The interface implemented by applications to provide custom extraction of index keys or column group values. More...
Public Attributes | |
int(* | extract )(WT_EXTRACTOR *extractor, WT_SESSION *session, const WT_ITEM *key, const WT_ITEM *value, WT_CURSOR *result_cursor) |
Callback to extract a value for an index or column group. More... | |
int(* | customize )(WT_EXTRACTOR *extractor, WT_SESSION *session, const char *uri, WT_CONFIG_ITEM *appcfg, WT_EXTRACTOR **customp) |
If non-NULL, this callback is called to customize the extractor for each index. More... | |
int(* | terminate )(WT_EXTRACTOR *extractor, WT_SESSION *session) |
If non-NULL a callback performed when the index or column group is closed for customized extractors otherwise when the database is closed. More... | |
The interface implemented by applications to provide custom extraction of index keys or column group values.
Applications register implementations with WiredTiger by calling WT_CONNECTION::add_extractor. See Custom Extractors for more information.
int(* WT_EXTRACTOR::customize) (WT_EXTRACTOR *extractor, WT_SESSION *session, const char *uri, WT_CONFIG_ITEM *appcfg, WT_EXTRACTOR **customp) |
If non-NULL, this callback is called to customize the extractor for each index.
If the callback returns a non-NULL extractor, that instance is used instead of this one for all comparisons.
int(* WT_EXTRACTOR::extract) (WT_EXTRACTOR *extractor, WT_SESSION *session, const WT_ITEM *key, const WT_ITEM *value, WT_CURSOR *result_cursor) |
Callback to extract a value for an index or column group.
extractor | the WT_EXTRACTOR implementation | |
session | the current WiredTiger session | |
key | the table key in raw format, see Raw mode for details | |
value | the table value in raw format, see Raw mode for details | |
[out] | result_cursor | the method should call WT_CURSOR::set_key and WT_CURSOR::insert on this cursor to return a key. The key_format of the cursor will match that passed to WT_SESSION::create for the index. Multiple index keys can be created for each record by calling WT_CURSOR::insert multiple times. |
int(* WT_EXTRACTOR::terminate) (WT_EXTRACTOR *extractor, WT_SESSION *session) |
If non-NULL a callback performed when the index or column group is closed for customized extractors otherwise when the database is closed.
The WT_EXTRACTOR::terminate callback is intended to allow cleanup; the handle will not be subsequently accessed by WiredTiger.