/**********************************************************************//**
Gets a pointer to the dictionary header and x-latches its page.
@return pointer to the dictionary header, page x-latched */
UNIV_INTERN
dict_hdr_t*
dict_hdr_get(
/*=========*/
mtr_t* mtr) /*!< in: mtr */
{
buf_block_t* block;
dict_hdr_t* header;
block = buf_page_get(DICT_HDR_SPACE, 0, DICT_HDR_PAGE_NO,
RW_X_LATCH, mtr);
header = DICT_HDR + buf_block_get_frame(block);
buf_block_dbg_add_level(block, SYNC_DICT_HEADER);
return(header);
}
/**************************************************************//**
Restores the stored position of a persistent cursor bufferfixing the page and
obtaining the specified latches. If the cursor position was saved when the
(1) cursor was positioned on a user record: this function restores the position
to the last record LESS OR EQUAL to the stored record;
(2) cursor was positioned on a page infimum record: restores the position to
the last record LESS than the user record which was the successor of the page
infimum;
(3) cursor was positioned on the page supremum: restores to the first record
GREATER than the user record which was the predecessor of the supremum.
(4) cursor was positioned before the first or after the last in an empty tree:
restores to before first or after the last in the tree.
@return TRUE if the cursor position was stored when it was on a user
record and it can be restored on a user record whose ordering fields
are identical to the ones of the original user record */
UNIV_INTERN
ibool
btr_pcur_restore_position_func(
/*===========================*/
ulint latch_mode, /*!< in: BTR_SEARCH_LEAF, ... */
btr_pcur_t* cursor, /*!< in: detached persistent cursor */
const char* file, /*!< in: file name */
ulint line, /*!< in: line where called */
mtr_t* mtr) /*!< in: mtr */
{
dict_index_t* index;
dtuple_t* tuple;
ulint mode;
ulint old_mode;
mem_heap_t* heap;
ut_ad(mtr);
ut_ad(mtr->state == MTR_ACTIVE);
index = btr_cur_get_index(btr_pcur_get_btr_cur(cursor));
if (UNIV_UNLIKELY(cursor->old_stored != BTR_PCUR_OLD_STORED)
|| UNIV_UNLIKELY(cursor->pos_state != BTR_PCUR_WAS_POSITIONED
&& cursor->pos_state != BTR_PCUR_IS_POSITIONED)) {
ut_print_buf(stderr, cursor, sizeof(btr_pcur_t));
putc('\n', stderr);
if (cursor->trx_if_known) {
trx_print(stderr, cursor->trx_if_known, 0);
}
ut_error;
}
if (UNIV_UNLIKELY
(cursor->rel_pos == BTR_PCUR_AFTER_LAST_IN_TREE
|| cursor->rel_pos == BTR_PCUR_BEFORE_FIRST_IN_TREE)) {
/* In these cases we do not try an optimistic restoration,
but always do a search */
btr_cur_open_at_index_side(
cursor->rel_pos == BTR_PCUR_BEFORE_FIRST_IN_TREE,
index, latch_mode, btr_pcur_get_btr_cur(cursor), mtr);
cursor->latch_mode = latch_mode;
cursor->pos_state = BTR_PCUR_IS_POSITIONED;
cursor->block_when_stored = btr_pcur_get_block(cursor);
return(FALSE);
}
ut_a(cursor->old_rec);
ut_a(cursor->old_n_fields);
if (UNIV_LIKELY(latch_mode == BTR_SEARCH_LEAF)
|| UNIV_LIKELY(latch_mode == BTR_MODIFY_LEAF)) {
/* Try optimistic restoration */
if (UNIV_LIKELY(buf_page_optimistic_get(
latch_mode,
cursor->block_when_stored,
cursor->modify_clock,
file, line, mtr))) {
cursor->pos_state = BTR_PCUR_IS_POSITIONED;
buf_block_dbg_add_level(
btr_pcur_get_block(cursor),
dict_index_is_ibuf(index)
? SYNC_IBUF_TREE_NODE : SYNC_TREE_NODE);
if (cursor->rel_pos == BTR_PCUR_ON) {
#ifdef UNIV_DEBUG
const rec_t* rec;
const ulint* offsets1;
const ulint* offsets2;
#endif /* UNIV_DEBUG */
cursor->latch_mode = latch_mode;
#ifdef UNIV_DEBUG
rec = btr_pcur_get_rec(cursor);
heap = mem_heap_create(256);
offsets1 = rec_get_offsets(
cursor->old_rec, index, NULL,
cursor->old_n_fields, &heap);
offsets2 = rec_get_offsets(
rec, index, NULL,
cursor->old_n_fields, &heap);
ut_ad(!cmp_rec_rec(cursor->old_rec,
rec, offsets1, offsets2,
index));
mem_heap_free(heap);
#endif /* UNIV_DEBUG */
return(TRUE);
}
return(FALSE);
}
}
/* If optimistic restoration did not succeed, open the cursor anew */
heap = mem_heap_create(256);
tuple = dict_index_build_data_tuple(index, cursor->old_rec,
cursor->old_n_fields, heap);
/* Save the old search mode of the cursor */
old_mode = cursor->search_mode;
switch (cursor->rel_pos) {
case BTR_PCUR_ON:
mode = PAGE_CUR_LE;
break;
case BTR_PCUR_AFTER:
mode = PAGE_CUR_G;
break;
case BTR_PCUR_BEFORE:
mode = PAGE_CUR_L;
break;
default:
ut_error;
mode = 0;
}
btr_pcur_open_with_no_init_func(index, tuple, mode, latch_mode,
cursor, 0, file, line, mtr);
/* Restore the old search mode */
cursor->search_mode = old_mode;
switch (cursor->rel_pos) {
case BTR_PCUR_ON:
if (btr_pcur_is_on_user_rec(cursor)
&& !cmp_dtuple_rec(
tuple, btr_pcur_get_rec(cursor),
rec_get_offsets(btr_pcur_get_rec(cursor),
index, NULL,
ULINT_UNDEFINED, &heap))) {
/* We have to store the NEW value for
the modify clock, since the cursor can
now be on a different page! But we can
retain the value of old_rec */
cursor->block_when_stored =
btr_pcur_get_block(cursor);
cursor->modify_clock =
buf_block_get_modify_clock(
cursor->block_when_stored);
cursor->old_stored = BTR_PCUR_OLD_STORED;
mem_heap_free(heap);
return(TRUE);
}
#ifdef UNIV_DEBUG
/* fall through */
case BTR_PCUR_BEFORE:
case BTR_PCUR_AFTER:
break;
default:
ut_error;
#endif /* UNIV_DEBUG */
}
mem_heap_free(heap);
/* We have to store new position information, modify_clock etc.,
to the cursor because it can now be on a different page, the record
under it may have been removed, etc. */
btr_pcur_store_position(cursor, mtr);
return(FALSE);
}
/****************************************************************//**
Creates a rollback segment header. This function is called only when
a new rollback segment is created in the database.
@return page number of the created segment, FIL_NULL if fail */
UNIV_INTERN
ulint
trx_rseg_header_create(
/*===================*/
ulint space, /*!< in: space id */
ulint zip_size, /*!< in: compressed page size in bytes
or 0 for uncompressed pages */
ulint max_size, /*!< in: max size in pages */
ulint rseg_slot_no, /*!< in: rseg id == slot number in trx sys */
mtr_t* mtr) /*!< in: mtr */
{
ulint page_no;
trx_rsegf_t* rsegf;
trx_sysf_t* sys_header;
ulint i;
buf_block_t* block;
ut_ad(mtr);
ut_ad(mutex_own(&kernel_mutex));
ut_ad(mtr_memo_contains(mtr, fil_space_get_latch(space, NULL),
MTR_MEMO_X_LOCK));
/* Allocate a new file segment for the rollback segment */
block = fseg_create(space, 0,
TRX_RSEG + TRX_RSEG_FSEG_HEADER, mtr);
if (block == NULL) {
/* No space left */
return(FIL_NULL);
}
buf_block_dbg_add_level(block, SYNC_RSEG_HEADER_NEW);
page_no = buf_block_get_page_no(block);
/* Get the rollback segment file page */
rsegf = trx_rsegf_get_new(space, zip_size, page_no, mtr);
/* Initialize max size field */
mlog_write_ulint(rsegf + TRX_RSEG_MAX_SIZE, max_size,
MLOG_4BYTES, mtr);
/* Initialize the history list */
mlog_write_ulint(rsegf + TRX_RSEG_HISTORY_SIZE, 0, MLOG_4BYTES, mtr);
flst_init(rsegf + TRX_RSEG_HISTORY, mtr);
/* Reset the undo log slots */
for (i = 0; i < TRX_RSEG_N_SLOTS; i++) {
trx_rsegf_set_nth_undo(rsegf, i, FIL_NULL, mtr);
}
/* Add the rollback segment info to the free slot in
the trx system header */
sys_header = trx_sysf_get(mtr);
trx_sysf_rseg_set_space(sys_header, rseg_slot_no, space, mtr);
trx_sysf_rseg_set_page_no(sys_header, rseg_slot_no, page_no, mtr);
return(page_no);
}
/***********************************************************//**
Purges an update of an existing record. Also purges an update of a delete
marked record if that record contained an externally stored field. */
static
void
row_purge_upd_exist_or_extern_func(
/*===============================*/
#ifdef UNIV_DEBUG
const que_thr_t*thr, /*!< in: query thread */
#endif /* UNIV_DEBUG */
purge_node_t* node) /*!< in: row purge node */
{
mem_heap_t* heap;
dtuple_t* entry;
dict_index_t* index;
ibool is_insert;
ulint rseg_id;
ulint page_no;
ulint offset;
ulint i;
mtr_t mtr;
ut_ad(node);
if (node->rec_type == TRX_UNDO_UPD_DEL_REC
|| (node->cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
goto skip_secondaries;
}
heap = mem_heap_create(1024);
while (node->index != NULL) {
dict_table_skip_corrupt_index(node->index);
if (!node->index) {
break;
}
index = node->index;
if (row_upd_changes_ord_field_binary(node->index, node->update,
thr, NULL, NULL)) {
/* Build the older version of the index entry */
entry = row_build_index_entry(node->row, NULL,
index, heap);
ut_a(entry);
row_purge_remove_sec_if_poss(node, index, entry);
}
node->index = dict_table_get_next_index(node->index);
}
mem_heap_free(heap);
skip_secondaries:
/* Free possible externally stored fields */
for (i = 0; i < upd_get_n_fields(node->update); i++) {
const upd_field_t* ufield
= upd_get_nth_field(node->update, i);
if (dfield_is_ext(&ufield->new_val)) {
buf_block_t* block;
ulint internal_offset;
byte* data_field;
/* We use the fact that new_val points to
node->undo_rec and get thus the offset of
dfield data inside the undo record. Then we
can calculate from node->roll_ptr the file
address of the new_val data */
internal_offset
= ((const byte*)
dfield_get_data(&ufield->new_val))
- node->undo_rec;
ut_a(internal_offset < UNIV_PAGE_SIZE);
trx_undo_decode_roll_ptr(node->roll_ptr,
&is_insert, &rseg_id,
&page_no, &offset);
mtr_start(&mtr);
/* We have to acquire an X-latch to the clustered
index tree */
index = dict_table_get_first_index(node->table);
mtr_x_lock(dict_index_get_lock(index), &mtr);
/* NOTE: we must also acquire an X-latch to the
root page of the tree. We will need it when we
free pages from the tree. If the tree is of height 1,
the tree X-latch does NOT protect the root page,
because it is also a leaf page. Since we will have a
latch on an undo log page, we would break the
latching order if we would only later latch the
root page of such a tree! */
btr_root_get(index, &mtr);
/* We assume in purge of externally stored fields
that the space id of the undo log record is 0! */
block = buf_page_get(0, 0, page_no, RW_X_LATCH, &mtr);
buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE);
data_field = buf_block_get_frame(block)
+ offset + internal_offset;
ut_a(dfield_get_len(&ufield->new_val)
>= BTR_EXTERN_FIELD_REF_SIZE);
btr_free_externally_stored_field(
index,
data_field + dfield_get_len(&ufield->new_val)
- BTR_EXTERN_FIELD_REF_SIZE,
NULL, NULL, NULL, 0, RB_NONE, &mtr);
mtr_commit(&mtr);
}
}
}
