Пример #1
0
/*
 * __cursor_fix_prev --
 *	Move to the previous, fixed-length column-store item.
 */
static inline int
__cursor_fix_prev(WT_CURSOR_BTREE *cbt, int newpage)
{
	WT_BTREE *btree;
	WT_ITEM *val;
	WT_SESSION_IMPL *session;
	WT_UPDATE *upd;

	session = (WT_SESSION_IMPL *)cbt->iface.session;
	btree = session->btree;
	val = &cbt->iface.value;

	/* Initialize for each new page. */
	if (newpage) {
		cbt->last_standard_recno = __col_last_recno(cbt->page);
		if (cbt->last_standard_recno == 0)
			return (WT_NOTFOUND);
		__cursor_set_recno(cbt, cbt->last_standard_recno);
		goto new_page;
	}

	/* Move to the previous entry and return the item. */
	for (;;) {
		if (cbt->recno == cbt->page->u.col_fix.recno)
			return (WT_NOTFOUND);
		__cursor_set_recno(cbt, cbt->recno - 1);

new_page:	/* Check any insert list for a matching record. */
		cbt->ins_head = WT_COL_UPDATE_SINGLE(cbt->page);
		cbt->ins = __col_insert_search(
		    cbt->ins_head, cbt->ins_stack, cbt->next_stack, cbt->recno);
		if (cbt->ins != NULL &&
		    cbt->recno != WT_INSERT_RECNO(cbt->ins))
			cbt->ins = NULL;
		upd = cbt->ins == NULL ?
		    NULL : __wt_txn_read(session, cbt->ins->upd);
		if (upd != NULL) {
			val->data = WT_UPDATE_DATA(upd);
			val->size = 1;
			return (0);
		}

		cbt->v = __bit_getv_recno(cbt->page, cbt->recno, btree->bitcnt);
		val->data = &cbt->v;
		val->size = 1;
		return (0);
	}
	/* NOTREACHED */
}
Пример #2
0
/*btree cursor移向下一个记录(fix col方式存储),在btree树空间上移动*/
static inline int __cursor_fix_next(WT_CURSOR_BTREE* cbt, int newpage)
{
	WT_BTREE *btree;
	WT_ITEM *val;
	WT_PAGE *page;
	WT_SESSION_IMPL *session;
	WT_UPDATE *upd;

	session = (WT_SESSION_IMPL *)cbt->iface.session;
	btree = S2BT(session);
	page = cbt->ref->page;
	val = &cbt->iface.value;

	/*切换到新的page上做next操作*/
	if (newpage){
		cbt->last_standard_recno = __col_fix_last_recno(page);
		if (cbt->last_standard_recno == 0)
			return (WT_NOTFOUND);

		__cursor_set_recno(cbt, page->pg_fix_recno);
		goto new_page;
	}

	/*记录序号超出最后一个序号,到末尾了*/
	if (cbt->recno >= cbt->last_standard_recno)
		return WT_NOTFOUND;
	__cursor_set_recno(cbt, cbt->recno + 1);

new_page:
	/*获得第一个修改列表*/
	cbt->ins_head = WT_COL_UPDATE_SINGLE(page);
	/*定位recno所在的修改条目*/
	cbt->ins = __col_insert_search(cbt->ins_head, cbt->ins_stack, cbt->next_stack, cbt->recno);
	if (cbt->ins != NULL && cbt->recno != WT_INSERT_RECNO(cbt->ins)) /*不正确的修改定位,将ins设置为NULL表示定位失败*/
		cbt->ins = NULL;
	
	/*做事务隔离读取记录版本*/
	upd = cbt->ins == NULL ? NULL : __wt_txn_read(session, cbt->ins->upd);
	if (upd == NULL){
		cbt->v = __bit_getv_recno(page, cbt->recno, btree->bitcnt); /*V赋值*/
		val->data = &cbt->v;
	}
	else
		val->data = WT_UPDATE_DATA(upd);
	val->size = 1;

	return 0;
}
Пример #3
0
/*
 * __cursor_fix_prev --
 *	Move to the previous, fixed-length column-store item.
 */
static inline int
__cursor_fix_prev(WT_CURSOR_BTREE *cbt, int newpage)
{
	WT_BTREE *btree;
	WT_INSERT *ins;
	WT_ITEM *val;
	WT_SESSION_IMPL *session;
	WT_UPDATE *upd;
	uint64_t *recnop;

	session = (WT_SESSION_IMPL *)cbt->iface.session;
	btree = session->btree;

	recnop = &cbt->iface.recno;
	val = &cbt->iface.value;

	/* Initialize for each new page. */
	if (newpage) {
		cbt->last_standard_recno = __col_last_recno(cbt->page);
		if (cbt->last_standard_recno == 0)
			return (WT_NOTFOUND);
		cbt->recno = cbt->last_standard_recno;
		goto new_page;
	}

	/* Move to the previous entry and return the item. */
	for (;;) {
		if (cbt->recno == cbt->page->u.col_fix.recno)
			return (WT_NOTFOUND);
		--cbt->recno;
new_page:	*recnop = cbt->recno;

		/* Check any insert list for a matching record. */
		if ((ins = cbt->ins = __col_insert_search_match(
		    WT_COL_UPDATE_SINGLE(cbt->page), cbt->recno)) != NULL &&
		    (upd = __wt_txn_read(session, ins->upd)) != NULL) {
			val->data = WT_UPDATE_DATA(upd);
			val->size = 1;
			return (0);
		}

		cbt->v = __bit_getv_recno(cbt->page, cbt->recno, btree->bitcnt);
		val->data = &cbt->v;
		val->size = 1;
		return (0);
	}
	/* NOTREACHED */
}
Пример #4
0
/*
 * __cursor_fix_next --
 *	Move to the next, fixed-length column-store item.
 */
static inline int
__cursor_fix_next(WT_CURSOR_BTREE *cbt, bool newpage)
{
	WT_BTREE *btree;
	WT_PAGE *page;
	WT_SESSION_IMPL *session;
	WT_UPDATE *upd;

	session = (WT_SESSION_IMPL *)cbt->iface.session;
	btree = S2BT(session);
	page = cbt->ref->page;

	/* Initialize for each new page. */
	if (newpage) {
		cbt->last_standard_recno = __col_fix_last_recno(cbt->ref);
		if (cbt->last_standard_recno == 0)
			return (WT_NOTFOUND);
		__cursor_set_recno(cbt, cbt->ref->ref_recno);
		goto new_page;
	}

	/* Move to the next entry and return the item. */
	if (cbt->recno >= cbt->last_standard_recno)
		return (WT_NOTFOUND);
	__cursor_set_recno(cbt, cbt->recno + 1);

new_page:
	/* Check any insert list for a matching record. */
	cbt->ins_head = WT_COL_UPDATE_SINGLE(page);
	cbt->ins = __col_insert_search(
	    cbt->ins_head, cbt->ins_stack, cbt->next_stack, cbt->recno);
	if (cbt->ins != NULL && cbt->recno != WT_INSERT_RECNO(cbt->ins))
		cbt->ins = NULL;
	upd = cbt->ins == NULL ? NULL : __wt_txn_read(session, cbt->ins->upd);
	if (upd == NULL) {
		cbt->v = __bit_getv_recno(cbt->ref, cbt->recno, btree->bitcnt);
		cbt->iface.value.data = &cbt->v;
	} else
		cbt->iface.value.data = upd->data;
	cbt->iface.value.size = 1;
	return (0);
}
Пример #5
0
int __wt_kv_return(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt, WT_UPDATE *upd)
{
	WT_BTREE *btree;
	WT_CELL *cell;
	WT_CELL_UNPACK unpack;
	WT_CURSOR *cursor;
	WT_PAGE *page;
	WT_ROW *rip;
	uint8_t v;

	switch (page->type){
	case WT_PAGE_COL_FIX:
		cursor->recno = cbt->recno;
		/*cursor对应的是一个upd,直接返回value*/
		if (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:
		cursor->recno = cbt->recno;

		if (upd != NULL) {
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}
		/*获得对应的cell,并通过cell得到K/V值*/
		cell = WT_COL_PTR(page, &page->pg_var_d[cbt->slot]);
		break;

	case WT_PAGE_ROW_LEAF:
		rip = &page->pg_row_d[cbt->slot];

		if (cbt->ins != NULL){ /*插入的k/v对*/
			cursor->key.data = WT_INSERT_KEY(cbt->ins);
			cursor->key.size = WT_INSERT_KEY_SIZE(cbt->ins);
		}
		else if (cbt->compare == 0){/*比较器定位到了对应的k/v对*/
			cursor->key.data = cbt->search_key.data;
			cursor->key.size = cbt->search_key.size;
		}
		else
			WT_RET(__wt_row_leaf_key(session, page, rip, &cursor->key, 0)); /*设置key的值*/

		/*值是在append/update list当中,从当中取*/
		if (upd != NULL) {
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}
		/*可以直接通过rip指针获得value,K/V是存储在cell空间之内*/
		if (__wt_row_leaf_value(page, rip, &cursor->value))
			return 0;

		/*不是连续存储的,需要通过解析cell来定位到value*/
		if (cell = __wt_row_leaf_value_cell(page, rip, NULL) == NULL){
			cursor->value.size = 0;
			return 0;
		}
		break;

		WT_ILLEGAL_VALUE(session);
	}
	/*通过cell解析到对应的value值, ovfl item*/
	__wt_cell_unpack(cell, &unpack);
	WT_RET(__wt_page_cell_data_ref(session, page, &unpack, &cursor->value));

	return 0;
}
Пример #6
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_UPDATE *upd)
{
	WT_BTREE *btree;
	WT_CELL *cell;
	WT_CELL_UNPACK unpack;
	WT_CURSOR *cursor;
	WT_ITEM *tmp;
	WT_PAGE *page;
	WT_ROW *rip;
	uint8_t v;

	btree = S2BT(session);

	page = cbt->ref->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_UPDATE item, return it. */
		if (upd != NULL) {
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}

		/* Take the value from the original page. */
		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_UPDATE item, return it. */
		if (upd != NULL) {
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}

		/* Take the value from the original page cell. */
		cell = WT_COL_PTR(page, &page->pg_var_d[cbt->slot]);
		break;
	case WT_PAGE_ROW_LEAF:
		rip = &page->pg_row_d[cbt->slot];

		/*
		 * If the cursor references a WT_INSERT item, take its key.
		 * Else, if we have an exact match, we copied the key in the
		 * search function, take it from there.
		 * If we don't have an exact match, take the key from the
		 * original page.
		 */
		if (cbt->ins != NULL) {
			cursor->key.data = WT_INSERT_KEY(cbt->ins);
			cursor->key.size = WT_INSERT_KEY_SIZE(cbt->ins);
		} else if (cbt->compare == 0) {
			/*
			 * If not in an insert list and there's an exact match,
			 * the row-store search function built the key we want
			 * to return in the cursor's temporary buffer. Swap the
			 * cursor's search-key and temporary buffers so we can
			 * return it (it's unsafe to return the temporary buffer
			 * itself because our caller might do another search in
			 * this table using the key we return, and we'd corrupt
			 * the search key during any subsequent search that used
			 * the temporary buffer.
			 */
			tmp = cbt->row_key;
			cbt->row_key = cbt->tmp;
			cbt->tmp = tmp;

			cursor->key.data = cbt->row_key->data;
			cursor->key.size = cbt->row_key->size;
		} else
			WT_RET(__wt_row_leaf_key(
			    session, page, rip, &cursor->key, false));

		/* If the cursor references a WT_UPDATE item, return it. */
		if (upd != NULL) {
			cursor->value.data = WT_UPDATE_DATA(upd);
			cursor->value.size = upd->size;
			return (0);
		}

		/* Simple values have their location encoded in the WT_ROW. */
		if (__wt_row_leaf_value(page, rip, &cursor->value))
			return (0);

		/*
		 * Take the value from the original page cell (which may be
		 * empty).
		 */
		if ((cell =
		    __wt_row_leaf_value_cell(page, rip, NULL)) == 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);
	WT_RET(__wt_page_cell_data_ref(session, page, &unpack, &cursor->value));

	return (0);
}
Пример #7
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));
}
Пример #8
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);
}