Revision 0:53c251120904, committed 2015-05-10

Comitter:

bjblazkowicz

Date:

Sun May 10 22:05:28 2015 +0000

Commit message:

Initial commit.

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gmtime_newlib.cpp	Sun May 10 22:05:28 2015 +0000
@@ -0,0 +1,159 @@
+/*
+ * gmtime_r.c
+ * Original Author: Adapted from tzcode maintained by Arthur David Olson.
+ * Modifications:
+ * - Changed to mktm_r and added __tzcalc_limits - 04/10/02, Jeff Johnston
+ * - Fixed bug in mday computations - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru>
+ * - Fixed bug in __tzcalc_limits - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru>
+ * - Move code from _mktm_r() to gmtime_r() - 05/09/14, Freddie Chopin <freddie_chopin@op.pl>
+ * - Fixed bug in calculations for dates after year 2069 or before year 1901. Ideas for
+ *   solution taken from musl's __secs_to_tm() - 07/12/2014, Freddie Chopin
+ *   <freddie_chopin@op.pl>
+ *
+ * Converts the calendar time pointed to by tim_p into a broken-down time
+ * expressed as local time. Returns a pointer to a structure containing the
+ * broken-down time.
+ */
+ 
+// *** ChrisP 5/10/15: Code taken from http://sourceware.org/newlib/; modified slightly to compile on mbed.org ***
+
+#include "mbed.h"
+
+/* move epoch from 01.01.1970 to 01.03.2000 - this is the first day of new
+ * 400-year long cycle, right after additional day of leap year. This adjustment
+ * is required only for date calculation, so instead of modifying time_t value
+ * (which would require 64-bit operations to work correctly) it's enough to
+ * adjust the calculated number of days since epoch. */
+#define EPOCH_ADJUSTMENT_DAYS   11017
+/* year to which the adjustment was made */
+#define ADJUSTED_EPOCH_YEAR 2000
+/* 1st March of 2000 is Wednesday */
+#define ADJUSTED_EPOCH_WDAY 3
+/* there are 97 leap years in 400-year periods. ((400 - 97) * 365 + 97 * 366) */
+#define DAYS_PER_400_YEARS  146097L
+/* there are 24 leap years in 100-year periods. ((100 - 24) * 365 + 24 * 366) */
+#define DAYS_PER_100_YEARS  36524L
+/* there is one leap year every 4 years */
+#define DAYS_PER_4_YEARS    (3 * 365 + 366)
+/* number of days in a non-leap year */
+#define DAYS_PER_YEAR       365
+/* number of days in January */
+#define DAYS_IN_JANUARY     31
+/* number of days in non-leap February */
+#define DAYS_IN_FEBRUARY    28
+
+#define SECSPERMIN  60L
+#define MINSPERHOUR 60L
+#define HOURSPERDAY 24L
+#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
+#define SECSPERDAY  (SECSPERHOUR * HOURSPERDAY)
+#define DAYSPERWEEK 7
+#define MONSPERYEAR 12
+
+#define YEAR_BASE   1900
+#define EPOCH_YEAR      1970
+#define EPOCH_WDAY      4
+#define EPOCH_YEARS_SINCE_LEAP 2
+#define EPOCH_YEARS_SINCE_CENTURY 70
+#define EPOCH_YEARS_SINCE_LEAP_CENTURY 370
+
+#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
+
+const int __month_lengths[2][MONSPERYEAR] = {
+  {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
+  {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
+} ;
+
+struct tm *
+gmtime_newlib(const time_t* tim_p, struct tm* res)
+{
+  long days, rem;
+  const time_t lcltime = *tim_p;
+  int year, month, yearday, weekday;
+  int years400, years100, years4, remainingyears;
+  int yearleap;
+  const int *ip;
+
+  days = ((long)lcltime) / SECSPERDAY - EPOCH_ADJUSTMENT_DAYS;
+  rem = ((long)lcltime) % SECSPERDAY;
+  if (rem < 0)
+    {
+      rem += SECSPERDAY;
+      --days;
+    }
+
+  /* compute hour, min, and sec */
+  res->tm_hour = (int) (rem / SECSPERHOUR);
+  rem %= SECSPERHOUR;
+  res->tm_min = (int) (rem / SECSPERMIN);
+  res->tm_sec = (int) (rem % SECSPERMIN);
+
+  /* compute day of week */
+  if ((weekday = ((ADJUSTED_EPOCH_WDAY + days) % DAYSPERWEEK)) < 0)
+    weekday += DAYSPERWEEK;
+  res->tm_wday = weekday;
+
+  /* compute year & day of year */
+  years400 = days / DAYS_PER_400_YEARS;
+  days -= years400 * DAYS_PER_400_YEARS;
+  /* simplify by making the values positive */
+  if (days < 0)
+    {
+      days += DAYS_PER_400_YEARS;
+      --years400;
+    }
+
+  years100 = days / DAYS_PER_100_YEARS;
+  if (years100 == 4) /* required for proper day of year calculation */
+    --years100;
+  days -= years100 * DAYS_PER_100_YEARS;
+  years4 = days / DAYS_PER_4_YEARS;
+  days -= years4 * DAYS_PER_4_YEARS;
+  remainingyears = days / DAYS_PER_YEAR;
+  if (remainingyears == 4) /* required for proper day of year calculation */
+    --remainingyears;
+  days -= remainingyears * DAYS_PER_YEAR;
+
+  year = ADJUSTED_EPOCH_YEAR + years400 * 400 + years100 * 100 + years4 * 4 +
+      remainingyears;
+
+  /* If remainingyears is zero, it means that the years were completely
+   * "consumed" by modulo calculations by 400, 100 and 4, so the year is:
+   * 1. a multiple of 4, but not a multiple of 100 or 400 - it's a leap year,
+   * 2. a multiple of 4 and 100, but not a multiple of 400 - it's not a leap
+   * year,
+   * 3. a multiple of 4, 100 and 400 - it's a leap year.
+   * If years4 is non-zero, it means that the year is not a multiple of 100 or
+   * 400 (case 1), so it's a leap year. If years100 is zero (and years4 is zero
+   * - due to short-circuiting), it means that the year is a multiple of 400
+   * (case 3), so it's also a leap year. */
+  yearleap = remainingyears == 0 && (years4 != 0 || years100 == 0);
+
+  /* adjust back to 1st January */
+  yearday = days + DAYS_IN_JANUARY + DAYS_IN_FEBRUARY + yearleap;
+  if (yearday >= DAYS_PER_YEAR + yearleap)
+    {
+      yearday -= DAYS_PER_YEAR + yearleap;
+      ++year;
+    }
+  res->tm_yday = yearday;
+  res->tm_year = year - YEAR_BASE;
+
+  /* Because "days" is the number of days since 1st March, the additional leap
+   * day (29th of February) is the last possible day, so it doesn't matter much
+   * whether the year is actually leap or not. */
+  ip = __month_lengths[1];
+  month = 2;
+  while (days >= ip[month])
+    {
+      days -= ip[month];
+      if (++month >= MONSPERYEAR)
+        month = 0;
+    }
+  res->tm_mon = month;
+  res->tm_mday = days + 1;
+
+  res->tm_isdst = 0;
+
+  return (res);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gmtime_newlib.h	Sun May 10 22:05:28 2015 +0000
@@ -0,0 +1,8 @@
+
+#ifndef GMTIME_NEWLIB_H
+#define GMTIME_NEWLIB_H
+
+struct tm *
+gmtime_newlib(const time_t* tim_p, struct tm* res);
+
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun May 10 22:05:28 2015 +0000
@@ -0,0 +1,27 @@
+#include "mbed.h"
+#include "gmtime_newlib.h"
+
+Serial console(USBTX, USBRX);
+
+int main() 
+{
+    console.baud(9600);
+    
+    // Set time to Tue, 10 Nov 2015 14:00:00 GMT
+    set_time(1447164000);
+
+    time_t rawTime;
+    time(&rawTime);
+    
+    // Prints: time_t: 1447164000, h:13773, m:1377, s:537067520
+    struct tm *parsedUsingMbed = gmtime(&rawTime);
+    console.printf("time_t: %d, h:%d, m:%d, s:%d\r\n", rawTime, parsedUsingMbed->tm_hour, parsedUsingMbed->tm_min, parsedUsingMbed->tm_sec);
+
+    // Prints: time_t: 1447164000, h:14, m:0, s:0
+    struct tm parsedUsingNewlib;
+    gmtime_newlib(&rawTime, &parsedUsingNewlib);
+    console.printf("time_t: %d, h:%d, m:%d, s:%d\r\n", rawTime, parsedUsingNewlib.tm_hour, parsedUsingNewlib.tm_min, parsedUsingNewlib.tm_sec);
+
+    while(1)
+        ;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sun May 10 22:05:28 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/8ab26030e058
\ No newline at end of file