src/include/tsearch/ts_public.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * ts_public.h
   4  *        Public interface to various tsearch modules, such as
   5  *        parsers and dictionaries.
   6  *
   7  * Copyright (c) 1998-2021, PostgreSQL Global Development Group
   8  *
   9  * src/include/tsearch/ts_public.h
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef _PG_TS_PUBLIC_H_
  14 #define _PG_TS_PUBLIC_H_
  15
  16 #include "tsearch/ts_type.h"
  17
  18 /*
  19  * Parser's framework
  20  */
  21
  22 /*
  23  * returning type for prslextype method of parser
  24  */
  25 typedef struct
  26 {
  27         int                     lexid;
  28         char       *alias;
  29         char       *descr;
  30 } LexDescr;
  31
  32 /*
  33  * Interface to headline generator
  34  */
  35 typedef struct
  36 {
  37         uint32          selected:1,
  38                                 in:1,
  39                                 replace:1,
  40                                 repeated:1,
  41                                 skip:1,
  42                                 unused:3,
  43                                 type:8,
  44                                 len:16;
  45         WordEntryPos pos;
  46         char       *word;
  47         QueryOperand *item;
  48 } HeadlineWordEntry;
  49
  50 typedef struct
  51 {
  52         HeadlineWordEntry *words;
  53         int32           lenwords;
  54         int32           curwords;
  55         int32           vectorpos;              /* positions a-la tsvector */
  56         char       *startsel;
  57         char       *stopsel;
  58         char       *fragdelim;
  59         int16           startsellen;
  60         int16           stopsellen;
  61         int16           fragdelimlen;
  62 } HeadlineParsedText;
  63
  64 /*
  65  * Common useful things for tsearch subsystem
  66  */
  67 extern char *get_tsearch_config_filename(const char *basename,
  68                                                                                  const char *extension);
  69
  70 /*
  71  * Often useful stopword list management
  72  */
  73 typedef struct
  74 {
  75         int                     len;
  76         char      **stop;
  77 } StopList;
  78
  79 extern void readstoplist(const char *fname, StopList *s,
  80                                                  char *(*wordop) (const char *));
  81 extern bool searchstoplist(StopList *s, char *key);
  82
  83 /*
  84  * Interface with dictionaries
  85  */
  86
  87 /* return struct for any lexize function */
  88 typedef struct
  89 {
  90         /*----------
  91          * Number of current variant of split word.  For example the Norwegian
  92          * word 'fotballklubber' has two variants to split: ( fotball, klubb )
  93          * and ( fot, ball, klubb ). So, dictionary should return:
  94          *
  95          * nvariant    lexeme
  96          *         1       fotball
  97          *         1       klubb
  98          *         2       fot
  99          *         2       ball
 100          *         2       klubb
 101          *
 102          * In general, a TSLexeme will be considered to belong to the same split
 103          * variant as the previous one if they have the same nvariant value.
 104          * The exact values don't matter, only changes from one lexeme to next.
 105          *----------
 106          */
 107         uint16          nvariant;
 108
 109         uint16          flags;                  /* See flag bits below */
 110
 111         char       *lexeme;                     /* C string */
 112 } TSLexeme;
 113
 114 /* Flag bits that can appear in TSLexeme.flags */
 115 #define TSL_ADDPOS              0x01
 116 #define TSL_PREFIX              0x02
 117 #define TSL_FILTER              0x04
 118
 119 /*
 120  * Struct for supporting complex dictionaries like thesaurus.
 121  * 4th argument for dictlexize method is a pointer to this
 122  */
 123 typedef struct
 124 {
 125         bool            isend;                  /* in: marks for lexize_info about text end is
 126                                                                  * reached */
 127         bool            getnext;                /* out: dict wants next lexeme */
 128         void       *private_state;      /* internal dict state between calls with
 129                                                                  * getnext == true */
 130 } DictSubState;
 131
 132 #endif                                                  /* _PG_TS_PUBLIC_H_ */