Add tracing helper functions for RNDT traces in C++ and Kotlin (facebook#55935)

Summary:

Changelog: [internal]

This diff adds helper functions to the PerformanceTracer class for tracing performance events in React Native Developer Tools traces.

In Kotlin, new `trace` method overloads are added to `PerformanceTracer` that wrap a block of code and automatically measure and report its execution time. These use a try/finally pattern to ensure timing is captured correctly.

In C++, a new `PerformanceTracerSection` RAII class is added that automatically reports timing when the section goes out of scope. It supports optional track, track group, and color parameters, as well as variadic key-value properties for additional metadata.

Reviewed By: sammy-SC

Differential Revision: D92061513

Author: rubennorte

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/tracing/PerformanceTracer.kt

@@ -23,6 +23,45 @@ public object PerformanceTracer {
     SoLoader.loadLibrary("react_performancetracerjni")
   }
 
+  public fun <T> trace(name: String, block: () -> T): T {
+    return trace(name, null /* track */, null /* trackGroup */, null /* color */, block)
+  }
+
+  public fun <T> trace(name: String, track: String, block: () -> T): T {
+    return trace(name, track, null /* trackGroup */, null /* color */, block)
+  }
+
+  public fun <T> trace(name: String, track: String, trackGroup: String, block: () -> T): T {
+    return trace(name, track, trackGroup, null /* color */, block)
+  }
+
+  public fun <T> trace(
+      name: String,
+      track: String?,
+      trackGroup: String?,
+      color: String?,
+      block: () -> T,
+  ): T {
+    if (!isTracing()) {
+      return block()
+    }
+
+    val startTimeNanos = java.lang.System.nanoTime()
+    try {
+      return block()
+    } finally {
+      val endTimeNanos = java.lang.System.nanoTime()
+      reportTimeStamp(
+          name,
+          startTimeNanos,
+          endTimeNanos,
+          track,
+          trackGroup,
+          color,
+      )
+    }
+  }
+
   /** Callback interface for tracing state changes. */
   @DoNotStrip
   public interface TracingStateCallback {

packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracerSection.h

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <folly/dynamic.h>
+
+#include <jsinspector-modern/tracing/PerformanceTracer.h>
+
+#include <string_view>
+
+namespace facebook::react::jsinspector_modern::tracing {
+
+/**
+ * This is a RAII class that reports a timeStamp block to the React Native
+ * Performance Tracer.
+ *
+ * @example
+ *   {
+ *     PerformanceTracerSection s("name", "track", "track group");
+ *     // do something
+ *   }
+ */
+template <typename... Args>
+class PerformanceTracerSection {
+ public:
+  explicit PerformanceTracerSection(
+      const char *name,
+      const char *track = nullptr,
+      const char *trackGroup = nullptr,
+      const char *color = nullptr,
+      Args... args) noexcept
+      : name_(name), track_(track), trackGroup_(trackGroup), color_(color), args_(std::move(args)...)
+  {
+    static_assert(
+        sizeof...(Args) % 2 == 0,
+        "PerformanceTracerSection expects an even number of variadic args representing [name, value] pairs.");
+  }
+
+  // Non-movable
+  PerformanceTracerSection(const PerformanceTracerSection &) = delete;
+  PerformanceTracerSection(PerformanceTracerSection &&) = delete;
+
+  // Non-copyable
+  PerformanceTracerSection &operator=(const PerformanceTracerSection &) = delete;
+  PerformanceTracerSection &operator=(PerformanceTracerSection &&) = delete;
+
+  ~PerformanceTracerSection() noexcept
+  {
+    auto &tracer = PerformanceTracer::getInstance();
+    if (!tracer.isTracing()) {
+      return;
+    }
+
+    auto endTime = HighResTimeStamp::now();
+
+    // Slow path when passing properties
+    if constexpr (sizeof...(Args) > 0) {
+      auto properties = folly::dynamic::array();
+      std::apply(
+          [&](const auto &...elems) {
+            size_t idx = 0;
+            (((idx % 2 == 0) ? properties.push_back(folly::dynamic::array(elems))
+                             : properties[properties.size() - 1].push_back(elems),
+              ++idx),
+             ...);
+          },
+          args_);
+
+      folly::dynamic devtools = folly::dynamic::object();
+      devtools["properties"] = std::move(properties);
+
+      if (track_ != nullptr) {
+        devtools["track"] = track_;
+      }
+
+      if (trackGroup_ != nullptr) {
+        devtools["trackGroup"] = trackGroup_;
+      }
+
+      if (color_ != nullptr) {
+        devtools["color"] = color_;
+      }
+
+      folly::dynamic detail = folly::dynamic::object();
+      detail["devtools"] = std::move(devtools);
+
+      tracer.reportMeasure(std::string(name_), startTime_, endTime - startTime_, std::move(detail));
+    } else {
+      tracer.reportTimeStamp(
+          std::string(name_),
+          startTime_,
+          endTime,
+          track_ != nullptr ? std::optional{track_} : std::nullopt,
+          trackGroup_ != nullptr ? std::optional{trackGroup_} : std::nullopt,
+          color_ != nullptr ? getConsoleTimeStampColorFromString(color_) : std::nullopt);
+    }
+  }
+
+ private:
+  HighResTimeStamp startTime_{HighResTimeStamp::now()};
+  std::string_view name_;
+  const char *track_;
+  const char *trackGroup_;
+  const char *color_;
+  std::tuple<Args...> args_;
+};
+
+} // namespace facebook::react::jsinspector_modern::tracing