Hide new functionality behind a flag

Author: szegedi

bindings/profilers/wall.cc

@@ -449,14 +449,17 @@ NAN_METHOD(WallProfiler::Start) {
   WallProfiler* wallProfiler =
       Nan::ObjectWrap::Unwrap<WallProfiler>(info.Holder());
 
-  if (info.Length() != 2) {
-    return Nan::ThrowTypeError("Start must have two arguments.");
+  if (info.Length() != 3) {
+    return Nan::ThrowTypeError("Start must have three arguments.");
   }
   if (!info[0]->IsString()) {
     return Nan::ThrowTypeError("Profile name must be a string.");
   }
   if (!info[1]->IsBoolean()) {
-    return Nan::ThrowTypeError("Include lines must be a boolean.");
+    return Nan::ThrowTypeError("Include lines flag must be a boolean.");
+  }
+  if (!info[2]->IsBoolean()) {
+    return Nan::ThrowTypeError("With labels flag must be a boolean.");
   }
 
   Local<String> name =
@@ -465,29 +468,34 @@ NAN_METHOD(WallProfiler::Start) {
   bool includeLines =
       Nan::MaybeLocal<Boolean>(info[1].As<Boolean>()).ToLocalChecked()->Value();
 
-  wallProfiler->StartImpl(name, includeLines);
+  bool withLabels =
+      Nan::MaybeLocal<Boolean>(info[2].As<Boolean>()).ToLocalChecked()->Value();
 
-#ifdef DD_WALL_USE_SIGPROF
-  struct sigaction sa, old_sa;
-  sa.sa_flags = SA_SIGINFO | SA_RESTART;
-  sa.sa_sigaction = &sighandler;
-  sigemptyset(&sa.sa_mask);
-  sigaction(SIGPROF, &sa, &old_sa);
+  wallProfiler->StartImpl(name, includeLines, withLabels);
 
-  // At the end of a cycle start is called before stop,
-  // at this point old_sa.sa_sigaction is sighandler !
-  if (!old_handler) {
-    old_handler = old_sa.sa_sigaction;
+#ifdef DD_WALL_USE_SIGPROF
+  if (withLabels) {
+    struct sigaction sa, old_sa;
+    sa.sa_flags = SA_SIGINFO | SA_RESTART;
+    sa.sa_sigaction = &sighandler;
+    sigemptyset(&sa.sa_mask);
+    sigaction(SIGPROF, &sa, &old_sa);
+
+    // At the end of a cycle start is called before stop,
+    // at this point old_sa.sa_sigaction is sighandler !
+    if (!old_handler) {
+      old_handler = old_sa.sa_sigaction;
+    }
   }
 #endif
 }
 
-void WallProfiler::StartImpl(Local<String> name, bool includeLines) {
+void WallProfiler::StartImpl(Local<String> name, bool includeLines, bool withLabels) {
   if (includeLines) {
     GetProfiler()->StartProfiling(
-        name, CpuProfilingMode::kCallerLineNumbers, true);
+        name, CpuProfilingMode::kCallerLineNumbers, withLabels);
   } else {
-    GetProfiler()->StartProfiling(name, true);
+    GetProfiler()->StartProfiling(name, withLabels);
   }
 
   last_start = current_start;

bindings/profilers/wall.hh

@@ -63,7 +63,7 @@ class WallProfiler : public Nan::ObjectWrap {
   }
 
   void PushContext();
-  void StartImpl(v8::Local<v8::String> name, bool includeLines);
+  void StartImpl(v8::Local<v8::String> name, bool includeLines, bool withLabels);
   v8::Local<v8::Value> StopImpl(v8::Local<v8::String> name, bool includeLines);
 
   static NAN_METHOD(New);

ts/src/time-profiler.ts

@@ -62,30 +62,49 @@ function ensureRunName(name?: string) {
   return name || `pprof-${Date.now()}-${Math.random()}`;
 }
 
-// Retained for backwards compatibility with older tracer
+// Temporarily retained for backwards compatibility with older tracer
 export function start(
   intervalMicros: Microseconds = DEFAULT_INTERVAL_MICROS,
   name?: string,
   sourceMapper?: SourceMapper,
   lineNumbers = true
 ) {
-  const {stop} = startWithLabels(
+  const {stop} = startInternal(
     intervalMicros,
     DEFAULT_DURATION_MILLIS,
     name,
     sourceMapper,
-    lineNumbers
+    lineNumbers,
+    false
   );
   return stop;
 }
 
-// NOTE: refreshing doesn't work if giving a profile name.
 export function startWithLabels(
   intervalMicros: Microseconds = DEFAULT_INTERVAL_MICROS,
   durationMillis: Milliseconds = DEFAULT_DURATION_MILLIS,
   name?: string,
   sourceMapper?: SourceMapper,
   lineNumbers = true
+) {
+  return startInternal(
+    intervalMicros,
+    durationMillis,
+    name,
+    sourceMapper,
+    lineNumbers,
+    true
+  )
+}
+
+// NOTE: refreshing doesn't work if giving a profile name.
+function startInternal(
+  intervalMicros: Microseconds,
+  durationMillis: Milliseconds,
+  name?: string,
+  sourceMapper?: SourceMapper,
+  lineNumbers?: boolean,
+  withLabels?: boolean
 ) {
   const profiler = new TimeProfiler(intervalMicros, durationMillis * 1000);
   let runName = start();
@@ -97,7 +116,7 @@ export function startWithLabels(
 
   function start() {
     const runName = ensureRunName(name);
-    profiler.start(runName, lineNumbers);
+    profiler.start(runName, lineNumbers, withLabels);
     return runName;
   }