/* * __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)); }