trgm.h

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/*
 * contrib/pg_trgm/trgm.h
 */
#ifndef __TRGM_H__
#define __TRGM_H__
 
#include "access/gist.h"
#include "access/itup.h"
#include "access/stratnum.h"
#include "storage/bufpage.h"
 
/*
 * Options ... but note that trgm_regexp.c effectively assumes these values
 * of LPADDING and RPADDING.
 */
#define LPADDING        2
#define RPADDING        1
/*
 * Caution: IGNORECASE macro means that trigrams are case-insensitive.
 * If this macro is disabled, the ~* and ~~* operators must be removed from
 * the operator classes, because we can't handle case-insensitive wildcard
 * search with case-sensitive trigrams.  Failure to do this will result in
 * "cannot handle ~*(~~*) with case-sensitive trigrams" errors.
 */
#define IGNORECASE
#define DIVUNION
 
/* operator strategy numbers */
#define SimilarityStrategyNumber            1
#define DistanceStrategyNumber              2
#define LikeStrategyNumber                  3
#define ILikeStrategyNumber                 4
#define RegExpStrategyNumber                5
#define RegExpICaseStrategyNumber           6
#define WordSimilarityStrategyNumber        7
#define WordDistanceStrategyNumber          8
#define StrictWordSimilarityStrategyNumber  9
#define StrictWordDistanceStrategyNumber    10
#define EqualStrategyNumber                 11
 
typedef char trgm[3];
 
#define CPTRGM(a,b) do {                \
    *(((char*)(a))+0) = *(((char*)(b))+0);  \
    *(((char*)(a))+1) = *(((char*)(b))+1);  \
    *(((char*)(a))+2) = *(((char*)(b))+2);  \
} while(0)
extern int  (*CMPTRGM) (const void *a, const void *b);
 
#define ISWORDCHR(c)    (t_isalnum(c))
#define ISPRINTABLECHAR(a)  ( isascii( *(unsigned char*)(a) ) && (isalnum( *(unsigned char*)(a) ) || *(unsigned char*)(a)==' ') )
#define ISPRINTABLETRGM(t)  ( ISPRINTABLECHAR( ((char*)(t)) ) && ISPRINTABLECHAR( ((char*)(t))+1 ) && ISPRINTABLECHAR( ((char*)(t))+2 ) )
 
#define ISESCAPECHAR(x) (*(x) == '\\')  /* Wildcard escape character */
#define ISWILDCARDCHAR(x) (*(x) == '_' || *(x) == '%')  /* Wildcard
                                                         * meta-character */
 
typedef struct
{
    int32       vl_len_;        /* varlena header (do not touch directly!) */
    uint8       flag;
    char        data[FLEXIBLE_ARRAY_MEMBER];
} TRGM;
 
#define TRGMHDRSIZE       (VARHDRSZ + sizeof(uint8))
 
/* gist */
#define SIGLEN_DEFAULT  (sizeof(int) * 3)
#define SIGLEN_MAX      GISTMaxIndexKeySize
#define BITBYTE 8
 
#define SIGLENBIT(siglen) ((siglen) * BITBYTE - 1)  /* see makesign */
 
typedef char *BITVECP;
 
#define LOOPBYTE(siglen) \
            for (i = 0; i < (siglen); i++)
 
#define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITBYTE ) ) )
#define GETBITBYTE(x,i) ( (((char)(x)) >> (i)) & 0x01 )
#define CLRBIT(x,i)   GETBYTE(x,i) &= ~( 0x01 << ( (i) % BITBYTE ) )
#define SETBIT(x,i)   GETBYTE(x,i) |=  ( 0x01 << ( (i) % BITBYTE ) )
#define GETBIT(x,i) ( (GETBYTE(x,i) >> ( (i) % BITBYTE )) & 0x01 )
 
#define HASHVAL(val, siglen) (((unsigned int)(val)) % SIGLENBIT(siglen))
#define HASH(sign, val, siglen) SETBIT((sign), HASHVAL(val, siglen))
 
#define ARRKEY          0x01
#define SIGNKEY         0x02
#define ALLISTRUE       0x04
 
#define ISARRKEY(x) ( ((TRGM*)x)->flag & ARRKEY )
#define ISSIGNKEY(x)    ( ((TRGM*)x)->flag & SIGNKEY )
#define ISALLTRUE(x)    ( ((TRGM*)x)->flag & ALLISTRUE )
 
#define CALCGTSIZE(flag, len) ( TRGMHDRSIZE + ( ( (flag) & ARRKEY ) ? ((len)*sizeof(trgm)) : (((flag) & ALLISTRUE) ? 0 : (len)) ) )
#define GETSIGN(x)      ( (BITVECP)( (char*)x+TRGMHDRSIZE ) )
#define GETARR(x)       ( (trgm*)( (char*)x+TRGMHDRSIZE ) )
#define ARRNELEM(x) ( ( VARSIZE(x) - TRGMHDRSIZE )/sizeof(trgm) )
 
/*
 * If DIVUNION is defined then similarity formula is:
 * count / (len1 + len2 - count)
 * else if DIVUNION is not defined then similarity formula is:
 * count / max(len1, len2)
 */
#ifdef DIVUNION
#define CALCSML(count, len1, len2) ((float4) (count)) / ((float4) ((len1) + (len2) - (count)))
#else
#define CALCSML(count, len1, len2) ((float4) (count)) / ((float4) (((len1) > (len2)) ? (len1) : (len2)))
#endif
 
typedef struct TrgmPackedGraph TrgmPackedGraph;
 
extern double similarity_threshold;
extern double word_similarity_threshold;
extern double strict_word_similarity_threshold;
 
extern double index_strategy_get_limit(StrategyNumber strategy);
extern uint32 trgm2int(trgm *ptr);
extern void compact_trigram(trgm *tptr, char *str, int bytelen);
extern TRGM *generate_trgm(char *str, int slen);
extern TRGM *generate_wildcard_trgm(const char *str, int slen);
extern float4 cnt_sml(TRGM *trg1, TRGM *trg2, bool inexact);
extern bool trgm_contained_by(TRGM *trg1, TRGM *trg2);
extern bool *trgm_presence_map(TRGM *query, TRGM *key);
extern TRGM *createTrgmNFA(text *text_re, Oid collation,
                           TrgmPackedGraph **graph, MemoryContext rcontext);
extern bool trigramsMatchGraph(TrgmPackedGraph *graph, bool *check);
 
#endif                          /* __TRGM_H__ */