/*********************************************************//**
Moves the persistent cursor to the first record on the next page. Releases the
latch on the current page, and bufferunfixes it. Note that there must not be
modifications on the current page, as then the x-latch can be released only in
mtr_commit. */
UNIV_INTERN
void
btr_pcur_move_to_next_page(
/*=======================*/
btr_pcur_t* cursor, /*!< in: persistent cursor; must be on the
last record of the current page */
mtr_t* mtr) /*!< in: mtr */
{
ulint next_page_no;
ulint space;
ulint zip_size;
page_t* page;
buf_block_t* next_block;
page_t* next_page;
ut_a(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
ut_ad(btr_pcur_is_after_last_on_page(cursor));
cursor->old_stored = BTR_PCUR_OLD_NOT_STORED;
page = btr_pcur_get_page(cursor);
next_page_no = btr_page_get_next(page, mtr);
space = buf_block_get_space(btr_pcur_get_block(cursor));
zip_size = buf_block_get_zip_size(btr_pcur_get_block(cursor));
ut_ad(next_page_no != FIL_NULL);
next_block = btr_block_get(space, zip_size, next_page_no,
cursor->latch_mode,
btr_pcur_get_btr_cur(cursor)->index, mtr);
next_page = buf_block_get_frame(next_block);
if (srv_pass_corrupt_table && !next_page) {
btr_leaf_page_release(btr_pcur_get_block(cursor),
cursor->latch_mode, mtr);
btr_pcur_get_page_cur(cursor)->block = 0;
btr_pcur_get_page_cur(cursor)->rec = 0;
return;
}
ut_a(next_page);
#ifdef UNIV_BTR_DEBUG
ut_a(page_is_comp(next_page) == page_is_comp(page));
ut_a(btr_page_get_prev(next_page, mtr)
== buf_block_get_page_no(btr_pcur_get_block(cursor)));
#endif /* UNIV_BTR_DEBUG */
next_block->check_index_page_at_flush = TRUE;
btr_leaf_page_release(btr_pcur_get_block(cursor),
cursor->latch_mode, mtr);
page_cur_set_before_first(next_block, btr_pcur_get_page_cur(cursor));
page_check_dir(next_page);
}
/*******************************************************************//**
Truncates the index tree associated with a row in SYS_INDEXES table.
@return new root page number, or FIL_NULL on failure */
UNIV_INTERN
ulint
dict_truncate_index_tree(
/*=====================*/
dict_table_t* table, /*!< in: the table the index belongs to */
ulint space, /*!< in: 0=truncate,
nonzero=create the index tree in the
given tablespace */
btr_pcur_t* pcur, /*!< in/out: persistent cursor pointing to
record in the clustered index of
SYS_INDEXES table. The cursor may be
repositioned in this call. */
mtr_t* mtr) /*!< in: mtr having the latch
on the record page. The mtr may be
committed and restarted in this call. */
{
ulint root_page_no;
ibool drop = !space;
ulint zip_size;
ulint type;
index_id_t index_id;
rec_t* rec;
const byte* ptr;
ulint len;
dict_index_t* index;
ut_ad(mutex_own(&(dict_sys->mutex)));
ut_a(!dict_table_is_comp(dict_sys->sys_indexes));
rec = btr_pcur_get_rec(pcur);
ptr = rec_get_nth_field_old(rec, DICT_SYS_INDEXES_PAGE_NO_FIELD, &len);
ut_ad(len == 4);
root_page_no = mtr_read_ulint(ptr, MLOG_4BYTES, mtr);
if (drop && root_page_no == FIL_NULL) {
/* The tree has been freed. */
ut_print_timestamp(stderr);
fprintf(stderr, " InnoDB: Trying to TRUNCATE"
" a missing index of table %s!\n", table->name);
drop = FALSE;
}
ptr = rec_get_nth_field_old(rec,
DICT_SYS_INDEXES_SPACE_NO_FIELD, &len);
ut_ad(len == 4);
if (drop) {
space = mtr_read_ulint(ptr, MLOG_4BYTES, mtr);
}
zip_size = fil_space_get_zip_size(space);
if (UNIV_UNLIKELY(zip_size == ULINT_UNDEFINED)) {
/* It is a single table tablespace and the .ibd file is
missing: do nothing */
ut_print_timestamp(stderr);
fprintf(stderr, " InnoDB: Trying to TRUNCATE"
" a missing .ibd file of table %s!\n", table->name);
return(FIL_NULL);
}
ptr = rec_get_nth_field_old(rec,
DICT_SYS_INDEXES_TYPE_FIELD, &len);
ut_ad(len == 4);
type = mach_read_from_4(ptr);
ptr = rec_get_nth_field_old(rec, 1, &len);
ut_ad(len == 8);
index_id = mach_read_from_8(ptr);
if (!drop) {
goto create;
}
/* We free all the pages but the root page first; this operation
may span several mini-transactions */
btr_free_but_not_root(space, zip_size, root_page_no);
/* Then we free the root page in the same mini-transaction where
we create the b-tree and write its new root page number to the
appropriate field in the SYS_INDEXES record: this mini-transaction
marks the B-tree totally truncated */
btr_block_get(space, zip_size, root_page_no, RW_X_LATCH, NULL, mtr);
btr_free_root(space, zip_size, root_page_no, mtr);
create:
/* We will temporarily write FIL_NULL to the PAGE_NO field
in SYS_INDEXES, so that the database will not get into an
inconsistent state in case it crashes between the mtr_commit()
below and the following mtr_commit() call. */
page_rec_write_field(rec, DICT_SYS_INDEXES_PAGE_NO_FIELD,
FIL_NULL, mtr);
/* We will need to commit the mini-transaction in order to avoid
deadlocks in the btr_create() call, because otherwise we would
be freeing and allocating pages in the same mini-transaction. */
btr_pcur_store_position(pcur, mtr);
mtr_commit(mtr);
mtr_start(mtr);
btr_pcur_restore_position(BTR_MODIFY_LEAF, pcur, mtr);
/* Find the index corresponding to this SYS_INDEXES record. */
for (index = UT_LIST_GET_FIRST(table->indexes);
index;
index = UT_LIST_GET_NEXT(indexes, index)) {
if (index->id == index_id) {
root_page_no = btr_create(type, space, zip_size,
index_id, index, mtr);
index->page = (unsigned int) root_page_no;
return(root_page_no);
}
}
ut_print_timestamp(stderr);
fprintf(stderr,
" InnoDB: Index %llu of table %s is missing\n"
"InnoDB: from the data dictionary during TRUNCATE!\n",
(ullint) index_id,
table->name);
return(FIL_NULL);
}
