commit 2c98676dca920b736b937ad33004bc05b75a450d
author Ed Tanous <edtanous@google.com> Sat Jul 23 17:32:15 2022 -0700
committer Ed Tanous <ed@tanous.net> Wed Aug 10 15:58:16 2022 +0000
tree 3dad8aa0a61f5127b064c1436f31f265a2ed49ae
parent 0553fb5703a0020e76bf5eef7dede50b3679ac82

Support micro and milli resolution on timestamps

Supporting higher precision on our timestamps seems worthwhile, and
useful to logging implementations for getting more accurate numbers from
redfish LogService interfaces.

This commit updates the code to add millisecond and microsecond
precision to timestamps.

Tested: Unit tests pass, pretty good coverage here.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I0914908966702a6cf1bcb59f22761dc24c46b4c3

http/ut/utility_test.cpp

diff --git a/http/ut/utility_test.cpp b/http/ut/utility_test.cpp
index a1125b4..8bc122f 100644
--- a/http/ut/utility_test.cpp
+++ b/http/ut/utility_test.cpp
@@ -118,11 +118,24 @@
 
 TEST(Utility, GetDateTimeUintMs)
 {
+    EXPECT_EQ(getDateTimeUintMs(uint64_t{1638312095123}),
+              "2021-11-30T22:41:35.123+00:00");
     // returns the maximum Redfish date
     EXPECT_EQ(getDateTimeUintMs(std::numeric_limits<uint64_t>::max()),
-              "9999-12-31T23:59:59+00:00");
+              "9999-12-31T23:59:59.999+00:00");
     EXPECT_EQ(getDateTimeUintMs(std::numeric_limits<uint64_t>::min()),
-              "1970-01-01T00:00:00+00:00");
+              "1970-01-01T00:00:00.000+00:00");
+}
+
+TEST(Utility, GetDateTimeUintUs)
+{
+    EXPECT_EQ(getDateTimeUintUs(uint64_t{1638312095123456}),
+              "2021-11-30T22:41:35.123456+00:00");
+    // returns the maximum Redfish date
+    EXPECT_EQ(getDateTimeUintUs(std::numeric_limits<uint64_t>::max()),
+              "9999-12-31T23:59:59.999999+00:00");
+    EXPECT_EQ(getDateTimeUintUs(std::numeric_limits<uint64_t>::min()),
+              "1970-01-01T00:00:00.000000+00:00");
 }
 
 TEST(Utility, UrlFromPieces)

http/utility.hpp

diff --git a/http/utility.hpp b/http/utility.hpp
index 5ca1dea..c9728f5 100644
--- a/http/utility.hpp
+++ b/http/utility.hpp
@@ -636,6 +636,22 @@
 
     seconds se = duration_cast<seconds>(t);
     out += details::padZeros(se.count(), 2);
+    t -= se;
+
+    if constexpr (std::is_same_v<typename decltype(t)::period, std::milli>)
+    {
+        out += '.';
+        using MilliDuration = std::chrono::duration<int, std::milli>;
+        MilliDuration subsec = duration_cast<MilliDuration>(t);
+        out += details::padZeros(subsec.count(), 3);
+    }
+    else if constexpr (std::is_same_v<typename decltype(t)::period, std::micro>)
+    {
+        out += '.';
+        using MicroDuration = std::chrono::duration<int, std::micro>;
+        MicroDuration subsec = duration_cast<MicroDuration>(t);
+        out += details::padZeros(subsec.count(), 6);
+    }
 
     out += "+00:00";
     return out;
@@ -653,7 +669,7 @@
     return details::toISO8061ExtendedStr(sinceEpoch);
 }
 
-// Returns the formatted date time string.
+// Returns the formatted date time string with millisecond precision
 // Note that the maximum supported date is 9999-12-31T23:59:59+00:00, if
 // the given |secondsSinceEpoch| is too large, we return the maximum supported
 // date.
@@ -664,6 +680,14 @@
     return details::toISO8061ExtendedStr(sinceEpoch);
 }
 
+// Returns the formatted date time string with microsecond precision
+inline std::string getDateTimeUintUs(uint64_t microSecondsSinceEpoch)
+{
+    using DurationType = std::chrono::duration<uint64_t, std::micro>;
+    DurationType sinceEpoch(microSecondsSinceEpoch);
+    return details::toISO8061ExtendedStr(sinceEpoch);
+}
+
 inline std::string getDateTimeStdtime(std::time_t secondsSinceEpoch)
 {
     using DurationType = std::chrono::duration<std::time_t>;