sqlite/ext/fts1/fts1_tokenizer.h
drh 5db455e7b5 Refactor the FTS1 module so that its name is "fts1" instead of "fulltext",
so that all symbols with external linkage begin with "sqlite3Fts1", and
so that all filenames begin with "fts1". (CVS 3377)

FossilOrigin-Name: e1891f0dc58e5498a8845d8b9b5b092d7f9c7003
2006-08-31 15:07:14 +00:00

90 lines
3.2 KiB
C

/*
** 2006 July 10
**
** The author disclaims copyright to this source code.
**
*************************************************************************
** Defines the interface to tokenizers used by fulltext-search. There
** are three basic components:
**
** sqlite3_tokenizer_module is a singleton defining the tokenizer
** interface functions. This is essentially the class structure for
** tokenizers.
**
** sqlite3_tokenizer is used to define a particular tokenizer, perhaps
** including customization information defined at creation time.
**
** sqlite3_tokenizer_cursor is generated by a tokenizer to generate
** tokens from a particular input.
*/
#ifndef _FTS1_TOKENIZER_H_
#define _FTS1_TOKENIZER_H_
/* TODO(shess) Only used for SQLITE_OK and SQLITE_DONE at this time.
** If tokenizers are to be allowed to call sqlite3_*() functions, then
** we will need a way to register the API consistently.
*/
#include "sqlite3.h"
/*
** Structures used by the tokenizer interface.
*/
typedef struct sqlite3_tokenizer sqlite3_tokenizer;
typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;
typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
struct sqlite3_tokenizer_module {
int iVersion; /* currently 0 */
/*
** Create and destroy a tokenizer. argc/argv are passed down from
** the fulltext virtual table creation to allow customization.
*/
int (*xCreate)(int argc, const char **argv,
sqlite3_tokenizer **ppTokenizer);
int (*xDestroy)(sqlite3_tokenizer *pTokenizer);
/*
** Tokenize a particular input. Call xOpen() to prepare to
** tokenize, xNext() repeatedly until it returns SQLITE_DONE, then
** xClose() to free any internal state. The pInput passed to
** xOpen() must exist until the cursor is closed. The ppToken
** result from xNext() is only valid until the next call to xNext()
** or until xClose() is called.
*/
/* TODO(shess) current implementation requires pInput to be
** nul-terminated. This should either be fixed, or pInput/nBytes
** should be converted to zInput.
*/
int (*xOpen)(sqlite3_tokenizer *pTokenizer,
const char *pInput, int nBytes,
sqlite3_tokenizer_cursor **ppCursor);
int (*xClose)(sqlite3_tokenizer_cursor *pCursor);
int (*xNext)(sqlite3_tokenizer_cursor *pCursor,
const char **ppToken, int *pnBytes,
int *piStartOffset, int *piEndOffset, int *piPosition);
};
struct sqlite3_tokenizer {
sqlite3_tokenizer_module *pModule; /* The module for this tokenizer */
/* Tokenizer implementations will typically add additional fields */
};
struct sqlite3_tokenizer_cursor {
sqlite3_tokenizer *pTokenizer; /* Tokenizer for this cursor. */
/* Tokenizer implementations will typically add additional fields */
};
/*
** Get the module for a tokenizer which generates tokens based on a
** set of non-token characters. The default is to break tokens at any
** non-alnum character, though the set of delimiters can also be
** specified by the first argv argument to xCreate().
*/
/* TODO(shess) This doesn't belong here. Need some sort of
** registration process.
*/
void sqlite3Fts1SimpleTokenizerModule(sqlite3_tokenizer_module **ppModule);
#endif /* _FTS1_TOKENIZER_H_ */