Optimize report sending by re-use protobuf

src/istio/mixerclient/attribute_compressor.cc

@@ -58,6 +58,11 @@ class MessageDictionary {
 
   const std::vector<std::string>& GetWords() const { return message_words_; }
 
+  void Clear() {
+    message_words_.clear();
+    message_dict_.clear();
+  }
+
  private:
   const GlobalDictionary& global_dict_;
 
@@ -121,28 +126,31 @@ void CompressByDict(const Attributes& attributes, MessageDictionary& dict,
 class BatchCompressorImpl : public BatchCompressor {
  public:
   BatchCompressorImpl(const GlobalDictionary& global_dict)
-      : dict_(global_dict), report_(new ::istio::mixer::v1::ReportRequest) {
-    report_->set_global_word_count(global_dict.size());
+      : dict_(global_dict) {
+    report_.set_global_word_count(global_dict.size());
   }
 
   void Add(const Attributes& attributes) override {
-    CompressedAttributes pb;
-    CompressByDict(attributes, dict_, &pb);
-    pb.GetReflection()->Swap(report_->add_attributes(), &pb);
+    CompressByDict(attributes, dict_, report_.add_attributes());
   }
 
-  int size() const override { return report_->attributes_size(); }
+  int size() const override { return report_.attributes_size(); }
 
-  std::unique_ptr<::istio::mixer::v1::ReportRequest> Finish() override {
+  const ::istio::mixer::v1::ReportRequest& Finish() override {
     for (const std::string& word : dict_.GetWords()) {
-      report_->add_default_words(word);
+      report_.add_default_words(word);
     }
-    return std::move(report_);
+    return report_;
+  }
+
+  void Clear() override {
+    dict_.Clear();
+    report_.Clear();
   }
 
  private:
   MessageDictionary dict_;
-  std::unique_ptr<::istio::mixer::v1::ReportRequest> report_;
+  ::istio::mixer::v1::ReportRequest report_;
 };
 
 }  // namespace

src/istio/mixerclient/attribute_compressor.h

@@ -56,7 +56,10 @@ class BatchCompressor {
   virtual int size() const = 0;
 
   // Finish the batch and create the batched report request.
-  virtual std::unique_ptr<::istio::mixer::v1::ReportRequest> Finish() = 0;
+  virtual const ::istio::mixer::v1::ReportRequest& Finish() = 0;
+
+  // Reset the object data.
+  virtual void Clear() = 0;
 };
 
 // Compress attributes.

src/istio/mixerclient/attribute_compressor_test.cc

@@ -337,14 +337,14 @@ TEST_F(AttributeCompressorTest, BatchCompressTest) {
   auto report_pb = batch_compressor->Finish();
 
   std::string out_str;
-  TextFormat::PrintToString(*report_pb, &out_str);
+  TextFormat::PrintToString(report_pb, &out_str);
   GOOGLE_LOG(INFO) << "===" << out_str << "===";
 
   ::istio::mixer::v1::ReportRequest expected_report_pb;
   ASSERT_TRUE(
       TextFormat::ParseFromString(kReportAttributes, &expected_report_pb));
-  report_pb->set_global_word_count(221);
-  EXPECT_TRUE(MessageDifferencer::Equals(*report_pb, expected_report_pb));
+  report_pb.set_global_word_count(221);
+  EXPECT_TRUE(MessageDifferencer::Equals(report_pb, expected_report_pb));
 }
 
 }  // namespace

src/istio/mixerclient/report_batch.cc

@@ -33,6 +33,7 @@ ReportBatch::ReportBatch(const ReportOptions& options,
       transport_(transport),
       timer_create_(timer_create),
       compressor_(compressor),
+      batch_compressor_(compressor.CreateBatchCompressor()),
       total_report_calls_(0),
       total_remote_report_calls_(0) {}
 
@@ -41,10 +42,6 @@ ReportBatch::~ReportBatch() { Flush(); }
 void ReportBatch::Report(const Attributes& request) {
   std::lock_guard<std::mutex> lock(mutex_);
   ++total_report_calls_;
-  if (!batch_compressor_) {
-    batch_compressor_ = compressor_.CreateBatchCompressor();
-  }
-
   batch_compressor_->Add(request);
   if (batch_compressor_->size() >= options_.max_batch_entries) {
     FlushWithLock();
@@ -59,19 +56,18 @@ void ReportBatch::Report(const Attributes& request) {
 }
 
 void ReportBatch::FlushWithLock() {
-  if (!batch_compressor_) {
+  if (batch_compressor_->size() == 0) {
     return;
   }
 
-  ++total_remote_report_calls_;
-  std::unique_ptr<ReportRequest> request = batch_compressor_->Finish();
-  batch_compressor_.reset();
   if (timer_) {
     timer_->Stop();
   }
 
+  ++total_remote_report_calls_;
+  auto request = batch_compressor_->Finish();
   ReportResponse* response = new ReportResponse;
-  transport_(*request, response, [this, response](const Status& status) {
+  transport_(request, response, [this, response](const Status& status) {
     delete response;
     if (!status.ok()) {
       GOOGLE_LOG(ERROR) << "Mixer Report failed with: " << status.ToString();
@@ -80,6 +76,8 @@ void ReportBatch::FlushWithLock() {
       }
     }
   });
+
+  batch_compressor_->Clear();
 }
 
 void ReportBatch::Flush() {

src/istio/mixerclient/report_batch_test.cc

@@ -65,7 +65,7 @@ class ReportBatchTest : public ::testing::Test {
     };
   }
 
-  MockReportTransport mock_report_transport_;
+  ::testing::NiceMock<MockReportTransport> mock_report_transport_;
   MockTimer* mock_timer_;
   AttributeCompressor compressor_;
   std::unique_ptr<ReportBatch> batch_;