/***************************************************************************** Copyright (c) 1996, 2009, Innobase Oy. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *****************************************************************************/ /**************************************************//** @file include/dict0mem.h Data dictionary memory object creation Created 1/8/1996 Heikki Tuuri *******************************************************/ #ifndef dict0mem_h #define dict0mem_h #include "univ.i" #include "dict0types.h" #include "data0type.h" #include "mem0mem.h" #include "rem0types.h" #include "btr0types.h" #ifndef UNIV_HOTBACKUP # include "lock0types.h" # include "que0types.h" # include "sync0rw.h" #endif /* !UNIV_HOTBACKUP */ #include "ut0mem.h" #include "ut0lst.h" #include "ut0rnd.h" #include "ut0byte.h" #include "hash0hash.h" #include "trx0types.h" /** Type flags of an index: OR'ing of the flags is allowed to define a combination of types */ /* @{ */ #define DICT_CLUSTERED 1 /*!< clustered index */ #define DICT_UNIQUE 2 /*!< unique index */ #define DICT_UNIVERSAL 4 /*!< index which can contain records from any other index */ #define DICT_IBUF 8 /*!< insert buffer tree */ /* @} */ /** Types for a table object */ #define DICT_TABLE_ORDINARY 1 /*!< ordinary table */ #if 0 /* not implemented */ #define DICT_TABLE_CLUSTER_MEMBER 2 #define DICT_TABLE_CLUSTER 3 /* this means that the table is really a cluster definition */ #endif /** Table flags. All unused bits must be 0. */ /* @{ */ #define DICT_TF_COMPACT 1 /* Compact page format. This must be set for new file formats (later than DICT_TF_FORMAT_51). */ /** Compressed page size (0=uncompressed, up to 15 compressed sizes) */ /* @{ */ #define DICT_TF_ZSSIZE_SHIFT 1 #define DICT_TF_ZSSIZE_MASK (15 << DICT_TF_ZSSIZE_SHIFT) #define DICT_TF_ZSSIZE_MAX (UNIV_PAGE_SIZE_SHIFT - PAGE_ZIP_MIN_SIZE_SHIFT + 1) /* @} */ /** File format */ /* @{ */ #define DICT_TF_FORMAT_SHIFT 5 /* file format */ #define DICT_TF_FORMAT_MASK (127 << DICT_TF_FORMAT_SHIFT) #define DICT_TF_FORMAT_51 0 /*!< InnoDB/MySQL up to 5.1 */ #define DICT_TF_FORMAT_ZIP 1 /*!< InnoDB plugin for 5.1: compressed tables, new BLOB treatment */ /** Maximum supported file format */ #define DICT_TF_FORMAT_MAX DICT_TF_FORMAT_ZIP #define DICT_TF_BITS 6 /*!< number of flag bits */ #if (1 << (DICT_TF_BITS - DICT_TF_FORMAT_SHIFT)) <= DICT_TF_FORMAT_MAX # error "DICT_TF_BITS is insufficient for DICT_TF_FORMAT_MAX" #endif /* @} */ /* @} */ /**********************************************************************//** Creates a table memory object. @return own: table object */ UNIV_INTERN dict_table_t* dict_mem_table_create( /*==================*/ const char* name, /*!< in: table name */ ulint space, /*!< in: space where the clustered index of the table is placed; this parameter is ignored if the table is made a member of a cluster */ ulint n_cols, /*!< in: number of columns */ ulint flags); /*!< in: table flags */ /****************************************************************//** Free a table memory object. */ UNIV_INTERN void dict_mem_table_free( /*================*/ dict_table_t* table); /*!< in: table */ /**********************************************************************//** Adds a column definition to a table. */ UNIV_INTERN void dict_mem_table_add_col( /*===================*/ dict_table_t* table, /*!< in: table */ mem_heap_t* heap, /*!< in: temporary memory heap, or NULL */ const char* name, /*!< in: column name, or NULL */ ulint mtype, /*!< in: main datatype */ ulint prtype, /*!< in: precise type */ ulint len); /*!< in: precision */ /**********************************************************************//** Creates an index memory object. @return own: index object */ UNIV_INTERN dict_index_t* dict_mem_index_create( /*==================*/ const char* table_name, /*!< in: table name */ const char* index_name, /*!< in: index name */ ulint space, /*!< in: space where the index tree is placed, ignored if the index is of the clustered type */ ulint type, /*!< in: DICT_UNIQUE, DICT_CLUSTERED, ... ORed */ ulint n_fields); /*!< in: number of fields */ /**********************************************************************//** Adds a field definition to an index. NOTE: does not take a copy of the column name if the field is a column. The memory occupied by the column name may be released only after publishing the index. */ UNIV_INTERN void dict_mem_index_add_field( /*=====================*/ dict_index_t* index, /*!< in: index */ const char* name, /*!< in: column name */ ulint prefix_len); /*!< in: 0 or the column prefix length in a MySQL index like INDEX (textcol(25)) */ /**********************************************************************//** Frees an index memory object. */ UNIV_INTERN void dict_mem_index_free( /*================*/ dict_index_t* index); /*!< in: index */ /**********************************************************************//** Creates and initializes a foreign constraint memory object. @return own: foreign constraint struct */ UNIV_INTERN dict_foreign_t* dict_mem_foreign_create(void); /*=========================*/ /** Data structure for a column in a table */ struct dict_col_struct{ /*----------------------*/ /** The following are copied from dtype_t, so that all bit-fields can be packed tightly. */ /* @{ */ unsigned mtype:8; /*!< main data type */ unsigned prtype:24; /*!< precise type; MySQL data type, charset code, flags to indicate nullability, signedness, whether this is a binary string, whether this is a true VARCHAR where MySQL uses 2 bytes to store the length */ /* the remaining fields do not affect alphabetical ordering: */ unsigned len:16; /*!< length; for MySQL data this is field->pack_length(), except that for a >= 5.0.3 type true VARCHAR this is the maximum byte length of the string data (in addition to the string, MySQL uses 1 or 2 bytes to store the string length) */ unsigned mbminlen:2; /*!< minimum length of a character, in bytes */ unsigned mbmaxlen:3; /*!< maximum length of a character, in bytes */ /*----------------------*/ /* End of definitions copied from dtype_t */ /* @} */ unsigned ind:10; /*!< table column position (starting from 0) */ unsigned ord_part:1; /*!< nonzero if this column appears in the ordering fields of an index */ }; /** @brief DICT_MAX_INDEX_COL_LEN is measured in bytes and is the maximum indexed column length (or indexed prefix length). It is set to 3*256, so that one can create a column prefix index on 256 characters of a TEXT or VARCHAR column also in the UTF-8 charset. In that charset, a character may take at most 3 bytes. This constant MUST NOT BE CHANGED, or the compatibility of InnoDB data files would be at risk! */ #define DICT_MAX_INDEX_COL_LEN REC_MAX_INDEX_COL_LEN /** Data structure for a field in an index */ struct dict_field_struct{ dict_col_t* col; /*!< pointer to the table column */ const char* name; /*!< name of the column */ unsigned prefix_len:10; /*!< 0 or the length of the column prefix in bytes in a MySQL index of type, e.g., INDEX (textcol(25)); must be smaller than DICT_MAX_INDEX_COL_LEN; NOTE that in the UTF-8 charset, MySQL sets this to 3 * the prefix len in UTF-8 chars */ unsigned fixed_len:10; /*!< 0 or the fixed length of the column if smaller than DICT_MAX_INDEX_COL_LEN */ }; /** Data structure for an index. Most fields will be initialized to 0, NULL or FALSE in dict_mem_index_create(). */ struct dict_index_struct{ dulint id; /*!< id of the index */ mem_heap_t* heap; /*!< memory heap */ const char* name; /*!< index name */ const char* table_name;/*!< table name */ dict_table_t* table; /*!< back pointer to table */ #ifndef UNIV_HOTBACKUP unsigned space:32; /*!< space where the index tree is placed */ unsigned page:32;/*!< index tree root page number */ #endif /* !UNIV_HOTBACKUP */ unsigned type:4; /*!< index type (DICT_CLUSTERED, DICT_UNIQUE, DICT_UNIVERSAL, DICT_IBUF) */ unsigned trx_id_offset:10;/*!< position of the trx id column in a clustered index record, if the fields before it are known to be of a fixed size, 0 otherwise */ unsigned n_user_defined_cols:10; /*!< number of columns the user defined to be in the index: in the internal representation we add more columns */ unsigned n_uniq:10;/*!< number of fields from the beginning which are enough to determine an index entry uniquely */ unsigned n_def:10;/*!< number of fields defined so far */ unsigned n_fields:10;/*!< number of fields in the index */ unsigned n_nullable:10;/*!< number of nullable fields */ unsigned cached:1;/*!< TRUE if the index object is in the dictionary cache */ unsigned to_be_dropped:1; /*!< TRUE if this index is marked to be dropped in ha_innobase::prepare_drop_index(), otherwise FALSE */ dict_field_t* fields; /*!< array of field descriptions */ #ifndef UNIV_HOTBACKUP UT_LIST_NODE_T(dict_index_t) indexes;/*!< list of indexes of the table */ btr_search_t* search_info; /*!< info used in optimistic searches */ /*----------------------*/ /** Statistics for query optimization */ /* @{ */ ib_int64_t* stat_n_diff_key_vals; /*!< approximate number of different key values for this index, for each n-column prefix where n <= dict_get_n_unique(index); we periodically calculate new estimates */ ulint stat_index_size; /*!< approximate index size in database pages */ ulint stat_n_leaf_pages; /*!< approximate number of leaf pages in the index tree */ /* @} */ rw_lock_t lock; /*!< read-write lock protecting the upper levels of the index tree */ ib_uint64_t trx_id; /*!< id of the transaction that created this index, or 0 if the index existed when InnoDB was started up */ #endif /* !UNIV_HOTBACKUP */ #ifdef UNIV_DEBUG ulint magic_n;/*!< magic number */ /** Value of dict_index_struct::magic_n */ # define DICT_INDEX_MAGIC_N 76789786 #endif }; /** Data structure for a foreign key constraint; an example: FOREIGN KEY (A, B) REFERENCES TABLE2 (C, D). Most fields will be initialized to 0, NULL or FALSE in dict_mem_foreign_create(). */ struct dict_foreign_struct{ mem_heap_t* heap; /*!< this object is allocated from this memory heap */ char* id; /*!< id of the constraint as a null-terminated string */ unsigned n_fields:10; /*!< number of indexes' first fields for which the the foreign key constraint is defined: we allow the indexes to contain more fields than mentioned in the constraint, as long as the first fields are as mentioned */ unsigned type:6; /*!< 0 or DICT_FOREIGN_ON_DELETE_CASCADE or DICT_FOREIGN_ON_DELETE_SET_NULL */ char* foreign_table_name;/*!< foreign table name */ dict_table_t* foreign_table; /*!< table where the foreign key is */ const char** foreign_col_names;/*!< names of the columns in the foreign key */ char* referenced_table_name;/*!< referenced table name */ dict_table_t* referenced_table;/*!< table where the referenced key is */ const char** referenced_col_names;/*!< names of the referenced columns in the referenced table */ dict_index_t* foreign_index; /*!< foreign index; we require that both tables contain explicitly defined indexes for the constraint: InnoDB does not generate new indexes implicitly */ dict_index_t* referenced_index;/*!< referenced index */ UT_LIST_NODE_T(dict_foreign_t) foreign_list; /*!< list node for foreign keys of the table */ UT_LIST_NODE_T(dict_foreign_t) referenced_list;/*!< list node for referenced keys of the table */ }; /** The flags for ON_UPDATE and ON_DELETE can be ORed; the default is that a foreign key constraint is enforced, therefore RESTRICT just means no flag */ /* @{ */ #define DICT_FOREIGN_ON_DELETE_CASCADE 1 /*!< ON DELETE CASCADE */ #define DICT_FOREIGN_ON_DELETE_SET_NULL 2 /*!< ON UPDATE SET NULL */ #define DICT_FOREIGN_ON_UPDATE_CASCADE 4 /*!< ON DELETE CASCADE */ #define DICT_FOREIGN_ON_UPDATE_SET_NULL 8 /*!< ON UPDATE SET NULL */ #define DICT_FOREIGN_ON_DELETE_NO_ACTION 16 /*!< ON DELETE NO ACTION */ #define DICT_FOREIGN_ON_UPDATE_NO_ACTION 32 /*!< ON UPDATE NO ACTION */ /* @} */ /** Data structure for a database table. Most fields will be initialized to 0, NULL or FALSE in dict_mem_table_create(). */ struct dict_table_struct{ dulint id; /*!< id of the table */ mem_heap_t* heap; /*!< memory heap */ const char* name; /*!< table name */ const char* dir_path_of_temp_table;/*!< NULL or the directory path where a TEMPORARY table that was explicitly created by a user should be placed if innodb_file_per_table is defined in my.cnf; in Unix this is usually /tmp/..., in Windows temp\... */ unsigned space:32; /*!< space where the clustered index of the table is placed */ unsigned flags:DICT_TF_BITS;/*!< DICT_TF_COMPACT, ... */ unsigned ibd_file_missing:1; /*!< TRUE if this is in a single-table tablespace and the .ibd file is missing; then we must return in ha_innodb.cc an error if the user tries to query such an orphaned table */ unsigned tablespace_discarded:1; /*!< this flag is set TRUE when the user calls DISCARD TABLESPACE on this table, and reset to FALSE in IMPORT TABLESPACE */ unsigned cached:1;/*!< TRUE if the table object has been added to the dictionary cache */ unsigned n_def:10;/*!< number of columns defined so far */ unsigned n_cols:10;/*!< number of columns */ dict_col_t* cols; /*!< array of column descriptions */ const char* col_names; /*!< Column names packed in a character string "name1\0name2\0...nameN\0". Until the string contains n_cols, it will be allocated from a temporary heap. The final string will be allocated from table->heap. */ #ifndef UNIV_HOTBACKUP hash_node_t name_hash; /*!< hash chain node */ hash_node_t id_hash; /*!< hash chain node */ UT_LIST_BASE_NODE_T(dict_index_t) indexes; /*!< list of indexes of the table */ UT_LIST_BASE_NODE_T(dict_foreign_t) foreign_list;/*!< list of foreign key constraints in the table; these refer to columns in other tables */ UT_LIST_BASE_NODE_T(dict_foreign_t) referenced_list;/*!< list of foreign key constraints which refer to this table */ UT_LIST_NODE_T(dict_table_t) table_LRU; /*!< node of the LRU list of tables */ ulint n_mysql_handles_opened; /*!< count of how many handles MySQL has opened to this table; dropping of the table is NOT allowed until this count gets to zero; MySQL does NOT itself check the number of open handles at drop */ ulint n_foreign_key_checks_running; /*!< count of how many foreign key check operations are currently being performed on the table: we cannot drop the table while there are foreign key checks running on it! */ trx_id_t query_cache_inv_trx_id; /*!< transactions whose trx id is smaller than this number are not allowed to store to the MySQL query cache or retrieve from it; when a trx with undo logs commits, it sets this to the value of the trx id counter for the tables it had an IX lock on */ UT_LIST_BASE_NODE_T(lock_t) locks; /*!< list of locks on the table */ #ifdef UNIV_DEBUG /*----------------------*/ ibool does_not_fit_in_memory; /*!< this field is used to specify in simulations tables which are so big that disk should be accessed: disk access is simulated by putting the thread to sleep for a while; NOTE that this flag is not stored to the data dictionary on disk, and the database will forget about value TRUE if it has to reload the table definition from disk */ #endif /* UNIV_DEBUG */ /*----------------------*/ unsigned big_rows:1; /*!< flag: TRUE if the maximum length of a single row exceeds BIG_ROW_SIZE; initialized in dict_table_add_to_cache() */ /** Statistics for query optimization */ /* @{ */ unsigned stat_initialized:1; /*!< TRUE if statistics have been calculated the first time after database startup or table creation */ ib_int64_t stat_n_rows; /*!< approximate number of rows in the table; we periodically calculate new estimates */ ulint stat_clustered_index_size; /*!< approximate clustered index size in database pages */ ulint stat_sum_of_other_index_sizes; /*!< other indexes in database pages */ ulint stat_modified_counter; /*!< when a row is inserted, updated, or deleted, we add 1 to this number; we calculate new estimates for the stat_... values for the table and the indexes at an interval of 2 GB or when about 1 / 16 of table has been modified; also when the estimate operation is called for MySQL SHOW TABLE STATUS; the counter is reset to zero at statistics calculation; this counter is not protected by any latch, because this is only used for heuristics */ /* @} */ /*----------------------*/ /**!< The following fields are used by the AUTOINC code. The actual collection of tables locked during AUTOINC read/write is kept in trx_t. In order to quickly determine whether a transaction has locked the AUTOINC lock we keep a pointer to the transaction here in the autoinc_trx variable. This is to avoid acquiring the kernel mutex and scanning the vector in trx_t. When an AUTOINC lock has to wait, the corresponding lock instance is created on the trx lock heap rather than use the pre-allocated instance in autoinc_lock below.*/ /* @{ */ lock_t* autoinc_lock; /*!< a buffer for an AUTOINC lock for this table: we allocate the memory here so that individual transactions can get it and release it without a need to allocate space from the lock heap of the trx: otherwise the lock heap would grow rapidly if we do a large insert from a select */ mutex_t autoinc_mutex; /*!< mutex protecting the autoincrement counter */ ib_uint64_t autoinc;/*!< autoinc counter value to give to the next inserted row */ ulong n_waiting_or_granted_auto_inc_locks; /*!< This counter is used to track the number of granted and pending autoinc locks on this table. This value is set after acquiring the kernel mutex but we peek the contents to determine whether other transactions have acquired the AUTOINC lock or not. Of course only one transaction can be granted the lock but there can be multiple waiters. */ const trx_t* autoinc_trx; /*!< The transaction that currently holds the the AUTOINC lock on this table. */ /* @} */ /*----------------------*/ #endif /* !UNIV_HOTBACKUP */ #ifdef UNIV_DEBUG ulint magic_n;/*!< magic number */ /** Value of dict_table_struct::magic_n */ # define DICT_TABLE_MAGIC_N 76333786 #endif /* UNIV_DEBUG */ }; #ifndef UNIV_NONINL #include "dict0mem.ic" #endif #endif