Bug 1693541 - Improve uses of nsBaseHashtable and descendants and avoid multiple subsequent lookups in dom/media. r=bryce

Differential Revision: https://phabricator.services.mozilla.com/D106095

dom/media/gmp/GMPServiceChild.cpp

@@ -473,23 +473,16 @@ void GeckoMediaPluginServiceChild::RemoveShutdownBlockerIfNeeded() {
 
 already_AddRefed<GMPContentParent> GMPServiceChild::GetBridgedGMPContentParent(
     ProcessId aOtherPid, ipc::Endpoint<PGMPContentParent>&& endpoint) {
-  RefPtr<GMPContentParent> parent;
-  mContentParents.Get(aOtherPid, getter_AddRefs(parent));
+  return do_AddRef(mContentParents.LookupOrInsertWith(aOtherPid, [&] {
+    MOZ_ASSERT(aOtherPid == endpoint.OtherPid());
 
-  if (parent) {
-    return parent.forget();
-  }
+    auto parent = MakeRefPtr<GMPContentParent>();
 
-  MOZ_ASSERT(aOtherPid == endpoint.OtherPid());
+    DebugOnly<bool> ok = endpoint.Bind(parent);
+    MOZ_ASSERT(ok);
 
-  parent = new GMPContentParent();
-
-  DebugOnly<bool> ok = endpoint.Bind(parent);
-  MOZ_ASSERT(ok);
-
-  mContentParents.InsertOrUpdate(aOtherPid, RefPtr{parent});
-
-  return parent.forget();
+    return parent;
+  }));
 }
 
 void GMPServiceChild::RemoveGMPContentParent(

dom/media/gmp/GMPServiceParent.cpp

@@ -1037,12 +1037,8 @@ nsresult ReadSalt(nsIFile* aPath, nsACString& aOutData) {
 
 already_AddRefed<GMPStorage> GeckoMediaPluginServiceParent::GetMemoryStorageFor(
     const nsACString& aNodeId) {
-  RefPtr<GMPStorage> s;
-  if (!mTempGMPStorage.Get(aNodeId, getter_AddRefs(s))) {
-    s = CreateGMPMemoryStorage();
-    mTempGMPStorage.InsertOrUpdate(aNodeId, RefPtr{s});
-  }
-  return s.forget();
+  return do_AddRef(mTempGMPStorage.LookupOrInsertWith(
+      aNodeId, [] { return CreateGMPMemoryStorage(); }));
 }
 
 NS_IMETHODIMP

dom/media/mediacontrol/MediaPlaybackStatus.cpp

@@ -104,11 +104,8 @@ bool MediaPlaybackStatus::IsAnyMediaBeingControlled() const {
 MediaPlaybackStatus::ContextMediaInfo&
 MediaPlaybackStatus::GetNotNullContextInfo(uint64_t aContextId) {
   MOZ_ASSERT(NS_IsMainThread());
-  if (!mContextInfoMap.Contains(aContextId)) {
-    mContextInfoMap.InsertOrUpdate(aContextId,
-                                   MakeUnique<ContextMediaInfo>(aContextId));
-  }
-  return *(mContextInfoMap.GetValue(aContextId)->get());
+  return *mContextInfoMap.LookupOrInsertWith(
+      aContextId, [&] { return MakeUnique<ContextMediaInfo>(aContextId); });
 }
 
 Maybe<uint64_t> MediaPlaybackStatus::GetAudioFocusOwnerContextId() const {

dom/media/mediacontrol/MediaStatusManager.cpp

@@ -62,28 +62,33 @@ void MediaStatusManager::NotifyMediaAudibleChanged(uint64_t aBrowsingContextId,
 }
 
 void MediaStatusManager::NotifySessionCreated(uint64_t aBrowsingContextId) {
-  if (mMediaSessionInfoMap.Contains(aBrowsingContextId)) {
-    return;
-  }
+  if (!mMediaSessionInfoMap.WithEntryHandle(
+          aBrowsingContextId, [&](auto&& entry) {
+            if (entry) return true;
 
-  LOG("Session %" PRIu64 " has been created", aBrowsingContextId);
-  mMediaSessionInfoMap.InsertOrUpdate(aBrowsingContextId,
-                                      MediaSessionInfo::EmptyInfo());
-  if (IsSessionOwningAudioFocus(aBrowsingContextId)) {
-    SetActiveMediaSessionContextId(aBrowsingContextId);
+            LOG("Session %" PRIu64 " has been created", aBrowsingContextId);
+            entry.Insert(MediaSessionInfo::EmptyInfo());
+            return false;
+          })) {
+    // This can't be done from within the WithEntryHandle functor, since it
+    // accesses mMediaSessionInfoMap.
+    if (IsSessionOwningAudioFocus(aBrowsingContextId)) {
+      SetActiveMediaSessionContextId(aBrowsingContextId);
+    }
   }
 }
 
 void MediaStatusManager::NotifySessionDestroyed(uint64_t aBrowsingContextId) {
-  if (!mMediaSessionInfoMap.Contains(aBrowsingContextId)) {
-    return;
-  }
-  LOG("Session %" PRIu64 " has been destroyed", aBrowsingContextId);
-  mMediaSessionInfoMap.Remove(aBrowsingContextId);
-  if (mActiveMediaSessionContextId &&
-      *mActiveMediaSessionContextId == aBrowsingContextId) {
-    ClearActiveMediaSessionContextIdIfNeeded();
-  }
+  mMediaSessionInfoMap.WithEntryHandle(aBrowsingContextId, [&](auto&& entry) {
+    if (entry) return;
+
+    LOG("Session %" PRIu64 " has been destroyed", aBrowsingContextId);
+    entry.Remove();
+    if (mActiveMediaSessionContextId &&
+        *mActiveMediaSessionContextId == aBrowsingContextId) {
+      ClearActiveMediaSessionContextIdIfNeeded();
+    }
+  });
 }
 
 void MediaStatusManager::UpdateMetadata(

dom/media/platforms/agnostic/eme/EMEDecoderModule.cpp

@@ -145,12 +145,12 @@ class EMEDecryptor : public MediaDataDecoder,
       return;
     }
 
-    mDecrypts.InsertOrUpdate(aSample,
-                             MakeUnique<DecryptPromiseRequestHolder>());
+    const auto& decrypt = mDecrypts.InsertOrUpdate(
+        aSample, MakeUnique<DecryptPromiseRequestHolder>());
     mProxy->Decrypt(aSample)
         ->Then(mThread, __func__, this, &EMEDecryptor::Decrypted,
                &EMEDecryptor::Decrypted)
-        ->Track(*mDecrypts.Get(aSample));
+        ->Track(*decrypt);
   }
 
   void Decrypted(const DecryptResult& aDecrypted) {

dom/media/systemservices/MediaSystemResourceManager.cpp

@@ -122,7 +122,7 @@ bool MediaSystemResourceManager::IsIpcClosed() { return mChild ? true : false; }
 void MediaSystemResourceManager::Register(MediaSystemResourceClient* aClient) {
   ReentrantMonitorAutoEnter mon(mReentrantMonitor);
   MOZ_ASSERT(aClient);
-  MOZ_ASSERT(!mResourceClients.Get(aClient->mId));
+  MOZ_ASSERT(!mResourceClients.Contains(aClient->mId));
 
   mResourceClients.InsertOrUpdate(aClient->mId, aClient);
 }
@@ -131,7 +131,7 @@ void MediaSystemResourceManager::Unregister(
     MediaSystemResourceClient* aClient) {
   ReentrantMonitorAutoEnter mon(mReentrantMonitor);
   MOZ_ASSERT(aClient);
-  MOZ_ASSERT(mResourceClients.Get(aClient->mId));
+  MOZ_ASSERT(mResourceClients.Contains(aClient->mId));
   MOZ_ASSERT(mResourceClients.Get(aClient->mId) == aClient);
 
   mResourceClients.Remove(aClient->mId);