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postgresql/src/include/tsearch/ts_utils.h

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/*-------------------------------------------------------------------------
*
* ts_utils.h
* helper utilities for tsearch
*
* Copyright (c) 1998-2019, PostgreSQL Global Development Group
*
* src/include/tsearch/ts_utils.h
*
*-------------------------------------------------------------------------
*/
#ifndef _PG_TS_UTILS_H_
#define _PG_TS_UTILS_H_
#include "nodes/pg_list.h"
#include "tsearch/ts_public.h"
#include "tsearch/ts_type.h"
/*
* Common parse definitions for tsvector and tsquery
*/
/* tsvector parser support. */
struct TSVectorParseStateData; /* opaque struct in tsvector_parser.c */
typedef struct TSVectorParseStateData *TSVectorParseState;
#define P_TSV_OPR_IS_DELIM (1 << 0)
#define P_TSV_IS_TSQUERY (1 << 1)
#define P_TSV_IS_WEB (1 << 2)
extern TSVectorParseState init_tsvector_parser(char *input, int flags);
extern void reset_tsvector_parser(TSVectorParseState state, char *input);
extern bool gettoken_tsvector(TSVectorParseState state,
char **token, int *len,
WordEntryPos **pos, int *poslen,
char **endptr);
extern void close_tsvector_parser(TSVectorParseState state);
/* phrase operator begins with '<' */
#define ISOPERATOR(x) \
( pg_mblen(x) == 1 && ( *(x) == '!' || \
*(x) == '&' || \
*(x) == '|' || \
*(x) == '(' || \
*(x) == ')' || \
*(x) == '<' \
) )
/* parse_tsquery */
struct TSQueryParserStateData; /* private in backend/utils/adt/tsquery.c */
typedef struct TSQueryParserStateData *TSQueryParserState;
typedef void (*PushFunction) (Datum opaque, TSQueryParserState state,
char *token, int tokenlen,
int16 tokenweights, /* bitmap as described in
* QueryOperand struct */
bool prefix);
#define P_TSQ_PLAIN (1 << 0)
#define P_TSQ_WEB (1 << 1)
extern TSQuery parse_tsquery(char *buf,
PushFunction pushval,
Datum opaque,
int flags);
/* Functions for use by PushFunction implementations */
extern void pushValue(TSQueryParserState state,
char *strval, int lenval, int16 weight, bool prefix);
extern void pushStop(TSQueryParserState state);
extern void pushOperator(TSQueryParserState state, int8 oper, int16 distance);
/*
* parse plain text and lexize words
*/
typedef struct
{
uint16 len;
uint16 nvariant;
union
{
uint16 pos;
/*
* When apos array is used, apos[0] is the number of elements in the
* array (excluding apos[0]), and alen is the allocated size of the
* array.
*/
uint16 *apos;
} pos;
uint16 flags; /* currently, only TSL_PREFIX */
char *word;
uint32 alen;
} ParsedWord;
typedef struct
{
ParsedWord *words;
int32 lenwords;
int32 curwords;
int32 pos;
} ParsedText;
extern void parsetext(Oid cfgId, ParsedText *prs, char *buf, int32 buflen);
/*
* headline framework, flow in common to generate:
* 1 parse text with hlparsetext
* 2 parser-specific function to find part
* 3 generateHeadline to generate result text
*/
extern void hlparsetext(Oid cfgId, HeadlineParsedText *prs, TSQuery query,
char *buf, int32 buflen);
extern text *generateHeadline(HeadlineParsedText *prs);
/*
* TSQuery execution support
*
* TS_execute() executes a tsquery against data that can be represented in
* various forms. The TSExecuteCallback callback function is called to check
* whether a given primitive tsquery value is matched in the data.
*/
/*
* struct ExecPhraseData is passed to a TSExecuteCallback function if we need
* lexeme position data (because of a phrase-match operator in the tsquery).
* The callback should fill in position data when it returns true (success).
* If it cannot return position data, it may leave "data" unchanged, but
* then the caller of TS_execute() must pass the TS_EXEC_PHRASE_NO_POS flag
* and must arrange for a later recheck with position data available.
*
* The reported lexeme positions must be sorted and unique. Callers must only
* consult the position bits of the pos array, ie, WEP_GETPOS(data->pos[i]).
* This allows the returned "pos" to point directly to the WordEntryPos
* portion of a tsvector value. If "allocated" is true then the pos array
* is palloc'd workspace and caller may free it when done.
*
* "negate" means that the pos array contains positions where the query does
* not match, rather than positions where it does. "width" is positive when
* the match is wider than one lexeme. Neither of these fields normally need
* to be touched by TSExecuteCallback functions; they are used for
* phrase-search processing within TS_execute.
*
* All fields of the ExecPhraseData struct are initially zeroed by caller.
*/
typedef struct ExecPhraseData
{
int npos; /* number of positions reported */
bool allocated; /* pos points to palloc'd data? */
bool negate; /* positions are where query is NOT matched */
WordEntryPos *pos; /* ordered, non-duplicate lexeme positions */
int width; /* width of match in lexemes, less 1 */
} ExecPhraseData;
/*
* Signature for TSQuery lexeme check functions
*
* arg: opaque value passed through from caller of TS_execute
* val: lexeme to test for presence of
* data: to be filled with lexeme positions; NULL if position data not needed
*
* Return true if lexeme is present in data, else false. If data is not
* NULL, it should be filled with lexeme positions, but function can leave
* it as zeroes if position data is not available.
*/
typedef bool (*TSExecuteCallback) (void *arg, QueryOperand *val,
ExecPhraseData *data);
/*
* Flag bits for TS_execute
*/
#define TS_EXEC_EMPTY (0x00)
/*
* If TS_EXEC_CALC_NOT is not set, then NOT expressions are automatically
* evaluated to be true. Useful in cases where NOT cannot be accurately
* computed (GiST) or it isn't important (ranking). From TS_execute's
* perspective, !CALC_NOT means that the TSExecuteCallback function might
* return false-positive indications of a lexeme's presence.
*/
#define TS_EXEC_CALC_NOT (0x01)
/*
* If TS_EXEC_PHRASE_NO_POS is set, allow OP_PHRASE to be executed lossily
* in the absence of position information: a true result indicates that the
* phrase might be present. Without this flag, OP_PHRASE always returns
* false if lexeme position information is not available.
*/
#define TS_EXEC_PHRASE_NO_POS (0x02)
extern bool TS_execute(QueryItem *curitem, void *arg, uint32 flags,
TSExecuteCallback chkcond);
extern bool tsquery_requires_match(QueryItem *curitem);
/*
* to_ts* - text transformation to tsvector, tsquery
*/
extern TSVector make_tsvector(ParsedText *prs);
extern int32 tsCompareString(char *a, int lena, char *b, int lenb, bool prefix);
/*
* Possible strategy numbers for indexes
* TSearchStrategyNumber - (tsvector|text) @@ tsquery
* TSearchWithClassStrategyNumber - tsvector @@@ tsquery
*/
#define TSearchStrategyNumber 1
#define TSearchWithClassStrategyNumber 2
/*
* TSQuery Utilities
*/
extern QueryItem *clean_NOT(QueryItem *ptr, int32 *len);
extern TSQuery cleanup_tsquery_stopwords(TSQuery in);
typedef struct QTNode
{
QueryItem *valnode;
uint32 flags;
int32 nchild;
char *word;
uint32 sign;
struct QTNode **child;
} QTNode;
/* bits in QTNode.flags */
#define QTN_NEEDFREE 0x01
#define QTN_NOCHANGE 0x02
#define QTN_WORDFREE 0x04
typedef uint64 TSQuerySign;
#define TSQS_SIGLEN (sizeof(TSQuerySign)*BITS_PER_BYTE)
#define TSQuerySignGetDatum(X) Int64GetDatum((int64) (X))
#define DatumGetTSQuerySign(X) ((TSQuerySign) DatumGetInt64(X))
#define PG_RETURN_TSQUERYSIGN(X) return TSQuerySignGetDatum(X)
#define PG_GETARG_TSQUERYSIGN(n) DatumGetTSQuerySign(PG_GETARG_DATUM(n))
extern QTNode *QT2QTN(QueryItem *in, char *operand);
extern TSQuery QTN2QT(QTNode *in);
extern void QTNFree(QTNode *in);
extern void QTNSort(QTNode *in);
extern void QTNTernary(QTNode *in);
extern void QTNBinary(QTNode *in);
extern int QTNodeCompare(QTNode *an, QTNode *bn);
extern QTNode *QTNCopy(QTNode *in);
extern void QTNClearFlags(QTNode *in, uint32 flags);
extern bool QTNEq(QTNode *a, QTNode *b);
extern TSQuerySign makeTSQuerySign(TSQuery a);
extern QTNode *findsubquery(QTNode *root, QTNode *ex, QTNode *subs,
bool *isfind);
#endif /* _PG_TS_UTILS_H_ */
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