/*
* __txn_op_log_row_key_check --
* Confirm the cursor references the correct key.
*/
static void
__txn_op_log_row_key_check(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt)
{
WT_CURSOR *cursor;
WT_ITEM key;
WT_PAGE *page;
WT_ROW *rip;
cursor = &cbt->iface;
WT_ASSERT(session, F_ISSET(cursor, WT_CURSTD_KEY_SET));
memset(&key, 0, sizeof(key));
/*
* We used to take the row-store logging key from the page referenced by
* the cursor, then switched to taking it from the cursor itself. Check
* they are the same.
*
* If the cursor references a WT_INSERT item, take the key from there,
* else take the key from the original page.
*/
if (cbt->ins == NULL) {
session = (WT_SESSION_IMPL *)cbt->iface.session;
page = cbt->ref->page;
rip = &page->pg_row[cbt->slot];
WT_ASSERT(session,
__wt_row_leaf_key(session, page, rip, &key, false) == 0);
} else {
key.data = WT_INSERT_KEY(cbt->ins);
key.size = WT_INSERT_KEY_SIZE(cbt->ins);
}
WT_ASSERT(session, key.size == cursor->key.size &&
memcmp(key.data, cursor->key.data, key.size) == 0);
__wt_buf_free(session, &key);
}
/*
* __wt_row_insert_alloc --
* Row-store insert: allocate a WT_INSERT structure and fill it in.
*/
int
__wt_row_insert_alloc(WT_SESSION_IMPL *session,
WT_ITEM *key, u_int skipdepth, WT_INSERT **insp, size_t *ins_sizep)
{
WT_INSERT *ins;
size_t ins_size;
/*
* Allocate the WT_INSERT structure, next pointers for the skip list,
* and room for the key. Then copy the key into place.
*/
ins_size = sizeof(WT_INSERT) +
skipdepth * sizeof(WT_INSERT *) + key->size;
WT_RET(__wt_calloc(session, 1, ins_size, &ins));
ins->u.key.offset = WT_STORE_SIZE(ins_size - key->size);
WT_INSERT_KEY_SIZE(ins) = key->size;
memcpy(WT_INSERT_KEY(ins), key->data, key->size);
*insp = ins;
if (ins_sizep != NULL)
*ins_sizep = ins_size;
return (0);
}
/*
* __cursor_row_prev --
* Move to the previous row-store item.
*/
static inline int
__cursor_row_prev(WT_CURSOR_BTREE *cbt, bool newpage)
{
WT_INSERT *ins;
WT_ITEM *key, *val;
WT_PAGE *page;
WT_ROW *rip;
WT_SESSION_IMPL *session;
WT_UPDATE *upd;
session = (WT_SESSION_IMPL *)cbt->iface.session;
page = cbt->ref->page;
key = &cbt->iface.key;
val = &cbt->iface.value;
/*
* For row-store pages, we need a single item that tells us the part
* of the page we're walking (otherwise switching from next to prev
* and vice-versa is just too complicated), so we map the WT_ROW and
* WT_INSERT_HEAD insert array slots into a single name space: slot 1
* is the "smallest key insert list", slot 2 is WT_ROW[0], slot 3 is
* WT_INSERT_HEAD[0], and so on. This means WT_INSERT lists are
* odd-numbered slots, and WT_ROW array slots are even-numbered slots.
*
* New page configuration.
*/
if (newpage) {
/*
* If we haven't instantiated keys on this page, do so, else it
* is a very, very slow traversal.
*/
if (!F_ISSET_ATOMIC(page, WT_PAGE_BUILD_KEYS))
WT_RET(__wt_row_leaf_keys(session, page));
if (page->pg_row_entries == 0)
cbt->ins_head = WT_ROW_INSERT_SMALLEST(page);
else
cbt->ins_head =
WT_ROW_INSERT_SLOT(page, page->pg_row_entries - 1);
cbt->ins = WT_SKIP_LAST(cbt->ins_head);
cbt->row_iteration_slot = page->pg_row_entries * 2 + 1;
goto new_insert;
}
/* Move to the previous entry and return the item. */
for (;;) {
/*
* Continue traversing any insert list. Maintain the reference
* to the current insert element in case we switch to a cursor
* next movement.
*/
if (cbt->ins != NULL)
WT_RET(__cursor_skip_prev(cbt));
new_insert: if ((ins = cbt->ins) != NULL) {
if ((upd = __wt_txn_read(session, ins->upd)) == NULL)
continue;
if (WT_UPDATE_DELETED_ISSET(upd)) {
if (__wt_txn_visible_all(session, upd->txnid))
++cbt->page_deleted_count;
continue;
}
key->data = WT_INSERT_KEY(ins);
key->size = WT_INSERT_KEY_SIZE(ins);
val->data = WT_UPDATE_DATA(upd);
val->size = upd->size;
return (0);
}
/* Check for the beginning of the page. */
if (cbt->row_iteration_slot == 1)
return (WT_NOTFOUND);
--cbt->row_iteration_slot;
/*
* Odd-numbered slots configure as WT_INSERT_HEAD entries,
* even-numbered slots configure as WT_ROW entries.
*/
if (cbt->row_iteration_slot & 0x01) {
cbt->ins_head = cbt->row_iteration_slot == 1 ?
WT_ROW_INSERT_SMALLEST(page) :
WT_ROW_INSERT_SLOT(
page, cbt->row_iteration_slot / 2 - 1);
cbt->ins = WT_SKIP_LAST(cbt->ins_head);
goto new_insert;
}
cbt->ins_head = NULL;
cbt->ins = NULL;
cbt->slot = cbt->row_iteration_slot / 2 - 1;
rip = &page->pg_row_d[cbt->slot];
upd = __wt_txn_read(session, WT_ROW_UPDATE(page, rip));
if (upd != NULL && WT_UPDATE_DELETED_ISSET(upd)) {
if (__wt_txn_visible_all(session, upd->txnid))
++cbt->page_deleted_count;
continue;
}
return (__cursor_row_slot_return(cbt, rip, upd));
}
/* NOTREACHED */
}
/*
* __cursor_skip_prev --
* Move back one position in a skip list stack (aka "finger").
*/
static inline int
__cursor_skip_prev(WT_CURSOR_BTREE *cbt)
{
WT_INSERT *current, *ins;
WT_ITEM key;
WT_SESSION_IMPL *session;
int i;
session = (WT_SESSION_IMPL *)cbt->iface.session;
restart:
/*
* If the search stack does not point at the current item, fill it in
* with a search.
*/
while ((current = cbt->ins) != PREV_INS(cbt, 0)) {
if (cbt->btree->type == BTREE_ROW) {
key.data = WT_INSERT_KEY(current);
key.size = WT_INSERT_KEY_SIZE(current);
WT_RET(__wt_search_insert(session, cbt, &key));
} else
cbt->ins = __col_insert_search(cbt->ins_head,
cbt->ins_stack, cbt->next_stack,
WT_INSERT_RECNO(current));
}
/*
* Find the first node up the search stack that does not move.
*
* The depth of the current item must be at least this level, since we
* see it in that many levels of the stack.
*
* !!! Watch these loops carefully: they all rely on the value of i,
* and the exit conditions to end up with the right values are
* non-trivial.
*/
ins = NULL; /* -Wconditional-uninitialized */
for (i = 0; i < WT_SKIP_MAXDEPTH - 1; i++)
if ((ins = PREV_INS(cbt, i + 1)) != current)
break;
/*
* Find a starting point for the new search. That is either at the
* non-moving node if we found a valid node, or the beginning of the
* next list down that is not the current node.
*
* Since it is the beginning of a list, and we know the current node is
* has a skip depth at least this high, any node we find must sort
* before the current node.
*/
if (ins == NULL || ins == current)
for (; i >= 0; i--) {
cbt->ins_stack[i] = NULL;
cbt->next_stack[i] = NULL;
ins = cbt->ins_head->head[i];
if (ins != NULL && ins != current)
break;
}
/* Walk any remaining levels until just before the current node. */
while (i >= 0) {
/*
* If we get to the end of a list without finding the current
* item, we must have raced with an insert. Restart the search.
*/
if (ins == NULL) {
cbt->ins_stack[0] = NULL;
cbt->next_stack[0] = NULL;
goto restart;
}
if (ins->next[i] != current) /* Stay at this level */
ins = ins->next[i];
else { /* Drop down a level */
cbt->ins_stack[i] = &ins->next[i];
cbt->next_stack[i] = ins->next[i];
--i;
}
}
/* If we found a previous node, the next one must be current. */
if (cbt->ins_stack[0] != NULL && *cbt->ins_stack[0] != current)
goto restart;
cbt->ins = PREV_INS(cbt, 0);
return (0);
}
/*
* __cursor_row_next --
* Move to the next row-store item.
*/
static inline int
__cursor_row_next(WT_CURSOR_BTREE *cbt, bool newpage)
{
WT_INSERT *ins;
WT_ITEM *key;
WT_PAGE *page;
WT_ROW *rip;
WT_SESSION_IMPL *session;
WT_UPDATE *upd;
session = (WT_SESSION_IMPL *)cbt->iface.session;
page = cbt->ref->page;
key = &cbt->iface.key;
/*
* For row-store pages, we need a single item that tells us the part
* of the page we're walking (otherwise switching from next to prev
* and vice-versa is just too complicated), so we map the WT_ROW and
* WT_INSERT_HEAD insert array slots into a single name space: slot 1
* is the "smallest key insert list", slot 2 is WT_ROW[0], slot 3 is
* WT_INSERT_HEAD[0], and so on. This means WT_INSERT lists are
* odd-numbered slots, and WT_ROW array slots are even-numbered slots.
*
* Initialize for each new page.
*/
if (newpage) {
cbt->ins_head = WT_ROW_INSERT_SMALLEST(page);
cbt->ins = WT_SKIP_FIRST(cbt->ins_head);
cbt->row_iteration_slot = 1;
cbt->rip_saved = NULL;
goto new_insert;
}
/* Move to the next entry and return the item. */
for (;;) {
/*
* Continue traversing any insert list; maintain the insert list
* head reference and entry count in case we switch to a cursor
* previous movement.
*/
if (cbt->ins != NULL)
cbt->ins = WT_SKIP_NEXT(cbt->ins);
new_insert: if ((ins = cbt->ins) != NULL) {
if ((upd = __wt_txn_read(session, ins->upd)) == NULL)
continue;
if (upd->type == WT_UPDATE_DELETED) {
if (__wt_txn_upd_visible_all(session, upd))
++cbt->page_deleted_count;
continue;
}
key->data = WT_INSERT_KEY(ins);
key->size = WT_INSERT_KEY_SIZE(ins);
return (__wt_value_return(session, cbt, upd));
}
/* Check for the end of the page. */
if (cbt->row_iteration_slot >= page->entries * 2 + 1)
return (WT_NOTFOUND);
++cbt->row_iteration_slot;
/*
* Odd-numbered slots configure as WT_INSERT_HEAD entries,
* even-numbered slots configure as WT_ROW entries.
*/
if (cbt->row_iteration_slot & 0x01) {
cbt->ins_head = WT_ROW_INSERT_SLOT(
page, cbt->row_iteration_slot / 2 - 1);
cbt->ins = WT_SKIP_FIRST(cbt->ins_head);
goto new_insert;
}
cbt->ins_head = NULL;
cbt->ins = NULL;
cbt->slot = cbt->row_iteration_slot / 2 - 1;
rip = &page->pg_row[cbt->slot];
upd = __wt_txn_read(session, WT_ROW_UPDATE(page, rip));
if (upd != NULL && upd->type == WT_UPDATE_DELETED) {
if (__wt_txn_upd_visible_all(session, upd))
++cbt->page_deleted_count;
continue;
}
return (__cursor_row_slot_return(cbt, rip, upd));
}
/* NOTREACHED */
}
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;
}
/*移向行存储的下一个行对象*/
static inline int __cursor_row_next(WT_CURSOR_BTREE* cbt, int newpage)
{
WT_INSERT *ins;
WT_ITEM *key, *val;
WT_PAGE *page;
WT_ROW *rip;
WT_SESSION_IMPL *session;
WT_UPDATE *upd;
session = (WT_SESSION_IMPL *)cbt->iface.session;
page = cbt->ref->page;
key = &cbt->iface.key;
val = &cbt->iface.value;
/*假如是newpage，定位到insert修改队列的头位置*/
if (newpage){
cbt->ins_head = WT_ROW_INSERT_SMALLEST(page);
cbt->ins = WT_SKIP_FIRST(cbt->ins_head);
cbt->row_iteration_slot = 1;
goto new_insert;
}
for (;;){
if (cbt->ins != NULL)
cbt->ins = WT_SKIP_NEXT(cbt->ins);
new_insert:
if ((ins = cbt->ins) != NULL) {
/*事务可见数据读取*/
if ((upd = __wt_txn_read(session, ins->upd)) == NULL)
continue;
/*判断是否删除，如果删除，跳过被删除的对象*/
if (WT_UPDATE_DELETED_ISSET(upd)) {
++cbt->page_deleted_count;
continue;
}
key->data = WT_INSERT_KEY(ins);
key->size = WT_INSERT_KEY_SIZE(ins);
val->data = WT_UPDATE_DATA(upd);
val->size = upd->size;
return 0;
}
/*检索page row entires数组， 到了page的末尾*/
if (cbt->row_iteration_slot >= page->pg_row_entries * 2 + 1)
return (WT_NOTFOUND);
++cbt->row_iteration_slot;
/*
* Odd-numbered slots configure as WT_INSERT_HEAD entries,
* even-numbered slots configure as WT_ROW entries.
*/
if (cbt->row_iteration_slot & 0x01) {
cbt->ins_head = WT_ROW_INSERT_SLOT(page, cbt->row_iteration_slot / 2 - 1);
cbt->ins = WT_SKIP_FIRST(cbt->ins_head);
goto new_insert;
}
cbt->ins_head = NULL;
cbt->ins = NULL;
/*计算定位slot*/
cbt->slot = cbt->row_iteration_slot / 2 - 1;
rip = &page->pg_row_d[cbt->slot];
upd = __wt_txn_read(session, WT_ROW_UPDATE(page, rip));
if (upd != NULL && WT_UPDATE_DELETED_ISSET(upd)) {
++cbt->page_deleted_count;
continue;
}
return __cursor_row_slot_return(cbt, rip, upd);
}
}
/*
* __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);
}
/*
* __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));
}
/*
* __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);
}
