From 971fb6453c51f85d1d38675133fcc0cdbe79653d Mon Sep 17 00:00:00 2001
From: Ruslan Lesiutin <hoxy@meta.com>
Date: Fri, 4 Apr 2025 14:06:40 -0700
Subject: [PATCH] Disallow copying RuntimeSamplingProfile and Sample

Summary:
# Changelog:  [Internal]

We should avoid allocating multiple of these, since they can get really big.

`RuntimeSamplingProfile` may contain up to 10k of `Sample` for every second of sampling. Every `Sample` may contain up to 500 of call frames, each of which may have a copy of strings like `functionName` and `url`.

> NOTE: The actual logic for deduplicating strings and not allocating too many of them is not part of this diff and will be published separately. Even with deduplication, there is a reason to avoid copying the profile.

Reviewed By: javache

Differential Revision: D72254364

fbshipit-source-id: fa7907fb5cabbd2ac99d3e4e05a93bcb07f7f7c7
---
 .../jsinspector-modern/InstanceAgent.cpp         |  2 +-
 .../tracing/InstanceTracingProfile.h             |  7 ++-----
 .../tracing/RuntimeSamplingProfile.h             | 16 ++++++++++++++++
 ...untimeSamplingProfileTraceEventSerializer.cpp |  8 ++++----
 4 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/packages/react-native/ReactCommon/jsinspector-modern/InstanceAgent.cpp b/packages/react-native/ReactCommon/jsinspector-modern/InstanceAgent.cpp
index 1af9f9448c9..7b2cd6c7734 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/InstanceAgent.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/InstanceAgent.cpp
@@ -170,7 +170,7 @@ tracing::InstanceTracingProfile InstanceAgent::collectTracingProfile() {
   tracing::RuntimeSamplingProfile runtimeSamplingProfile =
       runtimeAgent_->collectSamplingProfile();
 
-  return tracing::InstanceTracingProfile{runtimeSamplingProfile};
+  return tracing::InstanceTracingProfile{std::move(runtimeSamplingProfile)};
 }
 
 } // namespace facebook::react::jsinspector_modern
diff --git a/packages/react-native/ReactCommon/jsinspector-modern/tracing/InstanceTracingProfile.h b/packages/react-native/ReactCommon/jsinspector-modern/tracing/InstanceTracingProfile.h
index 4e23beb7618..e4045ff54e7 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/tracing/InstanceTracingProfile.h
+++ b/packages/react-native/ReactCommon/jsinspector-modern/tracing/InstanceTracingProfile.h
@@ -9,15 +9,12 @@
 
 #include "RuntimeSamplingProfile.h"
 
-#include <memory>
-
 namespace facebook::react::jsinspector_modern::tracing {
 
 struct InstanceTracingProfile {
  public:
-  explicit InstanceTracingProfile(
-      const RuntimeSamplingProfile runtimeSamplingProfile)
-      : runtimeSamplingProfile_(runtimeSamplingProfile) {}
+  explicit InstanceTracingProfile(RuntimeSamplingProfile runtimeSamplingProfile)
+      : runtimeSamplingProfile_(std::move(runtimeSamplingProfile)) {}
 
   const RuntimeSamplingProfile& getRuntimeSamplingProfile() const {
     return runtimeSamplingProfile_;
diff --git a/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfile.h b/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfile.h
index aeb86d8948c..e6373029b06 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfile.h
+++ b/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfile.h
@@ -113,6 +113,14 @@ struct RuntimeSamplingProfile {
           threadId_(threadId),
           callStack_(std::move(callStack)) {}
 
+    // Movable.
+    Sample& operator=(Sample&&) = default;
+    Sample(Sample&&) = default;
+
+    // Not copyable.
+    Sample(const Sample&) = delete;
+    Sample& operator=(const Sample&) = delete;
+
     /// \return serialized unix timestamp in microseconds granularity. The
     /// moment when this sample was recorded.
     uint64_t getTimestamp() const {
@@ -143,6 +151,14 @@ struct RuntimeSamplingProfile {
   RuntimeSamplingProfile(std::string runtimeName, std::vector<Sample> samples)
       : runtimeName_(std::move(runtimeName)), samples_(std::move(samples)) {}
 
+  // Movable.
+  RuntimeSamplingProfile& operator=(RuntimeSamplingProfile&&) = default;
+  RuntimeSamplingProfile(RuntimeSamplingProfile&&) = default;
+
+  // Not copyable.
+  RuntimeSamplingProfile(const RuntimeSamplingProfile&) = delete;
+  RuntimeSamplingProfile& operator=(const RuntimeSamplingProfile&) = delete;
+
   /// \return name of the JavaScript runtime, where sampling occurred.
   const std::string& getRuntimeName() const {
     return runtimeName_;
diff --git a/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfileTraceEventSerializer.cpp b/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfileTraceEventSerializer.cpp
index c203e6da85e..573d4c566cb 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfileTraceEventSerializer.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/tracing/RuntimeSamplingProfileTraceEventSerializer.cpp
@@ -87,15 +87,15 @@ RuntimeSamplingProfileTraceEventSerializer::serializeAndNotify(
         notificationCallback,
     uint16_t traceEventChunkSize,
     uint16_t profileChunkSize) {
-  std::vector<RuntimeSamplingProfile::Sample> runtimeSamples =
+  const std::vector<RuntimeSamplingProfile::Sample>& samples =
       profile.getSamples();
-  if (runtimeSamples.empty()) {
+  if (samples.empty()) {
     return;
   }
 
   std::vector<folly::dynamic> buffer;
 
-  uint64_t chunkThreadId = runtimeSamples.front().getThreadId();
+  uint64_t chunkThreadId = samples.front().getThreadId();
   uint64_t tracingStartUnixTimestamp =
       formatTimePointToUnixTimestamp(tracingStartTime);
   buffer.push_back(performanceTracer.getSerializedRuntimeProfileTraceEvent(
@@ -151,7 +151,7 @@ RuntimeSamplingProfileTraceEventSerializer::serializeAndNotify(
           0,
           "(garbage collector)"};
   uint64_t chunkTimestamp = tracingStartUnixTimestamp;
-  for (const RuntimeSamplingProfile::Sample& sample : runtimeSamples) {
+  for (const RuntimeSamplingProfile::Sample& sample : samples) {
     uint64_t sampleThreadId = sample.getThreadId();
     // If next sample was recorded on a different thread, emit the current chunk
     // and continue.