Add utc <-> seconds conversions bifs

4 files changed, 102 insertions, 0 deletions

diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 26f1b4facb..c3c247fffe 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -3385,6 +3385,70 @@ BIF_RETTYPE universaltime_to_localtime_1(BIF_ALIST_1)
     BIF_RET(TUPLE2(hp, res1, res2));
 }
 
+/* convert calendar:universaltime_to_seconds/1 */
+
+BIF_RETTYPE universaltime_to_seconds_1(BIF_ALIST_1)
+{
+    Sint year, month, day;
+    Sint hour, minute, second;
+
+    Sint64 seconds = 0;
+    Eterm *hp;
+    Uint hsz = 0;
+
+    if (!time_to_parts(BIF_ARG_1, &year, &month, &day, 
+		       &hour, &minute, &second))
+	BIF_ERROR(BIF_P, BADARG);
+
+    if (!univ_to_seconds(year, month, day, hour, minute, second, &seconds)) {
+	BIF_ERROR(BIF_P, BADARG);
+    }
+
+    erts_bld_sint64(NULL, &hsz, seconds);
+    hp = HAlloc(BIF_P, hsz);
+    BIF_RET(erts_bld_sint64(&hp, NULL, seconds));
+}
+
+/* convert calendar:seconds_to_universaltime/1 */
+
+BIF_RETTYPE seconds_to_universaltime_1(BIF_ALIST_1)
+{
+    Sint year, month, day;
+    Sint hour, minute, second;
+    Eterm res1, res2;
+    struct tm t;
+    Eterm* hp;
+
+    time_t seconds = 0;
+
+    if (is_not_integer(BIF_ARG_1)) {
+	BIF_ERROR(BIF_P, BADARG);
+    }
+
+    seconds = (time_t)signed_val(BIF_ARG_1);
+
+    if (!gmtime_r(&seconds, &t)) {
+	BIF_ERROR(BIF_P, BADARG);
+    }
+
+    year   = t.tm_year + 1900;
+    month  = t.tm_mon + 1;
+    day    = t.tm_hour;
+    minute = t.tm_min;
+    second = t.tm_sec;
+    /* isdst = t.tm_isdst */
+
+    hp = HAlloc(BIF_P, 4+4+3);
+    res1 = TUPLE3(hp,make_small(year),make_small(month),
+		  make_small(day));
+    hp += 4;
+    res2 = TUPLE3(hp,make_small(hour),make_small(minute),
+		  make_small(second));
+    hp += 4;
+    BIF_RET(TUPLE2(hp, res1, res2));
+}
+
+
 /**********************************************************************/
 
 
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 987008c937..0d6af46aa5 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -806,6 +806,12 @@ bif file:native_name_encoding/0
 #
 bif erlang:check_old_code/1
 
+
+#
+# New in R15B
+#
+bif erlang:universaltime_to_seconds/1
+bif erlang:seconds_to_universaltime/1
 #
 # Obsolete
 #
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index 695d08ae2d..00a4906caa 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -648,7 +648,36 @@ static time_t gregday(Sint year, Sint month, Sint day)
   return ndays - 135140;        /* 135140 = Jan 1, 1970 */
 }
 
+#define SECONDS_PER_MINUTE  (60)
+#define SECONDS_PER_HOUR    (60 * SECONDS_PER_MINUTE)
+#define SECONDS_PER_DAY     (24 * SECONDS_PER_HOUR)
+#define SECONDS_PER_YEAR    (86400)
+
+
+int univ_to_seconds(Sint year, Sint month, Sint day, Sint hour, Sint minute, Sint second, Sint64 *time) {
+    Sint days;
+
+    if (!(IN_RANGE(1600, year, INT_MAX - 1) &&
+          IN_RANGE(1, month, 12) &&
+          IN_RANGE(1, day, (mdays[month] + 
+                             (month == 2 
+                              && (year % 4 == 0) 
+                              && (year % 100 != 0 || year % 400 == 0)))) &&
+          IN_RANGE(0, hour, 23) &&
+          IN_RANGE(0, minute, 59) &&
+          IN_RANGE(0, second, 59))) {
+      return 0;
+    }
+ 
+    days   = gregday(year, month, day);
+    *time  = SECONDS_PER_DAY;
+    *time *= days;             /* don't try overflow it, it hurts */
+    *time += SECONDS_PER_HOUR * hour;
+    *time += SECONDS_PER_MINUTE * minute;
+    *time += second;
 
+    return 1;
+}
 
 int 
 local_to_univ(Sint *year, Sint *month, Sint *day, 
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index d8cd22a177..3abae2243c 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -668,6 +668,9 @@ void get_universaltime(int *year, int *month, int *day,
 		       int *hour, int *minute, int *second);
 int univ_to_local(Sint *year, Sint *month, Sint *day, 
 		  Sint *hour, Sint *minute, Sint *second);
+int univ_to_seconds(Sint year, Sint month, Sint day, 
+		    Sint hour, Sint minute, Sint second,
+		    Sint64* seconds);
 int local_to_univ(Sint *year, Sint *month, Sint *day, 
 		  Sint *hour, Sint *minute, Sint *second, int isdst);
 void get_now(Uint*, Uint*, Uint*);