WT_DATA_SOURCE Struct Reference

Applications can extend WiredTiger by providing new implementations of the WT_DATA_SOURCE class. More...

Public Attributes
int(*	create )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)
	Callback to create a new object. More...
int(*	compact )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)
	Callback to compact an object. More...
int(*	drop )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)
	Callback to drop an object. More...
int(*	open_cursor )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config, WT_CURSOR **new_cursor)
	Callback to initialize a cursor. More...
int(*	rename )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, const char *newuri, WT_CONFIG_ARG *config)
	Callback to rename an object. More...
int(*	salvage )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)
	Callback to salvage an object. More...
int(*	truncate )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)
	Callback to truncate an object. More...
int(*	range_truncate )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, WT_CURSOR *start, WT_CURSOR *stop)
	Callback to truncate a range of an object. More...
int(*	verify )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)
	Callback to verify an object. More...
int(*	checkpoint )(WT_DATA_SOURCE *dsrc, WT_SESSION *session, WT_CONFIG_ARG *config)
	Callback to checkpoint the database. More...
int(*	terminate )(WT_DATA_SOURCE *dsrc, WT_SESSION *session)
	If non-NULL, a callback performed when the database is closed. More...

Detailed Description

Applications can extend WiredTiger by providing new implementations of the WT_DATA_SOURCE class.

Each data source supports a different URI scheme for data sources to WT_SESSION::create, WT_SESSION::open_cursor and related methods. See Custom Data Sources for more information.

Thread safety: WiredTiger may invoke methods on the WT_DATA_SOURCE interface from multiple threads concurrently. It is the responsibility of the implementation to protect any shared data.

Applications register their implementation with WiredTiger by calling WT_CONNECTION::add_data_source.

        static WT_DATA_SOURCE my_dsrc = {
                my_create,
                my_compact,
                my_drop,
                my_open_cursor,
                my_rename,
                my_salvage,
                my_truncate,
                my_range_truncate,
                my_verify,
                my_checkpoint,
                my_terminate
        };
        ret = conn->add_data_source(conn, "dsrc:", &my_dsrc, NULL);

Member Data Documentation

int(* WT_DATA_SOURCE::checkpoint)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, WT_CONFIG_ARG *config)

Callback to checkpoint the database.

static int
my_checkpoint(WT_DATA_SOURCE *dsrc, WT_SESSION *session, WT_CONFIG_ARG *config)

int(* WT_DATA_SOURCE::compact)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)

Callback to compact an object.

static int
my_compact(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, WT_CONFIG_ARG *config)

int(* WT_DATA_SOURCE::create)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)

Callback to create a new object.

static int
my_create(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, WT_CONFIG_ARG *config)

int(* WT_DATA_SOURCE::drop)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)

Callback to drop an object.

static int
my_drop(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, WT_CONFIG_ARG *config)

int(* WT_DATA_SOURCE::open_cursor)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config, WT_CURSOR **new_cursor)

Callback to initialize a cursor.

typedef struct __my_cursor {
        WT_CURSOR wtcursor;             /* WiredTiger cursor, must come first */

        /*
         * Local cursor information: for example, we might want to have a
         * reference to the extension functions.
         */
        WT_EXTENSION_API *wtext;        /* Extension functions */
} MY_CURSOR;

static int
my_open_cursor(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, WT_CONFIG_ARG *config, WT_CURSOR **new_cursor)
{
        MY_CURSOR *cursor;

        /* Allocate and initialize a WiredTiger cursor. */
        if ((cursor = calloc(1, sizeof(*cursor))) == NULL)
                return (errno);

        cursor->wtcursor.next = my_cursor_next;
        cursor->wtcursor.prev = my_cursor_prev;
        cursor->wtcursor.reset = my_cursor_reset;
        cursor->wtcursor.search = my_cursor_search;
        cursor->wtcursor.search_near = my_cursor_search_near;
        cursor->wtcursor.insert = my_cursor_insert;
        cursor->wtcursor.update = my_cursor_update;
        cursor->wtcursor.remove = my_cursor_remove;
        cursor->wtcursor.close = my_cursor_close;

        /*
         * Configure local cursor information.
         */

        /* Return combined cursor to WiredTiger. */
        *new_cursor = (WT_CURSOR *)cursor;

int(* WT_DATA_SOURCE::range_truncate)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, WT_CURSOR *start, WT_CURSOR *stop)

Callback to truncate a range of an object.

static int
my_range_truncate(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    WT_CURSOR *start, WT_CURSOR *stop)

int(* WT_DATA_SOURCE::rename)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, const char *newuri, WT_CONFIG_ARG *config)

Callback to rename an object.

static int
my_rename(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, const char *newname, WT_CONFIG_ARG *config)

int(* WT_DATA_SOURCE::salvage)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)

Callback to salvage an object.

static int
my_salvage(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, WT_CONFIG_ARG *config)

int(* WT_DATA_SOURCE::terminate)(WT_DATA_SOURCE *dsrc, WT_SESSION *session)

If non-NULL, a callback performed when the database is closed.

The WT_DATA_SOURCE::terminate callback is intended to allow cleanup, the handle will not be subsequently accessed by WiredTiger.

static int
my_terminate(WT_DATA_SOURCE *dsrc, WT_SESSION *session)

int(* WT_DATA_SOURCE::truncate)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)

Callback to truncate an object.

static int
my_truncate(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, WT_CONFIG_ARG *config)

int(* WT_DATA_SOURCE::verify)(WT_DATA_SOURCE *dsrc, WT_SESSION *session, const char *uri, WT_CONFIG_ARG *config)

Callback to verify an object.

static int
my_verify(WT_DATA_SOURCE *dsrc, WT_SESSION *session,
    const char *uri, WT_CONFIG_ARG *config)