From: Thomas Lockhart <Thomas.G.Lockhart@jpl.nasa.gov>

Subject: [HACKERS] More patches for date/time

I have accumulated several patches to add functionality to the datetime
and timespan data types as well as to fix reported porting bugs on non-BSD
machines. These patches are:

dt.c.patch              - add datetime_part(), fix bugs
dt.h.patch              - add quarter and timezone support, add prototypes
globals.c.patch         - add time and timezone variables
miscadmin.h.patch       - add time and timezone variables
nabstime.c.patch        - add datetime conversion routine
nabstime.h.patch        - add prototypes
pg_operator.h.patch     - add datetime operators, clean up formatting
pg_proc.h.patch         - add datetime functions, reassign conflicting date OIDs
pg_type.h.patch         - add datetime and timespan data types

The dt.c and pg_proc.h patches are fairly large; the latter mostly because I tried
to get some columns for existing entries to line up.

src/backend/utils/adt/nabstime.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/utils/adt/nabstime.c,v 1.16 1997/03/21 18:53:28 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/utils/adt/nabstime.c,v 1.17 1997/03/25 08:09:35 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -62,13 +62,13 @@ GetCurrentAbsoluteTime(void)
 	CTimeZone = - tmnow->tm_gmtoff;	/* tm_gmtoff is Sun/DEC-ism */
 	CDayLight = (tmnow->tm_isdst > 0);
 	/* XXX is there a better way to get local timezone string in V7? - tgl 97/03/18 */
-	strftime( CTZName, 8, "%Z", localtime(&now));
+	strftime( CTZName, MAXTZLEN, "%Z", localtime(&now));
 #endif
 #else /* ! USE_POSIX_TIME */
 	CTimeZone = tbnow.timezone * 60;
 	CDayLight = (tbnow.dstflag != 0);
 	/* XXX does this work to get the local timezone string in V7? - tgl 97/03/18 */
-	strftime( CTZName, 8, "%Z", localtime(&now));
+	strftime( CTZName, MAXTZLEN, "%Z", localtime(&now));
 #endif 
     };
 
@@ -102,15 +102,61 @@ GetCurrentTime(struct tm *tm)
 } /* GetCurrentTime() */
 
 
+AbsoluteTime tm2abstime( struct tm *tm, int tz);
+
+AbsoluteTime
+tm2abstime( struct tm *tm, int tz)
+{
+    int day, sec;
+
+    /* validate, before going out of range on some members */
+    if (tm->tm_year < 1901 || tm->tm_year > 2038
+      || tm->tm_mon < 1 || tm->tm_mon > 12
+      || tm->tm_mday < 1 || tm->tm_mday > 31
+      || tm->tm_hour < 0 || tm->tm_hour >= 24
+      || tm->tm_min < 0 || tm->tm_min > 59
+      || tm->tm_sec < 0 || tm->tm_sec > 59)
+	return INVALID_ABSTIME;
+
+    day = (date2j( tm->tm_year, tm->tm_mon, tm->tm_mday) - date2j( 1970, 1, 1));
+
+    /* check for time out of range */
+    if ((day < MIN_DAYNUM) || (day > MAX_DAYNUM))
+	return INVALID_ABSTIME;
+
+    /* convert to seconds */
+    sec = tm->tm_sec + tz + (tm->tm_min +(day*24 + tm->tm_hour)*60)*60;
+
+    /* check for overflow */
+    if ((day == MAX_DAYNUM && sec < 0) ||
+      (day == MIN_DAYNUM && sec > 0))
+	return INVALID_ABSTIME;
+
+    /* daylight correction */
+    if (tm->tm_isdst < 0) {		/* unknown; find out */
+	tm->tm_isdst = (CDayLight > 0);
+    };
+    if (tm->tm_isdst > 0)
+	sec -= 60*60;
+
+    /* check for reserved values (e.g. "current" on edge of usual range */
+    if (!AbsoluteTimeIsReal(sec))
+	return INVALID_ABSTIME;
+
+    return sec;
+} /* tm2abstime() */
+
+
 /* nabstimein()
  * Decode date/time string and return abstime.
  */
 AbsoluteTime
 nabstimein(char* str)
 {
-    int sec;
+    AbsoluteTime result;
+
     double fsec;
-    int day, tz = 0;
+    int tz = 0;
     struct tm date, *tm = &date;
 
     char *field[MAXDATEFIELDS];
@@ -134,65 +180,35 @@ printf( "nabstimein- %d fields are type %d (DTK_DATE=%d)\n", nf, dtype, DTK_DATE
 
     switch (dtype) {
     case DTK_DATE:
-#if FALSE
-	return(dateconv( &date, tz));
-#endif
-	/* validate, before going out of range on some members */
-	if (tm->tm_year < 1901 || tm->tm_year > 2038
-	 || tm->tm_mon < 1 || tm->tm_mon > 12
-	 || tm->tm_mday < 1 || tm->tm_mday > 31
-	 || tm->tm_hour < 0 || tm->tm_hour >= 24
-	 || tm->tm_min < 0 || tm->tm_min > 59
-	 || tm->tm_sec < 0 || tm->tm_sec > 59)
-	    return INVALID_ABSTIME;
-
-	day = (date2j( tm->tm_year, tm->tm_mon, tm->tm_mday) - date2j( 1970, 1, 1));
-
-	/* check for time out of range */
-	if ((day < MIN_DAYNUM) || (day > MAX_DAYNUM))
-	return INVALID_ABSTIME;
-
-	/* convert to seconds */
-	sec = tm->tm_sec + tz + (tm->tm_min +(day*24 + tm->tm_hour)*60)*60;
-
-	/* check for overflow */
-	if ((day == MAX_DAYNUM && sec < 0) ||
-	 (day == MIN_DAYNUM && sec > 0))
-	    return INVALID_ABSTIME;
-
-	/* daylight correction */
-	if (tm->tm_isdst < 0) {		/* unknown; find out */
-	    tm->tm_isdst = (CDayLight > 0);
-	};
-	if (tm->tm_isdst > 0)
-	    sec -= 60*60;
-
-	/* check for reserved values (e.g. "current" on edge of usual range */
-	if (!AbsoluteTimeIsReal(sec))
-	    return INVALID_ABSTIME;
-
-	return sec;
+	result = tm2abstime(tm, tz);
+	break;
 
     case DTK_EPOCH:
-	return EPOCH_ABSTIME;
+	result = EPOCH_ABSTIME;
+	break;
 
     case DTK_CURRENT:
-	return CURRENT_ABSTIME;
+	result = CURRENT_ABSTIME;
+	break;
 
     case DTK_LATE:
-	return NOEND_ABSTIME;
+	result = NOEND_ABSTIME;
+	break;
 
     case DTK_EARLY:
-	return NOSTART_ABSTIME;
+	result = NOSTART_ABSTIME;
+	break;
 
     case DTK_INVALID:
-	return INVALID_ABSTIME;
+	result = INVALID_ABSTIME;
+	break;
 
     default:
+	elog(WARN,"Bad abstime (internal coding error) '%s'",str);
+	result = INVALID_ABSTIME;
     };
 
-    elog(WARN,"Bad abstime (internal coding error) '%s'",str);
-    return INVALID_ABSTIME;
+    return result;
 } /* nabstimein() */
 
 
@@ -432,3 +448,42 @@ abstimege(AbsoluteTime t1, AbsoluteTime t2)
 
     return(t1 >= t2);
 }
+
+/* datetime_abstime()
+ * Convert datetime to abstime.
+ */
+AbsoluteTime
+datetime_abstime(DateTime *datetime)
+{
+    AbsoluteTime result;
+
+    double fsec;
+    struct tm tt, *tm = &tt;
+
+    if (!PointerIsValid(datetime)) {
+	result = INVALID_ABSTIME;
+
+    } else if (DATETIME_IS_INVALID(*datetime)) {
+	result = INVALID_ABSTIME;
+
+    } else if (DATETIME_IS_NOBEGIN(*datetime)) {
+	result = NOSTART_ABSTIME;
+
+    } else if (DATETIME_IS_NOEND(*datetime)) {
+	result = NOEND_ABSTIME;
+
+    } else {
+	if (DATETIME_IS_RELATIVE(*datetime)) {
+	    datetime2tm( SetDateTime(*datetime), tm, &fsec);
+	    result = tm2abstime( tm, 0);
+
+	} else if (datetime2tm( *datetime, tm, &fsec) == 0) {
+	    result = tm2abstime( tm, 0);
+
+	} else {
+	    result = INVALID_ABSTIME;
+	};
+    };
+
+    return(result);
+} /* datetime_abstime() */

src/backend/utils/init/globals.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/utils/init/globals.c,v 1.7 1997/03/18 20:14:46 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/utils/init/globals.c,v 1.8 1997/03/25 08:09:43 scrappy Exp $
  *
  * NOTES
  *    Globals used all over the place should be declared here and not
@@ -65,11 +65,12 @@ bool		IsPostmaster = false;
 
 short		DebugLvl = 0;
 
+int		DateStyle = USE_ISO_DATES;
 bool		EuroDates = false;
 bool		HasCTZSet = false;
 bool		CDayLight = false;
 int		CTimeZone = 0;
-char		CTZName[8] = "";
+char		CTZName[MAXTZLEN+1] = "";
 
 char DateFormat[20] 	= "%d-%m-%Y";	/* mjl: sizes! or better malloc? XXX */
 char FloatFormat[20] = "%f";

src/include/miscadmin.h

@@ -11,7 +11,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: miscadmin.h,v 1.7 1997/03/18 20:15:19 scrappy Exp $
+ * $Id: miscadmin.h,v 1.8 1997/03/25 08:09:59 scrappy Exp $
  *
  * NOTES
  *    some of the information in this file will be moved to
@@ -58,12 +58,28 @@ extern bool	    IsPostmaster;
 extern short	    DebugLvl;
 
 /* Date/Time Configuration
- * HasCTZSet if client timezone is specified by client.
+ *
+ * Constants to pass info from runtime environment:
+ *  USE_POSTGRES_DATES specifies traditional postgres format for output.
+ *  USE_ISO_DATES specifies ISO-compliant format for output.
+ *  USE_SQL_DATES specified Oracle/Ingres-compliant format for output.
+ *
+ * DateStyle specifies preference for date formatting for output.
  * EuroDates if client prefers dates interpreted and written w/European conventions.
+ *
+ * HasCTZSet if client timezone is specified by client.
+ * CDayLight is the apparent daylight savings time status.
  * CTimeZone is the timezone offset in seconds.
  * CTZName is the timezone label.
  */
 
+#define MAXTZLEN	7
+
+#define USE_POSTGRES_DATES	0
+#define USE_ISO_DATES		1
+#define USE_SQL_DATES		2
+
+extern int	    DateStyle;
 extern bool	    EuroDates;
 extern bool	    HasCTZSet;
 extern bool	    CDayLight;

src/include/utils/dt.h

@@ -8,7 +8,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: dt.h,v 1.2 1997/03/18 16:36:50 scrappy Exp $
+ * $Id: dt.h,v 1.3 1997/03/25 08:11:18 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,19 +16,23 @@
 #define DT_H
 
 #include <time.h>
+#include <math.h>
 
 /*
  * DateTime represents absolute time.
- * TimeSpan represents delta time.
+ * TimeSpan represents delta time. Keep track of months (and years)
+ *  separately since the elapsed time spanned is unknown until instantiated
+ *  relative to an absolute time.
+ *
  * Note that Postgres uses "time interval" to mean a bounded interval,
- *  consisting of a beginning and ending time, not a time span.
+ *  consisting of a beginning and ending time, not a time span - tgl 97/03/20
  */
 
 typedef double DateTime;
 
 typedef struct {
     double      time;   /* all time units other than months and years */
-    int4        month;  /* months and years */
+    int4        month;  /* months and years, after time for alignment */
 } TimeSpan;
 
 
@@ -45,6 +49,7 @@ typedef struct {
  * Other alternate forms are hardcoded into token tables in dt.c.
  * ----------------------------------------------------------------
  */
+
 #define DAGO		"ago"
 #define DCURRENT	"current"
 #define EPOCH		"epoch"
@@ -65,12 +70,14 @@ typedef struct {
 #define DDAY		"day"
 #define DWEEK		"week"
 #define DMONTH		"month"
+#define DQUARTER	"quarter"
 #define DYEAR		"year"
 #define DDECADE		"decade"
 #define DCENTURY	"century"
 #define DMILLENIUM	"millenium"
 #define DA_D		"ad"
 #define DB_C		"bc"
+#define DTIMEZONE	"timezone"
 
 /*
  * Fundamental time field definitions for parsing.
@@ -78,6 +85,7 @@ typedef struct {
  *  Meridian:  am, pm, or 24-hour style.
  *  Millenium: ad, bc
  */
+
 #define AM	0
 #define PM	1
 #define HR24	2
@@ -90,6 +98,7 @@ typedef struct {
  * Can't have more of these than there are bits in an unsigned int
  *  since these are turned into bit masks during parsing and decoding.
  */
+
 #define RESERV	0
 #define MONTH	1
 #define YEAR	2
@@ -116,6 +125,7 @@ typedef struct {
  * These need to fit into the datetkn table type.
  * At the moment, that means keep them within [-127,127].
  */
+
 #define DTK_NUMBER	0
 #define DTK_STRING	1
 
@@ -143,17 +153,19 @@ typedef struct {
 #define DTK_DAY		36
 #define DTK_WEEK	37
 #define DTK_MONTH	38
-#define DTK_YEAR	39
-#define DTK_DECADE	40
-#define DTK_CENTURY	41
-#define DTK_MILLENIUM	42
-#define DTK_MILLISEC	43
-#define DTK_MICROSEC	44
-#define DTK_AGO		45
+#define DTK_QUARTER	39
+#define DTK_YEAR	40
+#define DTK_DECADE	41
+#define DTK_CENTURY	42
+#define DTK_MILLENIUM	43
+#define DTK_MILLISEC	44
+#define DTK_MICROSEC	45
+#define DTK_AGO		46
 
 /*
  * Bit mask definitions for time parsing.
  */
+
 #define DTK_M(t)	(0x01 << t)
 
 #define DTK_DATE_M	(DTK_M(YEAR) | DTK_M(MONTH) | DTK_M(DAY))
@@ -174,21 +186,95 @@ typedef struct {
     char value;		/* this may be unsigned, alas */
 } datetkn;
 
-extern void GetCurrentTime(struct tm *tm);
+#ifdef NAN
+#define DT_INVALID	(NAN)
+#else
+#define DT_INVALID	(DBL_MIN+DBL_MIN)
+#endif
+#ifdef HUGE_VAL
+#define DT_NOBEGIN	(-HUGE_VAL)
+#define DT_NOEND	(HUGE_VAL)
+#else
+#define DT_NOBEGIN	(-DBL_MAX)
+#define DT_NOEND	(DBL_MAX)
+#endif
+#define DT_CURRENT	(DBL_MIN)
+#define DT_EPOCH	(-DBL_MIN)
+
+#define DATETIME_INVALID(j)	{j = DT_INVALID;}
+#ifdef NAN
+#define DATETIME_IS_INVALID(j)	(isnan(j))
+#else
+#define DATETIME_IS_INVALID(j)	(j == DT_INVALID)
+#endif
+
+#define DATETIME_NOBEGIN(j)	{j = DT_NOBEGIN;}
+#define DATETIME_IS_NOBEGIN(j)	(j == DT_NOBEGIN)
+
+#define DATETIME_NOEND(j)	{j = DT_NOEND;}
+#define DATETIME_IS_NOEND(j)	(j == DT_NOEND)
+
+#define DATETIME_CURRENT(j)	{j = DT_CURRENT;}
+#define DATETIME_IS_CURRENT(j)	(j == DT_CURRENT)
+
+#define DATETIME_EPOCH(j)	{j = DT_EPOCH;}
+#define DATETIME_IS_EPOCH(j)	(j == DT_EPOCH)
+
+#define DATETIME_IS_RELATIVE(j)	(DATETIME_IS_CURRENT(j) || DATETIME_IS_EPOCH(j))
+#define DATETIME_NOT_FINITE(j)	(DATETIME_IS_INVALID(j) \
+				|| DATETIME_IS_NOBEGIN(j) || DATETIME_IS_NOEND(j))
+#define DATETIME_IS_RESERVED(j) (DATETIME_IS_RELATIVE(j) || DATETIME_NOT_FINITE(j))
+
+#define TIMESPAN_INVALID(j)	{j->time = DT_INVALID;}
+#ifdef NAN
+#define TIMESPAN_IS_INVALID(j)	(isnan((j).time))
+#else
+#define TIMESPAN_IS_INVALID(j)	((j).time == DT_INVALID)
+#endif
+
+#define TIME_PREC 1e-6
+#define JROUND(j) (rint(((double) j)/TIME_PREC)*TIME_PREC)
 
 /*
  * dt.c prototypes 
  */
+
 extern DateTime *datetime_in( char *str);
 extern char *datetime_out( DateTime *dt);
+extern bool datetime_eq(DateTime *dt1, DateTime *dt2);
+extern bool datetime_ne(DateTime *dt1, DateTime *dt2);
+extern bool datetime_lt(DateTime *dt1, DateTime *dt2);
+extern bool datetime_le(DateTime *dt1, DateTime *dt2);
+extern bool datetime_ge(DateTime *dt1, DateTime *dt2);
+extern bool datetime_gt(DateTime *dt1, DateTime *dt2);
+
 extern TimeSpan *timespan_in(char *str);
 extern char *timespan_out(TimeSpan *span);
+extern bool timespan_eq(TimeSpan *span1, TimeSpan *span2);
+extern bool timespan_ne(TimeSpan *span1, TimeSpan *span2);
+extern bool timespan_lt(TimeSpan *span1, TimeSpan *span2);
+extern bool timespan_le(TimeSpan *span1, TimeSpan *span2);
+extern bool timespan_ge(TimeSpan *span1, TimeSpan *span2);
+extern bool timespan_gt(TimeSpan *span1, TimeSpan *span2);
+
+float64 datetime_part(text *units, DateTime *datetime);
+float64 timespan_part(text *units, TimeSpan *timespan);
+
+extern TimeSpan *timespan_um(TimeSpan *span);
+extern TimeSpan *timespan_add(TimeSpan *span1, TimeSpan *span2);
+extern TimeSpan *timespan_sub(TimeSpan *span1, TimeSpan *span2);
 
 extern TimeSpan *datetime_sub(DateTime *dt1, DateTime *dt2);
 extern DateTime *datetime_add_span(DateTime *dt, TimeSpan *span);
 extern DateTime *datetime_sub_span(DateTime *dt, TimeSpan *span);
-extern TimeSpan *timespan_add(TimeSpan *span1, TimeSpan *span2);
-extern TimeSpan *timespan_sub(TimeSpan *span1, TimeSpan *span2);
+
+extern void GetCurrentTime(struct tm *tm);
+DateTime SetDateTime(DateTime datetime);
+DateTime tm2datetime(struct tm *tm, double fsec, int tzp);
+int datetime2tm( DateTime dt, struct tm *tm, double *fsec);
+
+int timespan2tm(TimeSpan span, struct tm *tm, float8 *fsec);
+int tm2timespan(struct tm *tm, double fsec, TimeSpan *span);
 
 extern DateTime dt2local( DateTime dt, int timezone);
 
@@ -199,12 +285,8 @@ extern int j2day( int jd);
 extern double time2t(const int hour, const int min, const double sec);
 extern void dt2time(DateTime dt, int *hour, int *min, double *sec);
 
-/*
-extern void GetCurrentTime(struct tm *tm);
-*/
 extern int ParseDateTime( char *timestr, char *lowstr,
   char *field[], int ftype[], int maxfields, int *numfields);
-
 extern int DecodeDateTime( char *field[], int ftype[],
  int nf, int *dtype, struct tm *tm, double *fsec, int *tzp);
 extern int DecodeDate(char *str, int fmask, int *tmask, struct tm *tm);
@@ -223,11 +305,10 @@ extern int DecodeDateDelta( char *field[], int ftype[],
  int nf, int *dtype, struct tm *tm, double *fsec);
 extern int DecodeUnits(int field, char *lowtoken, int *val);
 
-extern int EncodeSpecialDateTime(DateTime *dt, char *str);
+extern int EncodeSpecialDateTime(DateTime dt, char *str);
 extern int EncodePostgresDate(struct tm *tm, double fsec, char *str);
 extern int EncodePostgresSpan(struct tm *tm, double fsec, char *str);
 
-
 extern datetkn *datebsearch(char *key, datetkn *base, unsigned int nel);
 
 #endif /* DT_H */

src/include/utils/nabstime.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nabstime.h,v 1.5 1997/03/14 23:33:29 scrappy Exp $
+ * $Id: nabstime.h,v 1.6 1997/03/25 08:11:24 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -115,8 +115,6 @@ extern AbsoluteTime GetCurrentAbsoluteTime(void);
 extern AbsoluteTime nabstimein(char *timestr);
 extern char *nabstimeout(AbsoluteTime time);
 
-extern bool AbsoluteTimeIsBefore(AbsoluteTime time1, AbsoluteTime time2);
-extern bool AbsoluteTimeIsAfter(AbsoluteTime time1, AbsoluteTime time2);
 extern bool abstimeeq(AbsoluteTime t1, AbsoluteTime t2);
 extern bool abstimene(AbsoluteTime t1, AbsoluteTime t2);
 extern bool abstimelt(AbsoluteTime t1, AbsoluteTime t2);
@@ -124,6 +122,10 @@ extern bool abstimegt(AbsoluteTime t1, AbsoluteTime t2);
 extern bool abstimele(AbsoluteTime t1, AbsoluteTime t2);
 extern bool abstimege(AbsoluteTime t1, AbsoluteTime t2);
 
+extern AbsoluteTime datetime_abstime(DateTime *datetime);
+
+extern bool AbsoluteTimeIsBefore(AbsoluteTime time1, AbsoluteTime time2);
+extern bool AbsoluteTimeIsAfter(AbsoluteTime time1, AbsoluteTime time2);
 extern AbsoluteTime dateconv(struct tm *tm, int zone);
 extern time_t qmktime(struct tm *tp);