inspector: implement --heap-prof

In addition implements --heap-prof-name, --heap-prof-dir and
--heap-prof-interval.
These flags are similar to --cpu-prof flags but they are meant
for the V8 sampling heap profiler instead of the CPU profiler.

PR-URL: https://github.com/nodejs/node/pull/27596
Fixes: https://github.com/nodejs/node/issues/27421
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 58 insertions, 0 deletions

diff --git a/src/inspector_profiler.cc b/src/inspector_profiler.cc
index 2a1559f8f97..1b20398dba4 100644
--- a/src/inspector_profiler.cc
+++ b/src/inspector_profiler.cc
@@ -258,6 +258,44 @@ void V8CpuProfilerConnection::End() {
   DispatchMessage("Profiler.stop");
 }
 
+std::string V8HeapProfilerConnection::GetDirectory() const {
+  return env()->heap_prof_dir();
+}
+
+std::string V8HeapProfilerConnection::GetFilename() const {
+  return env()->heap_prof_name();
+}
+
+MaybeLocal<Object> V8HeapProfilerConnection::GetProfile(Local<Object> result) {
+  Local<Value> profile_v;
+  if (!result
+           ->Get(env()->context(),
+                 FIXED_ONE_BYTE_STRING(env()->isolate(), "profile"))
+           .ToLocal(&profile_v)) {
+    fprintf(stderr, "'profile' from heap profile result is undefined\n");
+    return MaybeLocal<Object>();
+  }
+  if (!profile_v->IsObject()) {
+    fprintf(stderr, "'profile' from heap profile result is not an Object\n");
+    return MaybeLocal<Object>();
+  }
+  return profile_v.As<Object>();
+}
+
+void V8HeapProfilerConnection::Start() {
+  DispatchMessage("HeapProfiler.enable");
+  std::string params = R"({ "samplingInterval": )";
+  params += std::to_string(env()->heap_prof_interval());
+  params += " }";
+  DispatchMessage("HeapProfiler.startSampling", params.c_str());
+}
+
+void V8HeapProfilerConnection::End() {
+  CHECK_EQ(ending_, false);
+  ending_ = true;
+  DispatchMessage("HeapProfiler.stopSampling");
+}
+
 // For now, we only support coverage profiling, but we may add more
 // in the future.
 void EndStartedProfilers(Environment* env) {
@@ -268,6 +306,12 @@ void EndStartedProfilers(Environment* env) {
     connection->End();
   }
 
+  connection = env->heap_profiler_connection();
+  if (connection != nullptr && !connection->ending()) {
+    Debug(env, DebugCategory::INSPECTOR_PROFILER, "Ending heap profiling\n");
+    connection->End();
+  }
+
   connection = env->coverage_connection();
   if (connection != nullptr && !connection->ending()) {
     Debug(
@@ -313,6 +357,20 @@ void StartProfilers(Environment* env) {
         std::make_unique<V8CpuProfilerConnection>(env));
     env->cpu_profiler_connection()->Start();
   }
+  if (env->options()->heap_prof) {
+    const std::string& dir = env->options()->heap_prof_dir;
+    env->set_heap_prof_interval(env->options()->heap_prof_interval);
+    env->set_heap_prof_dir(dir.empty() ? GetCwd() : dir);
+    if (env->options()->heap_prof_name.empty()) {
+      DiagnosticFilename filename(env, "Heap", "heapprofile");
+      env->set_heap_prof_name(*filename);
+    } else {
+      env->set_heap_prof_name(env->options()->heap_prof_name);
+    }
+    env->set_heap_profiler_connection(
+        std::make_unique<profiler::V8HeapProfilerConnection>(env));
+    env->heap_profiler_connection()->Start();
+  }
 }
 
 static void SetCoverageDirectory(const FunctionCallbackInfo<Value>& args) {