dict0dict.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

	col = dict_table_get_nth_col(index->table, n);

	if (index->type & DICT_CLUSTERED) {

		return(col->clust_pos);
	}

	n_fields = dict_index_get_n_fields(index);
	
	for (pos = 0; pos < n_fields; pos++) {
		field = dict_index_get_nth_field(index, pos);

		if (col == field->col && field->prefix_len == 0) {

			return(pos);
		}
	}

	return(ULINT_UNDEFINED);
}

/************************************************************************
Returns TRUE if the index contains a column or a prefix of that column. */

ibool
dict_index_contains_col_or_prefix(
/*==============================*/
				/* out: TRUE if contains the column or its
				prefix */
	dict_index_t*	index,	/* in: index */
	ulint		n)	/* in: column number */
{
	dict_field_t*	field;
	dict_col_t*	col;
	ulint		pos;
	ulint		n_fields;
	
	ut_ad(index);
	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);

	if (index->type & DICT_CLUSTERED) {

		return(TRUE);
	}

	col = dict_table_get_nth_col(index->table, n);

	n_fields = dict_index_get_n_fields(index);
	
	for (pos = 0; pos < n_fields; pos++) {
		field = dict_index_get_nth_field(index, pos);

		if (col == field->col) {

			return(TRUE);
		}
	}

	return(FALSE);
}

/************************************************************************
Looks for a matching field in an index. The column has to be the same. The
column in index must be complete, or must contain a prefix longer than the
column in index2. That is, we must be able to construct the prefix in index2
from the prefix in index. */

ulint
dict_index_get_nth_field_pos(
/*=========================*/
				/* out: position in internal representation
				of the index; if not contained, returns
				ULINT_UNDEFINED */
	dict_index_t*	index,	/* in: index from which to search */
	dict_index_t*	index2,	/* in: index */
	ulint		n)	/* in: field number in index2 */
{
	dict_field_t*	field;
	dict_field_t*	field2;
	ulint		n_fields;
	ulint		pos;
	
	ut_ad(index);
	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);

	field2 = dict_index_get_nth_field(index2, n);

	n_fields = dict_index_get_n_fields(index);
	
	for (pos = 0; pos < n_fields; pos++) {
		field = dict_index_get_nth_field(index, pos);

		if (field->col == field2->col
		    && (field->prefix_len == 0
			|| (field->prefix_len >= field2->prefix_len
			    && field2->prefix_len != 0))) {

			return(pos);
		}
	}

	return(ULINT_UNDEFINED);
}

/**************************************************************************
Returns a table object, based on table id, and memoryfixes it. */

dict_table_t*
dict_table_get_on_id(
/*=================*/
				/* out: table, NULL if does not exist */
	dulint	table_id,	/* in: table id */
	trx_t*	trx)		/* in: transaction handle */
{
	dict_table_t*	table;
	
	if (ut_dulint_cmp(table_id, DICT_FIELDS_ID) <= 0
	   || trx->dict_operation_lock_mode == RW_X_LATCH) {
		/* It is a system table which will always exist in the table
		cache: we avoid acquiring the dictionary mutex, because
		if we are doing a rollback to handle an error in TABLE
		CREATE, for example, we already have the mutex! */

#ifdef UNIV_SYNC_DEBUG
		ut_ad(mutex_own(&(dict_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */

		return(dict_table_get_on_id_low(table_id, trx));
	}

	mutex_enter(&(dict_sys->mutex));

	table = dict_table_get_on_id_low(table_id, trx);
	
	mutex_exit(&(dict_sys->mutex));

	return(table);
}

/************************************************************************
Looks for column n position in the clustered index. */

ulint
dict_table_get_nth_col_pos(
/*=======================*/
				/* out: position in internal representation
				of the clustered index */
	dict_table_t*	table,	/* in: table */
	ulint		n)	/* in: column number */
{
	return(dict_index_get_nth_col_pos(dict_table_get_first_index(table),
								n));
}

/************************************************************************
Checks if a column is in the ordering columns of the clustered index of a
table. Column prefixes are treated like whole columns. */

ibool
dict_table_col_in_clustered_key(
/*============================*/
				/* out: TRUE if the column, or its prefix, is
				in the clustered key */
	dict_table_t*	table,	/* in: table */
	ulint		n)	/* in: column number */
{
	dict_index_t*	index;
	dict_field_t*	field;
	dict_col_t*	col;
	ulint		pos;
	ulint		n_fields;
	
	ut_ad(table);

	col = dict_table_get_nth_col(table, n);

	index = dict_table_get_first_index(table);

	n_fields = dict_index_get_n_unique(index);
	
	for (pos = 0; pos < n_fields; pos++) {
		field = dict_index_get_nth_field(index, pos);

		if (col == field->col) {

			return(TRUE);
		}
	}

	return(FALSE);
}

/**************************************************************************
Inits the data dictionary module. */

void
dict_init(void)
/*===========*/
{
	dict_sys = mem_alloc(sizeof(dict_sys_t));

	mutex_create(&(dict_sys->mutex));
	mutex_set_level(&(dict_sys->mutex), SYNC_DICT);

	dict_sys->table_hash = hash_create(buf_pool_get_max_size() /
					(DICT_POOL_PER_TABLE_HASH *
					UNIV_WORD_SIZE));
	dict_sys->table_id_hash = hash_create(buf_pool_get_max_size() /
					(DICT_POOL_PER_TABLE_HASH *
					UNIV_WORD_SIZE));
	dict_sys->col_hash = hash_create(buf_pool_get_max_size() /
					(DICT_POOL_PER_COL_HASH *
					UNIV_WORD_SIZE));
	dict_sys->size = 0;

	UT_LIST_INIT(dict_sys->table_LRU);

	rw_lock_create(&dict_operation_lock);
	rw_lock_set_level(&dict_operation_lock, SYNC_DICT_OPERATION);

	dict_foreign_err_file = os_file_create_tmpfile();
	ut_a(dict_foreign_err_file);
	mutex_create(&dict_foreign_err_mutex);
	mutex_set_level(&dict_foreign_err_mutex, SYNC_ANY_LATCH);
}

/**************************************************************************
Returns a table object and memoryfixes it. NOTE! This is a high-level
function to be used mainly from outside the 'dict' directory. Inside this
directory dict_table_get_low is usually the appropriate function. */

dict_table_t*
dict_table_get(
/*===========*/
					/* out: table, NULL if
					does not exist */
	const char*	table_name,	/* in: table name */
	trx_t*		trx)		/* in: transaction handle or NULL */
{
	dict_table_t*	table;

	UT_NOT_USED(trx);

	mutex_enter(&(dict_sys->mutex));
	
	table = dict_table_get_low(table_name);

	mutex_exit(&(dict_sys->mutex));

	if (table != NULL) {
	        if (!table->stat_initialized) {
			dict_update_statistics(table);
		}
	}
	
	return(table);
}

/**************************************************************************
Returns a table object and increments MySQL open handle count on the table. */

dict_table_t*
dict_table_get_and_increment_handle_count(
/*======================================*/
					/* out: table, NULL if
					does not exist */
	const char*	table_name,	/* in: table name */
	trx_t*		trx)		/* in: transaction handle or NULL */
{
	dict_table_t*	table;

	UT_NOT_USED(trx);

	mutex_enter(&(dict_sys->mutex));
	
	table = dict_table_get_low(table_name);

	if (table != NULL) {

	        table->n_mysql_handles_opened++;
	}

	mutex_exit(&(dict_sys->mutex));

	if (table != NULL) {
	        if (!table->stat_initialized && !table->ibd_file_missing) {
			dict_update_statistics(table);
		}
	}
	
	return(table);
}

/**************************************************************************
Adds a table object to the dictionary cache. */

void
dict_table_add_to_cache(
/*====================*/
	dict_table_t*	table)	/* in: table */
{
	ulint	fold;
	ulint	id_fold;
	ulint	i;
	
	ut_ad(table);
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(dict_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */
	ut_ad(table->n_def == table->n_cols - DATA_N_SYS_COLS);
	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
	ut_ad(table->cached == FALSE);
	
	fold = ut_fold_string(table->name);
	id_fold = ut_fold_dulint(table->id);
	
	table->cached = TRUE;
	
	/* NOTE: the system columns MUST be added in the following order
	(so that they can be indexed by the numerical value of DATA_ROW_ID,
	etc.) and as the last columns of the table memory object.
	The clustered index will not always physically contain all
	system columns. */

	dict_mem_table_add_col(table, "DB_ROW_ID", DATA_SYS,
			DATA_ROW_ID | DATA_NOT_NULL, DATA_ROW_ID_LEN, 0);
#if DATA_ROW_ID != 0
#error "DATA_ROW_ID != 0"
#endif
	dict_mem_table_add_col(table, "DB_TRX_ID", DATA_SYS,
			DATA_TRX_ID | DATA_NOT_NULL, DATA_TRX_ID_LEN, 0);
#if DATA_TRX_ID != 1
#error "DATA_TRX_ID != 1"
#endif
	dict_mem_table_add_col(table, "DB_ROLL_PTR", DATA_SYS,
			DATA_ROLL_PTR | DATA_NOT_NULL, DATA_ROLL_PTR_LEN, 0);
#if DATA_ROLL_PTR != 2
#error "DATA_ROLL_PTR != 2"
#endif
	dict_mem_table_add_col(table, "DB_MIX_ID", DATA_SYS,
			DATA_MIX_ID | DATA_NOT_NULL, DATA_MIX_ID_LEN, 0);
#if DATA_MIX_ID != 3
#error "DATA_MIX_ID != 3"
#endif

	/* This check reminds that if a new system column is added to
	the program, it should be dealt with here */ 
#if DATA_N_SYS_COLS != 4
#error "DATA_N_SYS_COLS != 4"
#endif

	/* Look for a table with the same name: error if such exists */
	{
		dict_table_t*	table2;
		HASH_SEARCH(name_hash, dict_sys->table_hash, fold, table2,
				(ut_strcmp(table2->name, table->name) == 0));
		ut_a(table2 == NULL);
	}

	/* Look for a table with the same id: error if such exists */
	{
		dict_table_t*	table2;
		HASH_SEARCH(id_hash, dict_sys->table_id_hash, id_fold, table2,
				(ut_dulint_cmp(table2->id, table->id) == 0));
		ut_a(table2 == NULL);
	}

	if (table->type == DICT_TABLE_CLUSTER_MEMBER) {

		table->mix_id_len = mach_dulint_get_compressed_size(
								table->mix_id);
		mach_dulint_write_compressed(table->mix_id_buf, table->mix_id);
	}

	/* Add the columns to the column hash table */
	for (i = 0; i < table->n_cols; i++) {
		dict_col_add_to_cache(table, dict_table_get_nth_col(table, i));
	}

	/* Add table to hash table of tables */
	HASH_INSERT(dict_table_t, name_hash, dict_sys->table_hash, fold,
								   table);

	/* Add table to hash table of tables based on table id */
	HASH_INSERT(dict_table_t, id_hash, dict_sys->table_id_hash, id_fold,
								   table);
	/* Add table to LRU list of tables */
	UT_LIST_ADD_FIRST(table_LRU, dict_sys->table_LRU, table);

	/* If the dictionary cache grows too big, trim the table LRU list */

	dict_sys->size += mem_heap_get_size(table->heap);
	/* dict_table_LRU_trim(); */
}

/**************************************************************************
Looks for an index with the given id. NOTE that we do not reserve
the dictionary mutex: this function is for emergency purposes like
printing info of a corrupt database page! */

dict_index_t*
dict_index_find_on_id_low(
/*======================*/
			/* out: index or NULL if not found from cache */
	dulint	id)	/* in: index id */
{
	dict_table_t*	table;
	dict_index_t*	index;
	
	table = UT_LIST_GET_FIRST(dict_sys->table_LRU);

	while (table) {
		index = dict_table_get_first_index(table);

		while (index) {
			if (0 == ut_dulint_cmp(id, index->tree->id)) {
				/* Found */

				return(index);
			}

			index = dict_table_get_next_index(index);
		}

		table = UT_LIST_GET_NEXT(table_LRU, table);
	}

	return(NULL);
}

/**************************************************************************
Renames a table object. */

ibool
dict_table_rename_in_cache(
/*=======================*/
					/* out: TRUE if success */
	dict_table_t*	table,		/* in: table */
	const char*	new_name,	/* in: new name */
	ibool		rename_also_foreigns)/* in: in ALTER TABLE we want
					to preserve the original table name
					in constraints which reference it */
{
	dict_foreign_t*	foreign;
	dict_index_t*	index;
	ulint		fold;
	ulint		old_size;
	char*		old_name;
	ibool		success;
	ulint		i;
	
	ut_ad(table);
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(dict_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */

	old_size = mem_heap_get_size(table->heap);
	
	fold = ut_fold_string(new_name);
	
	/* Look for a table with the same name: error if such exists */
	{
		dict_table_t*	table2;
		HASH_SEARCH(name_hash, dict_sys->table_hash, fold, table2,
				(ut_strcmp(table2->name, new_name) == 0));
		if (table2) {
			fprintf(stderr,
"InnoDB: Error: dictionary cache already contains a table of name %s\n",
	 							     new_name);
			return(FALSE);
		}
	}

	/* If the table is stored in a single-table tablespace, rename the
	.ibd file */

	if (table->space != 0) {
		if (table->dir_path_of_temp_table != NULL) {
			fprintf(stderr,
"InnoDB: Error: trying to rename a table %s (%s) created with CREATE\n"
"InnoDB: TEMPORARY TABLE\n", table->name, table->dir_path_of_temp_table);
			success = FALSE;
		} else {
			success = fil_rename_tablespace(table->name,
						table->space, new_name);
		}

		if (!success) {

			return(FALSE);
		}
	}

	/* Reposition the columns in the column hash table; they are hashed
	according to the pair (table name, column name) */

	for (i = 0; i < table->n_cols; i++) {
		dict_col_reposition_in_cache(table,
				dict_table_get_nth_col(table, i), new_name);
	}

	/* Remove table from the hash tables of tables */
	HASH_DELETE(dict_table_t, name_hash, dict_sys->table_hash,