1 /*
2  * contrib/pg_trgm/trgm.h
3  */
4 #ifndef __TRGM_H__
5 #define __TRGM_H__
6 
7 #include "access/gist.h"
8 #include "access/itup.h"
9 #include "storage/bufpage.h"
10 
11 /*
12  * Options ... but note that trgm_regexp.c effectively assumes these values
13  * of LPADDING and RPADDING.
14  */
15 #define LPADDING		2
16 #define RPADDING		1
17 #define KEEPONLYALNUM
18 /*
19  * Caution: IGNORECASE macro means that trigrams are case-insensitive.
20  * If this macro is disabled, the ~* and ~~* operators must be removed from
21  * the operator classes, because we can't handle case-insensitive wildcard
22  * search with case-sensitive trigrams.  Failure to do this will result in
23  * "cannot handle ~*(~~*) with case-sensitive trigrams" errors.
24  */
25 #define IGNORECASE
26 #define DIVUNION
27 
28 /* operator strategy numbers */
29 #define SimilarityStrategyNumber		1
30 #define DistanceStrategyNumber			2
31 #define LikeStrategyNumber				3
32 #define ILikeStrategyNumber				4
33 #define RegExpStrategyNumber			5
34 #define RegExpICaseStrategyNumber		6
35 #define WordSimilarityStrategyNumber	7
36 #define WordDistanceStrategyNumber		8
37 
38 typedef char trgm[3];
39 
40 #define CMPCHAR(a,b) ( ((a)==(b)) ? 0 : ( ((a)<(b)) ? -1 : 1 ) )
41 #define CMPPCHAR(a,b,i)  CMPCHAR( *(((const char*)(a))+i), *(((const char*)(b))+i) )
42 #define CMPTRGM(a,b) ( CMPPCHAR(a,b,0) ? CMPPCHAR(a,b,0) : ( CMPPCHAR(a,b,1) ? CMPPCHAR(a,b,1) : CMPPCHAR(a,b,2) ) )
43 
44 #define CPTRGM(a,b) do {				\
45 	*(((char*)(a))+0) = *(((char*)(b))+0);	\
46 	*(((char*)(a))+1) = *(((char*)(b))+1);	\
47 	*(((char*)(a))+2) = *(((char*)(b))+2);	\
48 } while(0)
49 
50 #ifdef KEEPONLYALNUM
51 #define ISWORDCHR(c)	(t_isalpha(c) || t_isdigit(c))
52 #define ISPRINTABLECHAR(a)	( isascii( *(unsigned char*)(a) ) && (isalnum( *(unsigned char*)(a) ) || *(unsigned char*)(a)==' ') )
53 #else
54 #define ISWORDCHR(c)	(!t_isspace(c))
55 #define ISPRINTABLECHAR(a)	( isascii( *(unsigned char*)(a) ) && isprint( *(unsigned char*)(a) ) )
56 #endif
57 #define ISPRINTABLETRGM(t)	( ISPRINTABLECHAR( ((char*)(t)) ) && ISPRINTABLECHAR( ((char*)(t))+1 ) && ISPRINTABLECHAR( ((char*)(t))+2 ) )
58 
59 #define ISESCAPECHAR(x) (*(x) == '\\')	/* Wildcard escape character */
60 #define ISWILDCARDCHAR(x) (*(x) == '_' || *(x) == '%')	/* Wildcard
61 														 * meta-character */
62 
63 typedef struct
64 {
65 	int32		vl_len_;		/* varlena header (do not touch directly!) */
66 	uint8		flag;
67 	char		data[FLEXIBLE_ARRAY_MEMBER];
68 } TRGM;
69 
70 #define TRGMHDRSIZE		  (VARHDRSZ + sizeof(uint8))
71 
72 /* gist */
73 #define BITBYTE 8
74 #define SIGLENINT  3			/* >122 => key will toast, so very slow!!! */
75 #define SIGLEN	( sizeof(int)*SIGLENINT )
76 
77 #define SIGLENBIT (SIGLEN*BITBYTE - 1)	/* see makesign */
78 
79 typedef char BITVEC[SIGLEN];
80 typedef char *BITVECP;
81 
82 #define LOOPBYTE \
83 			for(i=0;i<SIGLEN;i++)
84 
85 #define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITBYTE ) ) )
86 #define GETBITBYTE(x,i) ( (((char)(x)) >> (i)) & 0x01 )
87 #define CLRBIT(x,i)   GETBYTE(x,i) &= ~( 0x01 << ( (i) % BITBYTE ) )
88 #define SETBIT(x,i)   GETBYTE(x,i) |=  ( 0x01 << ( (i) % BITBYTE ) )
89 #define GETBIT(x,i) ( (GETBYTE(x,i) >> ( (i) % BITBYTE )) & 0x01 )
90 
91 #define HASHVAL(val) (((unsigned int)(val)) % SIGLENBIT)
92 #define HASH(sign, val) SETBIT((sign), HASHVAL(val))
93 
94 #define ARRKEY			0x01
95 #define SIGNKEY			0x02
96 #define ALLISTRUE		0x04
97 
98 #define ISARRKEY(x) ( ((TRGM*)x)->flag & ARRKEY )
99 #define ISSIGNKEY(x)	( ((TRGM*)x)->flag & SIGNKEY )
100 #define ISALLTRUE(x)	( ((TRGM*)x)->flag & ALLISTRUE )
101 
102 #define CALCGTSIZE(flag, len) ( TRGMHDRSIZE + ( ( (flag) & ARRKEY ) ? ((len)*sizeof(trgm)) : (((flag) & ALLISTRUE) ? 0 : SIGLEN) ) )
103 #define GETSIGN(x)		( (BITVECP)( (char*)x+TRGMHDRSIZE ) )
104 #define GETARR(x)		( (trgm*)( (char*)x+TRGMHDRSIZE ) )
105 #define ARRNELEM(x) ( ( VARSIZE(x) - TRGMHDRSIZE )/sizeof(trgm) )
106 
107 /*
108  * If DIVUNION is defined then similarity formula is:
109  * count / (len1 + len2 - count)
110  * else if DIVUNION is not defined then similarity formula is:
111  * count / max(len1, len2)
112  */
113 #ifdef DIVUNION
114 #define CALCSML(count, len1, len2) ((float4) (count)) / ((float4) ((len1) + (len2) - (count)))
115 #else
116 #define CALCSML(count, len1, len2) ((float4) (count)) / ((float4) (((len1) > (len2)) ? (len1) : (len2)))
117 #endif
118 
119 typedef struct TrgmPackedGraph TrgmPackedGraph;
120 
121 extern double similarity_threshold;
122 extern double word_similarity_threshold;
123 
124 extern uint32 trgm2int(trgm *ptr);
125 extern void compact_trigram(trgm *tptr, char *str, int bytelen);
126 extern TRGM *generate_trgm(char *str, int slen);
127 extern TRGM *generate_wildcard_trgm(const char *str, int slen);
128 extern float4 cnt_sml(TRGM *trg1, TRGM *trg2, bool inexact);
129 extern bool trgm_contained_by(TRGM *trg1, TRGM *trg2);
130 extern bool *trgm_presence_map(TRGM *query, TRGM *key);
131 extern TRGM *createTrgmNFA(text *text_re, Oid collation,
132 			  TrgmPackedGraph **graph, MemoryContext rcontext);
133 extern bool trigramsMatchGraph(TrgmPackedGraph *graph, bool *check);
134 
135 #endif							/* __TRGM_H__ */
136