Beispiel #1
0
/*
 * __wt_kv_return --
 *	Return a page referenced key/value pair to the application.
 */
int
__wt_kv_return(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt, int key_ret)
{
	WT_BTREE *btree;
	WT_CELL *cell;
	WT_CELL_UNPACK *unpack, _unpack;
	WT_CURSOR *cursor;
	WT_IKEY *ikey;
	WT_PAGE *page;
	WT_ROW *rip;
	WT_UPDATE *upd;
	uint8_t v;

	btree = session->btree;
	unpack = &_unpack;

	page = cbt->page;
	cursor = &cbt->iface;

	switch (page->type) {
	case WT_PAGE_COL_FIX:
		if (key_ret)
			cursor->recno = cbt->recno;

		/*
		 * If the cursor references a WT_INSERT item, take the related
		 * WT_UPDATE item.
		 */
		if (cbt->ins != NULL) {
			upd = cbt->ins->upd;
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}
		v = __bit_getv_recno(page, cbt->iface.recno, btree->bitcnt);
		return (__wt_buf_set(session, &cursor->value, &v, 1));
	case WT_PAGE_COL_VAR:
		if (key_ret)
			cursor->recno = cbt->recno;

		/*
		 * If the cursor references a WT_INSERT item, take the related
		 * WT_UPDATE item.
		 */
		if (cbt->ins != NULL) {
			upd = cbt->ins->upd;
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}
		cell = WT_COL_PTR(page, &page->u.col_var.d[cbt->slot]);
		break;
	case WT_PAGE_ROW_LEAF:
		rip = &page->u.row.d[cbt->slot];

		/*
		 * If the cursor references a WT_INSERT item, take the key and
		 * related WT_UPDATE item.   Otherwise, take the key from the
		 * original page, and the value from any related WT_UPDATE item,
		 * or the page if the key was never updated.
		 */
		if (cbt->ins == NULL) {
			if (key_ret) {
				if (__wt_off_page(page, rip->key)) {
					ikey = rip->key;
					cursor->key.data = WT_IKEY_DATA(ikey);
					cursor->key.size = ikey->size;
				} else
					WT_RET(__wt_row_key(
					    session, page, rip, &cursor->key));
			}
			upd = WT_ROW_UPDATE(page, rip);
		} else {
			if (key_ret) {
				cursor->key.data = WT_INSERT_KEY(cbt->ins);
				cursor->key.size = WT_INSERT_KEY_SIZE(cbt->ins);
			}
			upd = cbt->ins->upd;
		}
		if (upd != NULL) {
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}

		/* Take the original cell (which may be empty). */
		if ((cell = __wt_row_value(page, rip)) == NULL) {
			cursor->value.size = 0;
			return (0);
		}
		break;
	WT_ILLEGAL_VALUE(session);
	}

	/* It's a cell, unpack and expand it as necessary. */
	__wt_cell_unpack(cell, unpack);
	if (btree->huffman_value == NULL && unpack->type == WT_CELL_VALUE) {
		cursor->value.data = unpack->data;
		cursor->value.size = unpack->size;
		return (0);
	} else
		return (__wt_cell_unpack_copy(session, unpack, &cursor->value));
}
Beispiel #2
0
/*
 * __wt_kv_return --
 *	Return a page referenced key/value pair to the application.
 */
int
__wt_kv_return(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt)
{
    WT_BTREE *btree;
    WT_CELL *cell;
    WT_CELL_UNPACK unpack;
    WT_CURSOR *cursor;
    WT_DECL_RET;
    WT_PAGE *page;
    WT_ROW *rip;
    WT_UPDATE *upd;
    uint8_t v;

    btree = S2BT(session);

    page = cbt->page;
    cursor = &cbt->iface;

    switch (page->type) {
    case WT_PAGE_COL_FIX:
        /*
         * The interface cursor's record has usually been set, but that
         * isn't universally true, specifically, cursor.search_near may
         * call here without first setting the interface cursor.
         */
        cursor->recno = cbt->recno;

        /*
         * If the cursor references a WT_INSERT item, take the related
         * WT_UPDATE item.
         */
        if (cbt->ins != NULL &&
                (upd = __wt_txn_read(session, cbt->ins->upd)) != NULL) {
            cursor->value.data = WT_UPDATE_DATA(upd);
            cursor->value.size = upd->size;
            return (0);
        }
        v = __bit_getv_recno(page, cbt->iface.recno, btree->bitcnt);
        return (__wt_buf_set(session, &cursor->value, &v, 1));
    case WT_PAGE_COL_VAR:
        /*
         * The interface cursor's record has usually been set, but that
         * isn't universally true, specifically, cursor.search_near may
         * call here without first setting the interface cursor.
         */
        cursor->recno = cbt->recno;

        /*
         * If the cursor references a WT_INSERT item, take the related
         * WT_UPDATE item.
         */
        if (cbt->ins != NULL &&
                (upd = __wt_txn_read(session, cbt->ins->upd)) != NULL) {
            cursor->value.data = WT_UPDATE_DATA(upd);
            cursor->value.size = upd->size;
            return (0);
        }
        cell = WT_COL_PTR(page, &page->u.col_var.d[cbt->slot]);
        break;
    case WT_PAGE_ROW_LEAF:
        rip = &page->u.row.d[cbt->slot];

        /*
         * If the cursor references a WT_INSERT item, take the key and
         * related WT_UPDATE item.   Otherwise, take the key from the
         * original page, and the value from any related WT_UPDATE item,
         * or the page if the key was never updated.
         */
        if (cbt->ins != NULL &&
                (upd = __wt_txn_read(session, cbt->ins->upd)) != NULL) {
            cursor->key.data = WT_INSERT_KEY(cbt->ins);
            cursor->key.size = WT_INSERT_KEY_SIZE(cbt->ins);
        } else {
            WT_RET(
                __wt_row_key(session, page, rip, &cursor->key, 0));
            upd = __wt_txn_read(session, WT_ROW_UPDATE(page, rip));
        }
        if (upd != NULL) {
            cursor->value.data = WT_UPDATE_DATA(upd);
            cursor->value.size = upd->size;
            return (0);
        }

        /* Take the original cell (which may be empty). */
        if ((cell = __wt_row_value(page, rip)) == NULL) {
            cursor->value.size = 0;
            return (0);
        }
        break;
        WT_ILLEGAL_VALUE(session);
    }

    /* The value is an on-page cell, unpack and expand it as necessary. */
    __wt_cell_unpack(cell, &unpack);
    ret = __wt_cell_unpack_ref(session, &unpack, &cursor->value);

    /*
     * Restart for a variable-length column-store.  We could catch restart
     * higher up the call-stack but there's no point to it: unlike row-store
     * (where a normal search path finds cached overflow values), we have to
     * access the page's reconciliation structures, and that's as easy here
     * as higher up the stack.
     */
    if (ret == WT_RESTART && page->type == WT_PAGE_COL_VAR)
        ret = __wt_ovfl_cache_col_restart(
                  session, page, &unpack, &cursor->value);
    return (ret);
}