all: Rename absolute time-based functions to include "epoch".

For time-based functions that work with absolute time there is the need for
an Epoch, to set the zero-point at which the absolute time starts counting.
Such functions include time.time() and filesystem stat return values.  And
different ports may use a different Epoch.

To make it clearer what functions use the Epoch (whatever it may be), and
make the ports more consistent with their use of the Epoch, this commit
renames all Epoch related functions to include the word "epoch" in their
name (and remove references to "2000").

Along with this rename, the following things have changed:

- mp_hal_time_ns() is now specified to return the number of nanoseconds
  since the Epoch, rather than since 1970 (but since this is an internal
  function it doesn't change anything for the user).

- littlefs timestamps on the esp8266 have been fixed (they were previously
  off by 30 years in nanoseconds).

Otherwise, there is no functional change made by this commit.

Signed-off-by: Damien George <damien@micropython.org>

1 files changed, 32 insertions, 11 deletions

diff --git a/lib/timeutils/timeutils.h b/lib/timeutils/timeutils.h
index 08b0dc2e8..14da831dc 100644
--- a/lib/timeutils/timeutils.h
+++ b/lib/timeutils/timeutils.h
@@ -42,14 +42,6 @@ typedef struct _timeutils_struct_time_t {
     uint16_t tm_yday;       // 1..366
 } timeutils_struct_time_t;
 
-static inline uint64_t timeutils_seconds_since_2000_to_nanoseconds_since_1970(mp_uint_t s) {
-    return ((uint64_t)s + TIMEUTILS_SECONDS_1970_TO_2000) * 1000000000ULL;
-}
-
-static inline mp_uint_t timeutils_seconds_since_2000_from_nanoseconds_since_1970(uint64_t ns) {
-    return ns / 1000000000ULL - TIMEUTILS_SECONDS_1970_TO_2000;
-}
-
 bool timeutils_is_leap_year(mp_uint_t year);
 mp_uint_t timeutils_days_in_month(mp_uint_t year, mp_uint_t month);
 mp_uint_t timeutils_year_day(mp_uint_t year, mp_uint_t month, mp_uint_t date);
@@ -63,10 +55,39 @@ mp_uint_t timeutils_seconds_since_2000(mp_uint_t year, mp_uint_t month,
 mp_uint_t timeutils_mktime(mp_uint_t year, mp_int_t month, mp_int_t mday,
     mp_int_t hours, mp_int_t minutes, mp_int_t seconds);
 
-static inline uint64_t timeutils_nanoseconds_since_1970(mp_uint_t year, mp_uint_t month,
+// Select the Epoch used by the port.
+#if MICROPY_EPOCH_IS_1970
+
+static inline uint64_t timeutils_seconds_since_epoch(mp_uint_t year, mp_uint_t month,
     mp_uint_t date, mp_uint_t hour, mp_uint_t minute, mp_uint_t second) {
-    return timeutils_seconds_since_2000_to_nanoseconds_since_1970(
-        timeutils_seconds_since_2000(year, month, date, hour, minute, second));
+    return timeutils_seconds_since_2000(year, month, date, hour, minute, second) + TIMEUTILS_SECONDS_1970_TO_2000;
+}
+
+static inline mp_uint_t timeutils_seconds_since_epoch_from_nanoseconds_since_1970(uint64_t ns) {
+    return ns / 1000000000ULL;
+}
+
+static inline uint64_t timeutils_nanoseconds_since_epoch_to_nanoseconds_since_1970(uint64_t ns) {
+    return ns;
 }
 
+#else // Epoch is 2000
+
+#define timeutils_seconds_since_epoch_to_struct_time timeutils_seconds_since_2000_to_struct_time
+#define timeutils_seconds_since_epoch timeutils_seconds_since_2000
+
+static inline uint64_t timeutils_seconds_since_epoch_to_nanoseconds_since_1970(mp_uint_t s) {
+    return ((uint64_t)s + TIMEUTILS_SECONDS_1970_TO_2000) * 1000000000ULL;
+}
+
+static inline mp_uint_t timeutils_seconds_since_epoch_from_nanoseconds_since_1970(uint64_t ns) {
+    return ns / 1000000000ULL - TIMEUTILS_SECONDS_1970_TO_2000;
+}
+
+static inline int64_t timeutils_nanoseconds_since_epoch_to_nanoseconds_since_1970(int64_t ns) {
+    return ns + TIMEUTILS_SECONDS_1970_TO_2000 * 1000000000ULL;
+}
+
+#endif
+
 #endif // MICROPY_INCLUDED_LIB_TIMEUTILS_TIMEUTILS_H