0 Must be present
<0 Must not be present
0 Neither; the word is optional but its presence increases the relevance
With the default settings of the ft_boolean_syntax system variable,
>0 corresponds to the '+' operator, <0 corrresponds to the '-' operator,
and 0 means neither operator was used.
weight_adjust: A weighting factor that determines how much a match
for the word counts. Positive values increase, negative - decrease the
relative word's importance in the query.
wasign: The sign of the word's weight in the query. If it's non-negative
the match for the word will increase document relevance, if it's
negative - decrease (the word becomes a "noise word", the less of it the
better).
trunc: Corresponds to the '*' operator in the default setting of the
ft_boolean_syntax system variable.
position: Start position in bytes of the word in the document, used by InnoDB FTS.
*/
typedef struct st_mysql_ftparser_boolean_info
{
enum enum_ft_token_type type;
int yesno;
int weight_adjust;
char wasign;
char trunc;
int position;
/* These are parser state and must be removed. */
char prev;
char *quot;
} MYSQL_FTPARSER_BOOLEAN_INFO;
/*
The following flag means that buffer with a string (document, word)
may be overwritten by the caller before the end of the parsing (that is
before st_mysql_ftparser::deinit() call). If one needs the string
to survive between two successive calls of the parsing function, she
needs to save a copy of it. The flag may be set by MySQL before calling
st_mysql_ftparser::parse(), or it may be set by a plugin before calling
st_mysql_ftparser_param::mysql_parse() or
st_mysql_ftparser_param::mysql_add_word().
*/
#define MYSQL_FTFLAGS_NEED_COPY 1
/*
An argument of the full-text parser plugin. This structure is
filled in by MySQL server and passed to the parsing function of the
plugin as an in/out parameter.
mysql_parse: A pointer to the built-in parser implementation of the
server. It's set by the server and can be used by the parser plugin
to invoke the MySQL default parser. If plugin's role is to extract
textual data from .doc, .pdf or .xml content, it might extract
plaintext from the content, and then pass the text to the default
MySQL parser to be parsed.
mysql_add_word: A server callback to add a new word. When parsing
a document, the server sets this to point at a function that adds
the word to MySQL full-text index. When parsing a search query,
this function will add the new word to the list of words to search
for. The boolean_info argument can be NULL for all cases except
when mode is MYSQL_FTPARSER_FULL_BOOLEAN_INFO.
ftparser_state: A generic pointer. The plugin can set it to point
to information to be used internally for its own purposes.
mysql_ftparam: This is set by the server. It is used by MySQL functions
called via mysql_parse() and mysql_add_word() callback. The plugin
should not modify it.
cs: Information about the character set of the document or query string.
doc: A pointer to the document or query string to be parsed.
length: Length of the document or query string, in bytes.
flags: See MYSQL_FTFLAGS_* constants above.
mode: The parsing mode. With boolean operators, with stopwords, or
nothing. See enum_ftparser_mode above.
*/
typedef struct st_mysql_ftparser_param
{
int (*mysql_parse)(struct st_mysql_ftparser_param *,
char *doc, int doc_len);
int (*mysql_add_word)(struct st_mysql_ftparser_param *,
char *word, int word_len,
MYSQL_FTPARSER_BOOLEAN_INFO *boolean_info);
void *ftparser_state;
void *mysql_ftparam;
const struct charset_info_st *cs;
char *doc;
int length;
int flags;
enum enum_ftparser_mode mode;
} MYSQL_FTPARSER_PARAM;
/*
Full-text parser descriptor.
interface_version is, e.g., MYSQL_FTPARSER_INTERFACE_VERSION.
The parsing, initialization, and deinitialization functions are
invoked per SQL statement for which the parser is used.
*/
struct st_mysql_ftparser
{
int interface_version;
int (*parse)(MYSQL_FTPARSER_PARAM *param);
int (*init)(MYSQL_FTPARSER_PARAM *param);
int (*deinit)(MYSQL_FTPARSER_PARAM *param);
};
#endif