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irix-657m-src/eoe/cmd/sss/ssdb/ssdbserver/sql/sql_delete.cc
2022-09-29 17:59:04 +03:00

152 lines
4.1 KiB
C++

/* Copyright (C) 1979-1996 TcX AB & Monty Program KB & Detron HB
This software is distributed with NO WARRANTY OF ANY KIND. No author or
distributor accepts any responsibility for the consequences of using it, or
for whether it serves any particular purpose or works at all, unless he or
she says so in writing. Refer to the Free Public License (the "License")
for full details.
Every copy of this file must include a copy of the License, normally in a
plain ASCII text file named PUBLIC. The License grants you the right to
copy, modify and redistribute this file, but only under certain conditions
described in the License. Among other things, the License requires that
the copyright notice and this notice be preserved on all copies. */
/* Delete of records */
#include "mysql_priv.h"
/*
Optimize delete of all rows by doing a full generate of the table
This will work even if the .ISM and .ISD tables are destroyed
*/
static int generate_table(THD *thd, TABLE_LIST *table_list,
TABLE *locked_table)
{
char path[FN_REFLEN];
int error;
DBUG_ENTER("generate_table");
thd->proc_info="generate_table";
(void) sprintf(path,"%s/%s/%s%s",mysql_data_home,table_list->db,
table_list->real_name,reg_ext);
VOID(pthread_mutex_lock(&LOCK_open));
if (locked_table)
mysql_lock_abort(locked_table); // end threads waiting on lock
// close all copies in use
if (remove_table_from_cache(table_list->db,table_list->real_name))
{
if (!locked_table)
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(1); // We must get a lock on table
}
}
if (locked_table)
VOID(ha_extra(locked_table,HA_EXTRA_FORCE_REOPEN)); // Close all NISAM files
close_data_tables(thd,table_list->db,table_list->real_name);
error= cre_database(path) ? -1 : 0;
if (reopen_tables(thd,1,0))
error= -1;
VOID(pthread_mutex_unlock(&LOCK_open));
if (!error)
{
send_ok(&thd->net); // This should return record count
mysql_update_log.write(thd->query);
}
DBUG_RETURN(error ? -1 : 0);
}
int mysql_delete(THD *thd,TABLE_LIST *table_list,COND *conds,ha_rows limit,
bool low_priority)
{
int error;
TABLE *table;
SQL_SELECT *select;
READ_RECORD info;
DBUG_ENTER("mysql_delete");
if (!table_list->db)
table_list->db=thd->db;
if (!conds && ! thd->open_tables)
{
error=generate_table(thd,table_list,(TABLE*) 0);
if (error <= 0)
DBUG_RETURN(error); // Error or ok
}
if (!(table = open_ltable(thd,table_list,
low_priority || limit != HA_POS_ERROR ?
TL_WRITE_DELAYED : TL_WRITE)))
DBUG_RETURN(-1);
thd->proc_info="init";
if (!conds)
DBUG_RETURN(generate_table(thd,table_list,table));
table->map=1;
if (setup_conds(thd,table_list,conds))
DBUG_RETURN(-1);
table->used_keys=0; // Can't use 'only index'
select=make_select(&table,1,0,1,conds,&error);
if (error)
DBUG_RETURN(-1);
if (select && select->check_quick())
{
delete select;
send_ok(&thd->net,0L);
DBUG_RETURN(0);
}
VOID(ha_extra(table,HA_EXTRA_NO_READCHECK));
init_read_record(&info,table,select,0);
ulong deleted=0L;
thd->proc_info="updating";
while ((error=info.read_record(&info)) <= 0 && !thd->killed)
{
if (error == 0 && !(select && select->skipp_record()))
{
if (!(error=ha_delete(table,table->record[0])))
{
deleted++;
if (limit != HA_POS_ERROR && !--limit)
{
error=HA_ERR_END_OF_FILE;
break;
}
}
else
{
ha_error(table,error,MYF(0));
error=0;
break;
}
}
}
thd->proc_info="end";
end_read_record(&info);
VOID(ha_extra(table,HA_EXTRA_READCHECK));
if (deleted)
mysql_update_log.write(thd->query);
if (thd->lock)
{
mysql_unlock_tables(thd->lock);
thd->lock=0;
}
delete select;
if (error != HA_ERR_END_OF_FILE)
{
ha_error(table,error,MYF(0)); /* purecov: inspected */
error= -1; /* purecov: inspected */
}
if (error <= 0)
send_error(&thd->net,thd->killed ? ER_SERVER_SHUTDOWN: 0);
else
{
send_ok(&thd->net,deleted);
DBUG_PRINT("info",("%d records deleted",deleted));
}
DBUG_RETURN(0);
}