summaryrefslogtreecommitdiffstats
path: root/contrib/pg_trgm/trgm.h
blob: afb0adb222b9178fa6868c768a631699f7cfee07 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
/*
 * 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
#define KEEPONLYALNUM
/*
 * 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 CMPCHAR(a,b) ( ((a)==(b)) ? 0 : ( ((a)<(b)) ? -1 : 1 ) )
#define CMPPCHAR(a,b,i)  CMPCHAR( *(((const char*)(a))+i), *(((const 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)

#ifdef KEEPONLYALNUM
#define ISWORDCHR(c)	(t_isalnum(c))
#define ISPRINTABLECHAR(a)	( isascii( *(unsigned char*)(a) ) && (isalnum( *(unsigned char*)(a) ) || *(unsigned char*)(a)==' ') )
#else
#define ISWORDCHR(c)	(!t_isspace(c))
#define ISPRINTABLECHAR(a)	( isascii( *(unsigned char*)(a) ) && isprint( *(unsigned char*)(a) ) )
#endif
#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__ */