formatting.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

/* -----------------------------------------------------------------------
 * formatting.c
 *
 * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.101.2.2 2005/12/03 16:45:23 momjian Exp $
 *
 *
 *	 Portions Copyright (c) 1999-2005, PostgreSQL Global Development Group
 *
 *
 *	 TO_CHAR(); TO_TIMESTAMP(); TO_DATE(); TO_NUMBER();
 *
 *	 The PostgreSQL routines for a timestamp/int/float/numeric formatting,
 *	 inspired by the Oracle TO_CHAR() / TO_DATE() / TO_NUMBER() routines.
 *
 *
 *	 Cache & Memory:
 *	Routines use (itself) internal cache for format pictures.
 *
 *	The cache uses a static buffers and is persistent across transactions.
 *	If format-picture is bigger than cache buffer, parser is called always.
 *
 *	 NOTE for Number version:
 *	All in this version is implemented as keywords ( => not used
 *	suffixes), because a format picture is for *one* item (number)
 *	only. It not is as a timestamp version, where each keyword (can)
 *	has suffix.
 *
 *	 NOTE for Timestamp routines:
 *	In this module the POSIX 'struct tm' type is *not* used, but rather
 *	PgSQL type, which has tm_mon based on one (*non* zero) and
 *	year *not* based on 1900, but is used full year number.
 *	Module supports AD / BC / AM / PM.
 *
 *	Supported types for to_char():
 *
 *		Timestamp, Numeric, int4, int8, float4, float8
 *
 *	Supported types for reverse conversion:
 *
 *		Timestamp	- to_timestamp()
 *		Date		- to_date()
 *		Numeric		- to_number()
 *
 *
 *	Karel Zak
 *
 * TODO
 *	- better number building (formatting) / parsing, now it isn't
 *		  ideal code
 *	- use Assert()
 *	- add support for abstime
 *	- add support for roman number to standard number conversion
 *	- add support for number spelling
 *	- add support for string to string formatting (we must be better
 *	  than Oracle :-),
 *		to_char('Hello', 'X X X X X') -> 'H e l l o'
 *
 * -----------------------------------------------------------------------
 */

/* ----------
 * UnComment me for DEBUG
 * ----------
 */
/***
#define DEBUG_TO_FROM_CHAR
#define DEBUG_elog_output	DEBUG3
***/

#include "postgres.h"

#include <ctype.h>
#include <unistd.h>
#include <math.h>
#include <float.h>

#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/datetime.h"
#include "utils/formatting.h"
#include "utils/int8.h"
#include "utils/numeric.h"
#include "utils/pg_locale.h"

/* ----------
 * Routines type
 * ----------
 */
#define DCH_TYPE		1		/* DATE-TIME version	*/
#define NUM_TYPE		2		/* NUMBER version	*/

/* ----------
 * KeyWord Index (ascii from position 32 (' ') to 126 (~))
 * ----------
 */
#define KeyWord_INDEX_SIZE		('~' - ' ')
#define KeyWord_INDEX_FILTER(_c)	((_c) <= ' ' || (_c) >= '~' ? 0 : 1)

/* ----------
 * Maximal length of one node
 * ----------
 */
#define DCH_MAX_ITEM_SIZ		9		/* max julian day		*/
#define NUM_MAX_ITEM_SIZ		8		/* roman number (RN has 15 chars)	*/

/* ----------
 * More is in float.c
 * ----------
 */
#define MAXFLOATWIDTH	64
#define MAXDOUBLEWIDTH	128

/* ----------
 * External (defined in PgSQL datetime.c (timestamp utils))
 * ----------
 */
extern char *months[],			/* month abbreviation	*/
		   *days[];				/* full days		*/

/* ----------
 * Format parser structs
 * ----------
 */
typedef struct
{
	char	   *name;			/* suffix string		*/
	int			len,			/* suffix length		*/
				id,				/* used in node->suffix */
				type;			/* prefix / postfix			*/
} KeySuffix;

typedef struct FormatNode FormatNode;

typedef struct
{
	const char *name;			/* keyword			*/
	int			len;			/* keyword length		*/
	int			(*action) (int arg, char *inout,		/* action for keyword */
								  int suf, bool is_to_char, bool is_interval,
									   FormatNode *node, void *data);
	int			id;				/* keyword id			*/
	bool		isitdigit;		/* is expected output/input digit */
} KeyWord;

struct FormatNode
{
	int			type;			/* node type			*/
	const KeyWord *key;			/* if node type is KEYWORD	*/
	int			character,		/* if node type is CHAR		*/
				suffix;			/* keyword suffix		*/
};

#define NODE_TYPE_END		1
#define NODE_TYPE_ACTION	2
#define NODE_TYPE_CHAR		3

#define SUFFTYPE_PREFIX		1
#define SUFFTYPE_POSTFIX	2


/* ----------
 * Full months
 * ----------
 */
static char *months_full[] = {
	"January", "February", "March", "April", "May", "June", "July",
	"August", "September", "October", "November", "December", NULL
};

/* ----------
 * AC / DC
 * ----------
 */
/*
 *	There is no 0 AD.  Years go from 1 BC to 1 AD, so we make it
 *	positive and map year == -1 to year zero, and shift all negative
 *	years up one.  For interval years, we just return the year.
 */
#define ADJUST_YEAR(year, is_interval)	((is_interval) ? (year) : ((year) <= 0 ? -((year) - 1) : (year)))
#define BC_STR_ORIG " BC"

#define A_D_STR		"A.D."
#define a_d_STR		"a.d."
#define AD_STR		"AD"
#define ad_STR		"ad"

#define B_C_STR		"B.C."
#define b_c_STR		"b.c."
#define BC_STR		"BC"
#define bc_STR		"bc"


/* ----------
 * AM / PM
 * ----------
 */
#define A_M_STR		"A.M."
#define a_m_STR		"a.m."
#define AM_STR		"AM"
#define am_STR		"am"

#define P_M_STR		"P.M."
#define p_m_STR		"p.m."
#define PM_STR		"PM"
#define pm_STR		"pm"


/* ----------
 * Months in roman-numeral
 * (Must be conversely for seq_search (in FROM_CHAR), because
 *	'VIII' must be over 'V')
 * ----------
 */
static char *rm_months_upper[] =
{"XII", "XI", "X", "IX", "VIII", "VII", "VI", "V", "IV", "III", "II", "I", NULL};

static char *rm_months_lower[] =
{"xii", "xi", "x", "ix", "viii", "vii", "vi", "v", "iv", "iii", "ii", "i", NULL};

/* ----------
 * Roman numbers
 * ----------
 */
static char *rm1[] = {"I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX", NULL};
static char *rm10[] = {"X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC", NULL};
static char *rm100[] = {"C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM", NULL};

/* ----------
 * Ordinal postfixes
 * ----------
 */
static char *numTH[] = {"ST", "ND", "RD", "TH", NULL};
static char *numth[] = {"st", "nd", "rd", "th", NULL};

/* ----------
 * Flags & Options:
 * ----------
 */
#define ONE_UPPER	1			/* Name */
#define ALL_UPPER	2			/* NAME */
#define ALL_LOWER	3			/* name */

#define FULL_SIZ	0

#define MAX_MON_LEN 3
#define MAX_DY_LEN	3

#define TH_UPPER	1
#define TH_LOWER	2

/* ----------
 * Flags for DCH version
 * ----------
 */
static bool DCH_global_fx = false;


/* ----------
 * Number description struct
 * ----------
 */
typedef struct
{
	int			pre,			/* (count) numbers before decimal */
				post,			/* (count) numbers after decimal  */
				lsign,			/* want locales sign		  */
				flag,			/* number parameters		  */
				pre_lsign_num,	/* tmp value for lsign		  */
				multi,			/* multiplier for 'V'		  */
				zero_start,		/* position of first zero	  */
				zero_end,		/* position of last zero	  */
				need_locale;	/* needs it locale		  */
} NUMDesc;

/* ----------
 * Flags for NUMBER version
 * ----------
 */
#define NUM_F_DECIMAL		(1 << 1)
#define NUM_F_LDECIMAL		(1 << 2)
#define NUM_F_ZERO			(1 << 3)
#define NUM_F_BLANK			(1 << 4)
#define NUM_F_FILLMODE		(1 << 5)
#define NUM_F_LSIGN			(1 << 6)
#define NUM_F_BRACKET		(1 << 7)
#define NUM_F_MINUS			(1 << 8)
#define NUM_F_PLUS			(1 << 9)
#define NUM_F_ROMAN			(1 << 10)
#define NUM_F_MULTI			(1 << 11)
#define NUM_F_PLUS_POST		(1 << 12)
#define NUM_F_MINUS_POST	(1 << 13)

#define NUM_LSIGN_PRE	(-1)
#define NUM_LSIGN_POST	1
#define NUM_LSIGN_NONE	0

/* ----------
 * Tests
 * ----------
 */
#define IS_DECIMAL(_f)	((_f)->flag & NUM_F_DECIMAL)
#define IS_LDECIMAL(_f) ((_f)->flag & NUM_F_LDECIMAL)
#define IS_ZERO(_f) ((_f)->flag & NUM_F_ZERO)
#define IS_BLANK(_f)	((_f)->flag & NUM_F_BLANK)
#define IS_FILLMODE(_f) ((_f)->flag & NUM_F_FILLMODE)
#define IS_BRACKET(_f)	((_f)->flag & NUM_F_BRACKET)
#define IS_MINUS(_f)	((_f)->flag & NUM_F_MINUS)
#define IS_LSIGN(_f)	((_f)->flag & NUM_F_LSIGN)
#define IS_PLUS(_f) ((_f)->flag & NUM_F_PLUS)
#define IS_ROMAN(_f)	((_f)->flag & NUM_F_ROMAN)
#define IS_MULTI(_f)	((_f)->flag & NUM_F_MULTI)

/* ----------
 * Format picture cache
 *	(cache size:
 *		Number part = NUM_CACHE_SIZE * NUM_CACHE_FIELDS
 *		Date-time part	= DCH_CACHE_SIZE * DCH_CACHE_FIELDS
 *	)
 * ----------
 */
#define NUM_CACHE_SIZE		64
#define NUM_CACHE_FIELDS	16
#define DCH_CACHE_SIZE		128
#define DCH_CACHE_FIELDS	16

typedef struct
{
	FormatNode	format[DCH_CACHE_SIZE + 1];
	char		str[DCH_CACHE_SIZE + 1];
	int			age;
} DCHCacheEntry;

typedef struct
{
	FormatNode	format[NUM_CACHE_SIZE + 1];
	char		str[NUM_CACHE_SIZE + 1];
	int			age;
	NUMDesc		Num;
} NUMCacheEntry;

/* global cache for --- date/time part */
static DCHCacheEntry DCHCache[DCH_CACHE_FIELDS + 1];

static int	n_DCHCache = 0;		/* number of entries */
static int	DCHCounter = 0;

/* global cache for --- number part */
static NUMCacheEntry NUMCache[NUM_CACHE_FIELDS + 1];
static NUMCacheEntry *last_NUMCacheEntry;

static int	n_NUMCache = 0;		/* number of entries */
static int	NUMCounter = 0;

#define MAX_INT32	(2147483600)

/* ----------
 * For char->date/time conversion
 * ----------
 */
typedef struct
{
	int			hh,
				am,
				pm,
				mi,
				ss,
				ssss,
				d,
				dd,
				ddd,
				mm,
				ms,
				year,
				bc,
				iw,
				ww,
				w,
				cc,
				q,
				j,
				us,
				yysz;			/* is it YY or YYYY ? */
} TmFromChar;

#define ZERO_tmfc(_X) memset(_X, 0, sizeof(TmFromChar))

/* ----------
 * Debug
 * ----------
 */
#ifdef DEBUG_TO_FROM_CHAR
#define DEBUG_TMFC(_X) \
		elog(DEBUG_elog_output, "TMFC:\nhh %d\nam %d\npm %d\nmi %d\nss %d\nssss %d\nd %d\ndd %d\nddd %d\nmm %d\nms: %d\nyear %d\nbc %d\niw %d\nww %d\nw %d\ncc %d\nq %d\nj %d\nus: %d\nyysz: %d", \
			(_X)->hh, (_X)->am, (_X)->pm, (_X)->mi, (_X)->ss, \
			(_X)->ssss, (_X)->d, (_X)->dd, (_X)->ddd, (_X)->mm, (_X)->ms, \
			(_X)->year, (_X)->bc, (_X)->iw, (_X)->ww, (_X)->w, \
			(_X)->cc, (_X)->q, (_X)->j, (_X)->us, (_X)->yysz);
#define DEBUG_TM(_X) \
		elog(DEBUG_elog_output, "TM:\nsec %d\nyear %d\nmin %d\nwday %d\nhour %d\nyday %d\nmday %d\nnisdst %d\nmon %d\n",\
			(_X)->tm_sec, (_X)->tm_year,\
			(_X)->tm_min, (_X)->tm_wday, (_X)->tm_hour, (_X)->tm_yday,\
			(_X)->tm_mday, (_X)->tm_isdst, (_X)->tm_mon)
#else
#define DEBUG_TMFC(_X)
#define DEBUG_TM(_X)
#endif

/* ----------
 * Datetime to char conversion
 * ----------
 */
typedef struct TmToChar
{
	struct pg_tm tm;			/* classic 'tm' struct */
	fsec_t		fsec;			/* fractional seconds */
	char	   *tzn;			/* timezone */
} TmToChar;

#define tmtcTm(_X)	(&(_X)->tm)
#define tmtcTzn(_X) ((_X)->tzn)
#define tmtcFsec(_X)	((_X)->fsec)

#define ZERO_tm(_X) \
do {	\
	(_X)->tm_sec  = (_X)->tm_year = (_X)->tm_min = (_X)->tm_wday = \
	(_X)->tm_hour = (_X)->tm_yday = (_X)->tm_isdst = 0; \
	(_X)->tm_mday = (_X)->tm_mon  = 1; \
} while(0)

#define ZERO_tmtc(_X) \
do { \
	ZERO_tm( tmtcTm(_X) ); \
	tmtcFsec(_X) = 0; \
	tmtcTzn(_X) = NULL; \
} while(0)

/*
 *	to_char(time) appears to to_char() as an interval, so this check
 *	is really for interval and time data types.
 */
#define INVALID_FOR_INTERVAL  \
do { \
	if (is_interval) \
		ereport(ERROR, \
				(errcode(ERRCODE_INVALID_DATETIME_FORMAT), \
				 errmsg("invalid format specification for an interval value"), \
				 errhint("Intervals are not tied to specific calendar dates."))); \
} while(0)

/*****************************************************************************
 *			KeyWords definition & action
 *****************************************************************************/

static int dch_global(int arg, char *inout, int suf, bool is_to_char,
		   bool is_interval, FormatNode *node, void *data);
static int dch_time(int arg, char *inout, int suf, bool is_to_char,
		 bool is_interval, FormatNode *node, void *data);
static int dch_date(int arg, char *inout, int suf, bool is_to_char,
		 bool is_interval, FormatNode *node, void *data);

/* ----------
 * Suffixes:
 * ----------
 */
#define DCH_S_FM	0x01
#define DCH_S_TH	0x02
#define DCH_S_th	0x04
#define DCH_S_SP	0x08

/* ----------
 * Suffix tests
 * ----------
 */
#define S_THth(_s)	((((_s) & DCH_S_TH) || ((_s) & DCH_S_th)) ? 1 : 0)
#define S_TH(_s)	(((_s) & DCH_S_TH) ? 1 : 0)
#define S_th(_s)	(((_s) & DCH_S_th) ? 1 : 0)
#define S_TH_TYPE(_s)	(((_s) & DCH_S_TH) ? TH_UPPER : TH_LOWER)

#define S_FM(_s)	(((_s) & DCH_S_FM) ? 1 : 0)
#define S_SP(_s)	(((_s) & DCH_S_SP) ? 1 : 0)

/* ----------
 * Suffixes definition for DATE-TIME TO/FROM CHAR
 * ----------
 */
static KeySuffix DCH_suff[] = {
	{"FM", 2, DCH_S_FM, SUFFTYPE_PREFIX},
	{"fm", 2, DCH_S_FM, SUFFTYPE_PREFIX},
	{"TH", 2, DCH_S_TH, SUFFTYPE_POSTFIX},
	{"th", 2, DCH_S_th, SUFFTYPE_POSTFIX},
	{"SP", 2, DCH_S_SP, SUFFTYPE_POSTFIX},
	/* last */
	{NULL, 0, 0, 0}
};

/* ----------
 * Format-pictures (KeyWord).
 *
 * The KeyWord field; alphabetic sorted, *BUT* strings alike is sorted
 *		  complicated -to-> easy:
 *
 *	(example: "DDD","DD","Day","D" )
 *
 * (this specific sort needs the algorithm for sequential search for strings,
 * which not has exact end; -> How keyword is in "HH12blabla" ? - "HH"
 * or "HH12"? You must first try "HH12", because "HH" is in string, but
 * it is not good.
 *
 * (!)
 *	 - Position for the keyword is similar as position in the enum DCH/NUM_poz.
 * (!)
 *
 * For fast search is used the 'int index[]', index is ascii table from position
 * 32 (' ') to 126 (~), in this index is DCH_ / NUM_ enums for each ASCII
 * position or -1 if char is not used in the KeyWord. Search example for
 * string "MM":
 *	1)	see in index to index['M' - 32],
 *	2)	take keywords position (enum DCH_MM) from index
 *	3)	run sequential search in keywords[] from this position
 *
 * ----------
 */

typedef enum
{
	DCH_A_D,
	DCH_A_M,
	DCH_AD,
	DCH_AM,
	DCH_B_C,
	DCH_BC,
	DCH_CC,
	DCH_DAY,
	DCH_DDD,
	DCH_DD,
	DCH_DY,
	DCH_Day,
	DCH_Dy,
	DCH_D,
	DCH_FX,						/* global suffix */
	DCH_HH24,
	DCH_HH12,
	DCH_HH,
	DCH_IW,
	DCH_IYYY,
	DCH_IYY,
	DCH_IY,
	DCH_I,
	DCH_J,
	DCH_MI,
	DCH_MM,
	DCH_MONTH,
	DCH_MON,
	DCH_MS,
	DCH_Month,
	DCH_Mon,
	DCH_P_M,
	DCH_PM,
	DCH_Q,
	DCH_RM,
	DCH_SSSS,
	DCH_SS,
	DCH_TZ,
	DCH_US,
	DCH_WW,
	DCH_W,
	DCH_Y_YYY,
	DCH_YYYY,
	DCH_YYY,
	DCH_YY,
	DCH_Y,
	DCH_a_d,
	DCH_a_m,
	DCH_ad,
	DCH_am,
	DCH_b_c,
	DCH_bc,
	DCH_cc,
	DCH_day,
	DCH_ddd,
	DCH_dd,
	DCH_dy,
	DCH_d,
	DCH_fx,