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cbfa4092bb
-------------------------------------- The pg_trgm contrib module provides functions and index classes for determining the similarity of text based on trigram matching.
89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
#ifndef __TRGM_H__
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#define __TRGM_H__
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#include "postgres.h"
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#include "access/gist.h"
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#include "access/itup.h"
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#include "utils/elog.h"
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#include "utils/palloc.h"
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#include "utils/builtins.h"
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#include "storage/bufpage.h"
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/* options */
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#define LPADDING 2
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#define RPADDING 1
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#define KEEPONLYALNUM
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#define IGNORECASE
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#define DIVUNION
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typedef char trgm[3];
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#define CMPCHAR(a,b) ( ((a)==(b)) ? 0 : ( ((a)<(b)) ? -1 : 1 ) )
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#define CMPPCHAR(a,b,i) CMPCHAR( *(((char*)(a))+i), *(((char*)(b))+i) )
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#define CMPTRGM(a,b) ( CMPPCHAR(a,b,0) ? CMPPCHAR(a,b,0) : ( CMPPCHAR(a,b,1) ? CMPPCHAR(a,b,1) : CMPPCHAR(a,b,2) ) )
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#define CPTRGM(a,b) do { \
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*(((char*)(a))+0) = *(((char*)(b))+0); \
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*(((char*)(a))+1) = *(((char*)(b))+1); \
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*(((char*)(a))+2) = *(((char*)(b))+2); \
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} while(0);
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typedef struct {
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int4 len;
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uint8 flag;
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char data[1];
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} TRGM;
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#define TRGMHRDSIZE (sizeof(int4)+sizeof(uint8))
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/* gist */
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#define BITBYTE 8
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#define SIGLENINT 3 /* >122 => key will toast, so very slow!!! */
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#define SIGLEN ( sizeof(int)*SIGLENINT )
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#define SIGLENBIT (SIGLEN*BITBYTE - 1) /* see makesign */
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typedef char BITVEC[SIGLEN];
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typedef char *BITVECP;
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#define LOOPBYTE(a) \
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for(i=0;i<SIGLEN;i++) {\
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a;\
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}
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#define LOOPBIT(a) \
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for(i=0;i<SIGLENBIT;i++) {\
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a;\
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}
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#define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITBYTE ) ) )
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#define GETBITBYTE(x,i) ( ((char)(x)) >> i & 0x01 )
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#define CLRBIT(x,i) GETBYTE(x,i) &= ~( 0x01 << ( (i) % BITBYTE ) )
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#define SETBIT(x,i) GETBYTE(x,i) |= ( 0x01 << ( (i) % BITBYTE ) )
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#define GETBIT(x,i) ( (GETBYTE(x,i) >> ( (i) % BITBYTE )) & 0x01 )
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#define HASHVAL(val) (((unsigned int)(val)) % SIGLENBIT)
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#define HASH(sign, val) SETBIT((sign), HASHVAL(val))
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#define ARRKEY 0x01
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#define SIGNKEY 0x02
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#define ALLISTRUE 0x04
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#define ISARRKEY(x) ( ((TRGM*)x)->flag & ARRKEY )
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#define ISSIGNKEY(x) ( ((TRGM*)x)->flag & SIGNKEY )
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#define ISALLTRUE(x) ( ((TRGM*)x)->flag & ALLISTRUE )
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#define CALCGTSIZE(flag, len) ( TRGMHRDSIZE + ( ( (flag) & ARRKEY ) ? ((len)*sizeof(trgm)) : (((flag) & ALLISTRUE) ? 0 : SIGLEN) ) )
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#define GETSIGN(x) ( (BITVECP)( (char*)x+TRGMHRDSIZE ) )
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#define GETARR(x) ( (trgm*)( (char*)x+TRGMHRDSIZE ) )
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#define ARRNELEM(x) ( ( ((TRGM*)x)->len - TRGMHRDSIZE )/sizeof(trgm) )
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extern float4 trgm_limit;
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TRGM* generate_trgm(char *str, int slen);
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float4 cnt_sml(TRGM *trg1, TRGM *trg2);
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#endif
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