src: use unique_ptr for internal JSON trace writer

PR-URL: #21867 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Eugene Ostroukhov <[email protected]> Reviewed-By: Ali Ijaz Sheikh <[email protected]>

Author: addaleax

src/tracing/node_trace_writer.cc

@@ -37,9 +37,7 @@ void NodeTraceWriter::WriteSuffix(){
 {
  Mutex::ScopedLock scoped_lock(stream_mutex_);
 if (total_traces_ > 0){
- total_traces_ = 0; // so we don't write it again in FlushPrivate
-// Appends "]}" to stream_.
-delete json_trace_writer_;
+ total_traces_ = kTracesPerFile; // Act as if we reached the file limit.
  should_flush = true;
  }
  }
@@ -111,7 +109,7 @@ void NodeTraceWriter::AppendTraceEvent(TraceObject* trace_event){
 // to a state where we can start writing trace events to it.
 // Repeatedly constructing and destroying json_trace_writer_ allows
 // us to use V8's JSON writer instead of implementing our own.
- json_trace_writer_ = TraceWriter::CreateJSONTraceWriter(stream_);
+ json_trace_writer_.reset(TraceWriter::CreateJSONTraceWriter(stream_));
  }
  ++total_traces_;
  json_trace_writer_->AppendTraceEvent(trace_event);
@@ -126,7 +124,7 @@ void NodeTraceWriter::FlushPrivate(){
  total_traces_ = 0;
 // Destroying the member JSONTraceWriter object appends "]}" to
 // stream_ - in other words, ending a JSON file.
-deletejson_trace_writer_;
+ json_trace_writer_.reset();
  }
 // str() makes a copy of the contents of the stream.
  str = stream_.str();

src/tracing/node_trace_writer.h

@@ -63,7 +63,7 @@ class NodeTraceWriter : public AsyncTraceWriter{
 int file_num_ = 0;
 const std::string& log_file_pattern_;
  std::ostringstream stream_;
- TraceWriter* json_trace_writer_ = nullptr;
+std::unique_ptr<TraceWriter> json_trace_writer_;
 bool exited_ = false;
 };