postgresql/contrib/pg_trgm/trgm.h
Teodor Sigaev cbfa4092bb trgm - Trigram matching for PostgreSQL
--------------------------------------

	The pg_trgm contrib module provides functions and index classes
	for determining the similarity of text based on trigram
	matching.
2004-05-31 17:18:12 +00:00

89 lines
2.5 KiB
C

#ifndef __TRGM_H__
#define __TRGM_H__
#include "postgres.h"
#include "access/gist.h"
#include "access/itup.h"
#include "utils/elog.h"
#include "utils/palloc.h"
#include "utils/builtins.h"
#include "storage/bufpage.h"
/* options */
#define LPADDING 2
#define RPADDING 1
#define KEEPONLYALNUM
#define IGNORECASE
#define DIVUNION
typedef char trgm[3];
#define CMPCHAR(a,b) ( ((a)==(b)) ? 0 : ( ((a)<(b)) ? -1 : 1 ) )
#define CMPPCHAR(a,b,i) CMPCHAR( *(((char*)(a))+i), *(((char*)(b))+i) )
#define CMPTRGM(a,b) ( CMPPCHAR(a,b,0) ? CMPPCHAR(a,b,0) : ( CMPPCHAR(a,b,1) ? CMPPCHAR(a,b,1) : CMPPCHAR(a,b,2) ) )
#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);
typedef struct {
int4 len;
uint8 flag;
char data[1];
} TRGM;
#define TRGMHRDSIZE (sizeof(int4)+sizeof(uint8))
/* gist */
#define BITBYTE 8
#define SIGLENINT 3 /* >122 => key will toast, so very slow!!! */
#define SIGLEN ( sizeof(int)*SIGLENINT )
#define SIGLENBIT (SIGLEN*BITBYTE - 1) /* see makesign */
typedef char BITVEC[SIGLEN];
typedef char *BITVECP;
#define LOOPBYTE(a) \
for(i=0;i<SIGLEN;i++) {\
a;\
}
#define LOOPBIT(a) \
for(i=0;i<SIGLENBIT;i++) {\
a;\
}
#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) (((unsigned int)(val)) % SIGLENBIT)
#define HASH(sign, val) SETBIT((sign), HASHVAL(val))
#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) ( TRGMHRDSIZE + ( ( (flag) & ARRKEY ) ? ((len)*sizeof(trgm)) : (((flag) & ALLISTRUE) ? 0 : SIGLEN) ) )
#define GETSIGN(x) ( (BITVECP)( (char*)x+TRGMHRDSIZE ) )
#define GETARR(x) ( (trgm*)( (char*)x+TRGMHRDSIZE ) )
#define ARRNELEM(x) ( ( ((TRGM*)x)->len - TRGMHRDSIZE )/sizeof(trgm) )
extern float4 trgm_limit;
TRGM* generate_trgm(char *str, int slen);
float4 cnt_sml(TRGM *trg1, TRGM *trg2);
#endif