UTIL: Add RFC3339 timestamps

3 files changed, 75 insertions, 0 deletions

diff --git a/src/include/gnunet_strings_lib.h b/src/include/gnunet_strings_lib.h
index 2e0c720ee..6c91edd05 100644
--- a/src/include/gnunet_strings_lib.h
+++ b/src/include/gnunet_strings_lib.h
@@ -95,6 +95,20 @@ enum GNUNET_GenericReturnValue
 GNUNET_STRINGS_fancy_time_to_absolute (const char *fancy_time,
                                        struct GNUNET_TIME_Absolute *atime);
 
+/**
+ * @ingroup time
+ * Convert a given RFC3339 time to our internal
+ * representation.
+ *
+ * @param rfc3339_time human readable string (e.g. %Y-%m-%dT%H:%M:%SZ)
+ * @param atime set to the absolute time
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
+ */
+enum GNUNET_GenericReturnValue
+GNUNET_STRINGS_rfc3339_time_to_absolute (const char *rfc3339_time,
+                                         struct GNUNET_TIME_Absolute *atime);
+
+
 
 /**
  * @ingroup time
@@ -270,6 +284,21 @@ GNUNET_STRINGS_absolute_time_to_string (struct GNUNET_TIME_Absolute t);
 
 /**
  * @ingroup time
+ * Like `asctime`, except for GNUnet time.  Converts a GNUnet internal
+ * absolute time (which is in UTC) to a string in local time according to
+ * RFC3339.
+ * Note that the returned value will be overwritten if this function
+ * is called again.
+ *
+ * @param t the absolute time to convert
+ * @return timestamp in human-readable form in local time (RFC3339)
+ */
+const char *
+GNUNET_STRINGS_absolute_time_to_rfc3339 (struct GNUNET_TIME_Absolute t);
+
+
+/**
+ * @ingroup time
  * Give relative time in human-readable fancy format.
  * This is one of the very few calls in the entire API that is
  * NOT reentrant!
diff --git a/src/util/strings.c b/src/util/strings.c
index db672da87..7be04ea82 100644
--- a/src/util/strings.c
+++ b/src/util/strings.c
@@ -355,6 +355,45 @@ GNUNET_STRINGS_fancy_time_to_absolute (const char *fancy_time,
 
 
 enum GNUNET_GenericReturnValue
+GNUNET_STRINGS_rfc3339_time_to_absolute (const char *rfc3339_time,
+                                         struct GNUNET_TIME_Absolute *atime)
+{
+  struct tm tv;
+  time_t t;
+  const char *eos;
+
+  eos = &rfc3339_time[strlen (rfc3339_time)];
+  memset (&tv, 0, sizeof(tv));
+  /**
+   * FIXME: There are a lot more formats for RFC3339.
+   * Actually, we also may want https://www.w3.org/TR/xmlschema11-2/#dateTime
+   * at some point?
+   */
+  if ((eos != strptime (rfc3339_time, "%Y-%m-%dT%H:%M:%SZ", &tv)) &&
+      (eos != strptime (rfc3339_time, "%Y-%m-%dT%H:%M:%S%z", &tv)))
+    return GNUNET_SYSERR;
+  t = timegm (&tv);
+  atime->abs_value_us = (uint64_t) ((uint64_t) t * 1000LL * 1000LL);
+  return GNUNET_OK;
+}
+
+
+const char *
+GNUNET_STRINGS_absolute_time_to_rfc3339 (struct GNUNET_TIME_Absolute t)
+{
+  static GNUNET_THREAD_LOCAL char buf[255];
+  time_t tt;
+  struct tm *tp;
+
+  tt = t.abs_value_us / 1000LL / 1000LL;
+  tp = gmtime (&tt);
+  strftime (buf, sizeof(buf), "%Y-%m-%dT%H:%M:%SZ", tp);
+
+  return buf;
+}
+
+
+enum GNUNET_GenericReturnValue
 GNUNET_STRINGS_fancy_time_to_timestamp (const char *fancy_time,
                                         struct GNUNET_TIME_Timestamp *atime)
 {
diff --git a/src/util/test_strings.c b/src/util/test_strings.c
index d986486d0..0167e5329 100644
--- a/src/util/test_strings.c
+++ b/src/util/test_strings.c
@@ -131,6 +131,13 @@ main (int argc, char *argv[])
     GNUNET_assert (0);
   }
 
+  at.abs_value_us = 1577906604000000; /* 2020-01-01T19:23:24Z */
+  bc = GNUNET_STRINGS_absolute_time_to_rfc3339 (at);
+  GNUNET_assert (0 == strcmp ("2020-01-01T19:23:24Z", bc));
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_STRINGS_rfc3339_time_to_absolute (bc, &atx));
+  GNUNET_assert (at.abs_value_us == atx.abs_value_us);
+
   GNUNET_log_skip (2, GNUNET_NO);
   b = GNUNET_STRINGS_to_utf8 ("TEST", 4, "unknown");
   GNUNET_log_skip (0, GNUNET_YES);