added benchmark test suite

test/utils/MetricsObserver.cpp

@@ -0,0 +1,51 @@
+#include "MetricsObserver.hpp"
+
+namespace matador::test {
+MetricsObserver::MetricsObserver(utils::message_bus& bus) {
+  subscriptions.push_back(bus.subscribe<sql::statement_lock_failed_event>([this](const sql::statement_lock_failed_event &ev) {
+    std::lock_guard lock(mutex_);
+    lock_failure_count_++;
+    total_lock_wait_time_ += ev.duration;
+  }));
+  subscriptions.push_back(bus.subscribe<sql::statement_execution_event>([this](const sql::statement_execution_event &ev) {
+    std::lock_guard lock(mutex_);
+    execution_count_++;
+    total_execution_time_ += ev.duration;
+  }));
+
+}
+
+std::chrono::milliseconds MetricsObserver::get_average_lock_wait_time() const {
+  std::lock_guard lock(mutex_);
+  if (lock_failure_count_ == 0) {
+    return std::chrono::milliseconds{0};
+  }
+  const auto millis = std::chrono::duration_cast<std::chrono::milliseconds>(total_lock_wait_time_);
+  return std::chrono::milliseconds(millis.count() / lock_failure_count_);
+}
+
+std::chrono::milliseconds MetricsObserver::get_average_execution_time() const {
+  std::lock_guard lock(mutex_);
+  if (execution_count_ == 0) {
+    return std::chrono::milliseconds{0};
+  }
+
+  const auto millis = std::chrono::duration_cast<std::chrono::milliseconds>(total_execution_time_);
+  return std::chrono::milliseconds(millis.count() / execution_count_);
+}
+
+std::chrono::milliseconds MetricsObserver::get_total_lock_wait_time() const {
+  std::lock_guard lock(mutex_);
+  return std::chrono::duration_cast<std::chrono::milliseconds>(total_lock_wait_time_);
+}
+
+std::chrono::milliseconds MetricsObserver::get_total_execution_time() const {
+  std::lock_guard lock(mutex_);
+  return std::chrono::duration_cast<std::chrono::milliseconds>(total_execution_time_);
+}
+
+size_t MetricsObserver::get_lock_failure_count() const {
+  std::lock_guard lock(mutex_);
+  return lock_failure_count_;
+}
+}