row0ins.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

	trx = thr_get_trx(thr);

	foreign = UT_LIST_GET_FIRST(table->foreign_list);

	while (foreign) {
		if (foreign->foreign_index == index) {

			if (foreign->referenced_table == NULL) {
				dict_table_get(foreign->referenced_table_name,
									trx);
			}

			if (0 == trx->dict_operation_lock_mode) {
				got_s_lock = TRUE;

				row_mysql_freeze_data_dictionary(trx);
			}

			if (foreign->referenced_table) {
				mutex_enter(&(dict_sys->mutex));

				(foreign->referenced_table
					->n_foreign_key_checks_running)++;

				mutex_exit(&(dict_sys->mutex));
			}

			/* NOTE that if the thread ends up waiting for a lock
			we will release dict_operation_lock temporarily!
			But the counter on the table protects the referenced
			table from being dropped while the check is running. */

			err = row_ins_check_foreign_constraint(TRUE, foreign,
						table, entry, thr);

			if (foreign->referenced_table) {
				mutex_enter(&(dict_sys->mutex));

				ut_a(foreign->referenced_table
					->n_foreign_key_checks_running > 0);
				(foreign->referenced_table
					->n_foreign_key_checks_running)--;

				mutex_exit(&(dict_sys->mutex));
			}

			if (got_s_lock) {
				row_mysql_unfreeze_data_dictionary(trx);
			}
				
			if (err != DB_SUCCESS) {
				return(err);
			}
		}

		foreign = UT_LIST_GET_NEXT(foreign_list, foreign);
	}

	return(DB_SUCCESS);
}

/*******************************************************************
Checks if a unique key violation to rec would occur at the index entry
insert. */
static
ibool
row_ins_dupl_error_with_rec(
/*========================*/
				/* out: TRUE if error */
	rec_t*		rec,	/* in: user record; NOTE that we assume
				that the caller already has a record lock on
				the record! */
	dtuple_t*	entry,	/* in: entry to insert */
	dict_index_t*	index,	/* in: index */
	const ulint*	offsets)/* in: rec_get_offsets(rec, index) */
{
	ulint	matched_fields;
	ulint	matched_bytes;
	ulint	n_unique;
	ulint   i;

	ut_ad(rec_offs_validate(rec, index, offsets));

	n_unique = dict_index_get_n_unique(index);

	matched_fields = 0;
	matched_bytes = 0;

	cmp_dtuple_rec_with_match(entry, rec, offsets,
					&matched_fields, &matched_bytes);

	if (matched_fields < n_unique) {

	        return(FALSE);
	}

	/* In a unique secondary index we allow equal key values if they
	contain SQL NULLs */

	if (!(index->type & DICT_CLUSTERED)) {

	        for (i = 0; i < n_unique; i++) {
	                if (UNIV_SQL_NULL == dfield_get_len(
                                         dtuple_get_nth_field(entry, i))) {

	                        return(FALSE);
	                }
	        }
	}

	return(!rec_get_deleted_flag(rec, rec_offs_comp(offsets)));
}	

/*******************************************************************
Scans a unique non-clustered index at a given index entry to determine
whether a uniqueness violation has occurred for the key value of the entry.
Set shared locks on possible duplicate records. */
static
ulint
row_ins_scan_sec_index_for_duplicate(
/*=================================*/
				/* out: DB_SUCCESS, DB_DUPLICATE_KEY, or
				DB_LOCK_WAIT */
	dict_index_t*	index,	/* in: non-clustered unique index */
	dtuple_t*	entry,	/* in: index entry */
	que_thr_t*	thr)	/* in: query thread */
{
#ifndef UNIV_HOTBACKUP
	ulint		n_unique;
	ulint		i;
	int		cmp;
	ulint		n_fields_cmp;
	rec_t*		rec;
	btr_pcur_t	pcur;
	ulint		err		= DB_SUCCESS;
	ibool		moved;
	mtr_t		mtr;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	n_unique = dict_index_get_n_unique(index);

	/* If the secondary index is unique, but one of the fields in the
	n_unique first fields is NULL, a unique key violation cannot occur,
	since we define NULL != NULL in this case */

	for (i = 0; i < n_unique; i++) {
		if (UNIV_SQL_NULL == dfield_get_len(
                                         dtuple_get_nth_field(entry, i))) {

			return(DB_SUCCESS);
		}
	}

	mtr_start(&mtr);

	/* Store old value on n_fields_cmp */

	n_fields_cmp = dtuple_get_n_fields_cmp(entry);

	dtuple_set_n_fields_cmp(entry, dict_index_get_n_unique(index));
	
	btr_pcur_open(index, entry, PAGE_CUR_GE, BTR_SEARCH_LEAF, &pcur, &mtr);

	/* Scan index records and check if there is a duplicate */

	for (;;) {
		rec = btr_pcur_get_rec(&pcur);

		if (rec == page_get_infimum_rec(buf_frame_align(rec))) {

			goto next_rec;
		}
				
		offsets = rec_get_offsets(rec, index, offsets,
					ULINT_UNDEFINED, &heap);

		if (innobase_query_is_update()) {

			/* If the SQL-query will update or replace
			duplicate key we will take X-lock for 
			duplicates ( REPLACE, LOAD DATAFILE REPLACE, 
			INSERT ON DUPLICATE KEY UPDATE). */
			
			err = row_ins_set_exclusive_rec_lock(LOCK_ORDINARY,
						rec, index, offsets, thr);
		} else {

			err = row_ins_set_shared_rec_lock(LOCK_ORDINARY,
						rec, index, offsets, thr);
		}

		if (err != DB_SUCCESS) {

			break;
		}

		if (page_rec_is_supremum(rec)) {
		
			goto next_rec;
		}

		cmp = cmp_dtuple_rec(entry, rec, offsets);

		if (cmp == 0) {
			if (row_ins_dupl_error_with_rec(rec, entry,
							index, offsets)) {
				err = DB_DUPLICATE_KEY;

				thr_get_trx(thr)->error_info = index;

				break;
			}
		}

		if (cmp < 0) {
			break;
		}

		ut_a(cmp == 0);
next_rec:
		moved = btr_pcur_move_to_next(&pcur, &mtr);

		if (!moved) {
			break;
		}
	}

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
	mtr_commit(&mtr);

	/* Restore old value */
	dtuple_set_n_fields_cmp(entry, n_fields_cmp);

	return(err);
#else /* UNIV_HOTBACKUP */
	/* This function depends on MySQL code that is not included in
	InnoDB Hot Backup builds.  Besides, this function should never
	be called in InnoDB Hot Backup. */
	ut_error;
#endif /* UNIV_HOTBACKUP */
}

/*******************************************************************
Checks if a unique key violation error would occur at an index entry
insert. Sets shared locks on possible duplicate records. Works only
for a clustered index! */
static
ulint
row_ins_duplicate_error_in_clust(
/*=============================*/
				/* out: DB_SUCCESS if no error,
				DB_DUPLICATE_KEY if error, DB_LOCK_WAIT if we
				have to wait for a lock on a possible
				duplicate record */
	btr_cur_t*	cursor,	/* in: B-tree cursor */
	dtuple_t*	entry,	/* in: entry to insert */
	que_thr_t*	thr,	/* in: query thread */
	mtr_t*		mtr)	/* in: mtr */
{
#ifndef UNIV_HOTBACKUP
	ulint	err;
	rec_t*	rec;
	ulint	n_unique;
	trx_t*	trx		= thr_get_trx(thr);
	mem_heap_t*heap		= NULL;
	ulint	offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*	offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	UT_NOT_USED(mtr);
	
	ut_a(cursor->index->type & DICT_CLUSTERED);
	ut_ad(cursor->index->type & DICT_UNIQUE);

	/* NOTE: For unique non-clustered indexes there may be any number
	of delete marked records with the same value for the non-clustered
	index key (remember multiversioning), and which differ only in
	the row refererence part of the index record, containing the
	clustered index key fields. For such a secondary index record,
	to avoid race condition, we must FIRST do the insertion and after
	that check that the uniqueness condition is not breached! */
	
	/* NOTE: A problem is that in the B-tree node pointers on an
	upper level may match more to the entry than the actual existing
	user records on the leaf level. So, even if low_match would suggest
	that a duplicate key violation may occur, this may not be the case. */

	n_unique = dict_index_get_n_unique(cursor->index);
	
	if (cursor->low_match >= n_unique) {
		
		rec = btr_cur_get_rec(cursor);

		if (!page_rec_is_infimum(rec)) {
			offsets = rec_get_offsets(rec, cursor->index, offsets,
						ULINT_UNDEFINED, &heap);

			/* We set a lock on the possible duplicate: this
			is needed in logical logging of MySQL to make
			sure that in roll-forward we get the same duplicate
			errors as in original execution */

			if (innobase_query_is_update()) {

				/* If the SQL-query will update or replace
				duplicate key we will take X-lock for 
				duplicates ( REPLACE, LOAD DATAFILE REPLACE, 
				INSERT ON DUPLICATE KEY UPDATE). */
				
				err = row_ins_set_exclusive_rec_lock(
					LOCK_REC_NOT_GAP,rec,cursor->index,
					offsets, thr);
			} else {
				
				err = row_ins_set_shared_rec_lock(
					LOCK_REC_NOT_GAP,rec, cursor->index, 
					offsets, thr);
			} 

			if (err != DB_SUCCESS) {
				goto func_exit;
			}

			if (row_ins_dupl_error_with_rec(rec, entry,
						cursor->index, offsets)) {
				trx->error_info = cursor->index;
				err = DB_DUPLICATE_KEY;
				goto func_exit;
			}
		}
	}

	if (cursor->up_match >= n_unique) {

		rec = page_rec_get_next(btr_cur_get_rec(cursor));

		if (!page_rec_is_supremum(rec)) {
			offsets = rec_get_offsets(rec, cursor->index, offsets,
						ULINT_UNDEFINED, &heap);

			if (innobase_query_is_update()) {

				/* If the SQL-query will update or replace
				duplicate key we will take X-lock for 
				duplicates ( REPLACE, LOAD DATAFILE REPLACE, 
				INSERT ON DUPLICATE KEY UPDATE). */

				err = row_ins_set_exclusive_rec_lock(
						LOCK_REC_NOT_GAP, rec,
						cursor->index, offsets, thr);
			} else {

				err = row_ins_set_shared_rec_lock(
						LOCK_REC_NOT_GAP, rec,
						cursor->index, offsets, thr);
			}

			if (err != DB_SUCCESS) {
				goto func_exit;
			}

			if (row_ins_dupl_error_with_rec(rec, entry,
						cursor->index, offsets)) {
				trx->error_info = cursor->index;
				err = DB_DUPLICATE_KEY;
				goto func_exit;
			}
		}

		ut_a(!(cursor->index->type & DICT_CLUSTERED));
						/* This should never happen */
	}

	err = DB_SUCCESS;
func_exit:
	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
	return(err);
#else /* UNIV_HOTBACKUP */
	/* This function depends on MySQL code that is not included in
	InnoDB Hot Backup builds.  Besides, this function should never
	be called in InnoDB Hot Backup. */
	ut_error;
#endif /* UNIV_HOTBACKUP */
}

/*******************************************************************
Checks if an index entry has long enough common prefix with an existing
record so that the intended insert of the entry must be changed to a modify of
the existing record. In the case of a clustered index, the prefix must be
n_unique fields long, and in the case of a secondary index, all fields must be
equal. */
UNIV_INLINE
ulint
row_ins_must_modify(
/*================*/
				/* out: 0 if no update, ROW_INS_PREV if
				previous should be updated; currently we
				do the search so that only the low_match
				record can match enough to the search tuple,
				not the next record */
	btr_cur_t*	cursor)	/* in: B-tree cursor */
{
	ulint	enough_match;
	rec_t*	rec;
	
	/* NOTE: (compare to the note in row_ins_duplicate_error) Because node
	pointers on upper levels of the B-tree may match more to entry than
	to actual user records on the leaf level, we have to check if the
	candidate record is actually a user record. In a clustered index
	node pointers contain index->n_unique first fields, and in the case
	of a secondary index, all fields of the index. */

	enough_match = dict_index_get_n_unique_in_tree(cursor->index);
	
	if (cursor->low_match >= enough_match) {

		rec = btr_cur_get_rec(cursor);

		if (!page_rec_is_infimum(rec)) {

			return(ROW_INS_PREV);
		}
	}

	return(0);
}

/*******************************************************************
Tries to insert an index entry to an index. If the index is clustered
and a record with the same unique key is found, the other record is
necessarily marked deleted by a committed transaction, or a unique key
violation error occurs. The delete marked record is then updated to an
existing record, and we must write an undo log record on the delete
marked record. If the index is secondary, and a record with exactly the
same fields is found, the other record is necessarily marked deleted.
It is then unmarked. Otherwise, the entry is just inserted to the index. */

ulint
row_ins_index_entry_low(
/*====================*/
				/* out: DB_SUCCESS, DB_LOCK_WAIT, DB_FAIL
				if pessimistic retry needed, or error code */
	ulint		mode,	/* in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE,
				depending on whether we wish optimistic or
				pessimistic descent down the index tree */
	dict_index_t*	index,	/* in: index */
	dtuple_t*	entry,	/* in: index entry to insert */
	ulint*		ext_vec,/* in: array containing field numbers of
				externally stored fields in entry, or NULL */
	ulint		n_ext_vec,/* in: number of fields in ext_vec */
	que_thr_t*	thr)	/* in: query thread */
{
	btr_cur_t	cursor;
	ulint		ignore_sec_unique	= 0;
	ulint		modify = 0; /* remove warning */
	rec_t*		insert_rec;
	rec_t*		rec;
	ulint		err;
	ulint		n_unique;
	big_rec_t*	big_rec			= NULL;
	mtr_t		mtr;
	mem_heap_t*	heap			= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets			= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	log_free_check();

	mtr_start(&mtr);

	cursor.thr = thr;

	/* Note that we use PAGE_CUR_LE as the search mode, because then
	the function will return in both low_match and up_match of the
	cursor sensible values */
	
	if (!(thr_get_trx(thr)->check_unique_secondary)) {
		ignore_sec_unique = BTR_IGNORE_SEC_UNIQUE;
	}

	btr_cur_search_to_nth_level(index, 0, entry, PAGE_CUR_LE,
				mode | BTR_INSERT | ignore_sec_unique,
				&cursor, 0, &mtr);

	if (cursor.flag == BTR_CUR_INSERT_TO_IBUF) {
		/* The insertion was made to the insert buffer already during
		the search: we are done */

		err = DB_SUCCESS;

		goto function_exit;
	}