static int
kvs_cursor_search(WT_CURSOR *wtcursor)
{
CURSOR_SOURCE *cursor;
DBC *dbc;
DBT *key, *value;
WT_EXTENSION_API *wt_api;
WT_SESSION *session;
int ret = 0;
session = wtcursor->session;
cursor = (CURSOR_SOURCE *)wtcursor;
wt_api = cursor->wt_api;
dbc = cursor->dbc;
key = &cursor->key;
value = &cursor->value;
if ((ret = copyin_key(wtcursor)) != 0)
return (ret);
if ((ret = dbc->get(dbc, key, value, DB_SET)) == 0) {
copyout_key(wtcursor);
copyout_value(wtcursor);
return (0);
}
if (ret == DB_NOTFOUND || ret == DB_KEYEMPTY)
return (WT_NOTFOUND);
ERET(wt_api, session, WT_ERROR, "DbCursor.get: %s", db_strerror(ret));
}
/*
* kvs_cursor_prev --
* WT_CURSOR::prev method.
*/
static int
kvs_cursor_prev(WT_CURSOR *wt_cursor)
{
int ret;
if ((ret = copy_key(wt_cursor)) != 0)
return (ret);
if ((ret = kvs_call(wt_cursor, "kvs_prev", kvs_prev)) != 0)
return (ret);
if ((ret = copyout_key(wt_cursor)) != 0)
return (ret);
if ((ret = copyout_val(wt_cursor)) != 0)
return (ret);
return (0);
}
static int
kvs_cursor_search_near(WT_CURSOR *wtcursor, int *exact)
{
CURSOR_SOURCE *cursor;
DBC *dbc;
DBT *key, *value;
WT_EXTENSION_API *wt_api;
WT_SESSION *session;
size_t len;
int ret = 0;
session = wtcursor->session;
cursor = (CURSOR_SOURCE *)wtcursor;
wt_api = cursor->wt_api;
dbc = cursor->dbc;
key = &cursor->key;
value = &cursor->value;
if ((ret = copyin_key(wtcursor)) != 0)
return (ret);
retry: if ((ret = dbc->get(dbc, key, value, DB_SET_RANGE)) == 0) {
/*
* WiredTiger returns the logically adjacent key (which might
* be less than, equal to, or greater than the specified key),
* Berkeley DB returns a key equal to or greater than the
* specified key. Check for an exact match, otherwise Berkeley
* DB must have returned a larger key than the one specified.
*/
if (key->size == wtcursor->key.size &&
memcmp(key->data, wtcursor->key.data, key->size) == 0)
*exact = 0;
else
*exact = 1;
copyout_key(wtcursor);
copyout_value(wtcursor);
return (0);
}
/*
* Berkeley DB only returns keys equal to or greater than the specified
* key, while WiredTiger returns adjacent keys, that is, if there's a
* key smaller than the specified key, it's supposed to be returned. In
* other words, WiredTiger only fails if the store is empty. Read the
* last key in the store, and see if it's less than the specified key,
* in which case we have the right key to return. If it's not less than
* the specified key, we're racing with some other thread, throw up our
* hands and try again.
*/
if ((ret = dbc->get(dbc, key, value, DB_LAST)) == 0) {
len = key->size < wtcursor->key.size ?
key->size : wtcursor->key.size;
if (memcmp(key->data, wtcursor->key.data, len) < 0) {
*exact = -1;
copyout_key(wtcursor);
copyout_value(wtcursor);
return (0);
}
goto retry;
}
if (ret == DB_NOTFOUND || ret == DB_KEYEMPTY)
return (WT_NOTFOUND);
ERET(wt_api, session, WT_ERROR, "DbCursor.get: %s", db_strerror(ret));
}
