Added 100ns as timestamp resolution.

UniStuttgart-VISUS · Jun 25, 2023 · 4cc2a94 · 4cc2a94
1 parent d792e63
commit 4cc2a94
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Showing 5 changed files with 69 additions and 22 deletions.
diff --git a/power_overwhelming/include/power_overwhelming/timestamp_resolution.h b/power_overwhelming/include/power_overwhelming/timestamp_resolution.h
@@ -29,6 +29,12 @@ namespace power_overwhelming {
         /// </summary>
         microseconds,
 
+        /// <summary>
+        /// Timestamp is specified in units of hundred nanoseconds (the native
+        /// quantity of many Windows APIs).
+        /// </summary>
+        hundred_nanoseconds,
+
         /// <summary>
         /// Timestamp is specified in nanoseconds (Billionth of a second).
         /// </summary>

diff --git a/power_overwhelming/src/timestamp.cpp b/power_overwhelming/src/timestamp.cpp
@@ -11,10 +11,10 @@
  */
 visus::power_overwhelming::timestamp_type
 visus::power_overwhelming::detail::convert(
-        const timestamp_type fileTime,
+        const timestamp_type file_time,
         const timestamp_resolution resolution) {
     using namespace std::chrono;
-    duration<decltype(fileTime), filetime_period> ft(fileTime);
+    duration<decltype(file_time), filetime_period> ft(file_time);
 
     switch (resolution) {
         case timestamp_resolution::microseconds:
@@ -26,11 +26,14 @@ visus::power_overwhelming::detail::convert(
         case timestamp_resolution::nanoseconds:
             return duration_cast<nanoseconds>(ft).count();
 
+        case timestamp_resolution::hundred_nanoseconds:
+            return file_time;
+
         case timestamp_resolution::seconds:
             return duration_cast<seconds>(ft).count();
 
         default:
-            return fileTime;
+            return file_time;
     }
 }
 

diff --git a/power_overwhelming/src/timestamp.h b/power_overwhelming/src/timestamp.h
@@ -41,26 +41,27 @@ namespace detail {
     /// This API is only exposed for unit tests and should not be accessed by
     /// any other clients.
     /// </remarks>
-    /// <param name="fileTime">The file time value in 100ns units.</param>
+    /// <param name="file_time">The file time value in 100ns units.</param>
     /// <param name="resolution">The desired resolution of the timestamp.
     /// </param>
     /// <returns>The timestamp in the requested resolution.</returns>
-    timestamp_type POWER_OVERWHELMING_API convert(const timestamp_type fileTime,
+    timestamp_type POWER_OVERWHELMING_API convert(
+        const timestamp_type file_time,
         const timestamp_resolution resolution);
 
 #if defined(_WIN32)
     /// <summary>
     /// Convert the given raw <see cref="LARGE_INTEGER" /> to a timestamp of the
     /// specified resolution.
     /// </summary>
-    /// <param name="fileTime">The file time value in 100ns units.</param>
+    /// <param name="file_time">The file time value in 100ns units.</param>
     /// <param name="resolution">The desired resolution of the timestamp.
     /// </param>
     /// <returns>The timestamp in the requested resolution.</returns>
     inline POWER_OVERWHELMING_API decltype(LARGE_INTEGER::QuadPart) convert(
-            const LARGE_INTEGER& fileTime,
+            const LARGE_INTEGER& file_time,
             const timestamp_resolution resolution) {
-        return convert(fileTime.QuadPart, resolution);
+        return convert(file_time.QuadPart, resolution);
     }
 #endif /* defined(_WIN32) */
 

diff --git a/power_overwhelming/src/timestamp.inl b/power_overwhelming/src/timestamp.inl
@@ -58,10 +58,11 @@ visus::power_overwhelming::detail::convert(
             TDuration>& timestamp,
         _In_ const timestamp_resolution resolution) {
     using namespace std::chrono;
+    typedef duration<timestamp_type, filetime_period> filetime_dur;
 
     // The offset of the FILETIME epoch to the UNIX epoch.
     const auto dz = duration<timestamp_type,
-        detail::filetime_period>(11644473600000LL);
+        detail::filetime_period>(116444736000000000LL);
 
     // Find out what the difference between the time point and the UNIX
     // epoch is. Because we cannot rely on the epoch of the STL clock being the
@@ -72,6 +73,9 @@ visus::power_overwhelming::detail::convert(
 
     // Transform the origin of the timestamp clock to the origin of FILETIME.
     switch (resolution) {
+        case timestamp_resolution::hundred_nanoseconds:
+            return duration_cast<filetime_dur>(dt + dz).count();
+
         case timestamp_resolution::microseconds:
             return duration_cast<microseconds>(dt + dz).count();
 

diff --git a/test/timestamp_test.cpp b/test/timestamp_test.cpp
@@ -38,36 +38,69 @@ namespace test {
             this->_system_zero = std::chrono::system_clock::from_time_t(0);
         }
 
+        TEST_METHOD(test_convert) {
+            auto a = detail::convert(std::chrono::system_clock::from_time_t(0), timestamp_resolution::hundred_nanoseconds);
+            Assert::AreEqual(this->_filetime_zero, a, L"Unix epoch as FILETIME", LINE_INFO());
+        }
+
         TEST_METHOD(test_microseconds) {
+            typedef std::chrono::microseconds unit;
+            static const auto resolution = timestamp_resolution::microseconds;
+            const auto max_dt = std::chrono::duration_cast<unit>(std::chrono::milliseconds(100)).count();
+
             auto n = std::chrono::system_clock::now();
-            auto t = detail::create_timestamp(timestamp_resolution::microseconds);
-            auto s = std::chrono::duration_cast<std::chrono::microseconds>(n - this->_system_zero).count();
-            auto z = detail::convert(this->_filetime_zero, timestamp_resolution::microseconds);
-            Assert::IsTrue(s - z - t < 1000000, L"timestamp microsecond", LINE_INFO());
+            auto t = detail::create_timestamp(resolution);
+            auto s = std::chrono::duration_cast<unit>(n - this->_system_zero).count();
+            auto z = detail::convert(this->_filetime_zero, resolution);
+            Assert::IsTrue(s - z - t < max_dt, L"timestamp microsecond", LINE_INFO());
         }
 
         TEST_METHOD(test_milliseconds) {
+            typedef std::chrono::milliseconds unit;
+            static const auto resolution = timestamp_resolution::milliseconds;
+            const auto max_dt = std::chrono::duration_cast<unit>(std::chrono::milliseconds(100)).count();
+
             auto n = std::chrono::system_clock::now();
             auto t = detail::create_timestamp(timestamp_resolution::milliseconds);
             auto s = std::chrono::duration_cast<std::chrono::milliseconds>(n - this->_system_zero).count();
             auto z = detail::convert(this->_filetime_zero, timestamp_resolution::milliseconds);
-            Assert::IsTrue(t - z - s < 1000, L"timestamp millisecond", LINE_INFO());
+            Assert::IsTrue(t - z - s < max_dt, L"timestamp millisecond", LINE_INFO());
+        }
+
+        TEST_METHOD(test_hundred_nanoseconds) {
+            typedef std::chrono::duration<std::chrono::system_clock::duration::rep, detail::filetime_period> unit;
+            static const auto resolution = timestamp_resolution::milliseconds;
+            const auto max_dt = std::chrono::duration_cast<unit>(std::chrono::milliseconds(100)).count();
+
+            auto n = std::chrono::system_clock::now();
+            auto t = detail::create_timestamp(resolution);
+            auto s = std::chrono::duration_cast<unit>(n - this->_system_zero).count();
+            auto z = detail::convert(this->_filetime_zero, resolution);
+            Assert::IsTrue(t - z - s < max_dt, L"timestamp 100 nanoseconds", LINE_INFO());
         }
 
         TEST_METHOD(test_nanoseconds) {
+            typedef std::chrono::milliseconds unit;
+            static const auto resolution = timestamp_resolution::milliseconds;
+            const auto max_dt = std::chrono::duration_cast<unit>(std::chrono::milliseconds(100)).count();
+
             auto n = std::chrono::system_clock::now();
-            auto t = detail::create_timestamp(timestamp_resolution::nanoseconds);
-            auto s = std::chrono::duration_cast<std::chrono::nanoseconds>(n - this->_system_zero).count();
-            auto z = detail::convert(this->_filetime_zero, timestamp_resolution::nanoseconds);
-            Assert::IsTrue(t - z - s < 1000000000, L"timestamp nanosecond", LINE_INFO());
+            auto t = detail::create_timestamp(resolution);
+            auto s = std::chrono::duration_cast<unit>(n - this->_system_zero).count();
+            auto z = detail::convert(this->_filetime_zero, resolution);
+            Assert::IsTrue(t - z - s < max_dt, L"timestamp nanosecond", LINE_INFO());
         }
 
         TEST_METHOD(test_seconds) {
+            typedef std::chrono::seconds unit;
+            static const auto resolution = timestamp_resolution::seconds;
+            const auto max_dt = std::chrono::duration_cast<unit>(std::chrono::milliseconds(100)).count();
+
             auto n = std::chrono::system_clock::now();
-            auto t = detail::create_timestamp(timestamp_resolution::seconds);
-            auto s = std::chrono::duration_cast<std::chrono::seconds>(n - this->_system_zero).count();
-            auto z = detail::convert(this->_filetime_zero, timestamp_resolution::seconds);
-            Assert::IsTrue(s - z - t < 1, L"timestamp second", LINE_INFO());
+            auto t = detail::create_timestamp(resolution);
+            auto s = std::chrono::duration_cast<unit>(n - this->_system_zero).count();
+            auto z = detail::convert(this->_filetime_zero, resolution);
+            Assert::IsTrue(s - z - t < max_dt, L"timestamp second", LINE_INFO());
         }
 
     private: