Eneboo - Documentación para desarrolladores: Fichero Fuente src/libpq/include/utils/timestamp.h

Eneboo - Documentación para desarrolladores
00001 /*-------------------------------------------------------------------------
00002  *
00003  * timestamp.h
00004  *        Definitions for the SQL92 "timestamp" and "interval" types.
00005  *
00006  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
00007  * Portions Copyright (c) 1994, Regents of the University of California
00008  *
00009  * $PostgreSQL: pgsql/src/include/utils/timestamp.h,v 1.57 2005/10/15 02:49:46 momjian Exp $
00010  *
00011  *-------------------------------------------------------------------------
00012  */
00013 #ifndef TIMESTAMP_H
00014 #define TIMESTAMP_H
00015 
00016 #include <math.h>
00017 #include <limits.h>
00018 #include <float.h>
00019 
00020 #include "fmgr.h"
00021 #include "pgtime.h"
00022 #ifdef HAVE_INT64_TIMESTAMP
00023 #include "utils/int8.h"
00024 #endif
00025 
00026 /*
00027  * Timestamp represents absolute time.
00028  * Interval represents delta time. Keep track of months (and years), days,
00029  *      and time separately since the elapsed time spanned is unknown until
00030  *      instantiated relative to an absolute time.
00031  *
00032  * Note that Postgres uses "time interval" to mean a bounded interval,
00033  * consisting of a beginning and ending time, not a time span - thomas 97/03/20
00034  */
00035 
00036 #ifdef HAVE_INT64_TIMESTAMP
00037 typedef int64 Timestamp;
00038 typedef int64 TimestampTz;
00039 #else
00040 typedef double Timestamp;
00041 typedef double TimestampTz;
00042 #endif
00043 
00044 typedef struct
00045 {
00046 #ifdef HAVE_INT64_TIMESTAMP
00047         int64           time;                   /* all time units other than days, months and
00048                                                                  * years */
00049 #else
00050         double          time;                   /* all time units other than days, months and
00051                                                                  * years */
00052 #endif
00053         int32           day;                    /* days, after time for alignment */
00054         int32           month;                  /* months and years, after time for alignment */
00055 } Interval;
00056 
00057 
00058 #define MAX_TIMESTAMP_PRECISION 6
00059 #define MAX_INTERVAL_PRECISION 6
00060 
00061 /* in both timestamp.h and ecpg/dt.h */
00062 #define DAYS_PER_YEAR   365.25  /* assumes leap year every four years */
00063 #define MONTHS_PER_YEAR 12
00064 /*
00065  *      DAYS_PER_MONTH is very imprecise.  The more accurate value is
00066  *      365.2425/12 = 30.436875, or '30 days 10:29:06'.  Right now we only
00067  *      return an integral number of days, but someday perhaps we should
00068  *      also return a 'time' value to be used as well.  ISO 8601 suggests
00069  *      30 days.
00070  */
00071 #define DAYS_PER_MONTH  30              /* assumes exactly 30 days per month */
00072 #define HOURS_PER_DAY   24              /* assume no daylight savings time changes */
00073 
00074 /*
00075  *      This doesn't adjust for uneven daylight savings time intervals or leap
00076  *      seconds, and it crudely estimates leap years.  A more accurate value
00077  *      for days per years is 365.2422.
00078  */
00079 #define SECS_PER_YEAR   (36525 * 864)   /* avoid floating-point computation */
00080 #define SECS_PER_DAY    86400
00081 #define SECS_PER_HOUR   3600
00082 #define SECS_PER_MINUTE 60
00083 #define MINS_PER_HOUR   60
00084 
00085 #ifdef HAVE_INT64_TIMESTAMP
00086 #define USECS_PER_DAY   INT64CONST(86400000000)
00087 #define USECS_PER_HOUR  INT64CONST(3600000000)
00088 #define USECS_PER_MINUTE INT64CONST(60000000)
00089 #define USECS_PER_SEC   INT64CONST(1000000)
00090 #endif
00091 
00092 /*
00093  * Macros for fmgr-callable functions.
00094  *
00095  * For Timestamp, we make use of the same support routines as for int64
00096  * or float8.  Therefore Timestamp is pass-by-reference if and only if
00097  * int64 or float8 is!
00098  */
00099 #ifdef HAVE_INT64_TIMESTAMP
00100 
00101 #define DatumGetTimestamp(X)  ((Timestamp) DatumGetInt64(X))
00102 #define DatumGetTimestampTz(X)  ((TimestampTz) DatumGetInt64(X))
00103 #define DatumGetIntervalP(X)  ((Interval *) DatumGetPointer(X))
00104 
00105 #define TimestampGetDatum(X) Int64GetDatum(X)
00106 #define TimestampTzGetDatum(X) Int64GetDatum(X)
00107 #define IntervalPGetDatum(X) PointerGetDatum(X)
00108 
00109 #define PG_GETARG_TIMESTAMP(n) PG_GETARG_INT64(n)
00110 #define PG_GETARG_TIMESTAMPTZ(n) PG_GETARG_INT64(n)
00111 #define PG_GETARG_INTERVAL_P(n) DatumGetIntervalP(PG_GETARG_DATUM(n))
00112 
00113 #define PG_RETURN_TIMESTAMP(x) PG_RETURN_INT64(x)
00114 #define PG_RETURN_TIMESTAMPTZ(x) PG_RETURN_INT64(x)
00115 #define PG_RETURN_INTERVAL_P(x) return IntervalPGetDatum(x)
00116 
00117 #define DT_NOBEGIN              (-INT64CONST(0x7fffffffffffffff) - 1)
00118 #define DT_NOEND                (INT64CONST(0x7fffffffffffffff))
00119 #else
00120 
00121 #define DatumGetTimestamp(X)  ((Timestamp) DatumGetFloat8(X))
00122 #define DatumGetTimestampTz(X)  ((TimestampTz) DatumGetFloat8(X))
00123 #define DatumGetIntervalP(X)  ((Interval *) DatumGetPointer(X))
00124 
00125 #define TimestampGetDatum(X) Float8GetDatum(X)
00126 #define TimestampTzGetDatum(X) Float8GetDatum(X)
00127 #define IntervalPGetDatum(X) PointerGetDatum(X)
00128 
00129 #define PG_GETARG_TIMESTAMP(n) DatumGetTimestamp(PG_GETARG_DATUM(n))
00130 #define PG_GETARG_TIMESTAMPTZ(n) DatumGetTimestampTz(PG_GETARG_DATUM(n))
00131 #define PG_GETARG_INTERVAL_P(n) DatumGetIntervalP(PG_GETARG_DATUM(n))
00132 
00133 #define PG_RETURN_TIMESTAMP(x) return TimestampGetDatum(x)
00134 #define PG_RETURN_TIMESTAMPTZ(x) return TimestampTzGetDatum(x)
00135 #define PG_RETURN_INTERVAL_P(x) return IntervalPGetDatum(x)
00136 
00137 #ifdef HUGE_VAL
00138 #define DT_NOBEGIN              (-HUGE_VAL)
00139 #define DT_NOEND                (HUGE_VAL)
00140 #else
00141 #define DT_NOBEGIN              (-DBL_MAX)
00142 #define DT_NOEND                (DBL_MAX)
00143 #endif
00144 #endif   /* HAVE_INT64_TIMESTAMP */
00145 
00146 
00147 #define TIMESTAMP_NOBEGIN(j)    do {(j) = DT_NOBEGIN;} while (0)
00148 #define TIMESTAMP_IS_NOBEGIN(j) ((j) == DT_NOBEGIN)
00149 
00150 #define TIMESTAMP_NOEND(j)              do {(j) = DT_NOEND;} while (0)
00151 #define TIMESTAMP_IS_NOEND(j)   ((j) == DT_NOEND)
00152 
00153 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
00154 
00155 #ifdef HAVE_INT64_TIMESTAMP
00156 
00157 typedef int32 fsec_t;
00158 #else
00159 
00160 typedef double fsec_t;
00161 
00162 /* round off to MAX_TIMESTAMP_PRECISION decimal places */
00163 /* note: this is also used for rounding off intervals */
00164 #define TS_PREC_INV 1000000.0
00165 #define TSROUND(j) (rint(((double) (j)) * TS_PREC_INV) / TS_PREC_INV)
00166 #endif
00167 
00168 #define TIMESTAMP_MASK(b) (1 << (b))
00169 #define INTERVAL_MASK(b) (1 << (b))
00170 
00171 /* Macros to handle packing and unpacking the typmod field for intervals */
00172 #define INTERVAL_FULL_RANGE (0x7FFF)
00173 #define INTERVAL_RANGE_MASK (0x7FFF)
00174 #define INTERVAL_FULL_PRECISION (0xFFFF)
00175 #define INTERVAL_PRECISION_MASK (0xFFFF)
00176 #define INTERVAL_TYPMOD(p,r) ((((r) & INTERVAL_RANGE_MASK) << 16) | ((p) & INTERVAL_PRECISION_MASK))
00177 #define INTERVAL_PRECISION(t) ((t) & INTERVAL_PRECISION_MASK)
00178 #define INTERVAL_RANGE(t) (((t) >> 16) & INTERVAL_RANGE_MASK)
00179 
00180 
00181 /* Set at postmaster start */
00182 extern TimestampTz PgStartTime;
00183 
00184 
00185 /*
00186  * timestamp.c prototypes
00187  */
00188 
00189 extern Datum timestamp_in(PG_FUNCTION_ARGS);
00190 extern Datum timestamp_out(PG_FUNCTION_ARGS);
00191 extern Datum timestamp_recv(PG_FUNCTION_ARGS);
00192 extern Datum timestamp_send(PG_FUNCTION_ARGS);
00193 extern Datum timestamp_scale(PG_FUNCTION_ARGS);
00194 extern Datum timestamp_eq(PG_FUNCTION_ARGS);
00195 extern Datum timestamp_ne(PG_FUNCTION_ARGS);
00196 extern Datum timestamp_lt(PG_FUNCTION_ARGS);
00197 extern Datum timestamp_le(PG_FUNCTION_ARGS);
00198 extern Datum timestamp_ge(PG_FUNCTION_ARGS);
00199 extern Datum timestamp_gt(PG_FUNCTION_ARGS);
00200 extern Datum timestamp_finite(PG_FUNCTION_ARGS);
00201 extern Datum timestamp_cmp(PG_FUNCTION_ARGS);
00202 extern Datum timestamp_smaller(PG_FUNCTION_ARGS);
00203 extern Datum timestamp_larger(PG_FUNCTION_ARGS);
00204 
00205 extern Datum timestamp_eq_timestamptz(PG_FUNCTION_ARGS);
00206 extern Datum timestamp_ne_timestamptz(PG_FUNCTION_ARGS);
00207 extern Datum timestamp_lt_timestamptz(PG_FUNCTION_ARGS);
00208 extern Datum timestamp_le_timestamptz(PG_FUNCTION_ARGS);
00209 extern Datum timestamp_gt_timestamptz(PG_FUNCTION_ARGS);
00210 extern Datum timestamp_ge_timestamptz(PG_FUNCTION_ARGS);
00211 extern Datum timestamp_cmp_timestamptz(PG_FUNCTION_ARGS);
00212 
00213 extern Datum timestamptz_eq_timestamp(PG_FUNCTION_ARGS);
00214 extern Datum timestamptz_ne_timestamp(PG_FUNCTION_ARGS);
00215 extern Datum timestamptz_lt_timestamp(PG_FUNCTION_ARGS);
00216 extern Datum timestamptz_le_timestamp(PG_FUNCTION_ARGS);
00217 extern Datum timestamptz_gt_timestamp(PG_FUNCTION_ARGS);
00218 extern Datum timestamptz_ge_timestamp(PG_FUNCTION_ARGS);
00219 extern Datum timestamptz_cmp_timestamp(PG_FUNCTION_ARGS);
00220 
00221 extern Datum interval_in(PG_FUNCTION_ARGS);
00222 extern Datum interval_out(PG_FUNCTION_ARGS);
00223 extern Datum interval_recv(PG_FUNCTION_ARGS);
00224 extern Datum interval_send(PG_FUNCTION_ARGS);
00225 extern Datum interval_scale(PG_FUNCTION_ARGS);
00226 extern Datum interval_eq(PG_FUNCTION_ARGS);
00227 extern Datum interval_ne(PG_FUNCTION_ARGS);
00228 extern Datum interval_lt(PG_FUNCTION_ARGS);
00229 extern Datum interval_le(PG_FUNCTION_ARGS);
00230 extern Datum interval_ge(PG_FUNCTION_ARGS);
00231 extern Datum interval_gt(PG_FUNCTION_ARGS);
00232 extern Datum interval_finite(PG_FUNCTION_ARGS);
00233 extern Datum interval_cmp(PG_FUNCTION_ARGS);
00234 extern Datum interval_hash(PG_FUNCTION_ARGS);
00235 extern Datum interval_smaller(PG_FUNCTION_ARGS);
00236 extern Datum interval_larger(PG_FUNCTION_ARGS);
00237 extern Datum interval_justify_hours(PG_FUNCTION_ARGS);
00238 extern Datum interval_justify_days(PG_FUNCTION_ARGS);
00239 
00240 extern Datum timestamp_text(PG_FUNCTION_ARGS);
00241 extern Datum text_timestamp(PG_FUNCTION_ARGS);
00242 extern Datum interval_text(PG_FUNCTION_ARGS);
00243 extern Datum text_interval(PG_FUNCTION_ARGS);
00244 extern Datum timestamp_trunc(PG_FUNCTION_ARGS);
00245 extern Datum interval_trunc(PG_FUNCTION_ARGS);
00246 extern Datum timestamp_part(PG_FUNCTION_ARGS);
00247 extern Datum interval_part(PG_FUNCTION_ARGS);
00248 extern Datum timestamp_zone(PG_FUNCTION_ARGS);
00249 extern Datum timestamp_izone(PG_FUNCTION_ARGS);
00250 extern Datum timestamp_timestamptz(PG_FUNCTION_ARGS);
00251 
00252 extern Datum timestamptz_in(PG_FUNCTION_ARGS);
00253 extern Datum timestamptz_out(PG_FUNCTION_ARGS);
00254 extern Datum timestamptz_recv(PG_FUNCTION_ARGS);
00255 extern Datum timestamptz_send(PG_FUNCTION_ARGS);
00256 extern Datum timestamptz_scale(PG_FUNCTION_ARGS);
00257 extern Datum timestamptz_timestamp(PG_FUNCTION_ARGS);
00258 extern Datum timestamptz_zone(PG_FUNCTION_ARGS);
00259 extern Datum timestamptz_izone(PG_FUNCTION_ARGS);
00260 extern Datum timestamptz_timestamptz(PG_FUNCTION_ARGS);
00261 
00262 extern Datum interval_um(PG_FUNCTION_ARGS);
00263 extern Datum interval_pl(PG_FUNCTION_ARGS);
00264 extern Datum interval_mi(PG_FUNCTION_ARGS);
00265 extern Datum interval_mul(PG_FUNCTION_ARGS);
00266 extern Datum mul_d_interval(PG_FUNCTION_ARGS);
00267 extern Datum interval_div(PG_FUNCTION_ARGS);
00268 extern Datum interval_accum(PG_FUNCTION_ARGS);
00269 extern Datum interval_avg(PG_FUNCTION_ARGS);
00270 
00271 extern Datum timestamp_mi(PG_FUNCTION_ARGS);
00272 extern Datum timestamp_pl_interval(PG_FUNCTION_ARGS);
00273 extern Datum timestamp_mi_interval(PG_FUNCTION_ARGS);
00274 extern Datum timestamp_age(PG_FUNCTION_ARGS);
00275 extern Datum overlaps_timestamp(PG_FUNCTION_ARGS);
00276 
00277 extern Datum timestamptz_text(PG_FUNCTION_ARGS);
00278 extern Datum text_timestamptz(PG_FUNCTION_ARGS);
00279 extern Datum timestamptz_pl_interval(PG_FUNCTION_ARGS);
00280 extern Datum timestamptz_mi_interval(PG_FUNCTION_ARGS);
00281 extern Datum timestamptz_age(PG_FUNCTION_ARGS);
00282 extern Datum timestamptz_trunc(PG_FUNCTION_ARGS);
00283 extern Datum timestamptz_part(PG_FUNCTION_ARGS);
00284 
00285 extern Datum now(PG_FUNCTION_ARGS);
00286 
00287 extern Datum pgsql_postmaster_start_time(PG_FUNCTION_ARGS);
00288 
00289 /* Internal routines (not fmgr-callable) */
00290 
00291 extern TimestampTz GetCurrentTimestamp(void);
00292 
00293 extern TimestampTz time_t_to_timestamptz(time_t tm);
00294 
00295 extern int      tm2timestamp(struct pg_tm * tm, fsec_t fsec, int *tzp, Timestamp *dt);
00296 extern int timestamp2tm(Timestamp dt, int *tzp, struct pg_tm * tm,
00297                          fsec_t *fsec, char **tzn, pg_tz *attimezone);
00298 extern void dt2time(Timestamp dt, int *hour, int *min, int *sec, fsec_t *fsec);
00299 
00300 extern int      interval2tm(Interval span, struct pg_tm * tm, fsec_t *fsec);
00301 extern int      tm2interval(struct pg_tm * tm, fsec_t fsec, Interval *span);
00302 
00303 extern Timestamp SetEpochTimestamp(void);
00304 extern void GetEpochTime(struct pg_tm * tm);
00305 
00306 extern int      timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
00307 
00308 /* timestamp comparison works for timestamptz also */
00309 #define timestamptz_cmp_internal(dt1,dt2)       timestamp_cmp_internal(dt1, dt2)
00310 
00311 extern void isoweek2date(int woy, int *year, int *mon, int *mday);
00312 extern int      date2isoweek(int year, int mon, int mday);
00313 extern int      date2isoyear(int year, int mon, int mday);
00314 
00315 #endif   /* TIMESTAMP_H */