genericopenlibs/cstdlib/LTIME/TIME.CPP
changeset 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/genericopenlibs/cstdlib/LTIME/TIME.CPP	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,283 @@
+// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+// Mapping between EPOC32 time and libc time
+// The basic philosophy is to work in time_t units (TInt) which
+// will be essentially TTimeIntervalSeconds from the start of Unix time.
+// To stay compliant with the C-Standard (with reference to C99 draft), we  
+// set the meaning of time_t to be Universal time.
+// 
+//
+
+#include <e32std.h>
+#include "LTIME.H"
+#include <sys/reent.h>	    // for _ASCTIME_SIZE
+#include <sys/time.h>	    // for gettimeofday
+#include <time.h>
+#include <string.h>	    // for strcpy
+
+#define UNIX_BASE   TTime(MAKE_TINT64(0x00dcddb3,0x0f2f8000))    // 00:00, Jan 1st 1970
+
+// Utility routines for converting between representations
+
+static struct tm& as_struct_tm (const time_t& t, struct tm& res)
+    {
+    TTime us = UNIX_BASE + TTimeIntervalSeconds(t);
+    TDateTime dt = us.DateTime();
+
+    res.tm_sec  = dt.Second();
+    res.tm_min  = dt.Minute();
+    res.tm_hour = dt.Hour();
+    res.tm_mday = dt.Day() + 1;
+    res.tm_mon  = dt.Month();
+    res.tm_year = dt.Year() - 1900;
+
+    // EPOC32 counts the year day as Jan 1st == day 1
+    res.tm_yday = us.DayNoInYear() - 1;
+
+    // EPOC32 counts the weekdays from 0==Monday to 6==Sunday
+    res.tm_wday = us.DayNoInWeek() + 1;
+    if (res.tm_wday==7)
+	    res.tm_wday=0;	// Sunday==0 in a struct tm
+
+    // newlib just sets this field to -1
+    // tm_isdst doesn't really make sense here since we don't 
+    // know the locale for which to interpret this time.
+
+    res.tm_isdst = -1;
+
+    return res;
+    }
+
+static void as_ttime (const struct tm& p, TTime& res, TBool normalise=EFalse)
+    {
+    TDateTime dt;
+    TInt err = dt.Set(p.tm_year+1900, (enum TMonth)p.tm_mon, p.tm_mday-1, 
+	p.tm_hour, p.tm_min, p.tm_sec, 0);
+    if (err == KErrNone)
+	{
+	res = dt;
+	return;
+	}
+    if (!normalise)
+	{
+	res = TInt64(-1);
+	return;
+	}
+    // Try to normalise things (for mktime)
+    dt.Set(p.tm_year+1900, EJanuary, 0, 0, 0, 0, 0);
+    res = dt;
+    res += TTimeIntervalMonths (p.tm_mon);
+    res += TTimeIntervalDays   (p.tm_mday-1);
+    res += TTimeIntervalHours  (p.tm_hour);
+    res += TTimeIntervalMinutes(p.tm_min);
+    res += TTimeIntervalSeconds(p.tm_sec);
+    }
+
+inline void as_ttime (const time_t& p, TTime& res)
+    {
+    res = UNIX_BASE + TTimeIntervalSeconds(p);
+    }
+
+GLDEF_C time_t as_time_t(const TTime& t)
+    {
+    TTimeIntervalSeconds res;
+    TInt err = t.SecondsFrom(UNIX_BASE, res);
+    if (err)
+	return -1;
+    else
+	return res.Int();
+    }
+
+// Utility routine for formatting a TTime into a descriptor using the
+// UNIX ctime format. NB. EPOC32 abbreviations can be up to KMaxDayNameAbb
+// and KMaxMonthNameAbb characters (both == 4). The %F is needed to
+// force the meanings of %D, %Y etc.
+
+static TDes8& as_string (TTime& t, TDes8& res)
+    {
+    // UNICODE problem - t.Format operates on TDes => TDes16
+
+#if !defined(_UNICODE)
+    TRAPD(err, t.FormatL(res, _L("%F%*E %*N %D %H:%T:%S %Y")));
+#else
+    TBuf<_ASCTIME_SIZE> unires;
+    TRAPD(err, t.FormatL(unires, _L("%F%*E %*N %D %H:%T:%S %Y")));
+    if (!err)
+	res.Copy(unires);
+#endif
+    if (err)
+	res = _L8("Error\n");
+    else
+	res.Append('\n');
+    return res;
+    }
+
+/**
+Intended Usage:	Utility routine for converting from UTC to localtime.
+@return   		Localtime in seconds
+@param 			aUniversalTime Universaltime in seconds
+*/
+inline time_t toLocal (const time_t aUniversalTime)
+    {
+    TTimeIntervalSeconds offset = User::UTCOffset();
+    return aUniversalTime + offset.Int();
+    }
+
+/**
+Intended Usage:	Utility routine for converting from localtime to UTC.
+				However, having decided that time_t is always Universal time, toGMT is empty.
+@return			Localtime Universaltime in seconds
+@param 			aLocalTime Universaltime in seconds (meaning of time_t is UTC)
+*/
+inline time_t toGMT (const time_t aLocalTime)
+    {
+    return aLocalTime;
+    }
+
+// external interface for the C library
+
+extern "C" {
+/**
+Intended Usage:	Get current UTC time.
+				Get the number of seconds elapsed since 00:00 hours, 
+				Jan 1, 1970 UTC from the system clock.
+@return   		Elapsed time in seconds, as described.
+@param 			p Location where to store the retrieved value. 
+				If this is NULL the value is not stored. 
+				But it is still returned by the function.
+				time_t is generally defined by default to long.
+*/
+EXPORT_C time_t time (time_t* p)
+    {
+    TTime t;
+    t.UniversalTime();
+	
+    time_t res = as_time_t(t);
+    if (p)
+		*p = res;
+    return res;
+    }
+/**
+Intended Usage:	The gettimeofday function obtains the current UTC time, which is 
+				expressed as seconds and microseconds since 00:00:00 Coordinated Universal Time (UTC), 
+				January 1, 1970, and stores it in a timeval structure.
+				Please note that tz_minuteswest includes daytime saving. The struct member tz_dsttime is no 
+				longer supported by Symbian OS and therefore set to Zero.
+@publishedAll
+@released
+@return
+@param 			tp	Struct with two members of type long (tv_sec, tv_usec)
+@param 			tzp Struct with two members of type integer (tz_minuteswest, tz_dsttime)
+*/
+EXPORT_C int gettimeofday (struct timeval *tp, struct timezone *tzp)
+    {
+    if (tp)
+	{
+	TTime t;
+	t.UniversalTime();
+	
+	TTimeIntervalSeconds sec;
+	TInt err = t.SecondsFrom(UNIX_BASE, sec);
+	if (err)
+	    return -1;
+	else
+	    tp->tv_sec = sec.Int();
+	t -= sec;
+	TTimeIntervalMicroSeconds usec = t.MicroSecondsFrom(UNIX_BASE);
+	TInt64 hackyfix = usec.Int64();	// because GetTInt() isn't declared const
+	tp->tv_usec = I64INT(hackyfix);
+	}
+    if (tzp)
+	{
+	    tzp->tz_minuteswest = (User::UTCOffset().Int())/60;
+	    tzp->tz_dsttime = 0;
+	}
+    return 0;
+    }
+/**
+Return number of clock ticks since process start.
+Returns the number of clock ticks elapsed.
+A macro constant called CLK_TCK defines the relation betwen
+clock tick and second (clock ticks per second).
+@return   The number of clock ticks elapsed since start.
+clock_t type is defined by default as long int by most compilers.
+*/
+EXPORT_C clock_t clock ()
+    {
+    return -1;
+    }
+/**
+A reentrant version of gmtime(). 
+*/
+EXPORT_C struct tm* gmtime_r (const time_t* p, struct tm* res)
+    {
+    return &as_struct_tm( toGMT(*p), *res);
+    }
+/**
+A reentrant version of localtime().
+*/
+EXPORT_C struct tm* localtime_r (const time_t* p, struct tm* res)
+    {
+    return &as_struct_tm( toLocal(*p), *res);
+    }
+/**
+Convert tm structure to time_t value.
+Checks the members of the tm structure passed as parameter ptm 
+adjusting the values if the ones provided are not in the possible range 
+or they are not complete or mistaken and then translates that structure 
+to a time_t value (seconds elapsed since Jan 1, 1970) that is returned.
+The original values of tm_wday and tm_yday members of ptm are ignored 
+and filled with the correspondent ones to the calculated date. 
+The range of tm_mday is not checked until tm_mon and tm_year are determined.
+@return A time_t value corresponding to the date and time passed in ptm parameter.
+On error, a -1 value is returned.
+@param p Pointer to a tm structure, that contains data to be computed.
+*/
+EXPORT_C time_t mktime (struct tm *p)
+    {
+    TTime t;
+    as_ttime(*p, t, ETrue);
+    time_t res = as_time_t(t);
+
+    as_struct_tm(res, *p);    // Must also update the struct tm passed to us...
+    return res;
+    }
+
+/**
+A reentrant version of asctime().
+*/
+EXPORT_C char* asctime_r (const struct tm *p, char* result)
+    {
+    TTime t;
+    as_ttime(*p, t);
+
+    TPtr8 rDes((TUint8*)result, _ASCTIME_SIZE);
+
+    return (char *)as_string(t, rDes).PtrZ();
+    }
+
+/**
+A reentrant version of ctime().
+*/
+EXPORT_C char* ctime_r (const time_t* p, char* result)
+    {
+    TTime t;
+    as_ttime(toLocal(*p), t);
+
+    TPtr8 rDes((TUint8*)result, _ASCTIME_SIZE);
+
+    return (char *)as_string(t, rDes).PtrZ();
+    }
+
+} // extern "C"