Feature/refactor datetime os dependency (#63)

* remove dependency on OS for time functions.

* add datetime epoch to and from seconds (yikes! 64-bit!). Add symmetric midnight seconds for unit test. Add unit tests.

* clean up BACnet date time warnings

* fix BACnet datetime warnings

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

apps/gateway/main.c

@@ -98,13 +98,8 @@ static void Devices_Init(uint32_t first_object_instance)
 
     /* Now initialize the remote Device objects. */
     for (i = 1; i < MAX_NUM_DEVICES; i++) {
-#ifdef _MSC_VER
-        _snprintf(nameText, MAX_DEV_NAME_LEN, "%s %d", DEV_NAME_BASE, i + 1);
-        _snprintf(descText, MAX_DEV_DESC_LEN, "%s %d", DEV_DESCR_REMOTE, i);
-#else
         snprintf(nameText, MAX_DEV_NAME_LEN, "%s %d", DEV_NAME_BASE, i + 1);
         snprintf(descText, MAX_DEV_DESC_LEN, "%s %d", DEV_DESCR_REMOTE, i);
-#endif
         characterstring_init_ansi(&name_string, nameText);
 
         Add_Routed_Device((first_object_instance + i), &name_string, descText);

ports/win32/bacport.h

@@ -63,11 +63,6 @@ and globals in favor of more secure versions.  */
 #include <sys/time.h>
 #endif
 #include <sys/timeb.h>
-#if defined(__BORLANDC__) || defined(_WIN32)
-/* seems to not be defined in time.h as specified by The Open Group */
-/* difference from UTC and local standard time  */
-extern long int timezone;
-#endif
 
 #ifdef _MSC_VER
 #define inline __inline

src/bacnet/basic/object/client/device-client.c

@@ -31,7 +31,6 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h> /* for memmove */
-#include <time.h> /* for timezone, localtime */
 /* OS specific include*/
 #include "bacport.h"
 #include "bacnet/basic/sys/mstimer.h"
@@ -41,6 +40,7 @@
 #include "bacnet/bacenum.h"
 #include "bacnet/bacapp.h"
 #include "bacnet/config.h" /* the custom stuff */
+#include "bacnet/datetime.h"
 #include "bacnet/apdu.h"
 #include "bacnet/rp.h" /* ReadProperty handling */
 #include "bacnet/version.h"
@@ -53,12 +53,6 @@
 /* include the device object */
 #include "bacnet/basic/object/device.h" /* me */
 
-#if defined(__BORLANDC__) || defined(_WIN32)
-/* seems to not be defined in time.h as specified by The Open Group */
-/* difference from UTC and local standard time  */
-long int timezone;
-#endif
-
 /* note: you really only need to define variables for
    properties that are writable or that may change.
    The properties that are constant can be hard coded
@@ -83,14 +77,10 @@ static char *Description = "command line client";
 /* static uint8_t Max_Segments_Accepted = 0; */
 /* VT_Classes_Supported */
 /* Active_VT_Sessions */
-static BACNET_TIME Local_Time; /* rely on OS, if there is one */
+static BACNET_TIME Local_Time;
-static BACNET_DATE Local_Date; /* rely on OS, if there is one */
+static BACNET_DATE Local_Date;
-/* NOTE: BACnet UTC Offset is inverse of common practice.
+static int16_t UTC_Offset;
-   If your UTC offset is -5hours of GMT,
+static bool Daylight_Savings_Status;
-   then BACnet UTC offset is +5hours.
-   BACnet UTC offset is expressed in minutes. */
-static int32_t UTC_Offset = 5 * 60;
-static bool Daylight_Savings_Status = false; /* rely on OS */
 #if defined(BACNET_TIME_MASTER)
 static bool Align_Intervals;
 static uint32_t Interval_Minutes;
@@ -696,57 +686,8 @@ bool Device_Object_Name_Copy(BACNET_OBJECT_TYPE object_type,
 
 static void Update_Current_Time(void)
 {
-    struct tm *tblock = NULL;
+    datetime_local(
-#if defined(_MSC_VER)
+        &Local_Date, &Local_Time, &UTC_Offset, &Daylight_Savings_Status);
-    time_t tTemp;
-#else
-    struct timeval tv;
-#endif
-/*
-struct tm
-
-int    tm_sec   Seconds [0,60].
-int    tm_min   Minutes [0,59].
-int    tm_hour  Hour [0,23].
-int    tm_mday  Day of month [1,31].
-int    tm_mon   Month of year [0,11].
-int    tm_year  Years since 1900.
-int    tm_wday  Day of week [0,6] (Sunday =0).
-int    tm_yday  Day of year [0,365].
-int    tm_isdst Daylight Savings flag.
-*/
-#if defined(_MSC_VER)
-    time(&tTemp);
-    tblock = (struct tm *)localtime(&tTemp);
-#else
-    if (gettimeofday(&tv, NULL) == 0) {
-        tblock = (struct tm *)localtime((const time_t *)&tv.tv_sec);
-    }
-#endif
-
-    if (tblock) {
-        datetime_set_date(&Local_Date, (uint16_t)tblock->tm_year + 1900,
-            (uint8_t)tblock->tm_mon + 1, (uint8_t)tblock->tm_mday);
-#if !defined(_MSC_VER)
-        datetime_set_time(&Local_Time, (uint8_t)tblock->tm_hour,
-            (uint8_t)tblock->tm_min, (uint8_t)tblock->tm_sec,
-            (uint8_t)(tv.tv_usec / 10000));
-#else
-        datetime_set_time(&Local_Time, (uint8_t)tblock->tm_hour,
-            (uint8_t)tblock->tm_min, (uint8_t)tblock->tm_sec, 0);
-#endif
-        if (tblock->tm_isdst) {
-            Daylight_Savings_Status = true;
-        } else {
-            Daylight_Savings_Status = false;
-        }
-        /* note: timezone is declared in <time.h> stdlib. */
-        UTC_Offset = timezone / 60;
-    } else {
-        datetime_date_wildcard_set(&Local_Date);
-        datetime_time_wildcard_set(&Local_Time);
-        Daylight_Savings_Status = false;
-    }
 }
 
 void Device_getCurrentDateTime(BACNET_DATE_TIME *DateTime)
@@ -1099,6 +1040,7 @@ void Device_Init(object_functions_t *object_table)
     struct object_functions *pObject = NULL;
 
     characterstring_init_ansi(&My_Object_Name, "SimpleClient");
+    datetime_init();
     /* we don't use the object table passed in */
     (void)object_table;
     pObject = &Object_Table[0];

src/bacnet/basic/object/device.c

@@ -29,12 +29,12 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h> /* for memmove */
-#include <time.h> /* for timezone, localtime */
 #include "bacnet/bacdef.h"
 #include "bacnet/bacdcode.h"
 #include "bacnet/bacenum.h"
 #include "bacnet/bacapp.h"
 #include "bacnet/config.h" /* the custom stuff */
+#include "bacnet/datetime.h"
 #include "bacnet/apdu.h"
 #include "bacnet/wp.h" /* WriteProperty handling */
 #include "bacnet/rp.h" /* ReadProperty handling */
@@ -79,12 +79,6 @@
 #include "bacnet/basic/ucix/ucix.h"
 #endif /* defined(BAC_UCI) */
 
-#if defined(__BORLANDC__) || defined(_WIN32)
-/* Not included in time.h as specified by The Open Group */
-/* Difference from UTC and local standard time */
-long int timezone;
-#endif
-
 /* local forward (semi-private) and external prototypes */
 int Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata);
 bool Device_Write_Property_Local(BACNET_WRITE_PROPERTY_DATA *wp_data);
@@ -1838,7 +1832,7 @@ void Device_Init(object_functions_t *object_table)
     }
     ucix_cleanup(ctx);
 #endif /* defined(BAC_UCI) */
-
+    datetime_init();
     if (object_table) {
         Object_Table = object_table;
     } else {

src/bacnet/basic/object/lc.c

@@ -30,7 +30,6 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h> /* for memcpy */
-#include <time.h>
 #include "bacnet/bacdef.h"
 #include "bacnet/bacdcode.h"
 #include "bacnet/datetime.h"
@@ -260,29 +259,9 @@ bool Load_Control_Object_Name(
 
 static void Update_Current_Time(BACNET_DATE_TIME *bdatetime)
 {
-    time_t timer;
+    if (bdatetime) {
-    struct tm *tblock;
+        datetime_local(&bdatetime->date, &bdatetime->time, NULL, NULL);
-
+    }
-    /*
-    struct tm {
-       int tm_sec;
-       int tm_min;
-       int tm_hour;
-       int tm_mday;
-       int tm_mon;
-       int tm_year;
-       int tm_wday;
-       int tm_yday;
-       int tm_isdst;
-    };
-    */
-
-    timer = time(NULL);
-    tblock = localtime(&timer);
-    datetime_set_values(bdatetime, (uint16_t)tblock->tm_year,
-        (uint8_t)tblock->tm_mon, (uint8_t)tblock->tm_mday,
-        (uint8_t)tblock->tm_hour, (uint8_t)tblock->tm_min,
-        (uint8_t)tblock->tm_sec, 0);
 }
 
 /* convert the shed level request into an Analog Output Present_Value */

src/bacnet/datetime.c

@@ -534,6 +534,22 @@ static void seconds_since_midnight_into_hms(
     }
 }
 
+/**
+ * @brief Converts the number of seconds since midnight into BACnet Time
+ * @param seconds since midnight
+ * @param btime [in] BACNET_TIME containing the time to convert
+ */
+void datetime_seconds_since_midnight_into_time(
+    uint32_t seconds,
+    BACNET_TIME *btime)
+{
+    if (btime) {
+        seconds_since_midnight_into_hms(seconds,
+            &btime->hour, &btime->min, &btime->sec);
+        btime->hundredths = 0;
+    }
+}
+
 /** Calculates the number of seconds since midnight
  *
  * @param btime [in] BACNET_TIME containing the time to convert
@@ -617,6 +633,54 @@ void datetime_add_minutes(BACNET_DATE_TIME *bdatetime, int32_t minutes)
     datetime_days_since_epoch_into_date(bdatetime_days, &bdatetime->date);
 }
 
+#ifdef UINT64_MAX
+/**
+ * @brief Calculates the number of seconds since epoch
+ * @param bdatetime [in] the starting date and time
+ * @return seconds since midnight
+ */
+uint64_t datetime_seconds_since_epoch(
+    BACNET_DATE_TIME * bdatetime)
+{
+    uint64_t seconds = 0;
+    uint32_t days = 0;
+
+    if (bdatetime) {
+        days = datetime_days_since_epoch(&bdatetime->date);
+        seconds = seconds_since_midnight(24, 0, 0);
+        seconds *= days;
+        seconds += datetime_seconds_since_midnight(&bdatetime->time);
+    }
+
+    return seconds;
+}
+#endif
+
+#ifdef UINT64_MAX
+/**
+ * @brief Calculates the number of seconds since epoch
+ * @param bdatetime [in] the starting date and time
+ * @return seconds since midnight
+ */
+void datetime_since_epoch_seconds(
+    BACNET_DATE_TIME * bdatetime,
+    uint64_t seconds)
+{
+    uint32_t seconds_after_midnight = 0;
+    uint32_t days = 0;
+    uint32_t day_seconds = 0;
+
+    if (bdatetime) {
+        day_seconds = seconds_since_midnight(24, 0, 0);
+        days = seconds / day_seconds;
+        seconds_after_midnight = seconds - (days * day_seconds);
+        datetime_seconds_since_midnight_into_time(
+            seconds_after_midnight, &bdatetime->time);
+        datetime_days_since_epoch_into_date(days, &bdatetime->date);
+    }
+}
+#endif
+
 /* Returns true if year is a wildcard */
 bool datetime_wildcard_year(BACNET_DATE *bdate)
 {
@@ -1011,6 +1075,20 @@ int bacapp_decode_context_datetime(
 #include <string.h>
 #include "ctest.h"
 
+static void datetime_print(const char *title,
+    BACNET_DATE_TIME *bdatetime)
+{
+    printf("%s: %04u/%02u/%02u %02u:%02u:%02u.%03u\n",
+        title,
+        (unsigned int)bdatetime->date.year,
+        (unsigned int)bdatetime->date.month,
+        (unsigned int)bdatetime->date.wday,
+        (unsigned int)bdatetime->time.hour,
+        (unsigned int)bdatetime->time.min,
+        (unsigned int)bdatetime->time.sec,
+        (unsigned int)bdatetime->time.hundredths);
+}
+
 static void testBACnetDateTimeWildcard(Test *pTest)
 {
     BACNET_DATE_TIME bdatetime;
@@ -1323,6 +1401,42 @@ static void testDayOfYear(Test *pTest)
     }
 }
 
+static void testDateEpochConversionCompare(Test *pTest,
+    uint16_t year, uint8_t month, uint8_t day,
+    uint8_t hour, uint8_t minute, uint8_t second, uint8_t hundredth)
+{
+    uint64_t epoch_seconds = 0;
+    BACNET_DATE_TIME bdatetime = {0};
+    BACNET_DATE_TIME test_bdatetime = {0};
+    int compare = 0;
+
+    datetime_set_date(&bdatetime.date, year, month, day);
+    datetime_set_time(&bdatetime.time, hour, minute, second,
+        hundredth);
+    epoch_seconds = datetime_seconds_since_epoch(&bdatetime);
+    datetime_since_epoch_seconds(&test_bdatetime,
+        epoch_seconds);
+    compare = datetime_compare(&bdatetime,&test_bdatetime);
+    ct_test(pTest,compare == 0);
+    if (compare != 0) {
+        datetime_print("bdatetime", &bdatetime);
+        datetime_print("test_bdatetime", &test_bdatetime);
+    }
+}
+
+static void testDateEpochConversion(Test *pTest)
+{
+    /* min */
+    testDateEpochConversionCompare(pTest,
+        BACNET_EPOCH_YEAR, 1, 1, 0, 0, 0, 0);
+    /* middle */
+    testDateEpochConversionCompare(pTest,
+        2020, 6, 26, 12, 30, 30, 0);
+    /* max */
+    testDateEpochConversionCompare(pTest,
+        BACNET_EPOCH_YEAR + 0xFF - 1, 12, 31, 23, 59, 59, 0);
+}
+
 static void testDateEpoch(Test *pTest)
 {
     uint32_t days = 0;
@@ -1479,6 +1593,8 @@ void testDateTime(Test *pTest)
     assert(rc);
     rc = ct_addTestFunction(pTest, testDateEpoch);
     assert(rc);
+    rc = ct_addTestFunction(pTest, testDateEpochConversion);
+    assert(rc);
     rc = ct_addTestFunction(pTest, testBACnetDateTimeSeconds);
     assert(rc);
     rc = ct_addTestFunction(pTest, testBACnetDateTimeAdd);

src/bacnet/datetime.h

@@ -149,6 +149,11 @@ extern "C" {
         uint16_t year,
         uint8_t month,
         uint8_t day);
+
+    BACNET_STACK_EXPORT
+    void datetime_seconds_since_midnight_into_time(
+        uint32_t seconds,
+        BACNET_TIME *btime);
     BACNET_STACK_EXPORT
     uint32_t datetime_seconds_since_midnight(
         BACNET_TIME * btime);
@@ -208,6 +213,14 @@ extern "C" {
         BACNET_DATE_TIME * bdatetime,
         int32_t minutes);
 
+    BACNET_STACK_EXPORT
+    uint64_t datetime_seconds_since_epoch(
+        BACNET_DATE_TIME * bdatetime);
+    BACNET_STACK_EXPORT
+    void datetime_since_epoch_seconds(
+        BACNET_DATE_TIME * bdatetime,
+        uint64_t seconds);
+
     /* date and time wildcards */
     BACNET_STACK_EXPORT
     bool datetime_wildcard_year(