From 64ae4c62a947b7438d93e32bfa7d26392992b6c3 Mon Sep 17 00:00:00 2001
From: Michael Mandl <mandlm@molez.net>
Date: Wed, 20 Mar 2024 09:58:40 +0100
Subject: [PATCH] refactor: return numerical value from timer

---
 lib_vector_search/include/timer.h |  7 ++++---
 lib_vector_search/src/timer.cpp   | 13 +++++--------
 vector_search_cli/main.cpp        | 13 ++++++++-----
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/lib_vector_search/include/timer.h b/lib_vector_search/include/timer.h
index 45226e4..c04724f 100644
--- a/lib_vector_search/include/timer.h
+++ b/lib_vector_search/include/timer.h
@@ -1,16 +1,17 @@
 #pragma once
 
 #include <chrono>
-#include <string>
 
 class Timer {
 private:
-  std::string name_;
   std::chrono::time_point<std::chrono::high_resolution_clock> start_;
+  std::chrono::time_point<std::chrono::high_resolution_clock> end_;
 
 public:
-  Timer(std::string_view name);
+  Timer();
 
   void start();
   void stop();
+
+  long us() const;
 };
diff --git a/lib_vector_search/src/timer.cpp b/lib_vector_search/src/timer.cpp
index 43987b5..960868c 100644
--- a/lib_vector_search/src/timer.cpp
+++ b/lib_vector_search/src/timer.cpp
@@ -1,17 +1,14 @@
 #include "timer.h"
 
 #include <chrono>
-#include <iostream>
 
-Timer::Timer(std::string_view name) : name_(name) { start(); };
+Timer::Timer() { start(); };
 
 void Timer::start() { start_ = std::chrono::high_resolution_clock::now(); }
 
-void Timer::stop() {
-  auto end = std::chrono::high_resolution_clock::now();
+void Timer::stop() { end_ = std::chrono::high_resolution_clock::now(); }
 
-  auto duration =
-      std::chrono::duration_cast<std::chrono::microseconds>(end - start_);
-
-  std::cout << name_ << " took " << duration << std::endl;
+long Timer::us() const {
+  return std::chrono::duration_cast<std::chrono::microseconds>(end_ - start_)
+      .count();
 }
diff --git a/vector_search_cli/main.cpp b/vector_search_cli/main.cpp
index f9c356e..f0377f9 100644
--- a/vector_search_cli/main.cpp
+++ b/vector_search_cli/main.cpp
@@ -13,10 +13,11 @@ using std::string, std::string_view, std::vector, std::thread, std::cout,
 vector<string> generate_word_list() {
   cout << "\ngenerating word list" << endl;
 
-  Timer generator_timer("word list generator");
+  Timer generator_timer;
   auto word_list = WordListGenerator().generate();
   generator_timer.stop();
 
+  cout << "word list generator took " << generator_timer.us() << " µs" << endl;
   cout << "word list is " << word_list.size() << " element(s) long" << endl;
 
   return word_list;
@@ -25,14 +26,15 @@ vector<string> generate_word_list() {
 void test_linear_finder(const vector<string> &word_list) {
   cout << "\nrunning linear finder" << endl;
 
-  Timer constructor_timer("linear finder constructor");
+  Timer constructor_timer;
   LinearFinder linear_finder(word_list);
   constructor_timer.stop();
 
-  Timer find_timer("linear finder find");
+  Timer find_timer;
   auto result = linear_finder.find_prefix("ABCD");
   find_timer.stop();
 
+  cout << "linear finder took " << find_timer.us() << " µs" << endl;
   cout << "result list is " << result.size() << " element(s) long" << endl;
 }
 
@@ -43,14 +45,15 @@ void test_parallel_finder(const vector<string> &word_list) {
 
   cout << "using " << thread_count << " threads" << endl;
 
-  Timer constructor_timer("parallel finder constructor");
+  Timer constructor_timer;
   ParallelFinder parallel_finder(word_list, thread_count);
   constructor_timer.stop();
 
-  Timer find_timer("parallel finder find");
+  Timer find_timer;
   auto result = parallel_finder.find_prefix("ABCD");
   find_timer.stop();
 
+  cout << "parallel finder took " << find_timer.us() << " µs" << endl;
   cout << "result list is " << result.size() << " element(s) long" << endl;
 }