStatsReportPromise> PeerConnectionImpl::GetStats(
           [report = std::move(report), idGen = mIdGenerator](
               const nsTArray<UniquePtr<dom::RTCStatsCollection>>&
                   aStats) mutable {
-            // Rewrite an Optional id
-            auto rewriteId = [&idGen](Optional<nsString>& id) {
-              if (id.WasPassed()) {
-                id.Value() = idGen->Id(id.Value());
-              }
-            };
-
-            // Involves a lot of copying, since webidl dictionaries don't have
-            // move semantics. Oh well.
-            for (const auto& stats : aStats) {
-              for (auto& stat : stats->mIceCandidatePairStats) {
-                rewriteId(stat.mLocalCandidateId);
-                rewriteId(stat.mRemoteCandidateId);
-              };
-              AssignWithOpaqueIds(stats->mIceCandidatePairStats,
-                                  report->mIceCandidatePairStats, idGen);
-
-              AssignWithOpaqueIds(stats->mIceCandidateStats,
-                                  report->mIceCandidateStats, idGen);
-
-              RewriteRemoteIds(stats->mInboundRtpStreamStats, idGen);
-              AssignWithOpaqueIds(stats->mInboundRtpStreamStats,
-                                  report->mInboundRtpStreamStats, idGen);
-
-              RewriteRemoteIds(stats->mOutboundRtpStreamStats, idGen);
-              AssignWithOpaqueIds(stats->mOutboundRtpStreamStats,
-                                  report->mOutboundRtpStreamStats, idGen);
-
-              RewriteLocalIds(stats->mRemoteInboundRtpStreamStats, idGen);
-              AssignWithOpaqueIds(stats->mRemoteInboundRtpStreamStats,
-                                  report->mRemoteInboundRtpStreamStats, idGen);
-
-              RewriteLocalIds(stats->mRemoteOutboundRtpStreamStats, idGen);
-              AssignWithOpaqueIds(stats->mRemoteOutboundRtpStreamStats,
-                                  report->mRemoteOutboundRtpStreamStats, idGen);
-
-              AssignWithOpaqueIds(stats->mRtpContributingSourceStats,
-                                  report->mRtpContributingSourceStats, idGen);
-              AssignWithOpaqueIds(stats->mTrickledIceCandidateStats,
-                                  report->mTrickledIceCandidateStats, idGen);
-              AssignWithOpaqueIds(stats->mDataChannelStats,
-                                  report->mDataChannelStats, idGen);
-              if (!report->mRawLocalCandidates.AppendElements(
-                      stats->mRawLocalCandidates, fallible) ||
-                  !report->mRawRemoteCandidates.AppendElements(
-                      stats->mRawRemoteCandidates, fallible) ||
-                  !report->mVideoFrameHistories.AppendElements(
-                      stats->mVideoFrameHistories, fallible) ||
-                  !report->mBandwidthEstimations.AppendElements(
-                      stats->mBandwidthEstimations, fallible)) {
-                // XXX(Bug 1632090) Instead of extending the array 1-by-1
-                // (which might involve multiple reallocations) and
-                // potentially crashing here, SetCapacity could be called
-                // outside the loop once.
-                mozalloc_handle_oom(0);
-              }
-            }
+            idGen->RewriteIds(aStats, report.get());
             return dom::RTCStatsReportPromise::CreateAndResolve(
                 std::move(report), __func__);
           },

dom/media/webrtc/jsapi/RTCStatsIdGenerator.cpp

@@ -5,13 +5,100 @@
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 
 #include "RTCStatsIdGenerator.h"
-#include "mozilla/RandomNum.h"
+
 #include <iostream>
+
+#include "mozilla/dom/RTCStatsReportBinding.h"
+#include "mozilla/RandomNum.h"
+
 namespace mozilla {
 
 RTCStatsIdGenerator::RTCStatsIdGenerator()
     : mSalt(RandomUint64().valueOr(0xa5a5a5a5)), mCounter(0) {}
 
+void RTCStatsIdGenerator::RewriteIds(
+    const nsTArray<UniquePtr<dom::RTCStatsCollection>>& aFromStats,
+    dom::RTCStatsCollection* aIntoReport) {
+  // Rewrite an Optional id
+  auto rewriteId = [&](dom::Optional<nsString>& id) {
+    if (id.WasPassed()) {
+      id.Value() = Id(id.Value());
+    }
+  };
+
+  auto assignWithOpaqueIds = [&](auto& aSource, auto& aDest) {
+    for (auto& stat : aSource) {
+      rewriteId(stat.mId);
+    }
+    if (!aDest.AppendElements(aSource, fallible)) {
+      mozalloc_handle_oom(0);
+    }
+  };
+
+  auto rewriteRemoteIds = [&](auto& aList) {
+    for (auto& stat : aList) {
+      rewriteId(stat.mRemoteId);
+    }
+  };
+
+  auto rewriteLocalIds = [&](auto& aList) {
+    for (auto& stat : aList) {
+      rewriteId(stat.mLocalId);
+    }
+  };
+
+  // Involves a lot of copying, since webidl dictionaries don't have
+  // move semantics. Oh well.
+  for (const auto& stats : aFromStats) {
+    for (auto& stat : stats->mIceCandidatePairStats) {
+      rewriteId(stat.mLocalCandidateId);
+      rewriteId(stat.mRemoteCandidateId);
+    };
+    assignWithOpaqueIds(stats->mIceCandidatePairStats,
+                        aIntoReport->mIceCandidatePairStats);
+
+    assignWithOpaqueIds(stats->mIceCandidateStats,
+                        aIntoReport->mIceCandidateStats);
+
+    rewriteRemoteIds(stats->mInboundRtpStreamStats);
+    assignWithOpaqueIds(stats->mInboundRtpStreamStats,
+                        aIntoReport->mInboundRtpStreamStats);
+
+    rewriteRemoteIds(stats->mOutboundRtpStreamStats);
+    assignWithOpaqueIds(stats->mOutboundRtpStreamStats,
+                        aIntoReport->mOutboundRtpStreamStats);
+
+    rewriteLocalIds(stats->mRemoteInboundRtpStreamStats);
+    assignWithOpaqueIds(stats->mRemoteInboundRtpStreamStats,
+                        aIntoReport->mRemoteInboundRtpStreamStats);
+
+    rewriteLocalIds(stats->mRemoteOutboundRtpStreamStats);
+    assignWithOpaqueIds(stats->mRemoteOutboundRtpStreamStats,
+                        aIntoReport->mRemoteOutboundRtpStreamStats);
+
+    assignWithOpaqueIds(stats->mRtpContributingSourceStats,
+                        aIntoReport->mRtpContributingSourceStats);
+    assignWithOpaqueIds(stats->mTrickledIceCandidateStats,
+                        aIntoReport->mTrickledIceCandidateStats);
+    assignWithOpaqueIds(stats->mDataChannelStats,
+                        aIntoReport->mDataChannelStats);
+    if (!aIntoReport->mRawLocalCandidates.AppendElements(
+            stats->mRawLocalCandidates, fallible) ||
+        !aIntoReport->mRawRemoteCandidates.AppendElements(
+            stats->mRawRemoteCandidates, fallible) ||
+        !aIntoReport->mVideoFrameHistories.AppendElements(
+            stats->mVideoFrameHistories, fallible) ||
+        !aIntoReport->mBandwidthEstimations.AppendElements(
+            stats->mBandwidthEstimations, fallible)) {
+      // XXX(Bug 1632090) Instead of extending the array 1-by-1
+      // (which might involve multiple reallocations) and
+      // potentially crashing here, SetCapacity could be called
+      // outside the loop once.
+      mozalloc_handle_oom(0);
+    }
+  }
+}
+
 nsString RTCStatsIdGenerator::Id(const nsString& aKey) {
   if (!aKey.Length()) {
     MOZ_ASSERT(aKey.Length(), "Stats IDs should never be empty.");

dom/media/webrtc/jsapi/RTCStatsIdGenerator.h

@@ -7,22 +7,31 @@
 #ifndef _RTCSTATSIDGENERATOR_H_
 #define _RTCSTATSIDGENERATOR_H_
 
-#include "mozilla/Atomics.h"
-#include "nsISupportsImpl.h"
-#include "nsString.h"
-
 #include <map>
 
+#include "mozilla/Atomics.h"
+#include "mozilla/UniquePtr.h"
+#include "nsISupportsImpl.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
 namespace mozilla {
+namespace dom {
+struct RTCStatsCollection;
+}  // namespace dom
 
 class RTCStatsIdGenerator {
  public:
   RTCStatsIdGenerator();
-  nsString Id(const nsString& aKey);
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(RTCStatsIdGenerator);
 
+  void RewriteIds(
+      const nsTArray<UniquePtr<dom::RTCStatsCollection>>& aFromStats,
+      dom::RTCStatsCollection* aIntoReport);
+
  private:
   virtual ~RTCStatsIdGenerator(){};
+  nsString Id(const nsString& aKey);
   nsString Generate();
 
   const uint64_t mSalt;