From 3ecc67784aa9ee44953c743362023015e9a09a56 Mon Sep 17 00:00:00 2001
From: Alexander Karatarakis <alkarata@microsoft.com>
Date: Mon, 10 Oct 2016 18:12:26 -0700
Subject: Add Stopwatch class

---
 toolsrc/include/Stopwatch.h                     |  40 +++++++++
 toolsrc/src/Stopwatch.cpp                       | 104 ++++++++++++++++++++++++
 toolsrc/vcpkgcommon/vcpkgcommon.vcxproj         |   2 +
 toolsrc/vcpkgcommon/vcpkgcommon.vcxproj.filters |   6 ++
 4 files changed, 152 insertions(+)
 create mode 100644 toolsrc/include/Stopwatch.h
 create mode 100644 toolsrc/src/Stopwatch.cpp

diff --git a/toolsrc/include/Stopwatch.h b/toolsrc/include/Stopwatch.h
new file mode 100644
index 000000000..2bd5c31bf
--- /dev/null
+++ b/toolsrc/include/Stopwatch.h
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <chrono>
+#include <string>
+
+namespace vcpkg
+{
+    class Stopwatch
+    {
+    public:
+        static Stopwatch createUnstarted();
+
+        static Stopwatch createStarted();
+
+        bool isRunning() const;
+
+        Stopwatch& start();
+
+        Stopwatch& stop();
+
+        Stopwatch& reset();
+
+        template <class TimeUnit>
+        TimeUnit elapsed() const
+        {
+            return std::chrono::duration_cast<TimeUnit>(elapsedNanos());
+        }
+
+        std::string toString() const;
+
+    private:
+        Stopwatch();
+
+        std::chrono::nanoseconds elapsedNanos() const;
+
+        bool m_isRunning;
+        std::chrono::nanoseconds m_elapsedNanos;
+        std::chrono::steady_clock::time_point m_startTick;
+    };
+}
diff --git a/toolsrc/src/Stopwatch.cpp b/toolsrc/src/Stopwatch.cpp
new file mode 100644
index 000000000..035d54c2b
--- /dev/null
+++ b/toolsrc/src/Stopwatch.cpp
@@ -0,0 +1,104 @@
+#include "Stopwatch.h"
+#include "vcpkg_Checks.h"
+
+namespace vcpkg
+{
+    Stopwatch Stopwatch::createUnstarted()
+    {
+        return Stopwatch();
+    }
+
+    Stopwatch Stopwatch::createStarted()
+    {
+        return Stopwatch().start();
+    }
+
+    bool Stopwatch::isRunning() const
+    {
+        return this->m_isRunning;
+    }
+
+    Stopwatch& Stopwatch::start()
+    {
+        Checks::check_exit(!this->m_isRunning, "This stopwatch is already running.");
+        this->m_isRunning = true;
+        this->m_startTick = std::chrono::high_resolution_clock::now();
+        return *this;
+    }
+
+    Stopwatch& Stopwatch::stop()
+    {
+        auto tick = std::chrono::high_resolution_clock::now();
+        Checks::check_exit(this->m_isRunning, "This stopwatch is already stopped.");
+        this->m_isRunning = false;
+        this->m_elapsedNanos += tick - this->m_startTick;
+        return *this;
+    }
+
+    Stopwatch& Stopwatch::reset()
+    {
+        this->m_elapsedNanos = std::chrono::nanoseconds();
+        this->m_isRunning = false;
+        return *this;
+    }
+
+    std::string Stopwatch::toString() const
+    {
+        using std::chrono::hours;
+        using std::chrono::minutes;
+        using std::chrono::seconds;
+        using std::chrono::milliseconds;
+        using std::chrono::microseconds;
+        using std::chrono::nanoseconds;
+        using std::chrono::duration_cast;
+
+        auto nanos = elapsedNanos();
+        auto nanos_as_double = static_cast<double>(nanos.count());
+
+        if (duration_cast<hours>(nanos) > hours())
+        {
+            auto t = nanos_as_double / duration_cast<nanoseconds>(hours(1)).count();
+            return Strings::format("%.4g h", t);
+        }
+
+        if (duration_cast<minutes>(nanos) > minutes())
+        {
+            auto t = nanos_as_double / duration_cast<nanoseconds>(minutes(1)).count();
+            return Strings::format("%.4g min", t);
+        }
+
+        if (duration_cast<seconds>(nanos) > seconds())
+        {
+            auto t = nanos_as_double / duration_cast<nanoseconds>(seconds(1)).count();
+            return Strings::format("%.4g s", t);
+        }
+
+        if (duration_cast<milliseconds>(nanos) > milliseconds())
+        {
+            auto t = nanos_as_double / duration_cast<nanoseconds>(milliseconds(1)).count();
+            return Strings::format("%.4g ms", t);
+        }
+
+        if (duration_cast<microseconds>(nanos) > microseconds())
+        {
+            auto t = nanos_as_double / duration_cast<nanoseconds>(microseconds(1)).count();
+            return Strings::format("%.4g micros", t);
+        }
+
+        return Strings::format("%.4g ns", nanos_as_double);
+    }
+
+    Stopwatch::Stopwatch() : m_isRunning(false), m_elapsedNanos(), m_startTick()
+    {
+    }
+
+    std::chrono::nanoseconds Stopwatch::elapsedNanos() const
+    {
+        if (this->m_isRunning)
+        {
+            return std::chrono::high_resolution_clock::now() - this->m_startTick + this->m_elapsedNanos;
+        }
+
+        return this->m_elapsedNanos;
+    }
+}
diff --git a/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj b/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj
index d5e68fde3..218a826ad 100644
--- a/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj
+++ b/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj
@@ -120,6 +120,7 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="..\src\Stopwatch.cpp" />
     <ClCompile Include="..\src\vcpkg_Checks.cpp" />
     <ClCompile Include="..\src\vcpkg_Files.cpp" />
     <ClCompile Include="..\src\vcpkg_Strings.cpp" />
@@ -128,6 +129,7 @@
   <ItemGroup>
     <ClInclude Include="..\include\expected.h" />
     <ClInclude Include="..\include\opt_bool.h" />
+    <ClInclude Include="..\include\Stopwatch.h" />
     <ClInclude Include="..\include\vcpkg_Checks.h" />
     <ClInclude Include="..\include\vcpkg_Files.h" />
     <ClInclude Include="..\include\vcpkg_Graphs.h" />
diff --git a/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj.filters b/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj.filters
index ae747d687..4d40bfbe2 100644
--- a/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj.filters
+++ b/toolsrc/vcpkgcommon/vcpkgcommon.vcxproj.filters
@@ -27,6 +27,9 @@
     <ClCompile Include="..\src\vcpkg_Files.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\Stopwatch.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\include\vcpkg_Checks.h">
@@ -56,5 +59,8 @@
     <ClInclude Include="..\include\vcpkg_Sets.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\include\Stopwatch.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file
-- 
cgit v1.2.3