Json telemetry

tests/RenderCadenceCompositorTelemetryTests.cpp

@@ -1,4 +1,5 @@
 #include "CadenceTelemetry.h"
+#include "CadenceTelemetryJson.h"
 
 #include <chrono>
 #include <cstdint>
@@ -128,12 +129,60 @@ void TestTelemetryComputesRatesFromDeltas()
 	Expect(snapshot.renderFps > 0.0, "render fps is computed from completed frame delta");
 	Expect(snapshot.scheduleFps > 0.0, "schedule fps is computed from scheduled frame delta");
 }
+
+void TestTelemetrySerializesToJson()
+{
+	RenderCadenceCompositor::CadenceTelemetrySnapshot snapshot;
+	snapshot.sampleSeconds = 1.0;
+	snapshot.renderFps = 59.94;
+	snapshot.scheduleFps = 60.0;
+	snapshot.freeFrames = 7;
+	snapshot.completedFrames = 1;
+	snapshot.scheduledFrames = 4;
+	snapshot.renderedTotal = 120;
+	snapshot.scheduledTotal = 118;
+	snapshot.completedPollMisses = 3;
+	snapshot.scheduleFailures = 0;
+	snapshot.completions = 117;
+	snapshot.displayedLate = 1;
+	snapshot.dropped = 2;
+	snapshot.shaderBuildsCommitted = 1;
+	snapshot.shaderBuildFailures = 0;
+	snapshot.deckLinkBufferedAvailable = true;
+	snapshot.deckLinkBuffered = 4;
+	snapshot.deckLinkScheduleCallMilliseconds = 1.25;
+
+	const std::string json = RenderCadenceCompositor::CadenceTelemetryToJson(snapshot);
+	const std::string expected =
+		"{\"sampleSeconds\":1,\"renderFps\":59.94,\"scheduleFps\":60,"
+		"\"free\":7,\"completed\":1,\"scheduled\":4,"
+		"\"renderedTotal\":120,\"scheduledTotal\":118,"
+		"\"completedPollMisses\":3,\"scheduleFailures\":0,"
+		"\"completions\":117,\"late\":1,\"dropped\":2,"
+		"\"shaderCommitted\":1,\"shaderFailures\":0,"
+		"\"deckLinkBufferedAvailable\":true,\"deckLinkBuffered\":4,"
+		"\"scheduleCallMs\":1.25}";
+	Expect(json == expected, "telemetry snapshot serializes to stable JSON");
+}
+
+void TestUnavailableDeckLinkBufferSerializesAsNull()
+{
+	RenderCadenceCompositor::CadenceTelemetrySnapshot snapshot;
+	snapshot.deckLinkBufferedAvailable = false;
+
+	const std::string json = RenderCadenceCompositor::CadenceTelemetryToJson(snapshot);
+	Expect(
+		json.find("\"deckLinkBufferedAvailable\":false,\"deckLinkBuffered\":null") != std::string::npos,
+		"unavailable DeckLink buffer depth serializes as null");
+}
 }
 
 int main()
 {
 	TestTelemetrySamplesCompletedPollMissesAndShaderCounts();
 	TestTelemetryComputesRatesFromDeltas();
+	TestTelemetrySerializesToJson();
+	TestUnavailableDeckLinkBufferSerializesAsNull();
 
 	if (gFailures != 0)
 	{