bigm.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * Portions Copyright (c) 2004-2012, PostgreSQL Global Development Group
   4  *
   5  * Changelog:
   6  *   2013/01/09
   7  *   Support full text search using bigrams.
   8  *   Author: NTT DATA Corporation
   9  *
  10  *-------------------------------------------------------------------------
  11  */
  12 #ifndef __BIGM_H__
  13 #define __BIGM_H__
  14
  15 #include "access/itup.h"
  16 #include "storage/bufpage.h"
  17 #include "utils/builtins.h"
  18
  19 /* GUC variable */
  20 extern bool     bigm_enable_recheck;
  21 extern int      bigm_gin_key_limit;
  22
  23 /* options */
  24 #define LPADDING                1
  25 #define RPADDING                1
  26
  27 /* operator strategy numbers */
  28 #define LikeStrategyNumber                      1
  29
  30 typedef struct
  31 {
  32         bool    pmatch;         /* partial match is required? */
  33         int             bytelen;        /* byte length of bi-gram string */
  34         /*
  35          * Bi-gram string; we assume here that the maximum bytes for
  36          * a character are four.
  37          */
  38         char    str[8];
  39 } bigm;
  40
  41 #define BIGMSIZE        sizeof(bigm)
  42
  43 int     bigmstrcmp(char *arg1, int len1, char *arg2, int len2);
  44 #define CMPBIGM(a,b) ( bigmstrcmp(((bigm *)a)->str, ((bigm *)a)->bytelen, ((bigm *)b)->str, ((bigm *)b)->bytelen) )
  45
  46 #define CPBIGM(bptr, s, len) do {               \
  47         Assert(len <= 8);                               \
  48         memcpy(bptr->str, s, len);              \
  49         bptr->bytelen = len;                    \
  50         bptr->pmatch = false;                   \
  51 } while(0);
  52
  53 #define ISESCAPECHAR(x) (*(x) == '\\')  /* Wildcard escape character */
  54 #define ISWILDCARDCHAR(x) (*(x) == '%' || *(x) == '_')  /* Wildcard
  55                                                                                                                  * meta-character */
  56 typedef struct
  57 {
  58         int32           vl_len_;                /* varlena header (do not touch directly!) */
  59         char            data[1];
  60 } BIGM;
  61
  62 #define CALCGTSIZE(len) (VARHDRSZ + len * sizeof(bigm))
  63 #define GETARR(x)               ( (bigm *)( (char*)x + VARHDRSZ ) )
  64 #define ARRNELEM(x) ( ( VARSIZE(x) - VARHDRSZ )/sizeof(bigm) )
  65
  66 BIGM       *generate_bigm(char *str, int slen);
  67 BIGM       *generate_wildcard_bigm(const char *str, int slen, bool *removeDups);
  68
  69 #endif   /* __BIGM_H__ */