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/*-
* Copyright (c) 2014-2016 MongoDB, Inc.
* Copyright (c) 2008-2014 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
#include "wt_internal.h"
/*
* __key_return --
* Change the cursor to reference an internal return key.
*/
static inline int
__key_return(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt)
{
WT_CURSOR *cursor;
WT_ITEM *tmp;
WT_PAGE *page;
WT_ROW *rip;
page = cbt->ref->page;
cursor = &cbt->iface;
if (page->type == WT_PAGE_ROW_LEAF) {
rip = &page->pg_row[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);
return (0);
}
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;
return (0);
}
return (__wt_row_leaf_key(
session, page, rip, &cursor->key, false));
}
/*
* WT_PAGE_COL_FIX, 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;
return (0);
}
/*
* __value_return --
* Change the cursor to reference an internal return value.
*/
static inline int
__value_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;
btree = S2BT(session);
page = cbt->ref->page;
cursor = &cbt->iface;
/* 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);
}
if (page->type == WT_PAGE_ROW_LEAF) {
rip = &page->pg_row[cbt->slot];
/* 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);
}
__wt_cell_unpack(cell, &unpack);
return (__wt_page_cell_data_ref(
session, page, &unpack, &cursor->value));
}
if (page->type == WT_PAGE_COL_VAR) {
/* Take the value from the original page cell. */
cell = WT_COL_PTR(page, &page->pg_var[cbt->slot]);
__wt_cell_unpack(cell, &unpack);
return (__wt_page_cell_data_ref(
session, page, &unpack, &cursor->value));
}
/* WT_PAGE_COL_FIX: Take the value from the original page. */
v = __bit_getv_recno(cbt->ref, cursor->recno, btree->bitcnt);
return (__wt_buf_set(session, &cursor->value, &v, 1));
}
/*
* __wt_key_return --
* Change the cursor to reference an internal return key.
*/
int
__wt_key_return(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt)
{
WT_CURSOR *cursor;
cursor = &cbt->iface;
/*
* We may already have an internal key, in which case the cursor may
* not be set up to get another copy (for example, when we rely on a
* search-function result).
*/
F_CLR(cursor, WT_CURSTD_KEY_EXT);
if (!F_ISSET(cursor, WT_CURSTD_KEY_INT)) {
WT_RET(__key_return(session, cbt));
F_SET(cursor, WT_CURSTD_KEY_INT);
}
return (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_CURSOR *cursor;
cursor = &cbt->iface;
WT_RET(__wt_key_return(session, cbt));
F_CLR(cursor, WT_CURSTD_VALUE_EXT);
WT_RET(__value_return(session, cbt, upd));
F_SET(cursor, WT_CURSTD_VALUE_INT);
return (0);
}
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