/*
* __cursor_var_prev --
* Move to the previous, variable-length column-store item.
*/
static inline int
__cursor_var_prev(WT_CURSOR_BTREE *cbt, int newpage)
{
WT_CELL *cell;
WT_CELL_UNPACK unpack;
WT_COL *cip;
WT_INSERT *ins;
WT_ITEM *val;
WT_SESSION_IMPL *session;
WT_UPDATE *upd;
uint64_t *recnop;
session = (WT_SESSION_IMPL *)cbt->iface.session;
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 (;;) {
--cbt->recno;
new_page: *recnop = cbt->recno;
if (cbt->recno < cbt->page->u.col_var.recno)
return (WT_NOTFOUND);
/* Find the matching WT_COL slot. */
if ((cip = __col_var_search(cbt->page, cbt->recno)) == NULL)
return (WT_NOTFOUND);
/* Check any insert list for a matching record. */
if ((ins = __col_insert_search_match(
WT_COL_UPDATE(cbt->page, cip), cbt->recno)) != NULL &&
(upd = __wt_txn_read(session, ins->upd)) != NULL) {
if (WT_UPDATE_DELETED_ISSET(upd))
continue;
cbt->ins = ins;
val->data = WT_UPDATE_DATA(upd);
val->size = upd->size;
return (0);
}
/*
* If we're at the same slot as the last reference and there's
* no matching insert list item, re-use the return information
* (so encoded items with large repeat counts aren't repeatedly
* decoded). Otherwise, unpack the cell and build the return
* information.
*/
if (cbt->cip_saved != cip) {
if ((cell = WT_COL_PTR(cbt->page, cip)) == NULL)
continue;
__wt_cell_unpack(cell, &unpack);
switch (unpack.type) {
case WT_CELL_DEL:
continue;
case WT_CELL_VALUE:
if (session->btree->huffman_value == NULL) {
cbt->tmp.data = unpack.data;
cbt->tmp.size = unpack.size;
break;
}
/* FALLTHROUGH */
default:
WT_RET(__wt_cell_unpack_copy(
session, &unpack, &cbt->tmp));
}
cbt->cip_saved = cip;
}
val->data = cbt->tmp.data;
val->size = cbt->tmp.size;
return (0);
}
/* NOTREACHED */
}
/*
* __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));
}
