From 76969171c79706e200d21e23d8bb384348ea6156 Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <messmer@cryfs.org>
Date: Thu, 2 Aug 2018 23:49:45 -0700
Subject: [PATCH] Fix time::now() on windows and simplify implementation

---
 src/cpp-utils/system/time.cpp | 62 +++++------------------------------
 1 file changed, 9 insertions(+), 53 deletions(-)

diff --git a/src/cpp-utils/system/time.cpp b/src/cpp-utils/system/time.cpp
index f988182c..a599faa4 100644
--- a/src/cpp-utils/system/time.cpp
+++ b/src/cpp-utils/system/time.cpp
@@ -1,65 +1,21 @@
 #include "time.h"
+#include <chrono>
 
-#if defined(_MSC_VER)
-// Windows
-// Implementation taken from https://stackoverflow.com/a/31335254
+using std::chrono::system_clock;
+using std::chrono::duration_cast;
+using std::chrono::seconds;
+using std::chrono::nanoseconds;
 
-#include <Windows.h>
-constexpr __int64 exp7 = 10000000i64;            //1E+7
-constexpr __int64 exp9 = 1000000000i64;          //1E+9
-constexpr __int64 w2ux = 116444736000000000i64;  //1.jan1601 to 1.jan1970
 namespace cpputils {
 namespace time {
-struct timespec now() {
-	__int64 wintime;
-	GetSystemTimeAsFileTime((FILETIME*)&wintime);
-	wintime -= w2ux;
 
+struct timespec now() {
+	auto now = system_clock::now().time_since_epoch();
 	struct timespec spec;
-	spec.tv_sec = wintime / exp7;
-	spec.tv_nsec = wintime % exp7 * 100;
+	spec.tv_sec = duration_cast<seconds>(now).count();
+	spec.tv_nsec = duration_cast<nanoseconds>(now).count() % 1000000000;
 	return spec;
 }
-}
-}
-
-#elif defined(__MACH__) && !defined(CLOCK_REALTIME)
-// OSX before 10.12 has no clock_gettime
-// Implementation taken from: http://stackoverflow.com/a/9781275/829568
-// Caution: The returned value is less precise than the returned value from a linux clock_gettime would be.
-
-#include <sys/time.h>
-namespace cpputils {
-namespace time {
-
-struct timespec now() {
-	struct timeval now {};
-	int rv = gettimeofday(&now, nullptr);
-	if (rv) {
-		throw std::runtime_error("gettimeofday failed with " + std::to_string(rv));
-	}
-	struct timespec result;
-	result->tv_sec = now.tv_sec;
-	result->tv_nsec = now.tv_usec * 1000;
-	return now;
-}
 
 }
 }
-
-#else
-// Linux or OSX with clock_gettime implementation
-
-namespace cpputils {
-namespace time {
-
-struct timespec now() {
-    struct timespec now{};
-    clock_gettime(CLOCK_REALTIME, &now);
-    return now;
-}
-
-}
-}
-
-#endif
\ No newline at end of file