From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 26 Mar 2007 20:08:11 +0000 (+0000)
Subject: Added DateTime
X-Git-Tag: 1.0~28
X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=commitdiff_plain;h=80bbee2f401b4af71cb1b80508bdb0d2bb61fa40

Added DateTime
Reworked operator<< for TimeDelta
---

diff --git a/source/time/datetime.cpp b/source/time/datetime.cpp
new file mode 100644
index 0000000..4fcec96
--- /dev/null
+++ b/source/time/datetime.cpp
@@ -0,0 +1,267 @@
+/* $Id$ */
+#include <sstream>
+#include <iomanip>
+#include <msp/error.h>
+#include "datetime.h"
+#include "timestamp.h"
+
+using namespace std;
+
+namespace {
+
+inline bool is_leap_year(int32_t y)
+{ return y%4==0 && (y%100 || y%400==0); }
+
+inline uint8_t month_days(int32_t y, uint8_t m)
+{
+	switch(m)
+	{
+	case 4:
+	case 6:
+	case 9:
+	case 11:
+		return 30;
+	case 2:
+		return is_leap_year(y)?29:28;
+	default:
+		return 31;
+	}
+}
+
+template<typename T>
+inline int cmp_(T a, T b)
+{
+	if(a<b)
+		return -1;
+	if(a>b)
+		return 1;
+	return 0;
+}
+
+}
+
+#include <iostream>
+using namespace std;
+
+namespace Msp {
+namespace Time {
+
+DateTime::DateTime(const TimeStamp &ts):
+	year(1970),
+	month(1),
+	mday(1),
+	hour(0),
+	minute(0),
+	second(0),
+	usec(0)
+{
+	add_raw(ts.raw());
+}
+
+DateTime::DateTime(int32_t y, uint8_t m, uint8_t d):
+	year(y),
+	month(m),
+	mday(d),
+	hour(0),
+	minute(0),
+	second(0),
+	usec(0)
+{ }
+
+void DateTime::add_days(int32_t days)
+{
+	unsigned new_year=year;
+
+	/* Leap years have a 400 year cycle, so any 400 consecutive years have a
+	constant number of days */
+	new_year+=days/146097*400;
+	days%=146097;
+
+	if(days<0)
+	{
+		new_year-=400;
+		days+=146097;
+	}
+
+	// Fudge factor for leap day
+	int fudge=(month<=2)?1:0;
+
+	// (Almost) every 4 year cycle has 1 leap year and 3 normal years
+	unsigned cycles=days/1461;
+	days%=1461;
+
+	new_year+=cycles*4;
+
+	// See how many non-leap-years we counted as leap years and reclaim the lost days
+	unsigned missed_leap_days=((year-fudge)%100+cycles*4)/100;
+	if((year-fudge)%400+cycles*4>=400)
+		--missed_leap_days;
+
+	days+=missed_leap_days;
+
+	// Count single years from the 4 year cycle
+	cycles=days/365;
+	days%=365;
+
+	new_year+=cycles;
+
+	if((year-fudge)%4+cycles>=4)
+	{
+		// We passed a leap year - decrement days
+		if(days==0)
+		{
+			--new_year;
+			days=is_leap_year(new_year)?365:364;
+		}
+		else
+			--days;
+	}
+
+	year=new_year;
+
+	// Step months
+	while(mday+days>month_days(year, month))
+	{
+		days-=month_days(year, month);
+		++month;
+		if(month>12)
+		{
+			++year;
+			month=1;
+		}
+	}
+
+	mday+=days;
+}
+
+DateTime DateTime::operator+(const TimeDelta &td) const
+{
+	DateTime dt(*this);
+	dt.add_raw(td.raw());
+	return dt;
+}
+
+DateTime &DateTime::operator+=(const TimeDelta &td)
+{
+	add_raw(td.raw());
+	return *this;
+}
+
+int DateTime::cmp(const DateTime &dt) const
+{
+	if(int c=cmp_(year, dt.year))
+		return c;
+	if(int c=cmp_(month, dt.month))
+		return c;
+	if(int c=cmp_(mday, dt.mday))
+		return c;
+	if(int c=cmp_(hour, dt.hour))
+		return c;
+	if(int c=cmp_(minute, dt.minute))
+		return c;
+	if(int c=cmp_(second, dt.second))
+		return c;
+	if(int c=cmp_(usec, dt.usec))
+		return c;
+	return 0;
+}
+
+TimeStamp DateTime::get_timestamp() const
+{
+	if(year<-289701 || year>293641)
+		throw Exception("DateTime is not representable as a TimeStamp");
+
+	int64_t raw=(((hour*60LL)+minute)*60+second)*1000000+usec;
+	int days=(year-1970)*365;
+	days+=(year-1)/4-(year-1)/100+(year-1)/400-477;
+	for(unsigned i=1; i<month; ++i)
+		days+=month_days(year, i);
+	days+=mday-1;
+
+	raw+=days*86400000000LL;
+
+	return TimeStamp(raw);
+}
+
+string DateTime::format(const string &fmt) const
+{
+	ostringstream ss;
+	ss.fill('0');
+	for(string::const_iterator i=fmt.begin(); i!=fmt.end(); ++i)
+	{
+		if(*i=='%')
+		{
+			++i;
+			if(i==fmt.end())
+				break;
+			else if(*i=='d')
+				ss<<setw(2)<<int(mday);
+			else if(*i=='H')
+				ss<<setw(2)<<int(hour);
+			else if(*i=='I')
+				ss<<setw(2)<<hour%12;
+			else if(*i=='m')
+				ss<<setw(2)<<int(month);
+			else if(*i=='M')
+				ss<<setw(2)<<int(minute);
+			else if(*i=='p')
+				ss<<((hour>=12) ? "PM" : "AM");
+			else if(*i=='S')
+				ss<<setw(2)<<int(second);
+			else if(*i=='y')
+				ss<<setw(2)<<year%100;
+			else if(*i=='Y')
+				ss<<year;
+			else if(*i=='%')
+				ss<<'%';
+		}
+		else
+			ss<<*i;
+	}
+
+	return ss.str();
+}
+
+void DateTime::add_raw(int64_t raw)
+{
+	int32_t days=raw/86400000000LL;
+	raw%=86400000000LL;
+	if(raw<0)
+	{
+		++days;
+		raw+=86400000000LL;
+	}
+
+	usec+=raw%1000000; raw/=1000000;
+	second+=raw%60;    raw/=60;
+	minute+=raw%60;    raw/=60;
+	hour+=raw%24;      raw/=24;
+
+	add_days(days);
+	normalize();
+}
+
+void DateTime::normalize()
+{
+	second+=usec/1000000;
+	usec%=1000000;
+	minute+=second/60;
+	second%=60;
+	hour+=minute/60;
+	minute%=60;
+	mday+=hour/24;
+	hour%=24;
+	while(mday>month_days(year, month))
+	{
+		mday-=month_days(year, month);
+		++month;
+		if(month>12)
+		{
+			++year;
+			month=1;
+		}
+	}
+}
+
+} // namespace Time
+} // namespace Msp
diff --git a/source/time/datetime.h b/source/time/datetime.h
new file mode 100644
index 0000000..4f439e6
--- /dev/null
+++ b/source/time/datetime.h
@@ -0,0 +1,70 @@
+/* $Id$ */
+#ifndef MSP_TIME_DATETIME_H_
+#define MSP_TIME_DATETIME_H_
+
+#include <stdint.h>
+#include <string>
+
+namespace Msp {
+namespace Time {
+
+class TimeDelta;
+class TimeStamp;
+
+/**
+Provides handling of arbitary dates and times.  Can represent a moment of time
+in the range of about ±2.1×10⁹ years.  It can also be formatted into a string
+for presentation to the user.
+
+Due to the complex internal representation, arithmetic operations on a DateTime
+are relatively slow.  For purposes of internal scheduling in a program, a
+TimeStamp is a better choice.
+*/
+class DateTime
+{
+public:
+	DateTime(const TimeStamp &);
+	DateTime(int32_t, uint8_t, uint8_t);
+	DateTime(int32_t, uint8_t, uint8_t, uint8_t, uint8_t, uint8_t);
+	DateTime(int32_t, uint8_t, uint8_t, uint8_t, uint8_t, uint8_t, uint32_t);
+	
+	int32_t  get_year() const   { return year; }
+	uint8_t  get_month() const  { return month; }
+	uint8_t  get_mday() const   { return mday; }
+	uint8_t  get_hour() const   { return hour; }
+	uint8_t  get_minute() const { return minute; }
+	uint8_t  get_second() const { return second; }
+	uint32_t get_usec() const   { return usec; }
+
+	void add_days(int32_t);
+
+	DateTime operator+(const TimeDelta &) const;
+	DateTime &operator+=(const TimeDelta &);
+
+	bool operator==(const DateTime &d) const { return cmp(d)==0; }
+	bool operator!=(const DateTime &d) const { return cmp(d)!=0; }
+	bool operator<(const DateTime &d) const { return cmp(d)<0; }
+	bool operator<=(const DateTime &d) const { return cmp(d)<=0; }
+	bool operator>(const DateTime &d) const { return cmp(d)>0; }
+	bool operator>=(const DateTime &d) const { return cmp(d)>=0; }
+
+	int cmp(const DateTime &) const;
+	TimeStamp get_timestamp() const;
+	std::string format(const std::string &) const;
+private:
+	int32_t year;
+	uint8_t month;
+	uint8_t mday;
+	uint8_t hour;
+	uint8_t minute;
+	uint8_t second;
+	uint32_t usec;
+
+	void add_raw(int64_t);
+	void normalize();
+};
+
+} // namespace Time
+} // namespace Msp
+
+#endif
diff --git a/source/time/timedelta.cpp b/source/time/timedelta.cpp
index acf9eef..f7b037e 100644
--- a/source/time/timedelta.cpp
+++ b/source/time/timedelta.cpp
@@ -4,88 +4,72 @@ Copyright © 2006  Mikko Rasa, Mikkosoft Productions
 Distributed under the LGPL
 */
 #include <sstream>
+#include <iomanip>
 #include "timedelta.h"
 #include "units.h"
 
 using namespace std;
 
-namespace Msp {
-namespace Time {
+namespace {
 
 void print_part(ostream &out, int64_t &value, int64_t unit, char sep, bool &first)
 {
-	if(value>=unit || !first)
-	{
-		if(first)
-			out<<value/unit;
-		else
-		{
-			out.width(2);
-			out<<value/unit;
-		}
-		if(sep) out<<sep;
-		value%=unit;
-		first=false;
-	}
+	if(!value || (value<unit && first))
+		return;
+	
+	if(!first)
+		out<<sep<<setw(2);
+	
+	out<<value/unit;
+	value%=unit;
+	first=false;
 }
 
+}
+
+namespace Msp {
+namespace Time {
+
 ostream &operator<<(ostream &out, const TimeDelta &td)
 {
 	ostringstream ss;
 	ss.fill('0');
-	if(td.usec<1000)
-		ss<<td.usec<<"µs";
-	else if(td.usec<1000000)
+
+	int64_t value=td.raw();
+
+	if(value<0)
 	{
-		ss<<td.usec/1000;
-		if(td.usec%1000)
-		{
-			ss<<'.';
-			ss.width(3);
-			ss<<td.usec%1000;
-		}
-		ss<<"ms";
+		ss<<'-';
+		value=-value;
 	}
-	else if(td.usec<60000000)
+
+	if(value==0)
+		ss<<'0';
+	else if(value<1000)
+		ss<<value<<"µs";
+	else if(value<1000000)
 	{
-		ss<<td.usec/1000000;
-		if(td.usec%1000000)
-		{
-			ss<<'.';
-			if(td.usec%1000)
-			{
-				ss.width(6);
-				ss<<td.usec%1000000;
-			}
-			else
-			{
-				ss.width(3);
-				ss<<td.usec/1000%1000;
-			}
-		}
-		ss<<"s";
+		ss<<value/1000;
+		value%=1000;
+		if(value)
+			ss<<'.'<<setw(3)<<value;
+		ss<<"ms";
 	}
 	else
 	{
-		int64_t temp=td.usec;
-		bool    first=true;
-		print_part(ss, temp, day.raw(),  '-', first);
-		print_part(ss, temp, hour.raw(), ':', first);
-		print_part(ss, temp, min.raw(),  ':', first);
-		print_part(ss, temp, sec.raw(),  0,   first);
-		if(temp)
+		bool first=true;
+		print_part(ss, value, 86400000000LL,  0,  first);
+		print_part(ss, value, 3600000000LL,  '-', first);
+		print_part(ss, value, 60000000LL,    ':', first);
+		print_part(ss, value, 1000000LL,     ':', first);
+
+		if(value)
 		{
 			ss<<'.';
-			if(temp%1000)
-			{
-				ss.width(6);
-				ss<<temp;
-			}
+			if(value%1000)
+				ss<<setw(6)<<value;
 			else
-			{
-				ss.width(3);
-				ss<<temp/1000;
-			}
+				ss<<setw(3)<<value/1000;
 		}
 		ss<<"s";
 	}
diff --git a/source/time/timedelta.h b/source/time/timedelta.h
index 5c5b633..2d46498 100644
--- a/source/time/timedelta.h
+++ b/source/time/timedelta.h
@@ -70,8 +70,6 @@ public:
 	bool      operator!=(const TimeDelta &t) const { return usec!=t.usec; }
 
 	operator bool() const                          { return usec; }
-
-	friend std::ostream &operator<<(std::ostream &, const TimeDelta &);
 private:
 	int64_t usec;
 };
@@ -79,6 +77,8 @@ private:
 template<typename T>
 inline TimeDelta operator*(T a, const TimeDelta &t)   { return t*a; }
 
+extern std::ostream &operator<<(std::ostream &, const TimeDelta &);
+
 } // namespace Time
 } // namespace Msp
 
diff --git a/source/time/timestamp.h b/source/time/timestamp.h
index 984333d..1e1b275 100644
--- a/source/time/timestamp.h
+++ b/source/time/timestamp.h
@@ -13,9 +13,10 @@ namespace Msp {
 namespace Time {
 
 /**
-Represents a moment in time, such as the last tick.  This class is NOT intended
-to be used for storing arbitary user-defined times, I'll add a DateTime class
-if the need arises.
+Represents a moment in time.  The main source of TimeStamps is the now()
+function.
+
+For representing user-specified times, use the DateTime class.
 */
 class TimeStamp
 {
@@ -33,8 +34,8 @@ public:
 	explicit TimeStamp(int64_t u): usec(u) { }
 
 	/**
-	Returns the raw number stored inside the TimeStamp.  This should only be used
-	for serialization and the result should not be interpreted in any way.
+	Returns the raw number stored inside the TimeStamp.  This value should be
+	considered opaque and only be used for serialization.
 	*/
 	int64_t   raw() const { return usec; }
 
diff --git a/source/time/utils.cpp b/source/time/utils.cpp
index d6b6332..ad0d245 100644
--- a/source/time/utils.cpp
+++ b/source/time/utils.cpp
@@ -9,11 +9,14 @@ Distributed under the LGPL
 #include <sys/resource.h>
 #include <sys/time.h>
 #endif
+#include "datetime.h"
 #include "timedelta.h"
 #include "timestamp.h"
 #include "units.h"
 #include "utils.h"
 
+using namespace std;
+
 namespace Msp {
 namespace Time {
 
@@ -50,6 +53,11 @@ TimeStamp now()
 #endif
 }
 
+string format_now(const string &fmt)
+{
+	return DateTime(now()).format(fmt);
+}
+
 /**
 Returns the CPU time used by the program so far.
 */
diff --git a/source/time/utils.h b/source/time/utils.h
index e16cb65..bc04bad 100644
--- a/source/time/utils.h
+++ b/source/time/utils.h
@@ -13,6 +13,7 @@ class TimeDelta;
 class TimeStamp;
 
 extern TimeStamp now();
+extern std::string format_now(const std::string &);
 extern TimeDelta get_cpu_time();
 extern int sleep(const TimeDelta &);