date.c

Go to the documentation of this file.

/*-------------------------------------------------------------------------
 *
 * date.c
 *    implements DATE and TIME data types specified in SQL standard
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994-5, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/utils/adt/date.c
 *
 *-------------------------------------------------------------------------
 */
 
#include "postgres.h"
 
#include <ctype.h>
#include <limits.h>
#include <float.h>
#include <math.h>
#include <time.h>
 
#include "access/xact.h"
#include "catalog/pg_type.h"
#include "common/hashfn.h"
#include "common/int.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "nodes/miscnodes.h"
#include "nodes/supportnodes.h"
#include "parser/scansup.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/datetime.h"
#include "utils/numeric.h"
#include "utils/skipsupport.h"
#include "utils/sortsupport.h"
 
 
/* common code for timetypmodin and timetztypmodin */
static int32
anytime_typmodin(bool istz, ArrayType *ta)
{
    int32      *tl;
    int         n;
 
    tl = ArrayGetIntegerTypmods(ta, &n);
 
    /*
     * we're not too tense about good error message here because grammar
     * shouldn't allow wrong number of modifiers for TIME
     */
    if (n != 1)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid type modifier")));
 
    return anytime_typmod_check(istz, tl[0]);
}
 
/* exported so parse_expr.c can use it */
int32
anytime_typmod_check(bool istz, int32 typmod)
{
    if (typmod < 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("TIME(%d)%s precision must not be negative",
                        typmod, (istz ? " WITH TIME ZONE" : ""))));
    if (typmod > MAX_TIME_PRECISION)
    {
        ereport(WARNING,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("TIME(%d)%s precision reduced to maximum allowed, %d",
                        typmod, (istz ? " WITH TIME ZONE" : ""),
                        MAX_TIME_PRECISION)));
        typmod = MAX_TIME_PRECISION;
    }
 
    return typmod;
}
 
/* common code for timetypmodout and timetztypmodout */
static char *
anytime_typmodout(bool istz, int32 typmod)
{
    const char *tz = istz ? " with time zone" : " without time zone";
 
    if (typmod >= 0)
        return psprintf("(%d)%s", (int) typmod, tz);
    else
        return pstrdup(tz);
}
 
 
/*****************************************************************************
 *   Date ADT
 *****************************************************************************/
 
 
/* date_in()
 * Given date text string, convert to internal date format.
 */
Datum
date_in(PG_FUNCTION_ARGS)
{
    char       *str = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    DateADT     date;
    fsec_t      fsec;
    struct pg_tm tt,
               *tm = &tt;
    int         tzp;
    int         dtype;
    int         nf;
    int         dterr;
    char       *field[MAXDATEFIELDS];
    int         ftype[MAXDATEFIELDS];
    char        workbuf[MAXDATELEN + 1];
    DateTimeErrorExtra extra;
 
    dterr = ParseDateTime(str, workbuf, sizeof(workbuf),
                          field, ftype, MAXDATEFIELDS, &nf);
    if (dterr == 0)
        dterr = DecodeDateTime(field, ftype, nf,
                               &dtype, tm, &fsec, &tzp, &extra);
    if (dterr != 0)
    {
        DateTimeParseError(dterr, &extra, str, "date", escontext);
        PG_RETURN_NULL();
    }
 
    switch (dtype)
    {
        case DTK_DATE:
            break;
 
        case DTK_EPOCH:
            GetEpochTime(tm);
            break;
 
        case DTK_LATE:
            DATE_NOEND(date);
            PG_RETURN_DATEADT(date);
 
        case DTK_EARLY:
            DATE_NOBEGIN(date);
            PG_RETURN_DATEADT(date);
 
        default:
            DateTimeParseError(DTERR_BAD_FORMAT, &extra, str, "date", escontext);
            PG_RETURN_NULL();
    }
 
    /* Prevent overflow in Julian-day routines */
    if (!IS_VALID_JULIAN(tm->tm_year, tm->tm_mon, tm->tm_mday))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: \"%s\"", str)));
 
    date = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
 
    /* Now check for just-out-of-range dates */
    if (!IS_VALID_DATE(date))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: \"%s\"", str)));
 
    PG_RETURN_DATEADT(date);
}
 
/* date_out()
 * Given internal format date, convert to text string.
 */
Datum
date_out(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    char       *result;
    struct pg_tm tt,
               *tm = &tt;
    char        buf[MAXDATELEN + 1];
 
    if (DATE_NOT_FINITE(date))
        EncodeSpecialDate(date, buf);
    else
    {
        j2date(date + POSTGRES_EPOCH_JDATE,
               &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
        EncodeDateOnly(tm, DateStyle, buf);
    }
 
    result = pstrdup(buf);
    PG_RETURN_CSTRING(result);
}
 
/*
 *      date_recv           - converts external binary format to date
 */
Datum
date_recv(PG_FUNCTION_ARGS)
{
    StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);
    DateADT     result;
 
    result = (DateADT) pq_getmsgint(buf, sizeof(DateADT));
 
    /* Limit to the same range that date_in() accepts. */
    if (DATE_NOT_FINITE(result))
         /* ok */ ;
    else if (!IS_VALID_DATE(result))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range")));
 
    PG_RETURN_DATEADT(result);
}
 
/*
 *      date_send           - converts date to binary format
 */
Datum
date_send(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    StringInfoData buf;
 
    pq_begintypsend(&buf);
    pq_sendint32(&buf, date);
    PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
 
/*
 *      make_date           - date constructor
 */
Datum
make_date(PG_FUNCTION_ARGS)
{
    struct pg_tm tm;
    DateADT     date;
    int         dterr;
    bool        bc = false;
 
    tm.tm_year = PG_GETARG_INT32(0);
    tm.tm_mon = PG_GETARG_INT32(1);
    tm.tm_mday = PG_GETARG_INT32(2);
 
    /* Handle negative years as BC */
    if (tm.tm_year < 0)
    {
        int         year = tm.tm_year;
 
        bc = true;
        if (pg_neg_s32_overflow(year, &year))
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_FIELD_OVERFLOW),
                     errmsg("date field value out of range: %d-%02d-%02d",
                            tm.tm_year, tm.tm_mon, tm.tm_mday)));
        tm.tm_year = year;
    }
 
    dterr = ValidateDate(DTK_DATE_M, false, false, bc, &tm);
 
    if (dterr != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_FIELD_OVERFLOW),
                 errmsg("date field value out of range: %d-%02d-%02d",
                        tm.tm_year, tm.tm_mon, tm.tm_mday)));
 
    /* Prevent overflow in Julian-day routines */
    if (!IS_VALID_JULIAN(tm.tm_year, tm.tm_mon, tm.tm_mday))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: %d-%02d-%02d",
                        tm.tm_year, tm.tm_mon, tm.tm_mday)));
 
    date = date2j(tm.tm_year, tm.tm_mon, tm.tm_mday) - POSTGRES_EPOCH_JDATE;
 
    /* Now check for just-out-of-range dates */
    if (!IS_VALID_DATE(date))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: %d-%02d-%02d",
                        tm.tm_year, tm.tm_mon, tm.tm_mday)));
 
    PG_RETURN_DATEADT(date);
}
 
/*
 * Convert reserved date values to string.
 */
void
EncodeSpecialDate(DateADT dt, char *str)
{
    if (DATE_IS_NOBEGIN(dt))
        strcpy(str, EARLY);
    else if (DATE_IS_NOEND(dt))
        strcpy(str, LATE);
    else                        /* shouldn't happen */
        elog(ERROR, "invalid argument for EncodeSpecialDate");
}
 
 
/*
 * GetSQLCurrentDate -- implements CURRENT_DATE
 */
DateADT
GetSQLCurrentDate(void)
{
    struct pg_tm tm;
 
    static int  cache_year = 0;
    static int  cache_mon = 0;
    static int  cache_mday = 0;
    static DateADT cache_date;
 
    GetCurrentDateTime(&tm);
 
    /*
     * date2j involves several integer divisions; moreover, unless our session
     * lives across local midnight, we don't really have to do it more than
     * once.  So it seems worth having a separate cache here.
     */
    if (tm.tm_year != cache_year ||
        tm.tm_mon != cache_mon ||
        tm.tm_mday != cache_mday)
    {
        cache_date = date2j(tm.tm_year, tm.tm_mon, tm.tm_mday) - POSTGRES_EPOCH_JDATE;
        cache_year = tm.tm_year;
        cache_mon = tm.tm_mon;
        cache_mday = tm.tm_mday;
    }
 
    return cache_date;
}
 
/*
 * GetSQLCurrentTime -- implements CURRENT_TIME, CURRENT_TIME(n)
 */
TimeTzADT *
GetSQLCurrentTime(int32 typmod)
{
    TimeTzADT  *result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;
 
    GetCurrentTimeUsec(tm, &fsec, &tz);
 
    result = palloc_object(TimeTzADT);
    tm2timetz(tm, fsec, tz, result);
    AdjustTimeForTypmod(&(result->time), typmod);
    return result;
}
 
/*
 * GetSQLLocalTime -- implements LOCALTIME, LOCALTIME(n)
 */
TimeADT
GetSQLLocalTime(int32 typmod)
{
    TimeADT     result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;
 
    GetCurrentTimeUsec(tm, &fsec, &tz);
 
    tm2time(tm, fsec, &result);
    AdjustTimeForTypmod(&result, typmod);
    return result;
}
 
 
/*
 * Comparison functions for dates
 */
 
Datum
date_eq(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(dateVal1 == dateVal2);
}
 
Datum
date_ne(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(dateVal1 != dateVal2);
}
 
Datum
date_lt(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(dateVal1 < dateVal2);
}
 
Datum
date_le(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(dateVal1 <= dateVal2);
}
 
Datum
date_gt(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(dateVal1 > dateVal2);
}
 
Datum
date_ge(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(dateVal1 >= dateVal2);
}
 
Datum
date_cmp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    if (dateVal1 < dateVal2)
        PG_RETURN_INT32(-1);
    else if (dateVal1 > dateVal2)
        PG_RETURN_INT32(1);
    PG_RETURN_INT32(0);
}
 
Datum
date_sortsupport(PG_FUNCTION_ARGS)
{
    SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
 
    ssup->comparator = ssup_datum_int32_cmp;
    PG_RETURN_VOID();
}
 
static Datum
date_decrement(Relation rel, Datum existing, bool *underflow)
{
    DateADT     dexisting = DatumGetDateADT(existing);
 
    if (dexisting == DATEVAL_NOBEGIN)
    {
        /* return value is undefined */
        *underflow = true;
        return (Datum) 0;
    }
 
    *underflow = false;
    return DateADTGetDatum(dexisting - 1);
}
 
static Datum
date_increment(Relation rel, Datum existing, bool *overflow)
{
    DateADT     dexisting = DatumGetDateADT(existing);
 
    if (dexisting == DATEVAL_NOEND)
    {
        /* return value is undefined */
        *overflow = true;
        return (Datum) 0;
    }
 
    *overflow = false;
    return DateADTGetDatum(dexisting + 1);
}
 
Datum
date_skipsupport(PG_FUNCTION_ARGS)
{
    SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
 
    sksup->decrement = date_decrement;
    sksup->increment = date_increment;
    sksup->low_elem = DateADTGetDatum(DATEVAL_NOBEGIN);
    sksup->high_elem = DateADTGetDatum(DATEVAL_NOEND);
 
    PG_RETURN_VOID();
}
 
Datum
hashdate(PG_FUNCTION_ARGS)
{
    return hash_uint32(PG_GETARG_DATEADT(0));
}
 
Datum
hashdateextended(PG_FUNCTION_ARGS)
{
    return hash_uint32_extended(PG_GETARG_DATEADT(0), PG_GETARG_INT64(1));
}
 
Datum
date_finite(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
 
    PG_RETURN_BOOL(!DATE_NOT_FINITE(date));
}
 
Datum
date_larger(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_DATEADT((dateVal1 > dateVal2) ? dateVal1 : dateVal2);
}
 
Datum
date_smaller(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    PG_RETURN_DATEADT((dateVal1 < dateVal2) ? dateVal1 : dateVal2);
}
 
/* Compute difference between two dates in days.
 */
Datum
date_mi(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);
 
    if (DATE_NOT_FINITE(dateVal1) || DATE_NOT_FINITE(dateVal2))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("cannot subtract infinite dates")));
 
    PG_RETURN_INT32((int32) (dateVal1 - dateVal2));
}
 
/* Add a number of days to a date, giving a new date.
 * Must handle both positive and negative numbers of days.
 */
Datum
date_pli(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    int32       days = PG_GETARG_INT32(1);
    DateADT     result;
 
    if (DATE_NOT_FINITE(dateVal))
        PG_RETURN_DATEADT(dateVal); /* can't change infinity */
 
    result = dateVal + days;
 
    /* Check for integer overflow and out-of-allowed-range */
    if ((days >= 0 ? (result < dateVal) : (result > dateVal)) ||
        !IS_VALID_DATE(result))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range")));
 
    PG_RETURN_DATEADT(result);
}
 
/* Subtract a number of days from a date, giving a new date.
 */
Datum
date_mii(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    int32       days = PG_GETARG_INT32(1);
    DateADT     result;
 
    if (DATE_NOT_FINITE(dateVal))
        PG_RETURN_DATEADT(dateVal); /* can't change infinity */
 
    result = dateVal - days;
 
    /* Check for integer overflow and out-of-allowed-range */
    if ((days >= 0 ? (result > dateVal) : (result < dateVal)) ||
        !IS_VALID_DATE(result))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range")));
 
    PG_RETURN_DATEADT(result);
}
 
 
/*
 * Promote date to timestamp.
 *
 * If the date falls out of the valid range for the timestamp type, error
 * handling proceeds based on escontext.
 *
 * If escontext is NULL, we throw an out-of-range error (hard error).
 * If escontext is not NULL, we return NOBEGIN or NOEND for lower bound or
 * upper bound overflow, respectively, and record a soft error.
 *
 * Note: Lower bound overflow is currently not possible, as both date and
 * timestamp datatypes share the same lower boundary: Julian day zero.
 */
Timestamp
date2timestamp_safe(DateADT dateVal, Node *escontext)
{
    Timestamp   result;
 
    if (DATE_IS_NOBEGIN(dateVal))
        TIMESTAMP_NOBEGIN(result);
    else if (DATE_IS_NOEND(dateVal))
        TIMESTAMP_NOEND(result);
    else
    {
        /*
         * Since dates have the same minimum values as timestamps, only upper
         * boundary need be checked for overflow.
         */
        if (dateVal >= (TIMESTAMP_END_JULIAN - POSTGRES_EPOCH_JDATE))
        {
            TIMESTAMP_NOEND(result);
            ereturn(escontext, result,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("date out of range for timestamp")));
        }
 
        /* date is days since 2000, timestamp is microseconds since same... */
        result = dateVal * USECS_PER_DAY;
    }
 
    return result;
}
 
/*
 * Promote date to timestamp, throwing error for overflow.
 */
static TimestampTz
date2timestamp(DateADT dateVal)
{
    return date2timestamp_safe(dateVal, NULL);
}
 
/*
 * Promote date to timestamp with time zone.
 *
 * If the date falls out of the valid range for the timestamp type, error
 * handling proceeds based on escontext.
 *
 * If escontext is NULL, we throw an out-of-range error (hard error).
 * If escontext is not NULL, we return NOBEGIN or NOEND for lower bound or
 * upper bound overflow, respectively, and record a soft error.
 */
TimestampTz
date2timestamptz_safe(DateADT dateVal, Node *escontext)
{
    TimestampTz result;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
 
    if (DATE_IS_NOBEGIN(dateVal))
        TIMESTAMP_NOBEGIN(result);
    else if (DATE_IS_NOEND(dateVal))
        TIMESTAMP_NOEND(result);
    else
    {
        /*
         * Since dates have the same minimum values as timestamps, only upper
         * boundary need be checked for overflow.
         */
        if (dateVal >= (TIMESTAMP_END_JULIAN - POSTGRES_EPOCH_JDATE))
        {
            TIMESTAMP_NOEND(result);
            ereturn(escontext, result,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("date out of range for timestamp")));
        }
 
        j2date(dateVal + POSTGRES_EPOCH_JDATE,
               &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
        tm->tm_hour = 0;
        tm->tm_min = 0;
        tm->tm_sec = 0;
        tz = DetermineTimeZoneOffset(tm, session_timezone);
 
        result = dateVal * USECS_PER_DAY + tz * USECS_PER_SEC;
 
        /*
         * Since it is possible to go beyond allowed timestamptz range because
         * of time zone, check for allowed timestamp range after adding tz.
         */
        if (!IS_VALID_TIMESTAMP(result))
        {
            if (result < MIN_TIMESTAMP)
                TIMESTAMP_NOBEGIN(result);
            else
                TIMESTAMP_NOEND(result);
 
            ereturn(escontext, result,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("date out of range for timestamp")));
        }
    }
 
    return result;
}
 
/*
 * date2timestamp_no_overflow
 *
 * This is chartered to produce a double value that is numerically
 * equivalent to the corresponding Timestamp value, if the date is in the
 * valid range of Timestamps, but in any case not throw an overflow error.
 * We can do this since the numerical range of double is greater than
 * that of non-erroneous timestamps.  The results are currently only
 * used for statistical estimation purposes.
 */
double
date2timestamp_no_overflow(DateADT dateVal)
{
    double      result;
 
    if (DATE_IS_NOBEGIN(dateVal))
        result = -DBL_MAX;
    else if (DATE_IS_NOEND(dateVal))
        result = DBL_MAX;
    else
    {
        /* date is days since 2000, timestamp is microseconds since same... */
        result = dateVal * (double) USECS_PER_DAY;
    }
 
    return result;
}
 
 
/*
 * Crosstype comparison functions for dates
 */
 
int32
date_cmp_timestamp_internal(DateADT dateVal, Timestamp dt2)
{
    Timestamp   dt1;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    dt1 = date2timestamp_safe(dateVal, (Node *) &escontext);
    if (escontext.error_occurred)
    {
        Assert(TIMESTAMP_IS_NOEND(dt1));    /* NOBEGIN case cannot occur */
 
        /* dt1 is larger than any finite timestamp, but less than infinity */
        return TIMESTAMP_IS_NOEND(dt2) ? -1 : +1;
    }
 
    return timestamp_cmp_internal(dt1, dt2);
}
 
Datum
date_eq_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt2) == 0);
}
 
Datum
date_ne_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt2) != 0);
}
 
Datum
date_lt_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt2) < 0);
}
 
Datum
date_gt_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt2) > 0);
}
 
Datum
date_le_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt2) <= 0);
}
 
Datum
date_ge_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt2) >= 0);
}
 
Datum
date_cmp_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
 
    PG_RETURN_INT32(date_cmp_timestamp_internal(dateVal, dt2));
}
 
int32
date_cmp_timestamptz_internal(DateADT dateVal, TimestampTz dt2)
{
    TimestampTz dt1;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    dt1 = date2timestamptz_safe(dateVal, (Node *) &escontext);
 
    if (escontext.error_occurred)
    {
        if (TIMESTAMP_IS_NOEND(dt1))
        {
            /* dt1 is larger than any finite timestamp, but less than infinity */
            return TIMESTAMP_IS_NOEND(dt2) ? -1 : +1;
        }
        if (TIMESTAMP_IS_NOBEGIN(dt1))
        {
            /* dt1 is less than any finite timestamp, but more than -infinity */
            return TIMESTAMP_IS_NOBEGIN(dt2) ? +1 : -1;
        }
    }
 
    return timestamptz_cmp_internal(dt1, dt2);
}
 
Datum
date_eq_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt2) == 0);
}
 
Datum
date_ne_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt2) != 0);
}
 
Datum
date_lt_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt2) < 0);
}
 
Datum
date_gt_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt2) > 0);
}
 
Datum
date_le_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt2) <= 0);
}
 
Datum
date_ge_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt2) >= 0);
}
 
Datum
date_cmp_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
 
    PG_RETURN_INT32(date_cmp_timestamptz_internal(dateVal, dt2));
}
 
Datum
timestamp_eq_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt1) == 0);
}
 
Datum
timestamp_ne_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt1) != 0);
}
 
Datum
timestamp_lt_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt1) > 0);
}
 
Datum
timestamp_gt_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt1) < 0);
}
 
Datum
timestamp_le_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt1) >= 0);
}
 
Datum
timestamp_ge_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamp_internal(dateVal, dt1) <= 0);
}
 
Datum
timestamp_cmp_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_INT32(-date_cmp_timestamp_internal(dateVal, dt1));
}
 
Datum
timestamptz_eq_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt1) == 0);
}
 
Datum
timestamptz_ne_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt1) != 0);
}
 
Datum
timestamptz_lt_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt1) > 0);
}
 
Datum
timestamptz_gt_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt1) < 0);
}
 
Datum
timestamptz_le_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt1) >= 0);
}
 
Datum
timestamptz_ge_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_BOOL(date_cmp_timestamptz_internal(dateVal, dt1) <= 0);
}
 
Datum
timestamptz_cmp_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
 
    PG_RETURN_INT32(-date_cmp_timestamptz_internal(dateVal, dt1));
}
 
/*
 * in_range support function for date.
 *
 * We implement this by promoting the dates to timestamp (without time zone)
 * and then using the timestamp-and-interval in_range function.
 */
Datum
in_range_date_interval(PG_FUNCTION_ARGS)
{
    DateADT     val = PG_GETARG_DATEADT(0);
    DateADT     base = PG_GETARG_DATEADT(1);
    Interval   *offset = PG_GETARG_INTERVAL_P(2);
    bool        sub = PG_GETARG_BOOL(3);
    bool        less = PG_GETARG_BOOL(4);
    Timestamp   valStamp;
    Timestamp   baseStamp;
 
    /* XXX we could support out-of-range cases here, perhaps */
    valStamp = date2timestamp(val);
    baseStamp = date2timestamp(base);
 
    return DirectFunctionCall5(in_range_timestamp_interval,
                               TimestampGetDatum(valStamp),
                               TimestampGetDatum(baseStamp),
                               IntervalPGetDatum(offset),
                               BoolGetDatum(sub),
                               BoolGetDatum(less));
}
 
 
/* extract_date()
 * Extract specified field from date type.
 */
Datum
extract_date(PG_FUNCTION_ARGS)
{
    text       *units = PG_GETARG_TEXT_PP(0);
    DateADT     date = PG_GETARG_DATEADT(1);
    int64       intresult;
    int         type,
                val;
    char       *lowunits;
    int         year,
                mon,
                mday;
 
    lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
                                            VARSIZE_ANY_EXHDR(units),
                                            false);
 
    type = DecodeUnits(0, lowunits, &val);
    if (type == UNKNOWN_FIELD)
        type = DecodeSpecial(0, lowunits, &val);
 
    if (DATE_NOT_FINITE(date) && (type == UNITS || type == RESERV))
    {
        switch (val)
        {
                /* Oscillating units */
            case DTK_DAY:
            case DTK_MONTH:
            case DTK_QUARTER:
            case DTK_WEEK:
            case DTK_DOW:
            case DTK_ISODOW:
            case DTK_DOY:
                PG_RETURN_NULL();
                break;
 
                /* Monotonically-increasing units */
            case DTK_YEAR:
            case DTK_DECADE:
            case DTK_CENTURY:
            case DTK_MILLENNIUM:
            case DTK_JULIAN:
            case DTK_ISOYEAR:
            case DTK_EPOCH:
                if (DATE_IS_NOBEGIN(date))
                    PG_RETURN_NUMERIC(DatumGetNumeric(DirectFunctionCall3(numeric_in,
                                                                          CStringGetDatum("-Infinity"),
                                                                          ObjectIdGetDatum(InvalidOid),
                                                                          Int32GetDatum(-1))));
                else
                    PG_RETURN_NUMERIC(DatumGetNumeric(DirectFunctionCall3(numeric_in,
                                                                          CStringGetDatum("Infinity"),
                                                                          ObjectIdGetDatum(InvalidOid),
                                                                          Int32GetDatum(-1))));
            default:
                ereport(ERROR,
                        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                         errmsg("unit \"%s\" not supported for type %s",
                                lowunits, format_type_be(DATEOID))));
        }
    }
    else if (type == UNITS)
    {
        j2date(date + POSTGRES_EPOCH_JDATE, &year, &mon, &mday);
 
        switch (val)
        {
            case DTK_DAY:
                intresult = mday;
                break;
 
            case DTK_MONTH:
                intresult = mon;
                break;
 
            case DTK_QUARTER:
                intresult = (mon - 1) / 3 + 1;
                break;
 
            case DTK_WEEK:
                intresult = date2isoweek(year, mon, mday);
                break;
 
            case DTK_YEAR:
                if (year > 0)
                    intresult = year;
                else
                    /* there is no year 0, just 1 BC and 1 AD */
                    intresult = year - 1;
                break;
 
            case DTK_DECADE:
                /* see comments in timestamp_part */
                if (year >= 0)
                    intresult = year / 10;
                else
                    intresult = -((8 - (year - 1)) / 10);
                break;
 
            case DTK_CENTURY:
                /* see comments in timestamp_part */
                if (year > 0)
                    intresult = (year + 99) / 100;
                else
                    intresult = -((99 - (year - 1)) / 100);
                break;
 
            case DTK_MILLENNIUM:
                /* see comments in timestamp_part */
                if (year > 0)
                    intresult = (year + 999) / 1000;
                else
                    intresult = -((999 - (year - 1)) / 1000);
                break;
 
            case DTK_JULIAN:
                intresult = date + POSTGRES_EPOCH_JDATE;
                break;
 
            case DTK_ISOYEAR:
                intresult = date2isoyear(year, mon, mday);
                /* Adjust BC years */
                if (intresult <= 0)
                    intresult -= 1;
                break;
 
            case DTK_DOW:
            case DTK_ISODOW:
                intresult = j2day(date + POSTGRES_EPOCH_JDATE);
                if (val == DTK_ISODOW && intresult == 0)
                    intresult = 7;
                break;
 
            case DTK_DOY:
                intresult = date2j(year, mon, mday) - date2j(year, 1, 1) + 1;
                break;
 
            default:
                ereport(ERROR,
                        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                         errmsg("unit \"%s\" not supported for type %s",
                                lowunits, format_type_be(DATEOID))));
                intresult = 0;
        }
    }
    else if (type == RESERV)
    {
        switch (val)
        {
            case DTK_EPOCH:
                intresult = ((int64) date + POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY;
                break;
 
            default:
                ereport(ERROR,
                        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                         errmsg("unit \"%s\" not supported for type %s",
                                lowunits, format_type_be(DATEOID))));
                intresult = 0;
        }
    }
    else
    {
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("unit \"%s\" not recognized for type %s",
                        lowunits, format_type_be(DATEOID))));
        intresult = 0;
    }
 
    PG_RETURN_NUMERIC(int64_to_numeric(intresult));
}
 
 
/* Add an interval to a date, giving a new date.
 * Must handle both positive and negative intervals.
 *
 * We implement this by promoting the date to timestamp (without time zone)
 * and then using the timestamp plus interval function.
 */
Datum
date_pl_interval(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    Timestamp   dateStamp;
 
    dateStamp = date2timestamp(dateVal);
 
    return DirectFunctionCall2(timestamp_pl_interval,
                               TimestampGetDatum(dateStamp),
                               PointerGetDatum(span));
}
 
/* Subtract an interval from a date, giving a new date.
 * Must handle both positive and negative intervals.
 *
 * We implement this by promoting the date to timestamp (without time zone)
 * and then using the timestamp minus interval function.
 */
Datum
date_mi_interval(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    Timestamp   dateStamp;
 
    dateStamp = date2timestamp(dateVal);
 
    return DirectFunctionCall2(timestamp_mi_interval,
                               TimestampGetDatum(dateStamp),
                               PointerGetDatum(span));
}
 
/* date_timestamp()
 * Convert date to timestamp data type.
 */
Datum
date_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   result;
 
    result = date2timestamp_safe(dateVal, fcinfo->context);
    if (SOFT_ERROR_OCCURRED(fcinfo->context))
        PG_RETURN_NULL();
 
    PG_RETURN_TIMESTAMP(result);
}
 
/* timestamp_date()
 * Convert timestamp to date data type.
 */
Datum
timestamp_date(PG_FUNCTION_ARGS)
{
    Timestamp   timestamp = PG_GETARG_TIMESTAMP(0);
    DateADT     result;
 
    result = timestamp2date_safe(timestamp, fcinfo->context);
    if (SOFT_ERROR_OCCURRED(fcinfo->context))
        PG_RETURN_NULL();
 
    PG_RETURN_DATEADT(result);
}
 
/*
 * Convert timestamp to date.
 *
 * If the timestamp falls out of the valid range for the date type, error
 * handling proceeds based on escontext.
 *
 * If escontext is NULL, we throw an out-of-range error (hard error).
 * If escontext is not NULL, we return NOBEGIN or NOEND for lower bound or
 * upper bound overflow, respectively, and record a soft error.
 *
 * Note: given the ranges of the types, overflow is only possible at
 * the lower bound of the range, but we don't assume that in this code.
 */
DateADT
timestamp2date_safe(Timestamp timestamp, Node *escontext)
{
    DateADT     result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
 
    if (TIMESTAMP_IS_NOBEGIN(timestamp))
        DATE_NOBEGIN(result);
    else if (TIMESTAMP_IS_NOEND(timestamp))
        DATE_NOEND(result);
    else
    {
        if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
        {
            if (timestamp < 0)
                DATE_NOBEGIN(result);
            else
                DATE_NOEND(result); /* not actually reachable */
 
            ereturn(escontext, result,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("timestamp out of range")));
        }
 
        result = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
    }
 
    return result;
}
 
 
/* date_timestamptz()
 * Convert date to timestamp with time zone data type.
 */
Datum
date_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz result;
 
    result = date2timestamptz_safe(dateVal, fcinfo->context);
    if (SOFT_ERROR_OCCURRED(fcinfo->context))
        PG_RETURN_NULL();
 
    PG_RETURN_TIMESTAMP(result);
}
 
 
/* timestamptz_date()
 * Convert timestamp with time zone to date data type.
 */
Datum
timestamptz_date(PG_FUNCTION_ARGS)
{
    TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
    DateADT     result;
 
    result = timestamptz2date_safe(timestamp, fcinfo->context);
    if (SOFT_ERROR_OCCURRED(fcinfo->context))
        PG_RETURN_NULL();
 
    PG_RETURN_DATEADT(result);
}
 
/*
 * Convert timestamptz to date.
 *
 * If the timestamp falls out of the valid range for the date type, error
 * handling proceeds based on escontext.
 *
 * If escontext is NULL, we throw an out-of-range error (hard error).
 * If escontext is not NULL, we return NOBEGIN or NOEND for lower bound or
 * upper bound overflow, respectively, and record a soft error.
 *
 * Note: given the ranges of the types, overflow is only possible at
 * the lower bound of the range, but we don't assume that in this code.
 */
DateADT
timestamptz2date_safe(TimestampTz timestamp, Node *escontext)
{
    DateADT     result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;
 
    if (TIMESTAMP_IS_NOBEGIN(timestamp))
        DATE_NOBEGIN(result);
    else if (TIMESTAMP_IS_NOEND(timestamp))
        DATE_NOEND(result);
    else
    {
        if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
        {
            if (timestamp < 0)
                DATE_NOBEGIN(result);
            else
                DATE_NOEND(result); /* not actually reachable */
 
            ereturn(escontext, result,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("timestamp out of range")));
        }
 
        result = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
    }
 
    return result;
}
 
 
/*****************************************************************************
 *   Time ADT
 *****************************************************************************/
 
Datum
time_in(PG_FUNCTION_ARGS)
{
    char       *str = PG_GETARG_CSTRING(0);
#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    Node       *escontext = fcinfo->context;
    TimeADT     result;
    fsec_t      fsec;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    int         nf;
    int         dterr;
    char        workbuf[MAXDATELEN + 1];
    char       *field[MAXDATEFIELDS];
    int         dtype;
    int         ftype[MAXDATEFIELDS];
    DateTimeErrorExtra extra;
 
    dterr = ParseDateTime(str, workbuf, sizeof(workbuf),
                          field, ftype, MAXDATEFIELDS, &nf);
    if (dterr == 0)
        dterr = DecodeTimeOnly(field, ftype, nf,
                               &dtype, tm, &fsec, &tz, &extra);
    if (dterr != 0)
    {
        DateTimeParseError(dterr, &extra, str, "time", escontext);
        PG_RETURN_NULL();
    }
 
    tm2time(tm, fsec, &result);
    AdjustTimeForTypmod(&result, typmod);
 
    PG_RETURN_TIMEADT(result);
}
 
/* tm2time()
 * Convert a tm structure to a time data type.
 */
int
tm2time(struct pg_tm *tm, fsec_t fsec, TimeADT *result)
{
    *result = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec)
               * USECS_PER_SEC) + fsec;
    return 0;
}
 
/* time_overflows()
 * Check to see if a broken-down time-of-day is out of range.
 */
bool
time_overflows(int hour, int min, int sec, fsec_t fsec)
{
    /* Range-check the fields individually. */
    if (hour < 0 || hour > HOURS_PER_DAY ||
        min < 0 || min >= MINS_PER_HOUR ||
        sec < 0 || sec > SECS_PER_MINUTE ||
        fsec < 0 || fsec > USECS_PER_SEC)
        return true;
 
    /*
     * Because we allow, eg, hour = 24 or sec = 60, we must check separately
     * that the total time value doesn't exceed 24:00:00.
     */
    if ((((((hour * MINS_PER_HOUR + min) * SECS_PER_MINUTE)
           + sec) * USECS_PER_SEC) + fsec) > USECS_PER_DAY)
        return true;
 
    return false;
}
 
/* float_time_overflows()
 * Same, when we have seconds + fractional seconds as one "double" value.
 */
bool
float_time_overflows(int hour, int min, double sec)
{
    /* Range-check the fields individually. */
    if (hour < 0 || hour > HOURS_PER_DAY ||
        min < 0 || min >= MINS_PER_HOUR)
        return true;
 
    /*
     * "sec", being double, requires extra care.  Cope with NaN, and round off
     * before applying the range check to avoid unexpected errors due to
     * imprecise input.  (We assume rint() behaves sanely with infinities.)
     */
    if (isnan(sec))
        return true;
    sec = rint(sec * USECS_PER_SEC);
    if (sec < 0 || sec > SECS_PER_MINUTE * USECS_PER_SEC)
        return true;
 
    /*
     * Because we allow, eg, hour = 24 or sec = 60, we must check separately
     * that the total time value doesn't exceed 24:00:00.  This must match the
     * way that callers will convert the fields to a time.
     */
    if (((((hour * MINS_PER_HOUR + min) * SECS_PER_MINUTE)
          * USECS_PER_SEC) + (int64) sec) > USECS_PER_DAY)
        return true;
 
    return false;
}
 
 
/* time2tm()
 * Convert time data type to POSIX time structure.
 *
 * Note that only the hour/min/sec/fractional-sec fields are filled in.
 */
int
time2tm(TimeADT time, struct pg_tm *tm, fsec_t *fsec)
{
    tm->tm_hour = time / USECS_PER_HOUR;
    time -= tm->tm_hour * USECS_PER_HOUR;
    tm->tm_min = time / USECS_PER_MINUTE;
    time -= tm->tm_min * USECS_PER_MINUTE;
    tm->tm_sec = time / USECS_PER_SEC;
    time -= tm->tm_sec * USECS_PER_SEC;
    *fsec = time;
    return 0;
}
 
Datum
time_out(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    char       *result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    char        buf[MAXDATELEN + 1];
 
    time2tm(time, tm, &fsec);
    EncodeTimeOnly(tm, fsec, false, 0, DateStyle, buf);
 
    result = pstrdup(buf);
    PG_RETURN_CSTRING(result);
}
 
/*
 *      time_recv           - converts external binary format to time
 */
Datum
time_recv(PG_FUNCTION_ARGS)
{
    StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);
 
#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    TimeADT     result;
 
    result = pq_getmsgint64(buf);
 
    if (result < INT64CONST(0) || result > USECS_PER_DAY)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("time out of range")));
 
    AdjustTimeForTypmod(&result, typmod);
 
    PG_RETURN_TIMEADT(result);
}
 
/*
 *      time_send           - converts time to binary format
 */
Datum
time_send(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    StringInfoData buf;
 
    pq_begintypsend(&buf);
    pq_sendint64(&buf, time);
    PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
 
Datum
timetypmodin(PG_FUNCTION_ARGS)
{
    ArrayType  *ta = PG_GETARG_ARRAYTYPE_P(0);
 
    PG_RETURN_INT32(anytime_typmodin(false, ta));
}
 
Datum
timetypmodout(PG_FUNCTION_ARGS)
{
    int32       typmod = PG_GETARG_INT32(0);
 
    PG_RETURN_CSTRING(anytime_typmodout(false, typmod));
}
 
/*
 *      make_time           - time constructor
 */
Datum
make_time(PG_FUNCTION_ARGS)
{
    int         tm_hour = PG_GETARG_INT32(0);
    int         tm_min = PG_GETARG_INT32(1);
    double      sec = PG_GETARG_FLOAT8(2);
    TimeADT     time;
 
    /* Check for time overflow */
    if (float_time_overflows(tm_hour, tm_min, sec))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_FIELD_OVERFLOW),
                 errmsg("time field value out of range: %d:%02d:%02g",
                        tm_hour, tm_min, sec)));
 
    /* This should match tm2time */
    time = (((tm_hour * MINS_PER_HOUR + tm_min) * SECS_PER_MINUTE)
            * USECS_PER_SEC) + (int64) rint(sec * USECS_PER_SEC);
 
    PG_RETURN_TIMEADT(time);
}
 
 
/* time_support()
 *
 * Planner support function for the time_scale() and timetz_scale()
 * length coercion functions (we need not distinguish them here).
 */
Datum
time_support(PG_FUNCTION_ARGS)
{
    Node       *rawreq = (Node *) PG_GETARG_POINTER(0);
    Node       *ret = NULL;
 
    if (IsA(rawreq, SupportRequestSimplify))
    {
        SupportRequestSimplify *req = (SupportRequestSimplify *) rawreq;
 
        ret = TemporalSimplify(MAX_TIME_PRECISION, (Node *) req->fcall);
    }
 
    PG_RETURN_POINTER(ret);
}
 
/* time_scale()
 * Adjust time type for specified scale factor.
 * Used by PostgreSQL type system to stuff columns.
 */
Datum
time_scale(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    int32       typmod = PG_GETARG_INT32(1);
    TimeADT     result;
 
    result = time;
    AdjustTimeForTypmod(&result, typmod);
 
    PG_RETURN_TIMEADT(result);
}
 
/* AdjustTimeForTypmod()
 * Force the precision of the time value to a specified value.
 * Uses *exactly* the same code as in AdjustTimestampForTypmod()
 * but we make a separate copy because those types do not
 * have a fundamental tie together but rather a coincidence of
 * implementation. - thomas
 */
void
AdjustTimeForTypmod(TimeADT *time, int32 typmod)
{
    static const int64 TimeScales[MAX_TIME_PRECISION + 1] = {
        INT64CONST(1000000),
        INT64CONST(100000),
        INT64CONST(10000),
        INT64CONST(1000),
        INT64CONST(100),
        INT64CONST(10),
        INT64CONST(1)
    };
 
    static const int64 TimeOffsets[MAX_TIME_PRECISION + 1] = {
        INT64CONST(500000),
        INT64CONST(50000),
        INT64CONST(5000),
        INT64CONST(500),
        INT64CONST(50),
        INT64CONST(5),
        INT64CONST(0)
    };
 
    if (typmod >= 0 && typmod <= MAX_TIME_PRECISION)
    {
        if (*time >= INT64CONST(0))
            *time = ((*time + TimeOffsets[typmod]) / TimeScales[typmod]) *
                TimeScales[typmod];
        else
            *time = -((((-*time) + TimeOffsets[typmod]) / TimeScales[typmod]) *
                      TimeScales[typmod]);
    }
}
 
 
Datum
time_eq(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_BOOL(time1 == time2);
}
 
Datum
time_ne(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_BOOL(time1 != time2);
}
 
Datum
time_lt(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_BOOL(time1 < time2);
}
 
Datum
time_le(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_BOOL(time1 <= time2);
}
 
Datum
time_gt(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_BOOL(time1 > time2);
}
 
Datum
time_ge(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_BOOL(time1 >= time2);
}
 
Datum
time_cmp(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    if (time1 < time2)
        PG_RETURN_INT32(-1);
    if (time1 > time2)
        PG_RETURN_INT32(1);
    PG_RETURN_INT32(0);
}
 
Datum
time_hash(PG_FUNCTION_ARGS)
{
    return hashint8(fcinfo);
}
 
Datum
time_hash_extended(PG_FUNCTION_ARGS)
{
    return hashint8extended(fcinfo);
}
 
Datum
time_larger(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_TIMEADT((time1 > time2) ? time1 : time2);
}
 
Datum
time_smaller(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
 
    PG_RETURN_TIMEADT((time1 < time2) ? time1 : time2);
}
 
/* overlaps_time() --- implements the SQL OVERLAPS operator.
 *
 * Algorithm is per SQL spec.  This is much harder than you'd think
 * because the spec requires us to deliver a non-null answer in some cases
 * where some of the inputs are null.
 */
Datum
overlaps_time(PG_FUNCTION_ARGS)
{
    /*
     * The arguments are TimeADT, but we leave them as generic Datums to avoid
     * dereferencing nulls (TimeADT is pass-by-reference!)
     */
    Datum       ts1 = PG_GETARG_DATUM(0);
    Datum       te1 = PG_GETARG_DATUM(1);
    Datum       ts2 = PG_GETARG_DATUM(2);
    Datum       te2 = PG_GETARG_DATUM(3);
    bool        ts1IsNull = PG_ARGISNULL(0);
    bool        te1IsNull = PG_ARGISNULL(1);
    bool        ts2IsNull = PG_ARGISNULL(2);
    bool        te2IsNull = PG_ARGISNULL(3);
 
#define TIMEADT_GT(t1,t2) \
    (DatumGetTimeADT(t1) > DatumGetTimeADT(t2))
#define TIMEADT_LT(t1,t2) \
    (DatumGetTimeADT(t1) < DatumGetTimeADT(t2))
 
    /*
     * If both endpoints of interval 1 are null, the result is null (unknown).
     * If just one endpoint is null, take ts1 as the non-null one. Otherwise,
     * take ts1 as the lesser endpoint.
     */
    if (ts1IsNull)
    {
        if (te1IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts1 = te1;
        te1IsNull = true;
    }
    else if (!te1IsNull)
    {
        if (TIMEADT_GT(ts1, te1))
        {
            Datum       tt = ts1;
 
            ts1 = te1;
            te1 = tt;
        }
    }
 
    /* Likewise for interval 2. */
    if (ts2IsNull)
    {
        if (te2IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts2 = te2;
        te2IsNull = true;
    }
    else if (!te2IsNull)
    {
        if (TIMEADT_GT(ts2, te2))
        {
            Datum       tt = ts2;
 
            ts2 = te2;
            te2 = tt;
        }
    }
 
    /*
     * At this point neither ts1 nor ts2 is null, so we can consider three
     * cases: ts1 > ts2, ts1 < ts2, ts1 = ts2
     */
    if (TIMEADT_GT(ts1, ts2))
    {
        /*
         * This case is ts1 < te2 OR te1 < te2, which may look redundant but
         * in the presence of nulls it's not quite completely so.
         */
        if (te2IsNull)
            PG_RETURN_NULL();
        if (TIMEADT_LT(ts1, te2))
            PG_RETURN_BOOL(true);
        if (te1IsNull)
            PG_RETURN_NULL();
 
        /*
         * If te1 is not null then we had ts1 <= te1 above, and we just found
         * ts1 >= te2, hence te1 >= te2.
         */
        PG_RETURN_BOOL(false);
    }
    else if (TIMEADT_LT(ts1, ts2))
    {
        /* This case is ts2 < te1 OR te2 < te1 */
        if (te1IsNull)
            PG_RETURN_NULL();
        if (TIMEADT_LT(ts2, te1))
            PG_RETURN_BOOL(true);
        if (te2IsNull)
            PG_RETURN_NULL();
 
        /*
         * If te2 is not null then we had ts2 <= te2 above, and we just found
         * ts2 >= te1, hence te2 >= te1.
         */
        PG_RETURN_BOOL(false);
    }
    else
    {
        /*
         * For ts1 = ts2 the spec says te1 <> te2 OR te1 = te2, which is a
         * rather silly way of saying "true if both are nonnull, else null".
         */
        if (te1IsNull || te2IsNull)
            PG_RETURN_NULL();
        PG_RETURN_BOOL(true);
    }
 
#undef TIMEADT_GT
#undef TIMEADT_LT
}
 
/* timestamp_time()
 * Convert timestamp to time data type.
 */
Datum
timestamp_time(PG_FUNCTION_ARGS)
{
    Timestamp   timestamp = PG_GETARG_TIMESTAMP(0);
    TimeADT     result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
 
    if (TIMESTAMP_NOT_FINITE(timestamp))
        PG_RETURN_NULL();
 
    if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
        ereturn(fcinfo->context, (Datum) 0,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));
 
    /*
     * Could also do this with time = (timestamp / USECS_PER_DAY *
     * USECS_PER_DAY) - timestamp;
     */
    result = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec) *
              USECS_PER_SEC) + fsec;
 
    PG_RETURN_TIMEADT(result);
}
 
/* timestamptz_time()
 * Convert timestamptz to time data type.
 */
Datum
timestamptz_time(PG_FUNCTION_ARGS)
{
    TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
    TimeADT     result;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    fsec_t      fsec;
 
    if (TIMESTAMP_NOT_FINITE(timestamp))
        PG_RETURN_NULL();
 
    if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
        ereturn(fcinfo->context, (Datum) 0,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));
 
    /*
     * Could also do this with time = (timestamp / USECS_PER_DAY *
     * USECS_PER_DAY) - timestamp;
     */
    result = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec) *
              USECS_PER_SEC) + fsec;
 
    PG_RETURN_TIMEADT(result);
}
 
/* datetime_timestamp()
 * Convert date and time to timestamp data type.
 */
Datum
datetime_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    TimeADT     time = PG_GETARG_TIMEADT(1);
    Timestamp   result;
 
    result = date2timestamp(date);
    if (!TIMESTAMP_NOT_FINITE(result))
    {
        result += time;
        if (!IS_VALID_TIMESTAMP(result))
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("timestamp out of range")));
    }
 
    PG_RETURN_TIMESTAMP(result);
}
 
/* time_interval()
 * Convert time to interval data type.
 */
Datum
time_interval(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    Interval   *result;
 
    result = palloc_object(Interval);
 
    result->time = time;
    result->day = 0;
    result->month = 0;
 
    PG_RETURN_INTERVAL_P(result);
}
 
/* interval_time()
 * Convert interval to time data type.
 *
 * This is defined as producing the fractional-day portion of the interval.
 * Therefore, we can just ignore the months field.  It is not real clear
 * what to do with negative intervals, but we choose to subtract the floor,
 * so that, say, '-2 hours' becomes '22:00:00'.
 */
Datum
interval_time(PG_FUNCTION_ARGS)
{
    Interval   *span = PG_GETARG_INTERVAL_P(0);
    TimeADT     result;
 
    if (INTERVAL_NOT_FINITE(span))
        ereturn(fcinfo->context, (Datum) 0,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("cannot convert infinite interval to time")));
 
    result = span->time % USECS_PER_DAY;
    if (result < 0)
        result += USECS_PER_DAY;
 
    PG_RETURN_TIMEADT(result);
}
 
/* time_mi_time()
 * Subtract two times to produce an interval.
 */
Datum
time_mi_time(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
    Interval   *result;
 
    result = palloc_object(Interval);
 
    result->month = 0;
    result->day = 0;
    result->time = time1 - time2;
 
    PG_RETURN_INTERVAL_P(result);
}
 
/* time_pl_interval()
 * Add interval to time.
 */
Datum
time_pl_interval(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeADT     result;
 
    if (INTERVAL_NOT_FINITE(span))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("cannot add infinite interval to time")));
 
    result = time + span->time;
    result -= result / USECS_PER_DAY * USECS_PER_DAY;
    if (result < INT64CONST(0))
        result += USECS_PER_DAY;
 
    PG_RETURN_TIMEADT(result);
}
 
/* time_mi_interval()
 * Subtract interval from time.
 */
Datum
time_mi_interval(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeADT     result;
 
    if (INTERVAL_NOT_FINITE(span))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("cannot subtract infinite interval from time")));
 
    result = time - span->time;
    result -= result / USECS_PER_DAY * USECS_PER_DAY;
    if (result < INT64CONST(0))
        result += USECS_PER_DAY;
 
    PG_RETURN_TIMEADT(result);
}
 
/*
 * in_range support function for time.
 */
Datum
in_range_time_interval(PG_FUNCTION_ARGS)
{
    TimeADT     val = PG_GETARG_TIMEADT(0);
    TimeADT     base = PG_GETARG_TIMEADT(1);
    Interval   *offset = PG_GETARG_INTERVAL_P(2);
    bool        sub = PG_GETARG_BOOL(3);
    bool        less = PG_GETARG_BOOL(4);
    TimeADT     sum;
 
    /*
     * Like time_pl_interval/time_mi_interval, we disregard the month and day
     * fields of the offset.  So our test for negative should too.  This also
     * catches -infinity, so we only need worry about +infinity below.
     */
    if (offset->time < 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
                 errmsg("invalid preceding or following size in window function")));
 
    /*
     * We can't use time_pl_interval/time_mi_interval here, because their
     * wraparound behavior would give wrong (or at least undesirable) answers.
     * Fortunately the equivalent non-wrapping behavior is trivial, except
     * that adding an infinite (or very large) interval might cause integer
     * overflow.  Subtraction cannot overflow here.
     */
    if (sub)
        sum = base - offset->time;
    else if (pg_add_s64_overflow(base, offset->time, &sum))
        PG_RETURN_BOOL(less);
 
    if (less)
        PG_RETURN_BOOL(val <= sum);
    else
        PG_RETURN_BOOL(val >= sum);
}
 
 
/* time_part() and extract_time()
 * Extract specified field from time type.
 */
static Datum
time_part_common(PG_FUNCTION_ARGS, bool retnumeric)
{
    text       *units = PG_GETARG_TEXT_PP(0);
    TimeADT     time = PG_GETARG_TIMEADT(1);
    int64       intresult;
    int         type,
                val;
    char       *lowunits;
 
    lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
                                            VARSIZE_ANY_EXHDR(units),
                                            false);
 
    type = DecodeUnits(0, lowunits, &val);
    if (type == UNKNOWN_FIELD)
        type = DecodeSpecial(0, lowunits, &val);
 
    if (type == UNITS)
    {
        fsec_t      fsec;
        struct pg_tm tt,
                   *tm = &tt;
 
        time2tm(time, tm, &fsec);
 
        switch (val)
        {
            case DTK_MICROSEC:
                intresult = tm->tm_sec * INT64CONST(1000000) + fsec;
                break;
 
            case DTK_MILLISEC:
                if (retnumeric)
                    /*---
                     * tm->tm_sec * 1000 + fsec / 1000
                     * = (tm->tm_sec * 1'000'000 + fsec) / 1000
                     */
                    PG_RETURN_NUMERIC(int64_div_fast_to_numeric(tm->tm_sec * INT64CONST(1000000) + fsec, 3));
                else
                    PG_RETURN_FLOAT8(tm->tm_sec * 1000.0 + fsec / 1000.0);
                break;
 
            case DTK_SECOND:
                if (retnumeric)
                    /*---
                     * tm->tm_sec + fsec / 1'000'000
                     * = (tm->tm_sec * 1'000'000 + fsec) / 1'000'000
                     */
                    PG_RETURN_NUMERIC(int64_div_fast_to_numeric(tm->tm_sec * INT64CONST(1000000) + fsec, 6));
                else
                    PG_RETURN_FLOAT8(tm->tm_sec + fsec / 1000000.0);
                break;
 
            case DTK_MINUTE:
                intresult = tm->tm_min;
                break;
 
            case DTK_HOUR:
                intresult = tm->tm_hour;
                break;
 
            case DTK_TZ:
            case DTK_TZ_MINUTE:
            case DTK_TZ_HOUR:
            case DTK_DAY:
            case DTK_MONTH:
            case DTK_QUARTER:
            case DTK_YEAR:
            case DTK_DECADE:
            case DTK_CENTURY:
            case DTK_MILLENNIUM:
            case DTK_ISOYEAR:
            default:
                ereport(ERROR,
                        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                         errmsg("unit \"%s\" not supported for type %s",
                                lowunits, format_type_be(TIMEOID))));
                intresult = 0;
        }
    }
    else if (type == RESERV && val == DTK_EPOCH)
    {
        if (retnumeric)
            PG_RETURN_NUMERIC(int64_div_fast_to_numeric(time, 6));
        else
            PG_RETURN_FLOAT8(time / 1000000.0);
    }
    else
    {
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("unit \"%s\" not recognized for type %s",
                        lowunits, format_type_be(TIMEOID))));
        intresult = 0;
    }
 
    if (retnumeric)
        PG_RETURN_NUMERIC(int64_to_numeric(intresult));
    else
        PG_RETURN_FLOAT8(intresult);
}
 
Datum
time_part(PG_FUNCTION_ARGS)
{
    return time_part_common(fcinfo, false);
}
 
Datum
extract_time(PG_FUNCTION_ARGS)
{
    return time_part_common(fcinfo, true);
}
 
 
/*****************************************************************************
 *   Time With Time Zone ADT
 *****************************************************************************/
 
/* tm2timetz()
 * Convert a tm structure to a time data type.
 */
int
tm2timetz(struct pg_tm *tm, fsec_t fsec, int tz, TimeTzADT *result)
{
    result->time = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec) *
                    USECS_PER_SEC) + fsec;
    result->zone = tz;
 
    return 0;
}
 
Datum
timetz_in(PG_FUNCTION_ARGS)
{
    char       *str = PG_GETARG_CSTRING(0);
#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    Node       *escontext = fcinfo->context;
    TimeTzADT  *result;
    fsec_t      fsec;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    int         nf;
    int         dterr;
    char        workbuf[MAXDATELEN + 1];
    char       *field[MAXDATEFIELDS];
    int         dtype;
    int         ftype[MAXDATEFIELDS];
    DateTimeErrorExtra extra;
 
    dterr = ParseDateTime(str, workbuf, sizeof(workbuf),
                          field, ftype, MAXDATEFIELDS, &nf);
    if (dterr == 0)
        dterr = DecodeTimeOnly(field, ftype, nf,
                               &dtype, tm, &fsec, &tz, &extra);
    if (dterr != 0)
    {
        DateTimeParseError(dterr, &extra, str, "time with time zone",
                           escontext);
        PG_RETURN_NULL();
    }
 
    result = palloc_object(TimeTzADT);
    tm2timetz(tm, fsec, tz, result);
    AdjustTimeForTypmod(&(result->time), typmod);
 
    PG_RETURN_TIMETZADT_P(result);
}
 
Datum
timetz_out(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    char       *result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;
    char        buf[MAXDATELEN + 1];
 
    timetz2tm(time, tm, &fsec, &tz);
    EncodeTimeOnly(tm, fsec, true, tz, DateStyle, buf);
 
    result = pstrdup(buf);
    PG_RETURN_CSTRING(result);
}
 
/*
 *      timetz_recv         - converts external binary format to timetz
 */
Datum
timetz_recv(PG_FUNCTION_ARGS)
{
    StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);
 
#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    TimeTzADT  *result;
 
    result = palloc_object(TimeTzADT);
 
    result->time = pq_getmsgint64(buf);
 
    if (result->time < INT64CONST(0) || result->time > USECS_PER_DAY)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("time out of range")));
 
    result->zone = pq_getmsgint(buf, sizeof(result->zone));
 
    /* Check for sane GMT displacement; see notes in datatype/timestamp.h */
    if (result->zone <= -TZDISP_LIMIT || result->zone >= TZDISP_LIMIT)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_TIME_ZONE_DISPLACEMENT_VALUE),
                 errmsg("time zone displacement out of range")));
 
    AdjustTimeForTypmod(&(result->time), typmod);
 
    PG_RETURN_TIMETZADT_P(result);
}
 
/*
 *      timetz_send         - converts timetz to binary format
 */
Datum
timetz_send(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    StringInfoData buf;
 
    pq_begintypsend(&buf);
    pq_sendint64(&buf, time->time);
    pq_sendint32(&buf, time->zone);
    PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
 
Datum
timetztypmodin(PG_FUNCTION_ARGS)
{
    ArrayType  *ta = PG_GETARG_ARRAYTYPE_P(0);
 
    PG_RETURN_INT32(anytime_typmodin(true, ta));
}
 
Datum
timetztypmodout(PG_FUNCTION_ARGS)
{
    int32       typmod = PG_GETARG_INT32(0);
 
    PG_RETURN_CSTRING(anytime_typmodout(true, typmod));
}
 
 
/* timetz2tm()
 * Convert TIME WITH TIME ZONE data type to POSIX time structure.
 */
int
timetz2tm(TimeTzADT *time, struct pg_tm *tm, fsec_t *fsec, int *tzp)
{
    TimeOffset  trem = time->time;
 
    tm->tm_hour = trem / USECS_PER_HOUR;
    trem -= tm->tm_hour * USECS_PER_HOUR;
    tm->tm_min = trem / USECS_PER_MINUTE;
    trem -= tm->tm_min * USECS_PER_MINUTE;
    tm->tm_sec = trem / USECS_PER_SEC;
    *fsec = trem - tm->tm_sec * USECS_PER_SEC;
 
    if (tzp != NULL)
        *tzp = time->zone;
 
    return 0;
}
 
/* timetz_scale()
 * Adjust time type for specified scale factor.
 * Used by PostgreSQL type system to stuff columns.
 */
Datum
timetz_scale(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    int32       typmod = PG_GETARG_INT32(1);
    TimeTzADT  *result;
 
    result = palloc_object(TimeTzADT);
 
    result->time = time->time;
    result->zone = time->zone;
 
    AdjustTimeForTypmod(&(result->time), typmod);
 
    PG_RETURN_TIMETZADT_P(result);
}
 
 
static int
timetz_cmp_internal(TimeTzADT *time1, TimeTzADT *time2)
{
    TimeOffset  t1,
                t2;
 
    /* Primary sort is by true (GMT-equivalent) time */
    t1 = time1->time + (time1->zone * USECS_PER_SEC);
    t2 = time2->time + (time2->zone * USECS_PER_SEC);
 
    if (t1 > t2)
        return 1;
    if (t1 < t2)
        return -1;
 
    /*
     * If same GMT time, sort by timezone; we only want to say that two
     * timetz's are equal if both the time and zone parts are equal.
     */
    if (time1->zone > time2->zone)
        return 1;
    if (time1->zone < time2->zone)
        return -1;
 
    return 0;
}
 
Datum
timetz_eq(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
 
    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) == 0);
}
 
Datum
timetz_ne(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
 
    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) != 0);
}
 
Datum
timetz_lt(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
 
    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) < 0);
}
 
Datum
timetz_le(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
 
    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) <= 0);
}
 
Datum
timetz_gt(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
 
    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) > 0);
}
 
Datum
timetz_ge(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
 
    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) >= 0);
}
 
Datum
timetz_cmp(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
 
    PG_RETURN_INT32(timetz_cmp_internal(time1, time2));
}
 
Datum
timetz_hash(PG_FUNCTION_ARGS)
{
    TimeTzADT  *key = PG_GETARG_TIMETZADT_P(0);
    uint32      thash;
 
    /*
     * To avoid any problems with padding bytes in the struct, we figure the
     * field hashes separately and XOR them.
     */
    thash = DatumGetUInt32(DirectFunctionCall1(hashint8,
                                               Int64GetDatumFast(key->time)));
    thash ^= DatumGetUInt32(hash_uint32(key->zone));
    PG_RETURN_UINT32(thash);
}
 
Datum
timetz_hash_extended(PG_FUNCTION_ARGS)
{
    TimeTzADT  *key = PG_GETARG_TIMETZADT_P(0);
    Datum       seed = PG_GETARG_DATUM(1);
    uint64      thash;
 
    /* Same approach as timetz_hash */
    thash = DatumGetUInt64(DirectFunctionCall2(hashint8extended,
                                               Int64GetDatumFast(key->time),
                                               seed));
    thash ^= DatumGetUInt64(hash_uint32_extended(key->zone,
                                                 DatumGetInt64(seed)));
    PG_RETURN_UINT64(thash);
}
 
Datum
timetz_larger(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;
 
    if (timetz_cmp_internal(time1, time2) > 0)
        result = time1;
    else
        result = time2;
    PG_RETURN_TIMETZADT_P(result);
}
 
Datum
timetz_smaller(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;
 
    if (timetz_cmp_internal(time1, time2) < 0)
        result = time1;
    else
        result = time2;
    PG_RETURN_TIMETZADT_P(result);
}
 
/* timetz_pl_interval()
 * Add interval to timetz.
 */
Datum
timetz_pl_interval(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeTzADT  *result;
 
    if (INTERVAL_NOT_FINITE(span))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("cannot add infinite interval to time")));
 
    result = palloc_object(TimeTzADT);
 
    result->time = time->time + span->time;
    result->time -= result->time / USECS_PER_DAY * USECS_PER_DAY;
    if (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;
 
    result->zone = time->zone;
 
    PG_RETURN_TIMETZADT_P(result);
}
 
/* timetz_mi_interval()
 * Subtract interval from timetz.
 */
Datum
timetz_mi_interval(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeTzADT  *result;
 
    if (INTERVAL_NOT_FINITE(span))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("cannot subtract infinite interval from time")));
 
    result = palloc_object(TimeTzADT);
 
    result->time = time->time - span->time;
    result->time -= result->time / USECS_PER_DAY * USECS_PER_DAY;
    if (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;
 
    result->zone = time->zone;
 
    PG_RETURN_TIMETZADT_P(result);
}
 
/*
 * in_range support function for timetz.
 */
Datum
in_range_timetz_interval(PG_FUNCTION_ARGS)
{
    TimeTzADT  *val = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *base = PG_GETARG_TIMETZADT_P(1);
    Interval   *offset = PG_GETARG_INTERVAL_P(2);
    bool        sub = PG_GETARG_BOOL(3);
    bool        less = PG_GETARG_BOOL(4);
    TimeTzADT   sum;
 
    /*
     * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
     * day fields of the offset.  So our test for negative should too. This
     * also catches -infinity, so we only need worry about +infinity below.
     */
    if (offset->time < 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
                 errmsg("invalid preceding or following size in window function")));
 
    /*
     * We can't use timetz_pl_interval/timetz_mi_interval here, because their
     * wraparound behavior would give wrong (or at least undesirable) answers.
     * Fortunately the equivalent non-wrapping behavior is trivial, except
     * that adding an infinite (or very large) interval might cause integer
     * overflow.  Subtraction cannot overflow here.
     */
    if (sub)
        sum.time = base->time - offset->time;
    else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
        PG_RETURN_BOOL(less);
    sum.zone = base->zone;
 
    if (less)
        PG_RETURN_BOOL(timetz_cmp_internal(val, &sum) <= 0);
    else
        PG_RETURN_BOOL(timetz_cmp_internal(val, &sum) >= 0);
}
 
/* overlaps_timetz() --- implements the SQL OVERLAPS operator.
 *
 * Algorithm is per SQL spec.  This is much harder than you'd think
 * because the spec requires us to deliver a non-null answer in some cases
 * where some of the inputs are null.
 */
Datum
overlaps_timetz(PG_FUNCTION_ARGS)
{
    /*
     * The arguments are TimeTzADT *, but we leave them as generic Datums for
     * convenience of notation --- and to avoid dereferencing nulls.
     */
    Datum       ts1 = PG_GETARG_DATUM(0);
    Datum       te1 = PG_GETARG_DATUM(1);
    Datum       ts2 = PG_GETARG_DATUM(2);
    Datum       te2 = PG_GETARG_DATUM(3);
    bool        ts1IsNull = PG_ARGISNULL(0);
    bool        te1IsNull = PG_ARGISNULL(1);
    bool        ts2IsNull = PG_ARGISNULL(2);
    bool        te2IsNull = PG_ARGISNULL(3);
 
#define TIMETZ_GT(t1,t2) \
    DatumGetBool(DirectFunctionCall2(timetz_gt,t1,t2))
#define TIMETZ_LT(t1,t2) \
    DatumGetBool(DirectFunctionCall2(timetz_lt,t1,t2))
 
    /*
     * If both endpoints of interval 1 are null, the result is null (unknown).
     * If just one endpoint is null, take ts1 as the non-null one. Otherwise,
     * take ts1 as the lesser endpoint.
     */
    if (ts1IsNull)
    {
        if (te1IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts1 = te1;
        te1IsNull = true;
    }
    else if (!te1IsNull)
    {
        if (TIMETZ_GT(ts1, te1))
        {
            Datum       tt = ts1;
 
            ts1 = te1;
            te1 = tt;
        }
    }
 
    /* Likewise for interval 2. */
    if (ts2IsNull)
    {
        if (te2IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts2 = te2;
        te2IsNull = true;
    }
    else if (!te2IsNull)
    {
        if (TIMETZ_GT(ts2, te2))
        {
            Datum       tt = ts2;
 
            ts2 = te2;
            te2 = tt;
        }
    }
 
    /*
     * At this point neither ts1 nor ts2 is null, so we can consider three
     * cases: ts1 > ts2, ts1 < ts2, ts1 = ts2
     */
    if (TIMETZ_GT(ts1, ts2))
    {
        /*
         * This case is ts1 < te2 OR te1 < te2, which may look redundant but
         * in the presence of nulls it's not quite completely so.
         */
        if (te2IsNull)
            PG_RETURN_NULL();
        if (TIMETZ_LT(ts1, te2))
            PG_RETURN_BOOL(true);
        if (te1IsNull)
            PG_RETURN_NULL();
 
        /*
         * If te1 is not null then we had ts1 <= te1 above, and we just found
         * ts1 >= te2, hence te1 >= te2.
         */
        PG_RETURN_BOOL(false);
    }
    else if (TIMETZ_LT(ts1, ts2))
    {
        /* This case is ts2 < te1 OR te2 < te1 */
        if (te1IsNull)
            PG_RETURN_NULL();
        if (TIMETZ_LT(ts2, te1))
            PG_RETURN_BOOL(true);
        if (te2IsNull)
            PG_RETURN_NULL();
 
        /*
         * If te2 is not null then we had ts2 <= te2 above, and we just found
         * ts2 >= te1, hence te2 >= te1.
         */
        PG_RETURN_BOOL(false);
    }
    else
    {
        /*
         * For ts1 = ts2 the spec says te1 <> te2 OR te1 = te2, which is a
         * rather silly way of saying "true if both are nonnull, else null".
         */
        if (te1IsNull || te2IsNull)
            PG_RETURN_NULL();
        PG_RETURN_BOOL(true);
    }
 
#undef TIMETZ_GT
#undef TIMETZ_LT
}
 
 
Datum
timetz_time(PG_FUNCTION_ARGS)
{
    TimeTzADT  *timetz = PG_GETARG_TIMETZADT_P(0);
    TimeADT     result;
 
    /* swallow the time zone and just return the time */
    result = timetz->time;
 
    PG_RETURN_TIMEADT(result);
}
 
 
Datum
time_timetz(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    TimeTzADT  *result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;
 
    GetCurrentDateTime(tm);
    time2tm(time, tm, &fsec);
    tz = DetermineTimeZoneOffset(tm, session_timezone);
 
    result = palloc_object(TimeTzADT);
 
    result->time = time;
    result->zone = tz;
 
    PG_RETURN_TIMETZADT_P(result);
}
 
 
/* timestamptz_timetz()
 * Convert timestamp to timetz data type.
 */
Datum
timestamptz_timetz(PG_FUNCTION_ARGS)
{
    TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
    TimeTzADT  *result;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    fsec_t      fsec;
 
    if (TIMESTAMP_NOT_FINITE(timestamp))
        PG_RETURN_NULL();
 
    if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
        ereturn(fcinfo->context, (Datum) 0,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));
 
    result = palloc_object(TimeTzADT);
 
    tm2timetz(tm, fsec, tz, result);
 
    PG_RETURN_TIMETZADT_P(result);
}
 
 
/* datetimetz_timestamptz()
 * Convert date and timetz to timestamp with time zone data type.
 * Timestamp is stored in GMT, so add the time zone
 * stored with the timetz to the result.
 * - thomas 2000-03-10
 */
Datum
datetimetz_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
    TimestampTz result;
 
    if (DATE_IS_NOBEGIN(date))
        TIMESTAMP_NOBEGIN(result);
    else if (DATE_IS_NOEND(date))
        TIMESTAMP_NOEND(result);
    else
    {
        /*
         * Date's range is wider than timestamp's, so check for boundaries.
         * Since dates have the same minimum values as timestamps, only upper
         * boundary need be checked for overflow.
         */
        if (date >= (TIMESTAMP_END_JULIAN - POSTGRES_EPOCH_JDATE))
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("date out of range for timestamp")));
        result = date * USECS_PER_DAY + time->time + time->zone * USECS_PER_SEC;
 
        /*
         * Since it is possible to go beyond allowed timestamptz range because
         * of time zone, check for allowed timestamp range after adding tz.
         */
        if (!IS_VALID_TIMESTAMP(result))
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("date out of range for timestamp")));
    }
 
    PG_RETURN_TIMESTAMP(result);
}
 
 
/* timetz_part() and extract_timetz()
 * Extract specified field from time type.
 */
static Datum
timetz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
{
    text       *units = PG_GETARG_TEXT_PP(0);
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
    int64       intresult;
    int         type,
                val;
    char       *lowunits;
 
    lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
                                            VARSIZE_ANY_EXHDR(units),
                                            false);
 
    type = DecodeUnits(0, lowunits, &val);
    if (type == UNKNOWN_FIELD)
        type = DecodeSpecial(0, lowunits, &val);
 
    if (type == UNITS)
    {
        int         tz;
        fsec_t      fsec;
        struct pg_tm tt,
                   *tm = &tt;
 
        timetz2tm(time, tm, &fsec, &tz);
 
        switch (val)
        {
            case DTK_TZ:
                intresult = -tz;
                break;
 
            case DTK_TZ_MINUTE:
                intresult = (-tz / SECS_PER_MINUTE) % MINS_PER_HOUR;
                break;
 
            case DTK_TZ_HOUR:
                intresult = -tz / SECS_PER_HOUR;
                break;
 
            case DTK_MICROSEC:
                intresult = tm->tm_sec * INT64CONST(1000000) + fsec;
                break;
 
            case DTK_MILLISEC:
                if (retnumeric)
                    /*---
                     * tm->tm_sec * 1000 + fsec / 1000
                     * = (tm->tm_sec * 1'000'000 + fsec) / 1000
                     */
                    PG_RETURN_NUMERIC(int64_div_fast_to_numeric(tm->tm_sec * INT64CONST(1000000) + fsec, 3));
                else
                    PG_RETURN_FLOAT8(tm->tm_sec * 1000.0 + fsec / 1000.0);
                break;
 
            case DTK_SECOND:
                if (retnumeric)
                    /*---
                     * tm->tm_sec + fsec / 1'000'000
                     * = (tm->tm_sec * 1'000'000 + fsec) / 1'000'000
                     */
                    PG_RETURN_NUMERIC(int64_div_fast_to_numeric(tm->tm_sec * INT64CONST(1000000) + fsec, 6));
                else
                    PG_RETURN_FLOAT8(tm->tm_sec + fsec / 1000000.0);
                break;
 
            case DTK_MINUTE:
                intresult = tm->tm_min;
                break;
 
            case DTK_HOUR:
                intresult = tm->tm_hour;
                break;
 
            case DTK_DAY:
            case DTK_MONTH:
            case DTK_QUARTER:
            case DTK_YEAR:
            case DTK_DECADE:
            case DTK_CENTURY:
            case DTK_MILLENNIUM:
            default:
                ereport(ERROR,
                        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                         errmsg("unit \"%s\" not supported for type %s",
                                lowunits, format_type_be(TIMETZOID))));
                intresult = 0;
        }
    }
    else if (type == RESERV && val == DTK_EPOCH)
    {
        if (retnumeric)
            /*---
             * time->time / 1'000'000 + time->zone
             * = (time->time + time->zone * 1'000'000) / 1'000'000
             */
            PG_RETURN_NUMERIC(int64_div_fast_to_numeric(time->time + time->zone * INT64CONST(1000000), 6));
        else
            PG_RETURN_FLOAT8(time->time / 1000000.0 + time->zone);
    }
    else
    {
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("unit \"%s\" not recognized for type %s",
                        lowunits, format_type_be(TIMETZOID))));
        intresult = 0;
    }
 
    if (retnumeric)
        PG_RETURN_NUMERIC(int64_to_numeric(intresult));
    else
        PG_RETURN_FLOAT8(intresult);
}
 
 
Datum
timetz_part(PG_FUNCTION_ARGS)
{
    return timetz_part_common(fcinfo, false);
}
 
Datum
extract_timetz(PG_FUNCTION_ARGS)
{
    return timetz_part_common(fcinfo, true);
}
 
/* timetz_zone()
 * Encode time with time zone type with specified time zone.
 * Applies DST rules as of the transaction start time.
 */
Datum
timetz_zone(PG_FUNCTION_ARGS)
{
    text       *zone = PG_GETARG_TEXT_PP(0);
    TimeTzADT  *t = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;
    int         tz;
    char        tzname[TZ_STRLEN_MAX + 1];
    int         type,
                val;
    pg_tz      *tzp;
 
    /*
     * Look up the requested timezone.
     */
    text_to_cstring_buffer(zone, tzname, sizeof(tzname));
 
    type = DecodeTimezoneName(tzname, &val, &tzp);
 
    if (type == TZNAME_FIXED_OFFSET)
    {
        /* fixed-offset abbreviation */
        tz = -val;
    }
    else if (type == TZNAME_DYNTZ)
    {
        /* dynamic-offset abbreviation, resolve using transaction start time */
        TimestampTz now = GetCurrentTransactionStartTimestamp();
        int         isdst;
 
        tz = DetermineTimeZoneAbbrevOffsetTS(now, tzname, tzp, &isdst);
    }
    else
    {
        /* Get the offset-from-GMT that is valid now for the zone name */
        TimestampTz now = GetCurrentTransactionStartTimestamp();
        struct pg_tm tm;
        fsec_t      fsec;
 
        if (timestamp2tm(now, &tz, &tm, &fsec, NULL, tzp) != 0)
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("timestamp out of range")));
    }
 
    result = palloc_object(TimeTzADT);
 
    result->time = t->time + (t->zone - tz) * USECS_PER_SEC;
    /* C99 modulo has the wrong sign convention for negative input */
    while (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;
    if (result->time >= USECS_PER_DAY)
        result->time %= USECS_PER_DAY;
 
    result->zone = tz;
 
    PG_RETURN_TIMETZADT_P(result);
}
 
/* timetz_izone()
 * Encode time with time zone type with specified time interval as time zone.
 */
Datum
timetz_izone(PG_FUNCTION_ARGS)
{
    Interval   *zone = PG_GETARG_INTERVAL_P(0);
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;
    int         tz;
 
    if (INTERVAL_NOT_FINITE(zone))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("interval time zone \"%s\" must be finite",
                        DatumGetCString(DirectFunctionCall1(interval_out,
                                                            PointerGetDatum(zone))))));
 
    if (zone->month != 0 || zone->day != 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("interval time zone \"%s\" must not include months or days",
                        DatumGetCString(DirectFunctionCall1(interval_out,
                                                            PointerGetDatum(zone))))));
 
    tz = -(zone->time / USECS_PER_SEC);
 
    result = palloc_object(TimeTzADT);
 
    result->time = time->time + (time->zone - tz) * USECS_PER_SEC;
    /* C99 modulo has the wrong sign convention for negative input */
    while (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;
    if (result->time >= USECS_PER_DAY)
        result->time %= USECS_PER_DAY;
 
    result->zone = tz;
 
    PG_RETURN_TIMETZADT_P(result);
}
 
/* timetz_at_local()
 *
 * Unlike for timestamp[tz]_at_local, the type for timetz does not flip between
 * time with/without time zone, so we cannot just call the conversion function.
 */
Datum
timetz_at_local(PG_FUNCTION_ARGS)
{
    Datum       time = PG_GETARG_DATUM(0);
    const char *tzn = pg_get_timezone_name(session_timezone);
    Datum       zone = PointerGetDatum(cstring_to_text(tzn));
 
    return DirectFunctionCall2(timetz_zone, zone, time);
}