From 2644dc8128276c91ae20a71c2010cc15460e9ffb Mon Sep 17 00:00:00 2001
From: Lucas Alber <lucasd.alber@gmail.com>
Date: Mon, 4 Nov 2024 13:03:14 +0100
Subject: [PATCH] merian: utils: Add formatter for stopwatch

---
 include/merian/utils/stopwatch.hpp |  4 ++++
 include/merian/utils/string.hpp    | 21 ++++++++++++++++-----
 src/merian/utils/stopwatch.cpp     |  9 +++++++++
 3 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/include/merian/utils/stopwatch.hpp b/include/merian/utils/stopwatch.hpp
index 67ac9b2d..dce0b647 100644
--- a/include/merian/utils/stopwatch.hpp
+++ b/include/merian/utils/stopwatch.hpp
@@ -17,8 +17,12 @@ class Stopwatch {
     double seconds() const;
     std::chrono::nanoseconds duration() const;
 
+    friend std::ostream& operator<<(std::ostream& stream, const Stopwatch& sw);
+
   private:
     chrono_clock::time_point start;
 };
 
+auto format_as(const Stopwatch& sw);
+
 } // namespace merian
diff --git a/include/merian/utils/string.hpp b/include/merian/utils/string.hpp
index a4b0dec5..68e37908 100644
--- a/include/merian/utils/string.hpp
+++ b/include/merian/utils/string.hpp
@@ -9,15 +9,26 @@
 
 namespace merian {
 
-[[nodiscard]] inline std::string format_size(const uint64_t size) {
-    std::vector<const char*> units = {"B", "KB", "MB", "GB", "TB"};
+[[nodiscard]] inline std::string format_size(const uint64_t size_bytes) {
+    const std::vector<const char*> units = {"B", "KB", "MB", "GB", "TB"};
     std::size_t unit_index;
-    if (size == 0) {
+    if (size_bytes == 0) {
         unit_index = 0;
     } else {
-        unit_index = std::min((std::size_t)std::log2(size) / 10, units.size() - 1);
+        unit_index = std::min((std::size_t)std::log2(size_bytes) / 10, units.size() - 1);
     }
-    return fmt::format("{} {}", size / std::pow(1024, unit_index), units[unit_index]);
+    return fmt::format("{} {}", (double)size_bytes / std::pow(1024, unit_index), units[unit_index]);
+}
+
+[[nodiscard]] inline std::string format_duration(const uint64_t duration_ns) {
+    const std::vector<const char*> units = {"ns", "μs", "ms", "s"};
+    std::size_t unit_index;
+    if (duration_ns == 0) {
+        unit_index = 0;
+    } else {
+        unit_index = std::min((std::size_t)(std::log10(duration_ns) / 3), units.size() - 1);
+    }
+    return fmt::format("{} {}", (double)duration_ns / std::pow(1000, unit_index), units[unit_index]);
 }
 
 [[nodiscard]] inline bool ends_with(const std::string& value, const std::string& suffix) {
diff --git a/src/merian/utils/stopwatch.cpp b/src/merian/utils/stopwatch.cpp
index 9c7b330c..ce826572 100644
--- a/src/merian/utils/stopwatch.cpp
+++ b/src/merian/utils/stopwatch.cpp
@@ -1,5 +1,6 @@
 #include "merian/utils/stopwatch.hpp"
 #include "merian/utils/chrono.hpp"
+#include "merian/utils/string.hpp"
 #include <atomic>
 
 namespace merian {
@@ -37,4 +38,12 @@ std::chrono::nanoseconds Stopwatch::duration() const {
     return end - start;
 }
 
+std::ostream& operator<<(std::ostream& stream, const Stopwatch& sw) {
+    return stream << format_duration(sw.nanos());
+}
+
+auto format_as(const Stopwatch& sw) {
+    return format_duration(sw.nanos());
+}
+
 } // namespace merian