ibool
row_undo_search_clust_to_pcur(
/*==========================*/
/* out: TRUE if found; NOTE the node->pcur
must be closed by the caller, regardless of
the return value */
undo_node_t* node) /* in: row undo node */
{
dict_index_t* clust_index;
ibool found;
mtr_t mtr;
ibool ret;
rec_t* rec;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
*offsets_ = (sizeof offsets_) / sizeof *offsets_;
mtr_start(&mtr);
clust_index = dict_table_get_first_index(node->table);
found = row_search_on_row_ref(&(node->pcur), BTR_MODIFY_LEAF,
node->table, node->ref, &mtr);
rec = btr_pcur_get_rec(&(node->pcur));
offsets = rec_get_offsets(rec, clust_index, offsets,
ULINT_UNDEFINED, &heap);
if (!found || 0 != ut_dulint_cmp(node->roll_ptr,
row_get_rec_roll_ptr(rec, clust_index,
offsets))) {
/* We must remove the reservation on the undo log record
BEFORE releasing the latch on the clustered index page: this
is to make sure that some thread will eventually undo the
modification corresponding to node->roll_ptr. */
/* fputs("--------------------undoing a previous version\n",
stderr); */
ret = FALSE;
} else {
node->row = row_build(ROW_COPY_DATA, clust_index, rec,
offsets, node->heap);
btr_pcur_store_position(&(node->pcur), &mtr);
ret = TRUE;
}
btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(ret);
}
ibool
row_undo_search_clust_to_pcur(
/*==========================*/
/* out: TRUE if found; NOTE the node->pcur
must be closed by the caller, regardless of
the return value */
undo_node_t* node, /* in: row undo node */
que_thr_t* thr) /* in: query thread */
{
dict_index_t* clust_index;
ibool found;
mtr_t mtr;
ibool ret;
rec_t* rec;
UT_NOT_USED(thr);
mtr_start(&mtr);
clust_index = dict_table_get_first_index(node->table);
found = row_search_on_row_ref(&(node->pcur), BTR_MODIFY_LEAF,
node->table, node->ref, &mtr);
rec = btr_pcur_get_rec(&(node->pcur));
if (!found || 0 != ut_dulint_cmp(node->roll_ptr,
row_get_rec_roll_ptr(rec, clust_index))) {
/* We must remove the reservation on the undo log record
BEFORE releasing the latch on the clustered index page: this
is to make sure that some thread will eventually undo the
modification corresponding to node->roll_ptr. */
/* printf("--------------------undoing a previous version\n");
*/
ret = FALSE;
} else {
node->row = row_build(ROW_COPY_DATA, clust_index, rec,
node->heap);
btr_pcur_store_position(&(node->pcur), &mtr);
ret = TRUE;
}
btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);
return(ret);
}
/***********************************************************//**
Determines if it is possible to remove a secondary index entry.
Removal is possible if the secondary index entry does not refer to any
not delete marked version of a clustered index record where DB_TRX_ID
is newer than the purge view.
NOTE: This function should only be called by the purge thread, only
while holding a latch on the leaf page of the secondary index entry
(or keeping the buffer pool watch on the page). It is possible that
this function first returns TRUE and then FALSE, if a user transaction
inserts a record that the secondary index entry would refer to.
However, in that case, the user transaction would also re-insert the
secondary index entry after purge has removed it and released the leaf
page latch.
@return TRUE if the secondary index record can be purged */
UNIV_INTERN
ibool
row_purge_poss_sec(
/*===============*/
purge_node_t* node, /*!< in/out: row purge node */
dict_index_t* index, /*!< in: secondary index */
const dtuple_t* entry) /*!< in: secondary index entry */
{
ibool can_delete;
mtr_t mtr;
ut_ad(!dict_index_is_clust(index));
mtr_start(&mtr);
can_delete = !row_purge_reposition_pcur(BTR_SEARCH_LEAF, node, &mtr)
|| !row_vers_old_has_index_entry(TRUE,
btr_pcur_get_rec(&node->pcur),
&mtr, index, entry);
btr_pcur_commit_specify_mtr(&node->pcur, &mtr);
return(can_delete);
}
/*******************************************************************
Removes a clustered index record. The pcur in node was positioned on the
record, now it is detached. */
static
ulint
row_undo_ins_remove_clust_rec(
/*==========================*/
/* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
undo_node_t* node, /* in: undo node */
que_thr_t* thr) /* in: query thread */
{
btr_cur_t* btr_cur;
ibool success;
ulint err;
ulint n_tries = 0;
mtr_t mtr;
UT_NOT_USED(thr);
mtr_start(&mtr);
success = btr_pcur_restore_position(BTR_MODIFY_LEAF, &(node->pcur),
&mtr);
ut_a(success);
if (ut_dulint_cmp(node->table->id, DICT_INDEXES_ID) == 0) {
/* Drop the index tree associated with the row in
SYS_INDEXES table: */
dict_drop_index_tree(btr_pcur_get_rec(&(node->pcur)), &mtr);
mtr_commit(&mtr);
mtr_start(&mtr);
success = btr_pcur_restore_position(BTR_MODIFY_LEAF,
&(node->pcur), &mtr);
ut_a(success);
}
btr_cur = btr_pcur_get_btr_cur(&(node->pcur));
success = btr_cur_optimistic_delete(btr_cur, &mtr);
btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);
if (success) {
trx_undo_rec_release(node->trx, node->undo_no);
return(DB_SUCCESS);
}
retry:
/* If did not succeed, try pessimistic descent to tree */
mtr_start(&mtr);
success = btr_pcur_restore_position(BTR_MODIFY_TREE,
&(node->pcur), &mtr);
ut_a(success);
btr_cur_pessimistic_delete(&err, FALSE, btr_cur, TRUE, &mtr);
/* The delete operation may fail if we have little
file space left: TODO: easiest to crash the database
and restart with more file space */
if (err == DB_OUT_OF_FILE_SPACE
&& n_tries < BTR_CUR_RETRY_DELETE_N_TIMES) {
btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);
n_tries++;
os_thread_sleep(BTR_CUR_RETRY_SLEEP_TIME);
goto retry;
}
btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);
trx_undo_rec_release(node->trx, node->undo_no);
return(err);
}
/***********************************************************//**
Looks for the clustered index record when node has the row reference.
The pcur in node is used in the search. If found, stores the row to node,
and stores the position of pcur, and detaches it. The pcur must be closed
by the caller in any case.
@return TRUE if found; NOTE the node->pcur must be closed by the
caller, regardless of the return value */
UNIV_INTERN
ibool
row_undo_search_clust_to_pcur(
/*==========================*/
undo_node_t* node) /*!< in: row undo node */
{
dict_index_t* clust_index;
ibool found;
mtr_t mtr;
ibool ret;
rec_t* rec;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
mtr_start(&mtr);
clust_index = dict_table_get_first_index(node->table);
found = row_search_on_row_ref(&(node->pcur), BTR_MODIFY_LEAF,
node->table, node->ref, &mtr);
rec = btr_pcur_get_rec(&(node->pcur));
offsets = rec_get_offsets(rec, clust_index, offsets,
ULINT_UNDEFINED, &heap);
if (!found || 0 != ut_dulint_cmp(node->roll_ptr,
row_get_rec_roll_ptr(rec, clust_index,
offsets))) {
/* We must remove the reservation on the undo log record
BEFORE releasing the latch on the clustered index page: this
is to make sure that some thread will eventually undo the
modification corresponding to node->roll_ptr. */
/* fputs("--------------------undoing a previous version\n",
stderr); */
ret = FALSE;
} else {
row_ext_t** ext;
if (dict_table_get_format(node->table) >= DICT_TF_FORMAT_ZIP) {
/* In DYNAMIC or COMPRESSED format, there is
no prefix of externally stored columns in the
clustered index record. Build a cache of
column prefixes. */
ext = &node->ext;
} else {
/* REDUNDANT and COMPACT formats store a local
768-byte prefix of each externally stored
column. No cache is needed. */
ext = NULL;
node->ext = NULL;
}
node->row = row_build(ROW_COPY_DATA, clust_index, rec,
offsets, NULL, ext, node->heap);
if (node->update) {
node->undo_row = dtuple_copy(node->row, node->heap);
row_upd_replace(node->undo_row, &node->undo_ext,
clust_index, node->update, node->heap);
} else {
node->undo_row = NULL;
node->undo_ext = NULL;
}
btr_pcur_store_position(&(node->pcur), &mtr);
ret = TRUE;
}
btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(ret);
}
/***********************************************************//**
Removes a delete marked clustered index record if possible.
@return TRUE if success, or if not found, or if modified after the
delete marking */
static
ibool
row_purge_remove_clust_if_poss_low(
/*===============================*/
purge_node_t* node, /*!< in: row purge node */
ulint mode) /*!< in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
dict_index_t* index;
btr_pcur_t* pcur;
btr_cur_t* btr_cur;
ibool success;
ulint err;
mtr_t mtr;
rec_t* rec;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
rec_offs_init(offsets_);
index = dict_table_get_first_index(node->table);
pcur = &(node->pcur);
btr_cur = btr_pcur_get_btr_cur(pcur);
log_free_check();
mtr_start(&mtr);
success = row_purge_reposition_pcur(mode, node, &mtr);
if (!success) {
/* The record is already removed */
btr_pcur_commit_specify_mtr(pcur, &mtr);
return(TRUE);
}
rec = btr_pcur_get_rec(pcur);
if (node->roll_ptr != row_get_rec_roll_ptr(
rec, index, rec_get_offsets(rec, index, offsets_,
ULINT_UNDEFINED, &heap))) {
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
/* Someone else has modified the record later: do not remove */
btr_pcur_commit_specify_mtr(pcur, &mtr);
return(TRUE);
}
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
if (mode == BTR_MODIFY_LEAF) {
success = btr_cur_optimistic_delete(btr_cur, &mtr);
} else {
ut_ad(mode == BTR_MODIFY_TREE);
btr_cur_pessimistic_delete(&err, FALSE, btr_cur,
RB_NONE, &mtr);
if (err == DB_SUCCESS) {
success = TRUE;
} else if (err == DB_OUT_OF_FILE_SPACE) {
success = FALSE;
} else {
ut_error;
}
}
btr_pcur_commit_specify_mtr(pcur, &mtr);
return(success);
}
/***************************************************************
Removes a delete marked clustered index record if possible. */
static
ibool
row_purge_remove_clust_if_poss_low(
/*===============================*/
/* out: TRUE if success, or if not found, or
if modified after the delete marking */
purge_node_t* node, /* in: row purge node */
que_thr_t* thr, /* in: query thread */
ulint mode) /* in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
dict_index_t* index;
btr_pcur_t* pcur;
btr_cur_t* btr_cur;
ibool success;
ulint err;
mtr_t mtr;
UT_NOT_USED(thr);
index = dict_table_get_first_index(node->table);
pcur = &(node->pcur);
btr_cur = btr_pcur_get_btr_cur(pcur);
mtr_start(&mtr);
success = row_purge_reposition_pcur(mode, node, &mtr);
if (!success) {
/* The record is already removed */
btr_pcur_commit_specify_mtr(pcur, &mtr);
return(TRUE);
}
if (0 != ut_dulint_cmp(node->roll_ptr,
row_get_rec_roll_ptr(btr_pcur_get_rec(pcur), index))) {
/* Someone else has modified the record later: do not remove */
btr_pcur_commit_specify_mtr(pcur, &mtr);
return(TRUE);
}
if (mode == BTR_MODIFY_LEAF) {
success = btr_cur_optimistic_delete(btr_cur, &mtr);
} else {
ut_ad(mode == BTR_MODIFY_TREE);
btr_cur_pessimistic_delete(&err, FALSE, btr_cur, FALSE, &mtr);
if (err == DB_SUCCESS) {
success = TRUE;
} else if (err == DB_OUT_OF_FILE_SPACE) {
success = FALSE;
} else {
ut_a(0);
}
}
btr_pcur_commit_specify_mtr(pcur, &mtr);
return(success);
}
/***************************************************************
Removes a secondary index entry if possible. */
static
ibool
row_purge_remove_sec_if_poss_low(
/*=============================*/
/* out: TRUE if success or if not found */
purge_node_t* node, /* in: row purge node */
que_thr_t* thr, /* in: query thread */
dict_index_t* index, /* in: index */
dtuple_t* entry, /* in: index entry */
ulint mode) /* in: latch mode BTR_MODIFY_LEAF or
BTR_MODIFY_TREE */
{
btr_pcur_t pcur;
btr_cur_t* btr_cur;
ibool success;
ibool old_has;
ibool found;
ulint err;
mtr_t mtr;
mtr_t* mtr_vers;
UT_NOT_USED(thr);
log_free_check();
mtr_start(&mtr);
found = row_search_index_entry(index, entry, mode, &pcur, &mtr);
if (!found) {
/* Not found */
/* printf("PURGE:........sec entry not found\n"); */
/* dtuple_print(entry); */
btr_pcur_close(&pcur);
mtr_commit(&mtr);
return(TRUE);
}
btr_cur = btr_pcur_get_btr_cur(&pcur);
/* We should remove the index record if no later version of the row,
which cannot be purged yet, requires its existence. If some requires,
we should do nothing. */
mtr_vers = mem_alloc(sizeof(mtr_t));
mtr_start(mtr_vers);
success = row_purge_reposition_pcur(BTR_SEARCH_LEAF, node, mtr_vers);
if (success) {
old_has = row_vers_old_has_index_entry(TRUE,
btr_pcur_get_rec(&(node->pcur)),
mtr_vers, index, entry);
}
btr_pcur_commit_specify_mtr(&(node->pcur), mtr_vers);
mem_free(mtr_vers);
if (!success || !old_has) {
/* Remove the index record */
if (mode == BTR_MODIFY_LEAF) {
success = btr_cur_optimistic_delete(btr_cur, &mtr);
} else {
ut_ad(mode == BTR_MODIFY_TREE);
btr_cur_pessimistic_delete(&err, FALSE, btr_cur,
FALSE, &mtr);
if (err == DB_SUCCESS) {
success = TRUE;
} else if (err == DB_OUT_OF_FILE_SPACE) {
success = FALSE;
} else {
ut_a(0);
}
}
}
btr_pcur_close(&pcur);
mtr_commit(&mtr);
return(success);
}
/***********************************************************//**
Delete marks or removes a secondary index entry if found.
@return DB_SUCCESS, DB_FAIL, or DB_OUT_OF_FILE_SPACE */
static
ulint
row_undo_mod_del_mark_or_remove_sec_low(
/*====================================*/
undo_node_t* node, /*!< in: row undo node */
que_thr_t* thr, /*!< in: query thread */
dict_index_t* index, /*!< in: index */
dtuple_t* entry, /*!< in: index entry */
ulint mode) /*!< in: latch mode BTR_MODIFY_LEAF or
BTR_MODIFY_TREE */
{
btr_pcur_t pcur;
btr_cur_t* btr_cur;
ibool success;
ibool old_has;
ulint err;
mtr_t mtr;
mtr_t mtr_vers;
enum row_search_result search_result;
log_free_check();
mtr_start(&mtr);
btr_cur = btr_pcur_get_btr_cur(&pcur);
ut_ad(mode == BTR_MODIFY_TREE || mode == BTR_MODIFY_LEAF);
search_result = row_search_index_entry(index, entry, mode,
&pcur, &mtr);
switch (UNIV_EXPECT(search_result, ROW_FOUND)) {
case ROW_NOT_FOUND:
/* In crash recovery, the secondary index record may
be missing if the UPDATE did not have time to insert
the secondary index records before the crash. When we
are undoing that UPDATE in crash recovery, the record
may be missing.
In normal processing, if an update ends in a deadlock
before it has inserted all updated secondary index
records, then the undo will not find those records. */
err = DB_SUCCESS;
goto func_exit;
case ROW_FOUND:
break;
case ROW_BUFFERED:
case ROW_NOT_DELETED_REF:
/* These are invalid outcomes, because the mode passed
to row_search_index_entry() did not include any of the
flags BTR_INSERT, BTR_DELETE, or BTR_DELETE_MARK. */
ut_error;
}
/* We should remove the index record if no prior version of the row,
which cannot be purged yet, requires its existence. If some requires,
we should delete mark the record. */
mtr_start(&mtr_vers);
success = btr_pcur_restore_position(BTR_SEARCH_LEAF, &(node->pcur),
&mtr_vers);
ut_a(success);
old_has = row_vers_old_has_index_entry(FALSE,
btr_pcur_get_rec(&(node->pcur)),
&mtr_vers, index, entry);
if (old_has) {
err = btr_cur_del_mark_set_sec_rec(BTR_NO_LOCKING_FLAG,
btr_cur, TRUE, thr, &mtr);
ut_ad(err == DB_SUCCESS);
} else {
/* Remove the index record */
if (mode == BTR_MODIFY_LEAF) {
success = btr_cur_optimistic_delete(btr_cur, &mtr);
if (success) {
err = DB_SUCCESS;
} else {
err = DB_FAIL;
}
} else {
ut_ad(mode == BTR_MODIFY_TREE);
/* No need to distinguish RB_RECOVERY_PURGE here,
because we are deleting a secondary index record:
the distinction between RB_NORMAL and
RB_RECOVERY_PURGE only matters when deleting a
record that contains externally stored
columns. */
ut_ad(!dict_index_is_clust(index));
btr_cur_pessimistic_delete(&err, FALSE, btr_cur,
RB_NORMAL, &mtr);
/* The delete operation may fail if we have little
file space left: TODO: easiest to crash the database
and restart with more file space */
}
}
btr_pcur_commit_specify_mtr(&(node->pcur), &mtr_vers);
func_exit:
btr_pcur_close(&pcur);
mtr_commit(&mtr);
return(err);
}
/***********************************************************//**
Undoes a modify in a clustered index record. Sets also the node state for the
next round of undo.
@return DB_SUCCESS or error code: we may run out of file space */
static
ulint
row_undo_mod_clust(
/*===============*/
undo_node_t* node, /*!< in: row undo node */
que_thr_t* thr) /*!< in: query thread */
{
btr_pcur_t* pcur;
mtr_t mtr;
ulint err;
ibool success;
ibool more_vers;
undo_no_t new_undo_no;
ut_ad(node && thr);
log_free_check();
/* Check if also the previous version of the clustered index record
should be undone in this same rollback operation */
more_vers = row_undo_mod_undo_also_prev_vers(node, &new_undo_no);
pcur = &(node->pcur);
mtr_start(&mtr);
/* Try optimistic processing of the record, keeping changes within
the index page */
err = row_undo_mod_clust_low(node, thr, &mtr, BTR_MODIFY_LEAF);
if (err != DB_SUCCESS) {
btr_pcur_commit_specify_mtr(pcur, &mtr);
/* We may have to modify tree structure: do a pessimistic
descent down the index tree */
mtr_start(&mtr);
err = row_undo_mod_clust_low(node, thr, &mtr, BTR_MODIFY_TREE);
}
btr_pcur_commit_specify_mtr(pcur, &mtr);
if (err == DB_SUCCESS && node->rec_type == TRX_UNDO_UPD_DEL_REC) {
mtr_start(&mtr);
err = row_undo_mod_remove_clust_low(node, thr, &mtr,
BTR_MODIFY_LEAF);
if (err != DB_SUCCESS) {
btr_pcur_commit_specify_mtr(pcur, &mtr);
/* We may have to modify tree structure: do a
pessimistic descent down the index tree */
mtr_start(&mtr);
err = row_undo_mod_remove_clust_low(node, thr, &mtr,
BTR_MODIFY_TREE);
}
btr_pcur_commit_specify_mtr(pcur, &mtr);
}
node->state = UNDO_NODE_FETCH_NEXT;
trx_undo_rec_release(node->trx, node->undo_no);
if (more_vers && err == DB_SUCCESS) {
/* Reserve the undo log record to the prior version after
committing &mtr: this is necessary to comply with the latching
order, as &mtr may contain the fsp latch which is lower in
the latch hierarchy than trx->undo_mutex. */
success = trx_undo_rec_reserve(node->trx, new_undo_no);
if (success) {
node->state = UNDO_NODE_PREV_VERS;
}
}
return(err);
}
