Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * ts_utils.h
4 : * helper utilities for tsearch
5 : *
6 : * Copyright (c) 1998-2024, PostgreSQL Global Development Group
7 : *
8 : * src/include/tsearch/ts_utils.h
9 : *
10 : *-------------------------------------------------------------------------
11 : */
12 : #ifndef _PG_TS_UTILS_H_
13 : #define _PG_TS_UTILS_H_
14 :
15 : #include "nodes/pg_list.h"
16 : #include "tsearch/ts_public.h"
17 : #include "tsearch/ts_type.h"
18 :
19 : /*
20 : * Common parse definitions for tsvector and tsquery
21 : */
22 :
23 : /* tsvector parser support. */
24 :
25 : struct TSVectorParseStateData; /* opaque struct in tsvector_parser.c */
26 : typedef struct TSVectorParseStateData *TSVectorParseState;
27 :
28 : /* flag bits that can be passed to init_tsvector_parser: */
29 : #define P_TSV_OPR_IS_DELIM (1 << 0)
30 : #define P_TSV_IS_TSQUERY (1 << 1)
31 : #define P_TSV_IS_WEB (1 << 2)
32 :
33 : extern TSVectorParseState init_tsvector_parser(char *input, int flags,
34 : Node *escontext);
35 : extern void reset_tsvector_parser(TSVectorParseState state, char *input);
36 : extern bool gettoken_tsvector(TSVectorParseState state,
37 : char **strval, int *lenval,
38 : WordEntryPos **pos_ptr, int *poslen,
39 : char **endptr);
40 : extern void close_tsvector_parser(TSVectorParseState state);
41 :
42 : /* phrase operator begins with '<' */
43 : #define ISOPERATOR(x) \
44 : ( pg_mblen(x) == 1 && ( *(x) == '!' || \
45 : *(x) == '&' || \
46 : *(x) == '|' || \
47 : *(x) == '(' || \
48 : *(x) == ')' || \
49 : *(x) == '<' \
50 : ) )
51 :
52 : /* parse_tsquery */
53 :
54 : struct TSQueryParserStateData; /* private in backend/utils/adt/tsquery.c */
55 : typedef struct TSQueryParserStateData *TSQueryParserState;
56 :
57 : typedef void (*PushFunction) (Datum opaque, TSQueryParserState state,
58 : char *token, int tokenlen,
59 : int16 tokenweights, /* bitmap as described in
60 : * QueryOperand struct */
61 : bool prefix);
62 :
63 : /* flag bits that can be passed to parse_tsquery: */
64 : #define P_TSQ_PLAIN (1 << 0)
65 : #define P_TSQ_WEB (1 << 1)
66 :
67 : extern TSQuery parse_tsquery(char *buf,
68 : PushFunction pushval,
69 : Datum opaque,
70 : int flags,
71 : Node *escontext);
72 :
73 : /* Functions for use by PushFunction implementations */
74 : extern void pushValue(TSQueryParserState state,
75 : char *strval, int lenval, int16 weight, bool prefix);
76 : extern void pushStop(TSQueryParserState state);
77 : extern void pushOperator(TSQueryParserState state, int8 oper, int16 distance);
78 :
79 : /*
80 : * parse plain text and lexize words
81 : */
82 : typedef struct
83 : {
84 : uint16 flags; /* currently, only TSL_PREFIX */
85 : uint16 len;
86 : uint16 nvariant;
87 : uint16 alen;
88 : union
89 : {
90 : uint16 pos;
91 :
92 : /*
93 : * When apos array is used, apos[0] is the number of elements in the
94 : * array (excluding apos[0]), and alen is the allocated size of the
95 : * array. We do not allow more than MAXNUMPOS array elements.
96 : */
97 : uint16 *apos;
98 : } pos;
99 : char *word;
100 : } ParsedWord;
101 :
102 : typedef struct
103 : {
104 : ParsedWord *words;
105 : int32 lenwords;
106 : int32 curwords;
107 : int32 pos;
108 : } ParsedText;
109 :
110 : extern void parsetext(Oid cfgId, ParsedText *prs, char *buf, int32 buflen);
111 :
112 : /*
113 : * headline framework, flow in common to generate:
114 : * 1 parse text with hlparsetext
115 : * 2 parser-specific function to find part
116 : * 3 generateHeadline to generate result text
117 : */
118 :
119 : extern void hlparsetext(Oid cfgId, HeadlineParsedText *prs, TSQuery query,
120 : char *buf, int32 buflen);
121 : extern text *generateHeadline(HeadlineParsedText *prs);
122 :
123 : /*
124 : * TSQuery execution support
125 : *
126 : * TS_execute() executes a tsquery against data that can be represented in
127 : * various forms. The TSExecuteCallback callback function is called to check
128 : * whether a given primitive tsquery value is matched in the data.
129 : */
130 :
131 : /* TS_execute requires ternary logic to handle NOT with phrase matches */
132 : typedef enum
133 : {
134 : TS_NO, /* definitely no match */
135 : TS_YES, /* definitely does match */
136 : TS_MAYBE, /* can't verify match for lack of pos data */
137 : } TSTernaryValue;
138 :
139 : /*
140 : * struct ExecPhraseData is passed to a TSExecuteCallback function if we need
141 : * lexeme position data (because of a phrase-match operator in the tsquery).
142 : * The callback should fill in position data when it returns TS_YES (success).
143 : * If it cannot return position data, it should leave "data" unchanged and
144 : * return TS_MAYBE. The caller of TS_execute() must then arrange for a later
145 : * recheck with position data available.
146 : *
147 : * The reported lexeme positions must be sorted and unique. Callers must only
148 : * consult the position bits of the pos array, ie, WEP_GETPOS(data->pos[i]).
149 : * This allows the returned "pos" to point directly to the WordEntryPos
150 : * portion of a tsvector value. If "allocated" is true then the pos array
151 : * is palloc'd workspace and caller may free it when done.
152 : *
153 : * "negate" means that the pos array contains positions where the query does
154 : * not match, rather than positions where it does. "width" is positive when
155 : * the match is wider than one lexeme. Neither of these fields normally need
156 : * to be touched by TSExecuteCallback functions; they are used for
157 : * phrase-search processing within TS_execute.
158 : *
159 : * All fields of the ExecPhraseData struct are initially zeroed by caller.
160 : */
161 : typedef struct ExecPhraseData
162 : {
163 : int npos; /* number of positions reported */
164 : bool allocated; /* pos points to palloc'd data? */
165 : bool negate; /* positions are where query is NOT matched */
166 : WordEntryPos *pos; /* ordered, non-duplicate lexeme positions */
167 : int width; /* width of match in lexemes, less 1 */
168 : } ExecPhraseData;
169 :
170 : /*
171 : * Signature for TSQuery lexeme check functions
172 : *
173 : * arg: opaque value passed through from caller of TS_execute
174 : * val: lexeme to test for presence of
175 : * data: to be filled with lexeme positions; NULL if position data not needed
176 : *
177 : * Return TS_YES if lexeme is present in data, TS_MAYBE if it might be
178 : * present, TS_NO if it definitely is not present. If data is not NULL,
179 : * it must be filled with lexeme positions if available. If position data
180 : * is not available, leave *data as zeroes and return TS_MAYBE, never TS_YES.
181 : */
182 : typedef TSTernaryValue (*TSExecuteCallback) (void *arg, QueryOperand *val,
183 : ExecPhraseData *data);
184 :
185 : /*
186 : * Flag bits for TS_execute
187 : */
188 : #define TS_EXEC_EMPTY (0x00)
189 : /*
190 : * If TS_EXEC_SKIP_NOT is set, then NOT sub-expressions are automatically
191 : * evaluated to be true. This was formerly the default behavior. It's now
192 : * deprecated because it tends to give silly answers, but some applications
193 : * might still have a use for it.
194 : */
195 : #define TS_EXEC_SKIP_NOT (0x01)
196 : /*
197 : * If TS_EXEC_PHRASE_NO_POS is set, allow OP_PHRASE to be executed lossily
198 : * in the absence of position information: a true result indicates that the
199 : * phrase might be present. Without this flag, OP_PHRASE always returns
200 : * false if lexeme position information is not available.
201 : */
202 : #define TS_EXEC_PHRASE_NO_POS (0x02)
203 :
204 : extern bool TS_execute(QueryItem *curitem, void *arg, uint32 flags,
205 : TSExecuteCallback chkcond);
206 : extern TSTernaryValue TS_execute_ternary(QueryItem *curitem, void *arg,
207 : uint32 flags,
208 : TSExecuteCallback chkcond);
209 : extern List *TS_execute_locations(QueryItem *curitem, void *arg,
210 : uint32 flags,
211 : TSExecuteCallback chkcond);
212 : extern bool tsquery_requires_match(QueryItem *curitem);
213 :
214 : /*
215 : * to_ts* - text transformation to tsvector, tsquery
216 : */
217 : extern TSVector make_tsvector(ParsedText *prs);
218 : extern int32 tsCompareString(char *a, int lena, char *b, int lenb, bool prefix);
219 :
220 : /*
221 : * Possible strategy numbers for indexes
222 : * TSearchStrategyNumber - (tsvector|text) @@ tsquery
223 : * TSearchWithClassStrategyNumber - tsvector @@@ tsquery
224 : */
225 : #define TSearchStrategyNumber 1
226 : #define TSearchWithClassStrategyNumber 2
227 :
228 : /*
229 : * TSQuery Utilities
230 : */
231 : extern QueryItem *clean_NOT(QueryItem *ptr, int32 *len);
232 : extern TSQuery cleanup_tsquery_stopwords(TSQuery in, bool noisy);
233 :
234 : typedef struct QTNode
235 : {
236 : QueryItem *valnode;
237 : uint32 flags;
238 : int32 nchild;
239 : char *word;
240 : uint32 sign;
241 : struct QTNode **child;
242 : } QTNode;
243 :
244 : /* bits in QTNode.flags */
245 : #define QTN_NEEDFREE 0x01
246 : #define QTN_NOCHANGE 0x02
247 : #define QTN_WORDFREE 0x04
248 :
249 : typedef uint64 TSQuerySign;
250 :
251 : #define TSQS_SIGLEN (sizeof(TSQuerySign)*BITS_PER_BYTE)
252 :
253 : static inline Datum
254 36 : TSQuerySignGetDatum(TSQuerySign X)
255 : {
256 36 : return Int64GetDatum((int64) X);
257 : }
258 :
259 : static inline TSQuerySign
260 144 : DatumGetTSQuerySign(Datum X)
261 : {
262 144 : return (TSQuerySign) DatumGetInt64(X);
263 : }
264 :
265 : #define PG_RETURN_TSQUERYSIGN(X) return TSQuerySignGetDatum(X)
266 : #define PG_GETARG_TSQUERYSIGN(n) DatumGetTSQuerySign(PG_GETARG_DATUM(n))
267 :
268 :
269 : extern QTNode *QT2QTN(QueryItem *in, char *operand);
270 : extern TSQuery QTN2QT(QTNode *in);
271 : extern void QTNFree(QTNode *in);
272 : extern void QTNSort(QTNode *in);
273 : extern void QTNTernary(QTNode *in);
274 : extern void QTNBinary(QTNode *in);
275 : extern int QTNodeCompare(QTNode *an, QTNode *bn);
276 : extern QTNode *QTNCopy(QTNode *in);
277 : extern void QTNClearFlags(QTNode *in, uint32 flags);
278 : extern bool QTNEq(QTNode *a, QTNode *b);
279 : extern TSQuerySign makeTSQuerySign(TSQuery a);
280 : extern QTNode *findsubquery(QTNode *root, QTNode *ex, QTNode *subs,
281 : bool *isfind);
282 :
283 : #endif /* _PG_TS_UTILS_H_ */
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