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Diffstat (limited to 'sql/sql_sequence.cc')
| -rw-r--r-- | sql/sql_sequence.cc | 993 |
1 files changed, 993 insertions, 0 deletions
diff --git a/sql/sql_sequence.cc b/sql/sql_sequence.cc new file mode 100644 index 00000000..307a0b29 --- /dev/null +++ b/sql/sql_sequence.cc @@ -0,0 +1,993 @@ +/* + Copyright (c) 2017, MariaDB Corporation, Alibaba Corporation + Copyrgiht (c) 2020, MariaDB Corporation. + + 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +*/ + +#include "mariadb.h" +#include "sql_class.h" +#include "sql_list.h" +#include "sql_sequence.h" +#include "ha_sequence.h" +#include "sql_base.h" +#include "sql_table.h" // write_bin_log +#include "transaction.h" +#include "lock.h" +#include "sql_acl.h" + +struct Field_definition +{ + const char *field_name; + uint length; + const Type_handler *type_handler; + LEX_CSTRING comment; + ulong flags; +}; + +/* + Structure for all SEQUENCE tables + + Note that the first field is named "next_val" to all us to have + NEXTVAL a reserved word that will on access be changed to + NEXTVAL(sequence_table). For this to work, the table can't have + a column named NEXTVAL. +*/ + +#define FL (NOT_NULL_FLAG | NO_DEFAULT_VALUE_FLAG) + +static Field_definition sequence_structure[]= +{ + {"next_not_cached_value", 21, &type_handler_slonglong, + {STRING_WITH_LEN("")}, FL}, + {"minimum_value", 21, &type_handler_slonglong, {STRING_WITH_LEN("")}, FL}, + {"maximum_value", 21, &type_handler_slonglong, {STRING_WITH_LEN("")}, FL}, + {"start_value", 21, &type_handler_slonglong, {STRING_WITH_LEN("start value when sequences is created or value if RESTART is used")}, FL}, + {"increment", 21, &type_handler_slonglong, + {STRING_WITH_LEN("increment value")}, FL}, + {"cache_size", 21, &type_handler_ulonglong, {STRING_WITH_LEN("")}, + FL | UNSIGNED_FLAG}, + {"cycle_option", 1, &type_handler_utiny, {STRING_WITH_LEN("0 if no cycles are allowed, 1 if the sequence should begin a new cycle when maximum_value is passed")}, + FL | UNSIGNED_FLAG }, + {"cycle_count", 21, &type_handler_slonglong, + {STRING_WITH_LEN("How many cycles have been done")}, FL}, + {NULL, 0, &type_handler_slonglong, {STRING_WITH_LEN("")}, 0} +}; + +#undef FL + + +#define MAX_AUTO_INCREMENT_VALUE 65535 + +/* + Check whether sequence values are valid. + Sets default values for fields that are not used, according to Oracle spec. + + RETURN VALUES + false valid + true invalid +*/ + +bool sequence_definition::check_and_adjust(bool set_reserved_until) +{ + longlong max_increment; + DBUG_ENTER("sequence_definition::check"); + + if (!(real_increment= increment)) + real_increment= global_system_variables.auto_increment_increment; + + /* + If min_value is not set, set it to LONGLONG_MIN or 1, depending on + real_increment + */ + if (!(used_fields & seq_field_used_min_value)) + min_value= real_increment < 0 ? LONGLONG_MIN+1 : 1; + + /* + If max_value is not set, set it to LONGLONG_MAX or -1, depending on + real_increment + */ + if (!(used_fields & seq_field_used_max_value)) + max_value= real_increment < 0 ? -1 : LONGLONG_MAX-1; + + if (!(used_fields & seq_field_used_start)) + { + /* Use min_value or max_value for start depending on real_increment */ + start= real_increment < 0 ? max_value : min_value; + } + + if (set_reserved_until) + reserved_until= start; + + adjust_values(reserved_until); + + /* To ensure that cache * real_increment will never overflow */ + max_increment= (real_increment ? + llabs(real_increment) : + MAX_AUTO_INCREMENT_VALUE); + + if (max_value >= start && + max_value > min_value && + start >= min_value && + max_value != LONGLONG_MAX && + min_value != LONGLONG_MIN && + cache < (LONGLONG_MAX - max_increment) / max_increment && + ((real_increment > 0 && reserved_until >= min_value) || + (real_increment < 0 && reserved_until <= max_value))) + DBUG_RETURN(FALSE); + + DBUG_RETURN(TRUE); // Error +} + + +/* + Read sequence values from a table +*/ + +void sequence_definition::read_fields(TABLE *table) +{ + MY_BITMAP *old_map= dbug_tmp_use_all_columns(table, &table->read_set); + reserved_until= table->field[0]->val_int(); + min_value= table->field[1]->val_int(); + max_value= table->field[2]->val_int(); + start= table->field[3]->val_int(); + increment= table->field[4]->val_int(); + cache= table->field[5]->val_int(); + cycle= table->field[6]->val_int(); + round= table->field[7]->val_int(); + dbug_tmp_restore_column_map(&table->read_set, old_map); + used_fields= ~(uint) 0; + print_dbug(); +} + + +/* + Store sequence into a table row +*/ + +void sequence_definition::store_fields(TABLE *table) +{ + MY_BITMAP *old_map= dbug_tmp_use_all_columns(table, &table->write_set); + + /* zero possible delete markers & null bits */ + memcpy(table->record[0], table->s->default_values, table->s->null_bytes); + table->field[0]->store(reserved_until, 0); + table->field[1]->store(min_value, 0); + table->field[2]->store(max_value, 0); + table->field[3]->store(start, 0); + table->field[4]->store(increment, 0); + table->field[5]->store(cache, 0); + table->field[6]->store((longlong) cycle != 0, 0); + table->field[7]->store((longlong) round, 1); + + dbug_tmp_restore_column_map(&table->write_set, old_map); + print_dbug(); +} + + +/* + Check the sequence fields through seq_fields when creating a sequence. + + RETURN VALUES + false Success + true Failure +*/ + +bool check_sequence_fields(LEX *lex, List<Create_field> *fields) +{ + Create_field *field; + List_iterator_fast<Create_field> it(*fields); + uint field_count; + uint field_no; + const char *reason; + DBUG_ENTER("check_sequence_fields"); + + field_count= fields->elements; + if (field_count != array_elements(sequence_structure)-1) + { + reason= "Wrong number of columns"; + goto err; + } + if (lex->alter_info.key_list.elements > 0) + { + reason= "Sequence tables cannot have any keys"; + goto err; + } + if (lex->alter_info.check_constraint_list.elements > 0) + { + reason= "Sequence tables cannot have any constraints"; + goto err; + } + if (lex->alter_info.flags & ALTER_ORDER) + { + reason= "ORDER BY"; + goto err; + } + + for (field_no= 0; (field= it++); field_no++) + { + Field_definition *field_def= &sequence_structure[field_no]; + if (my_strcasecmp(system_charset_info, field_def->field_name, + field->field_name.str) || + field->flags != field_def->flags || + field->type_handler() != field_def->type_handler || + field->check_constraint || field->vcol_info) + { + reason= field->field_name.str; + goto err; + } + } + DBUG_RETURN(FALSE); + +err: + my_error(ER_SEQUENCE_INVALID_TABLE_STRUCTURE, MYF(0), + lex->first_select_lex()->table_list.first->db.str, + lex->first_select_lex()->table_list.first->table_name.str, reason); + DBUG_RETURN(TRUE); +} + + +/* + Create the fields for a SEQUENCE TABLE + + RETURN VALUES + false Success + true Failure (out of memory) +*/ + +bool prepare_sequence_fields(THD *thd, List<Create_field> *fields) +{ + Field_definition *field_info; + DBUG_ENTER("prepare_sequence_fields"); + + for (field_info= sequence_structure; field_info->field_name ; field_info++) + { + Create_field *new_field; + LEX_CSTRING field_name= {field_info->field_name, + strlen(field_info->field_name)}; + + if (unlikely(!(new_field= new Create_field()))) + DBUG_RETURN(TRUE); /* purify inspected */ + + new_field->field_name= field_name; + new_field->set_handler(field_info->type_handler); + new_field->length= field_info->length; + new_field->char_length= field_info->length; + new_field->comment= field_info->comment; + new_field->flags= field_info->flags; + if (unlikely(fields->push_back(new_field))) + DBUG_RETURN(TRUE); /* purify inspected */ + } + DBUG_RETURN(FALSE); +} + +/* + Initialize the sequence table record as part of CREATE SEQUENCE + + Store one row with sequence information. + + RETURN VALUES + false Success + true Failure. Error reported. + + NOTES + This function is called as part of CREATE SEQUENCE. When called + there are now active transactions and no open tables. + There is also a MDL lock on the table. +*/ + +bool sequence_insert(THD *thd, LEX *lex, TABLE_LIST *org_table_list) +{ + int error; + TABLE *table; + Reprepare_observer *save_reprepare_observer; + sequence_definition *seq= lex->create_info.seq_create_info; + bool temporary_table= org_table_list->table != 0; + Open_tables_backup open_tables_backup; + Query_tables_list query_tables_list_backup; + TABLE_LIST table_list; // For sequence table + DBUG_ENTER("sequence_insert"); + + /* + seq is 0 if sequence was created with CREATE TABLE instead of + CREATE SEQUENCE + */ + if (!seq) + { + if (!(seq= new (thd->mem_root) sequence_definition)) + DBUG_RETURN(TRUE); + } + + /* If not temporary table */ + if (!temporary_table) + { + /* + The following code works like open_system_tables_for_read() + The idea is: + - Copy the table_list object for the sequence that was created + - Backup the current state of open tables and create a new + environment for open tables without any tables opened + - open the newly sequence table for write + This is safe as the sequence table has a mdl lock thanks to the + create sequence statement that is calling this function + */ + + table_list.init_one_table(&org_table_list->db, + &org_table_list->table_name, + NULL, TL_WRITE_DEFAULT); + table_list.updating= 1; + table_list.open_strategy= TABLE_LIST::OPEN_IF_EXISTS; + table_list.open_type= OT_BASE_ONLY; + + DBUG_ASSERT(!thd->locked_tables_mode || + (thd->variables.option_bits & OPTION_TABLE_LOCK)); + lex->reset_n_backup_query_tables_list(&query_tables_list_backup); + thd->reset_n_backup_open_tables_state(&open_tables_backup); + + /* + The FOR CREATE flag is needed to ensure that ha_open() doesn't try to + read the not yet existing row in the sequence table + */ + thd->open_options|= HA_OPEN_FOR_CREATE; + /* + We have to reset the reprepare observer to be able to open the + table under prepared statements. + */ + save_reprepare_observer= thd->m_reprepare_observer; + thd->m_reprepare_observer= 0; + lex->sql_command= SQLCOM_CREATE_SEQUENCE; + error= open_and_lock_tables(thd, &table_list, FALSE, + MYSQL_LOCK_IGNORE_TIMEOUT | + MYSQL_OPEN_HAS_MDL_LOCK); + thd->open_options&= ~HA_OPEN_FOR_CREATE; + thd->m_reprepare_observer= save_reprepare_observer; + if (unlikely(error)) + { + lex->restore_backup_query_tables_list(&query_tables_list_backup); + thd->restore_backup_open_tables_state(&open_tables_backup); + DBUG_RETURN(error); + } + table= table_list.table; + } + else + table= org_table_list->table; + + seq->reserved_until= seq->start; + error= seq->write_initial_sequence(table); + + if (trans_commit_stmt(thd)) + error= 1; + if (trans_commit_implicit(thd)) + error= 1; + + if (!temporary_table) + { + close_thread_tables(thd); + lex->restore_backup_query_tables_list(&query_tables_list_backup); + thd->restore_backup_open_tables_state(&open_tables_backup); + + /* OPTION_TABLE_LOCK was reset in trans_commit_implicit */ + if (thd->locked_tables_mode) + thd->variables.option_bits|= OPTION_TABLE_LOCK; + } + DBUG_RETURN(error); +} + + +/* Create a SQUENCE object */ + +SEQUENCE::SEQUENCE() :all_values_used(0), initialized(SEQ_UNINTIALIZED) +{ + mysql_rwlock_init(key_LOCK_SEQUENCE, &mutex); +} + +SEQUENCE::~SEQUENCE() +{ + mysql_rwlock_destroy(&mutex); +} + +/* + The following functions is to ensure that we when reserve new values + trough sequence object sequence we have only one writer at at time. + A sequence table can have many readers (trough normal SELECT's). + + We mark that we have a write lock in the table object so that + ha_sequence::ha_write() can check if we have a lock. If already locked, then + ha_write() knows that we are running a sequence operation. If not, then + ha_write() knows that it's an INSERT. +*/ + +void SEQUENCE::write_lock(TABLE *table) +{ + DBUG_ASSERT(((ha_sequence*) table->file)->is_locked() == 0); + mysql_rwlock_wrlock(&mutex); + ((ha_sequence*) table->file)->write_lock(); +} +void SEQUENCE::write_unlock(TABLE *table) +{ + ((ha_sequence*) table->file)->unlock(); + mysql_rwlock_unlock(&mutex); +} +void SEQUENCE::read_lock(TABLE *table) +{ + if (!((ha_sequence*) table->file)->is_locked()) + mysql_rwlock_rdlock(&mutex); +} +void SEQUENCE::read_unlock(TABLE *table) +{ + if (!((ha_sequence*) table->file)->is_locked()) + mysql_rwlock_unlock(&mutex); +} + +/** + Read values from the sequence tables to table_share->sequence. + This is called from ha_open() when the table is not yet locked +*/ + +int SEQUENCE::read_initial_values(TABLE *table) +{ + int error= 0; + enum thr_lock_type save_lock_type; + MDL_request mdl_request; // Empty constructor! + DBUG_ENTER("SEQUENCE::read_initial_values"); + + if (likely(initialized != SEQ_UNINTIALIZED)) + DBUG_RETURN(0); + write_lock(table); + if (likely(initialized == SEQ_UNINTIALIZED)) + { + MYSQL_LOCK *lock; + bool mdl_lock_used= 0; + THD *thd= table->in_use; + bool has_active_transaction= !thd->transaction->stmt.is_empty(); + /* + There is already a mdl_ticket for this table. However, for list_fields + the MDL lock is of type MDL_SHARED_HIGH_PRIO which is not usable + for doing a table lock. Get a proper read lock to solve this. + */ + if (table->mdl_ticket == 0) + { + MDL_request_list mdl_requests; + mdl_lock_used= 1; + /* + This happens if first request is SHOW CREATE TABLE or LIST FIELDS + where we don't have a mdl lock on the table + */ + + MDL_REQUEST_INIT(&mdl_request, MDL_key::TABLE, table->s->db.str, + table->s->table_name.str, MDL_SHARED_READ, + MDL_EXPLICIT); + mdl_requests.push_front(&mdl_request); + if (thd->mdl_context.acquire_locks(&mdl_requests, + thd->variables.lock_wait_timeout)) + { + write_unlock(table); + DBUG_RETURN(HA_ERR_LOCK_WAIT_TIMEOUT); + } + } + save_lock_type= table->reginfo.lock_type; + table->reginfo.lock_type= TL_READ; + if (!(lock= mysql_lock_tables(thd, &table, 1, + MYSQL_LOCK_IGNORE_GLOBAL_READ_ONLY))) + { + if (mdl_lock_used) + thd->mdl_context.release_lock(mdl_request.ticket); + write_unlock(table); + + if (!has_active_transaction && !thd->transaction->stmt.is_empty() && + !thd->in_sub_stmt) + trans_commit_stmt(thd); + DBUG_RETURN(HA_ERR_LOCK_WAIT_TIMEOUT); + } + DBUG_ASSERT(table->reginfo.lock_type == TL_READ); + if (likely(!(error= read_stored_values(table)))) + initialized= SEQ_READY_TO_USE; + mysql_unlock_tables(thd, lock); + if (mdl_lock_used) + thd->mdl_context.release_lock(mdl_request.ticket); + + /* Reset value to default */ + table->reginfo.lock_type= save_lock_type; + /* + Doing mysql_lock_tables() may have started a read only transaction. + If that happend, it's better that we commit it now, as a lot of + code assumes that there is no active stmt transaction directly after + open_tables(). + But we also don't want to commit the stmt transaction while in a + substatement, see MDEV-15977. + */ + if (!has_active_transaction && !thd->transaction->stmt.is_empty() && + !thd->in_sub_stmt) + trans_commit_stmt(thd); + } + write_unlock(table); + DBUG_RETURN(error); +} + + +/* + Do the actiual reading of data from sequence table and + update values in the sequence object. + + Called once from when table is opened +*/ + +int SEQUENCE::read_stored_values(TABLE *table) +{ + int error; + DBUG_ENTER("SEQUENCE::read_stored_values"); + + MY_BITMAP *save_read_set= tmp_use_all_columns(table, &table->read_set); + error= table->file->ha_read_first_row(table->record[0], MAX_KEY); + tmp_restore_column_map(&table->read_set, save_read_set); + + if (unlikely(error)) + { + table->file->print_error(error, MYF(0)); + DBUG_RETURN(error); + } + read_fields(table); + adjust_values(reserved_until); + + all_values_used= 0; + DBUG_RETURN(0); +} + + +/* + Adjust values after reading a the stored state +*/ + +void sequence_definition::adjust_values(longlong next_value) +{ + next_free_value= next_value; + if (!(real_increment= increment)) + { + longlong offset= 0; + longlong off, to_add; + /* Use auto_increment_increment and auto_increment_offset */ + + if ((real_increment= global_system_variables.auto_increment_increment) + != 1) + offset= (global_system_variables.auto_increment_offset % + global_system_variables.auto_increment_increment); + + /* + Ensure that next_free_value has the right offset, so that we + can generate a serie by just adding real_increment. + */ + off= next_free_value % real_increment; + if (off < 0) + off+= real_increment; + to_add= (real_increment + offset - off) % real_increment; + + /* + Check if add will make next_free_value bigger than max_value, + taken into account that next_free_value or max_value addition + may overflow + */ + if (next_free_value > max_value - to_add || + next_free_value + to_add > max_value) + next_free_value= max_value+1; + else + { + next_free_value+= to_add; + DBUG_ASSERT(llabs(next_free_value % real_increment) == offset); + } + } +} + + +/** + Write initial sequence information for CREATE and ALTER to sequence table +*/ + +int sequence_definition::write_initial_sequence(TABLE *table) +{ + int error; + MY_BITMAP *save_write_set; + + store_fields(table); + /* Store the sequence values in table share */ + table->s->sequence->copy(this); + /* + Sequence values will be replicated as a statement + like 'create sequence'. So disable row logging for this table & statement + */ + table->file->row_logging= table->file->row_logging_init= 0; + save_write_set= table->write_set; + table->write_set= &table->s->all_set; + table->s->sequence->initialized= SEQUENCE::SEQ_IN_PREPARE; + error= table->file->ha_write_row(table->record[0]); + table->s->sequence->initialized= SEQUENCE::SEQ_UNINTIALIZED; + table->write_set= save_write_set; + if (unlikely(error)) + table->file->print_error(error, MYF(0)); + else + { + /* + Sequence structure is up to date and table has one row, + sequence is now usable + */ + table->s->sequence->initialized= SEQUENCE::SEQ_READY_TO_USE; + } + return error; +} + + +/** + Store current sequence values into the sequence table +*/ + +int sequence_definition::write(TABLE *table, bool all_fields) +{ + int error; + MY_BITMAP *save_rpl_write_set, *save_write_set, *save_read_set; + DBUG_ASSERT(((ha_sequence*) table->file)->is_locked()); + + save_rpl_write_set= table->rpl_write_set; + if (likely(!all_fields)) + { + /* Only write next_value and round to binary log */ + table->rpl_write_set= &table->def_rpl_write_set; + bitmap_clear_all(table->rpl_write_set); + bitmap_set_bit(table->rpl_write_set, NEXT_FIELD_NO); + bitmap_set_bit(table->rpl_write_set, ROUND_FIELD_NO); + } + else + table->rpl_write_set= &table->s->all_set; + + /* Update table */ + save_write_set= table->write_set; + save_read_set= table->read_set; + table->read_set= table->write_set= &table->s->all_set; + table->file->column_bitmaps_signal(); + store_fields(table); + if (unlikely((error= table->file->ha_write_row(table->record[0])))) + table->file->print_error(error, MYF(0)); + table->rpl_write_set= save_rpl_write_set; + table->read_set= save_read_set; + table->write_set= save_write_set; + table->file->column_bitmaps_signal(); + return error; +} + + +/** + Get next value for sequence + + @param in table Sequence table + @param in second_round + 1 if recursive call (out of values once) + @param out error Set this to <> 0 in case of error + push_warning_printf(WARN_LEVEL_WARN) has been called + + + @retval 0 Next number or error. Check error variable + # Next sequence number + + NOTES: + Return next_free_value and increment next_free_value to next allowed + value or reserved_value if out of range + if next_free_value >= reserved_value reserve a new range by writing + a record to the sequence table. + + The state of the variables: + next_free_value contains next value to use. It may be + bigger than max_value or less than min_value if end of sequence. + reserved_until contains the last value written to the file. All + values up to this one can be used. + If next_free_value >= reserved_until we have to reserve new + values from the sequence. +*/ + +longlong SEQUENCE::next_value(TABLE *table, bool second_round, int *error) +{ + longlong res_value, org_reserved_until, add_to; + bool out_of_values; + DBUG_ENTER("SEQUENCE::next_value"); + + *error= 0; + if (!second_round) + write_lock(table); + + res_value= next_free_value; + next_free_value= increment_value(next_free_value); + + if ((real_increment > 0 && res_value < reserved_until) || + (real_increment < 0 && res_value > reserved_until)) + { + write_unlock(table); + DBUG_RETURN(res_value); + } + + if (all_values_used) + goto err; + + org_reserved_until= reserved_until; + + /* + Out of cached values, reserve 'cache' new ones + The cache value is checked on insert so the following can't + overflow + */ + add_to= cache ? real_increment * cache : real_increment; + out_of_values= 0; + + if (real_increment > 0) + { + if (reserved_until > max_value - add_to || + reserved_until + add_to > max_value) + { + reserved_until= max_value + 1; + out_of_values= res_value >= reserved_until; + } + else + reserved_until+= add_to; + } + else + { + if (reserved_until + add_to < min_value || + reserved_until < min_value - add_to) + { + reserved_until= min_value - 1; + out_of_values= res_value <= reserved_until; + } + else + reserved_until+= add_to; + } + if (out_of_values) + { + if (!cycle || second_round) + goto err; + round++; + reserved_until= real_increment >0 ? min_value : max_value; + adjust_values(reserved_until); // Fix next_free_value + /* + We have to do everything again to ensure that the given range was + not empty, which could happen if increment == 0 + */ + DBUG_RETURN(next_value(table, 1, error)); + } + + if (unlikely((*error= write(table, 0)))) + { + reserved_until= org_reserved_until; + next_free_value= res_value; + } + + write_unlock(table); + DBUG_RETURN(res_value); + +err: + write_unlock(table); + my_error(ER_SEQUENCE_RUN_OUT, MYF(0), table->s->db.str, + table->s->table_name.str); + *error= ER_SEQUENCE_RUN_OUT; + all_values_used= 1; + DBUG_RETURN(0); +} + + +/* + The following functions is to detect if a table has been dropped + and re-created since last call to PREVIOUS VALUE. + + This is needed as we don't delete dropped sequences from THD->sequence + for DROP TABLE. +*/ + +bool SEQUENCE_LAST_VALUE::check_version(TABLE *table) +{ + DBUG_ASSERT(table->s->tabledef_version.length == MY_UUID_SIZE); + return memcmp(table->s->tabledef_version.str, table_version, + MY_UUID_SIZE) != 0; +} + +void SEQUENCE_LAST_VALUE::set_version(TABLE *table) +{ + memcpy(table_version, table->s->tabledef_version.str, MY_UUID_SIZE); +} + +/** + Set the next value for sequence + + @param in table Sequence table + @param in next_val Next free value + @param in next_round Round for 'next_value' (in case of cycles) + @param in is_used 1 if next_val is already used + + @retval 0 ok, value adjusted + -1 value was less than current value + 1 error when storing value + + @comment + A new value is set only if "nextval,next_round" is less than + "next_free_value,round". This is needed as in replication + setvalue() calls may come out to the slave out-of-order. + Storing only the highest value ensures that sequence object will always + contain the highest used value when the slave is promoted to a master. +*/ + +int SEQUENCE::set_value(TABLE *table, longlong next_val, ulonglong next_round, + bool is_used) +{ + int error= -1; + bool needs_to_be_stored= 0; + longlong org_reserved_until= reserved_until; + longlong org_next_free_value= next_free_value; + ulonglong org_round= round; + DBUG_ENTER("SEQUENCE::set_value"); + + write_lock(table); + if (is_used) + next_val= increment_value(next_val); + + if (round > next_round) + goto end; // error = -1 + if (round == next_round) + { + if (real_increment > 0 ? + next_val < next_free_value : + next_val > next_free_value) + goto end; // error = -1 + if (next_val == next_free_value) + { + error= 0; + goto end; + } + } + else if (cycle == 0) + { + // round < next_round && no cycles, which is impossible + my_error(ER_SEQUENCE_RUN_OUT, MYF(0), table->s->db.str, + table->s->table_name.str); + error= 1; + goto end; + } + else + needs_to_be_stored= 1; + + round= next_round; + adjust_values(next_val); + if ((real_increment > 0 ? + next_free_value > reserved_until : + next_free_value < reserved_until) || + needs_to_be_stored) + { + reserved_until= next_free_value; + if (write(table, 0)) + { + reserved_until= org_reserved_until; + next_free_value= org_next_free_value; + round= org_round; + error= 1; + goto end; + } + } + error= 0; + +end: + write_unlock(table); + DBUG_RETURN(error); +} + + +bool Sql_cmd_alter_sequence::execute(THD *thd) +{ + int error= 0; + int trapped_errors= 0; + LEX *lex= thd->lex; + TABLE_LIST *first_table= lex->query_tables; + TABLE *table; + sequence_definition *new_seq= lex->create_info.seq_create_info; + SEQUENCE *seq; + No_such_table_error_handler no_such_table_handler; + DBUG_ENTER("Sql_cmd_alter_sequence::execute"); + + if (check_access(thd, ALTER_ACL, first_table->db.str, + &first_table->grant.privilege, + &first_table->grant.m_internal, + 0, 0)) + DBUG_RETURN(TRUE); /* purecov: inspected */ + + if (check_grant(thd, ALTER_ACL, first_table, FALSE, 1, FALSE)) + DBUG_RETURN(TRUE); /* purecov: inspected */ + + if (if_exists()) + thd->push_internal_handler(&no_such_table_handler); + error= open_and_lock_tables(thd, first_table, FALSE, 0); + if (if_exists()) + { + trapped_errors= no_such_table_handler.safely_trapped_errors(); + thd->pop_internal_handler(); + } + if (unlikely(error)) + { + if (trapped_errors) + { + StringBuffer<FN_REFLEN> tbl_name; + tbl_name.append(&first_table->db); + tbl_name.append('.'); + tbl_name.append(&first_table->table_name); + push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE, + ER_UNKNOWN_SEQUENCES, + ER_THD(thd, ER_UNKNOWN_SEQUENCES), + tbl_name.c_ptr_safe()); + my_ok(thd); + DBUG_RETURN(FALSE); + } + DBUG_RETURN(TRUE); + } + + table= first_table->table; + seq= table->s->sequence; + + seq->write_lock(table); + new_seq->reserved_until= seq->reserved_until; + + /* Copy from old sequence those fields that the user didn't specified */ + if (!(new_seq->used_fields & seq_field_used_increment)) + new_seq->increment= seq->increment; + if (!(new_seq->used_fields & seq_field_used_min_value)) + new_seq->min_value= seq->min_value; + if (!(new_seq->used_fields & seq_field_used_max_value)) + new_seq->max_value= seq->max_value; + if (!(new_seq->used_fields & seq_field_used_start)) + new_seq->start= seq->start; + if (!(new_seq->used_fields & seq_field_used_cache)) + new_seq->cache= seq->cache; + if (!(new_seq->used_fields & seq_field_used_cycle)) + new_seq->cycle= seq->cycle; + + /* If we should restart from a new value */ + if (new_seq->used_fields & seq_field_used_restart) + { + if (!(new_seq->used_fields & seq_field_used_restart_value)) + new_seq->restart= new_seq->start; + new_seq->reserved_until= new_seq->restart; + } + + /* Let check_and_adjust think all fields are used */ + new_seq->used_fields= ~0; + if (new_seq->check_and_adjust(0)) + { + my_error(ER_SEQUENCE_INVALID_DATA, MYF(0), + first_table->db.str, + first_table->table_name.str); + error= 1; + seq->write_unlock(table); + goto end; + } + + if (likely(!(error= new_seq->write(table, 1)))) + { + /* Store the sequence values in table share */ + seq->copy(new_seq); + } + else + table->file->print_error(error, MYF(0)); + seq->write_unlock(table); + if (trans_commit_stmt(thd)) + error= 1; + if (trans_commit_implicit(thd)) + error= 1; + if (likely(!error)) + error= write_bin_log(thd, 1, thd->query(), thd->query_length()); + if (likely(!error)) + my_ok(thd); + +end: + DBUG_RETURN(error); +} |