Initial Commit - Lesson 31 (Commit #1)

Plugins/GameLiftServerSDK/Source/GameLiftMetrics/Private/UnrealStatCollector.cpp

@@ -0,0 +1,136 @@
+/*
+* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
+* its licensors.
+*
+* For complete copyright and license terms please see the LICENSE at the root of this
+* distribution (the "License"). All use of this software is governed by the License,
+* or, if provided, by the license below or the license accompanying this file. Do not
+* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*
+*/
+
+#include "UnrealStatCollector.h"
+
+#include "Runtime/Launch/Resources/Version.h"
+
+#include "TimeStats.h"
+
+#include "Async/TaskGraphInterfaces.h"
+#include "Stats/Stats.h"
+#include "Stats/StatsData.h"
+#include "EngineStats.h"
+
+
+#if STATS
+namespace
+{
+#if ENGINE_MAJOR_VERSION >= 5
+    void IncrementStatsRefCount()
+    {
+        StatsPrimaryEnableAdd();
+    }
+
+    void DecrementStatsRefCount()
+    {
+        StatsPrimaryEnableSubtract();
+    }
+#else
+    void IncrementStatsRefCount()
+    {
+        StatsMasterEnableAdd();
+    }
+
+    void DecrementStatsRefCount()
+    {
+        StatsMasterEnableSubtract();
+    }
+#endif
+}
+
+void FUnrealStatCollector::Subscribe()
+{
+    IncrementStatsRefCount();
+
+/*
+ * From 5.2.0 onwards, UE_STATS_THREAD_AS_PIPE is undefined and the only way to
+ * access the stat system is via the new API.
+ *
+ * Between 5.0.0 and 5.2.0, UE_STATS_THREAD_AS_PIPE enables new API. If it is 0,
+ * the old API can be used.
+ *
+ * See UE engine source commits 10b5e05d00df4f23d3b75f6af5ec08f8ae0e8618
+ *                              327a94d1a4e021714f2c3ca820fe9ed5606465bf
+ *                              d48f6660b807c7377926cffd12020645f91772f8
+ *
+ * All references to UE_STATS_THREAD_AS_PIPE are removed in
+ * d48f6660b807c7377926cffd12020645f91772f8.
+ */
+#if ENGINE_MAJOR_VERSION >= 5 && (ENGINE_MINOR_VERSION >= 2 || UE_STATS_THREAD_AS_PIPE)
+    {
+        auto& StatsState = FStatsThreadState::GetLocalState();
+        StatsState.NewFrameDelegate.AddSP(this, &FUnrealStatCollector::OnNewFrame);
+    }
+#else
+    FSimpleDelegateGraphTask::CreateAndDispatchWhenReady
+    (
+        FSimpleDelegateGraphTask::FDelegate::CreateLambda(
+            [WeakCollector = TWeakPtr<FUnrealStatCollector>(this->AsShared())]() {
+                if (!WeakCollector.IsValid()) { return; }
+
+                auto& StatsState = FStatsThreadState::GetLocalState();
+                StatsState.NewFrameDelegate.AddSP(WeakCollector.Pin().Get(), &FUnrealStatCollector::OnNewFrame);
+            }
+        ),
+        TStatId{},
+        nullptr,
+        /*
+         * StatsThread is deprecated since 5.0
+         *
+         * Need to verify post-5.0 behaviour but:
+         * - 4.27 to 5.0 should use the current method to subscribe to NewFrameDelegate
+         * - 5.0 on can subscribe from game thread directly. (See FThreadStats::bUseThreadAsPipe)
+         */
+        ENamedThreads::StatsThread
+    );
+#endif // UE_STATS_THREAD_AS_PIPE
+}
+
+void FUnrealStatCollector::Unsubscribe()
+{
+    DecrementStatsRefCount();
+}
+
+void FUnrealStatCollector::OnNewFrame(int64 Frame)
+{
+    TArray<FStatMessage> OutStats;
+
+    auto& Stats = FStatsThreadState::GetLocalState();
+    Stats.GetInclusiveAggregateStackStats(Frame, OutStats);
+
+    for (auto& Message : OutStats)
+    {
+        // GetShortName() is expensive and we're calling it for every stat.
+        // In practice: we'll stick filter by GetRawName first and stick things in a hashmap
+        //              might also be able to compare FName indices
+        FName ShortName = Message.NameAndInfo.GetShortName();
+
+        // Robustness: we can check the value type from message before blindly grabbing duration (or other types)
+
+        // Consult EngineStats.h for stat names
+        // (There's also many other stats in other subsystems.)
+        if (ShortName == TEXT("STAT_GameEngineTick"))
+        {
+            GAMELIFT_METRICS_SET_MS(Aws::GameLift::Metrics::MetricGameTickTime, FPlatformTime::ToMilliseconds(Message.GetValue_Duration()));
+        }
+        else if (ShortName == TEXT("STAT_WorldTickTime"))
+        {
+            GAMELIFT_METRICS_SET_MS(Aws::GameLift::Metrics::MetricWorldTickTime, FPlatformTime::ToMilliseconds(Message.GetValue_Duration()));
+        }
+    }
+}
+#else
+void FUnrealStatCollector::Subscribe() {}
+void FUnrealStatCollector::Unsubscribe() {}
+void FUnrealStatCollector::OnNewFrame(int64 Frame) {}
+#endif // STATS