gstreamer/gst/gstdatetime.c

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/* GStreamer
* Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst_private.h"
#include "gstdatetime.h"
/**
* SECTION:gst-date-time
* @title: GstDateTime
* @short_description: A date, time and timezone structure
*
* Struct to store date, time and timezone information altogether.
* #GstDateTime is refcounted and immutable.
*
* Date information is handled using the proleptic Gregorian calendar.
*
* Provides basic creation functions and accessor functions to its fields.
*
* Since: 0.10.31
*/
#define GST_DATE_TIME_SEC_PER_DAY (G_GINT64_CONSTANT (86400))
#define GST_DATE_TIME_USEC_PER_DAY (G_GINT64_CONSTANT (86400000000))
#define GST_DATE_TIME_USEC_PER_HOUR (G_GINT64_CONSTANT (3600000000))
#define GST_DATE_TIME_USEC_PER_MINUTE (G_GINT64_CONSTANT (60000000))
#define GST_DATE_TIME_USEC_PER_SECOND (G_GINT64_CONSTANT (1000000))
#define GST_DATE_TIME_USEC_PER_MILLISECOND (G_GINT64_CONSTANT (1000))
#define MAX_SUPPORTED_YEAR 9999
#define GREGORIAN_LEAP(y) (((y%4)==0)&&(!(((y%100)==0)&&((y%400)!=0))))
static const guint16 days_in_months[2][13] = {
{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
{0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
};
struct _GstDateTime
{
/*
* As we don't have a math API, we can have fields split here.
* (There is still some math done internally, but nothing really relevant).
*
* If we ever add one, we should go for a days since some epoch counter.
* (Proleptic Gregorian with 0001-01-01 as day 1)
*/
gint16 year;
gint8 month;
gint8 day;
guint64 usec; /* Microsecond timekeeping within Day */
gint tzoffset;
volatile gint ref_count;
};
/*
* Returns the utc offset in seconds for this time structure
*/
static gint
gmt_offset (struct tm *tm, time_t t)
{
#if defined (HAVE_TM_GMTOFF)
return tm->tm_gmtoff;
#else
struct tm g;
time_t t2;
#ifdef HAVE_GMTIME_R
gmtime_r (&t, &g);
#else
g = *gmtime (&t);
#endif
t2 = mktime (&g);
return (int) difftime (t, t2);
#endif
}
static void
gst_date_time_set_local_timezone (GstDateTime * dt)
{
struct tm tt;
time_t t;
g_return_if_fail (dt != NULL);
memset (&tt, 0, sizeof (tt));
tt.tm_mday = gst_date_time_get_day (dt);
tt.tm_mon = gst_date_time_get_month (dt) - 1;
tt.tm_year = gst_date_time_get_year (dt) - 1900;
tt.tm_hour = gst_date_time_get_hour (dt);
tt.tm_min = gst_date_time_get_minute (dt);
tt.tm_sec = gst_date_time_get_second (dt);
t = mktime (&tt);
dt->tzoffset = gmt_offset (&tt, t) / 60;
}
static GstDateTime *
gst_date_time_alloc (void)
{
GstDateTime *datetime;
datetime = g_slice_new0 (GstDateTime);
datetime->ref_count = 1;
return datetime;
}
static void
gst_date_time_free (GstDateTime * datetime)
{
g_slice_free (GstDateTime, datetime);
}
static GstDateTime *
gst_date_time_new_from_date (gint year, gint month, gint day)
{
GstDateTime *dt;
g_return_val_if_fail (year > 0 && year <= 9999, NULL);
g_return_val_if_fail ((month > 0 && month <= 12), NULL);
g_return_val_if_fail ((day > 0 && day <= 31), NULL);
dt = gst_date_time_alloc ();
dt->year = year;
dt->month = month;
dt->day = day;
gst_date_time_set_local_timezone (dt);
return dt;
}
/**
* gst_date_time_get_year:
* @datetime: a #GstDateTime
*
* Returns the year of this #GstDateTime
*
* Return value: The year of this #GstDateTime
* Since: 0.10.31
*/
gint
gst_date_time_get_year (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return datetime->year;
}
/**
* gst_date_time_get_month:
* @datetime: a #GstDateTime
*
* Returns the month of this #GstDateTime. January is 1, February is 2, etc..
*
* Return value: The month of this #GstDateTime
* Since: 0.10.31
*/
gint
gst_date_time_get_month (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return datetime->month;
}
/**
* gst_date_time_get_day:
* @datetime: a #GstDateTime
*
* Returns the day of this #GstDateTime.
*
* Return value: The day of this #GstDateTime
* Since: 0.10.31
*/
gint
gst_date_time_get_day (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return datetime->day;
}
/**
* gst_date_time_get_hour:
* @datetime: a #GstDateTime
*
* Retrieves the hour of the day represented by @datetime in the gregorian
* calendar. The return is in the range of 0 to 23.
*
* Return value: the hour of the day
*
* Since: 0.10.31
*/
gint
gst_date_time_get_hour (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return (datetime->usec / GST_DATE_TIME_USEC_PER_HOUR);
}
/**
* gst_date_time_get_microsecond:
* @datetime: a #GstDateTime
*
* Retrieves the fractional part of the seconds in microseconds represented by
* @datetime in the gregorian calendar.
*
* Return value: the microsecond of the second
*
* Since: 0.10.31
*/
gint
gst_date_time_get_microsecond (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return (datetime->usec % GST_DATE_TIME_USEC_PER_SECOND);
}
/**
* gst_date_time_get_minute:
* @datetime: a #GstDateTime
*
* Retrieves the minute of the hour represented by @datetime in the gregorian
* calendar.
*
* Return value: the minute of the hour
*
* Since: 0.10.31
*/
gint
gst_date_time_get_minute (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return (datetime->usec % GST_DATE_TIME_USEC_PER_HOUR) /
GST_DATE_TIME_USEC_PER_MINUTE;
}
/**
* gst_date_time_get_second:
* @datetime: a #GstDateTime
*
* Retrieves the second of the minute represented by @datetime in the gregorian
* calendar.
*
* Return value: the second represented by @datetime
*
* Since: 0.10.31
*/
gint
gst_date_time_get_second (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return (datetime->usec % GST_DATE_TIME_USEC_PER_MINUTE) /
GST_DATE_TIME_USEC_PER_SECOND;
}
/**
* gst_date_time_get_time_zone_offset:
* @datetime: a #GstDateTime
*
* Retrieves the offset from UTC in hours that the timezone specified
* by @datetime represents. Timezones ahead (to the east) of UTC have positive
* values, timezones before (to the west) of UTC have negative values.
* If @datetime represents UTC time, then the offset is zero.
*
* Return value: the offset from UTC in hours
* Since: 0.10.31
*/
gfloat
gst_date_time_get_time_zone_offset (const GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, 0);
return datetime->tzoffset / 60.0f;
}
/**
* gst_date_time_new_from_unix_epoch:
* @t: seconds from the Unix epoch
*
* Creates a new #GstDateTime using the time since Jan 1, 1970 specified by @t.
* The #GstDateTime is in the local timezone.
*
* Return value: the newly created #GstDateTime
*
* Since: 0.10.31
*/
GstDateTime *
gst_date_time_new_from_unix_epoch (gint64 t)
{
GstDateTime *dt;
struct tm tm;
time_t tt;
memset (&tm, 0, sizeof (tm));
tt = (time_t) t;
#ifdef HAVE_LOCALTIME_R
localtime_r (&tt, &tm);
#else
localtime (&tt, &tm);
#endif
dt = gst_date_time_new (tm.tm_year + 1900,
tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, 0, 0);
gst_date_time_set_local_timezone (dt);
return dt;
}
/**
* gst_date_time_new_local_time:
* @year: the gregorian year
* @month: the gregorian month
* @day: the day of the gregorian month
* @hour: the hour of the day
* @minute: the minute of the hour
* @second: the second of the minute
* @microsecond: the microsecond of the second
*
* Creates a new #GstDateTime using the date and times in the gregorian calendar
* in the local timezone.
*
* @year should be from 1 to 9999, @month should be from 1 to 12, @day from
* 1 to 31, @hour from 0 to 23, @minutes and @seconds from 0 to 59 and
* @microsecond from 0 to 999999.
*
* Return value: the newly created #GstDateTime
*
* Since: 0.10.31
*/
GstDateTime *
gst_date_time_new_local_time (gint year, gint month, gint day, gint hour,
gint minute, gint second, gint microsecond)
{
GstDateTime *dt;
dt = gst_date_time_new (year, month, day, hour, minute, second, microsecond,
0);
gst_date_time_set_local_timezone (dt);
return dt;
}
/**
* gst_date_time_new:
* @year: the gregorian year
* @month: the gregorian month
* @day: the day of the gregorian month
* @hour: the hour of the day
* @minute: the minute of the hour
* @second: the second of the minute
* @microsecond: the microsecond of the second
* @tzoffset: Offset from UTC in hours.
*
* Creates a new #GstDateTime using the date and times in the gregorian calendar
* in the supplied timezone.
*
* @year should be from 1 to 9999, @month should be from 1 to 12, @day from
* 1 to 31, @hour from 0 to 23, @minutes and @seconds from 0 to 59 and
* @microsecond from 0 to 999999.
*
* Note that @tzoffset is a float and was chosen so for being able to handle
* some fractional timezones, while it still keeps the readability of
* represeting it in hours for most timezones.
*
* Return value: the newly created #GstDateTime
*
* Since: 0.10.31
*/
GstDateTime *
gst_date_time_new (gint year, gint month, gint day, gint hour,
gint minute, gint second, gint microsecond, gfloat tzoffset)
{
GstDateTime *dt;
g_return_val_if_fail (hour >= 0 && hour < 24, NULL);
g_return_val_if_fail (minute >= 0 && minute < 60, NULL);
g_return_val_if_fail (second >= 0 && second < 60, NULL);
g_return_val_if_fail (microsecond >= 0 && microsecond < 1000000, NULL);
if (!(dt = gst_date_time_new_from_date (year, month, day)))
return NULL;
dt->usec = (hour * GST_DATE_TIME_USEC_PER_HOUR)
+ (minute * GST_DATE_TIME_USEC_PER_MINUTE)
+ (second * GST_DATE_TIME_USEC_PER_SECOND)
+ microsecond;
dt->tzoffset = (gint) (60 * tzoffset);
return dt;
}
/**
* gst_date_time_new_now_local_time:
*
* Creates a new #GstDateTime representing the current date and time.
*
* Return value: the newly created #GstDateTime which should be freed with
* gst_date_time_unref().
*
* Since: 0.10.31
*/
GstDateTime *
gst_date_time_new_now_local_time (void)
{
GstDateTime *datetime;
GTimeVal tv;
g_get_current_time (&tv);
datetime = gst_date_time_new_from_unix_epoch (tv.tv_sec);
datetime->usec += tv.tv_usec;
gst_date_time_set_local_timezone (datetime);
return datetime;
}
/**
* gst_date_time_ref:
* @datetime: a #GstDateTime
*
* Atomically increments the reference count of @datetime by one.
*
* Return value: the reference @datetime
*
* Since: 0.10.31
*/
GstDateTime *
gst_date_time_ref (GstDateTime * datetime)
{
g_return_val_if_fail (datetime != NULL, NULL);
g_return_val_if_fail (datetime->ref_count > 0, NULL);
g_atomic_int_inc (&datetime->ref_count);
return datetime;
}
/**
* gst_date_time_unref:
* @datetime: a #GstDateTime
*
* Atomically decrements the reference count of @datetime by one. When the
* reference count reaches zero, the structure is freed.
*
* Since: 0.10.31
*/
void
gst_date_time_unref (GstDateTime * datetime)
{
g_return_if_fail (datetime != NULL);
g_return_if_fail (datetime->ref_count > 0);
if (g_atomic_int_dec_and_test (&datetime->ref_count))
gst_date_time_free (datetime);
}
static GstDateTime *
gst_date_time_copy (const GstDateTime * dt)
{
GstDateTime *copy = gst_date_time_alloc ();
memcpy (copy, dt, sizeof (GstDateTime));
copy->ref_count = 1;
return copy;
}
static GstDateTime *
gst_date_time_to_utc (const GstDateTime * dt)
{
GstDateTime *utc;
gint64 usec;
gint days;
gint leap;
g_return_val_if_fail (dt != NULL, NULL);
utc = gst_date_time_copy (dt);
usec = dt->usec - dt->tzoffset * GST_DATE_TIME_USEC_PER_MINUTE;
days = usec / GST_DATE_TIME_USEC_PER_DAY;
if (usec < 0)
days--;
utc->day += days;
leap = GREGORIAN_LEAP (utc->year) ? 1 : 0;
/* check if we should update month/year */
if (utc->day < 1) {
if (utc->month == 1) {
utc->year--;
utc->month = 12;
} else {
utc->month--;
}
if (GREGORIAN_LEAP (utc->year))
utc->day = days_in_months[1][utc->month];
else
utc->day = days_in_months[0][utc->month];
} else if (utc->day > days_in_months[leap][utc->month]) {
if (utc->month == 12) {
utc->year++;
utc->month = 1;
} else {
utc->month++;
}
utc->day = 1;
}
if (usec < 0)
utc->usec =
GST_DATE_TIME_USEC_PER_DAY + (usec % GST_DATE_TIME_USEC_PER_DAY);
else
utc->usec = usec % GST_DATE_TIME_USEC_PER_DAY;
return utc;
}
/**
* gst_date_time_new_now_utc:
*
* Creates a new #GstDateTime that represents the current instant at Universal
* coordinated time.
*
* Return value: the newly created #GstDateTime which should be freed with
* gst_date_time_unref().
*
* Since: 0.10.31
*/
GstDateTime *
gst_date_time_new_now_utc (void)
{
GstDateTime *now, *utc;
now = gst_date_time_new_now_local_time ();
utc = gst_date_time_to_utc (now);
gst_date_time_unref (now);
return utc;
}
gint
priv_gst_date_time_compare (gconstpointer dt1, gconstpointer dt2)
{
GstDateTime *a, *b;
gint res = 0;
a = gst_date_time_to_utc (dt1);
b = gst_date_time_to_utc (dt2);
#define GST_DATE_TIME_COMPARE_VALUE(a,b,v) \
if ((a)->v > (b)->v) { \
res = 1; \
goto done; \
} else if ((a)->v < (b)->v) { \
res = -1; \
goto done; \
}
GST_DATE_TIME_COMPARE_VALUE (a, b, year);
GST_DATE_TIME_COMPARE_VALUE (a, b, month);
GST_DATE_TIME_COMPARE_VALUE (a, b, day);
GST_DATE_TIME_COMPARE_VALUE (a, b, usec);
#undef GST_DATE_TIME_COMPARE_VALUE
done:
gst_date_time_unref (a);
gst_date_time_unref (b);
return res;
}