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mariadb/sql/sql_class.cc
unknown 54b00f5453 A fix and test case for Bug#5985 ""prepare stmt from "select rand(?)" 
crashes server." The fix makes Item_func_rand prepared-statements
aware plus it fixes the case when RAND is used in prepared
statements and replication is on (as well as several similar issues).
Until now we did not reset THD before every execution of a prepared
statement, so if some execution had set thd->time_zone_used
or thd->rand_used they would not be reset until next mysql_parse.
Some of post-review fixes done.


mysql-test/r/ps.result:
  A test case for Bug#5985: test results fixed.
mysql-test/t/ps.test:
  A test case for Bug#5985 "prepare stmt from "select rand(?)" crashes
  server."
sql/item_func.cc:
  Actual fix for Bug#5985: Item_func_rand rewritten to be 
  prepared statements aware.
sql/item_func.h:
  Actual fix for Bug#5985: Item_func_rand rewritten to be 
  prepared statements aware.
sql/mysql_priv.h:
  We need a separate call to reset THD state before every execute of
  a prepared statement. Otherwise things like THD->user_var_events
  are never cleaned up and bloat binary log (as the list of events
  grows from execution to execution).
sql/sql_class.cc:
  Statement::end_statement -> THD::end_statement()
  (a leftover from some design change which is not to pushed now, but the
  leftover is to be pushed).
sql/sql_class.h:
  Statement::end_statement -> THD::end_statement()
  (a leftover from some design change which is not to pushed now, but the
  leftover is to be pushed).
sql/sql_lex.cc:
  Move the part responsible for initializing LEX from mysql_init_query
  to lex_start.
sql/sql_lex.h:
  All lex-related initialization is now in lex_start.
  Move thd->select_number to lex->select_number to be able to use it
  easily in lex_start.
sql/sql_parse.cc:
  Split mysql_init_query into two functions: mysql_reset_thd_for_next_query,
  which is used in PS and conventional execution, and lex_start, used only
  when we want to parse something.
  Fix init_connect to use initialized THD.
sql/sql_prepare.cc:
  Deploy mysql_reset_thd_for_next_query to reset THD state before
  execution of a prepared statement.
  Normally this should have been added to just one place, but
  we have to reset thd before assigning placeholders from variables,
  thus we can't do that in execute_stmt (yuck).
2004-10-14 02:53:59 +04:00

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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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; either version 2 of the License, or
(at your option) any later version.
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 */
/*****************************************************************************
**
** This file implements classes defined in sql_class.h
** Especially the classes to handle a result from a select
**
*****************************************************************************/
#ifdef __GNUC__
#pragma implementation // gcc: Class implementation
#endif
#include "mysql_priv.h"
#include "sql_acl.h"
#include <m_ctype.h>
#include <sys/stat.h>
#include <thr_alarm.h>
#ifdef __WIN__
#include <io.h>
#endif
#include <mysys_err.h>
/*
The following is used to initialise Table_ident with a internal
table name
*/
char internal_table_name[2]= "*";
/*****************************************************************************
** Instansiate templates
*****************************************************************************/
#ifdef __GNUC__
/* Used templates */
template class List<Key>;
template class List_iterator<Key>;
template class List<key_part_spec>;
template class List_iterator<key_part_spec>;
template class List<Alter_drop>;
template class List_iterator<Alter_drop>;
template class List<Alter_column>;
template class List_iterator<Alter_column>;
#endif
/****************************************************************************
** User variables
****************************************************************************/
extern "C" byte *get_var_key(user_var_entry *entry, uint *length,
my_bool not_used __attribute__((unused)))
{
*length=(uint) entry->name.length;
return (byte*) entry->name.str;
}
extern "C" void free_user_var(user_var_entry *entry)
{
char *pos= (char*) entry+ALIGN_SIZE(sizeof(*entry));
if (entry->value && entry->value != pos)
my_free(entry->value, MYF(0));
my_free((char*) entry,MYF(0));
}
bool key_part_spec::operator==(const key_part_spec& other) const
{
return length == other.length && !strcmp(field_name, other.field_name);
}
/*
Test if a foreign key (= generated key) is a prefix of the given key
(ignoring key name, key type and order of columns)
NOTES:
This is only used to test if an index for a FOREIGN KEY exists
IMPLEMENTATION
We only compare field names
RETURN
0 Generated key is a prefix of other key
1 Not equal
*/
bool foreign_key_prefix(Key *a, Key *b)
{
/* Ensure that 'a' is the generated key */
if (a->generated)
{
if (b->generated && a->columns.elements > b->columns.elements)
swap_variables(Key*, a, b); // Put shorter key in 'a'
}
else
{
if (!b->generated)
return TRUE; // No foreign key
swap_variables(Key*, a, b); // Put generated key in 'a'
}
/* Test if 'a' is a prefix of 'b' */
if (a->columns.elements > b->columns.elements)
return TRUE; // Can't be prefix
List_iterator<key_part_spec> col_it1(a->columns);
List_iterator<key_part_spec> col_it2(b->columns);
const key_part_spec *col1, *col2;
#ifdef ENABLE_WHEN_INNODB_CAN_HANDLE_SWAPED_FOREIGN_KEY_COLUMNS
while ((col1= col_it1++))
{
bool found= 0;
col_it2.rewind();
while ((col2= col_it2++))
{
if (*col1 == *col2)
{
found= TRUE;
break;
}
}
if (!found)
return TRUE; // Error
}
return FALSE; // Is prefix
#else
while ((col1= col_it1++))
{
col2= col_it2++;
if (!(*col1 == *col2))
return TRUE;
}
return FALSE; // Is prefix
#endif
}
/****************************************************************************
** Thread specific functions
****************************************************************************/
THD::THD()
:user_time(0), global_read_lock(0), is_fatal_error(0),
last_insert_id_used(0),
insert_id_used(0), rand_used(0), time_zone_used(0),
in_lock_tables(0), bootstrap(0)
{
current_arena= this;
host= user= priv_user= db= ip=0;
host_or_ip= "connecting host";
locked=some_tables_deleted=no_errors=password= 0;
killed=0;
query_start_used= 0;
count_cuted_fields= CHECK_FIELD_IGNORE;
db_length= col_access= 0;
query_error= tmp_table_used= 0;
next_insert_id=last_insert_id=0;
open_tables= temporary_tables= handler_tables= derived_tables= 0;
hash_clear(&handler_tables_hash);
tmp_table=0;
lock=locked_tables=0;
used_tables=0;
cuted_fields= sent_row_count= 0L;
statement_id_counter= 0UL;
// Must be reset to handle error with THD's created for init of mysqld
lex->current_select= 0;
start_time=(time_t) 0;
current_linfo = 0;
slave_thread = 0;
variables.pseudo_thread_id= 0;
one_shot_set= 0;
file_id = 0;
warn_id= 0;
db_charset= global_system_variables.collation_database;
mysys_var=0;
#ifndef DBUG_OFF
dbug_sentry=THD_SENTRY_MAGIC;
#endif
#ifndef EMBEDDED_LIBRARY
net.vio=0;
#endif
net.last_error[0]=0; // If error on boot
ull=0;
system_thread=cleanup_done=0;
peer_port= 0; // For SHOW PROCESSLIST
transaction.changed_tables = 0;
#ifdef __WIN__
real_id = 0;
#endif
#ifdef SIGNAL_WITH_VIO_CLOSE
active_vio = 0;
#endif
pthread_mutex_init(&LOCK_delete, MY_MUTEX_INIT_FAST);
/* Variables with default values */
proc_info="login";
where="field list";
server_id = ::server_id;
slave_net = 0;
command=COM_CONNECT;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
db_access=NO_ACCESS;
#endif
version=refresh_version; // For boot
*scramble= '\0';
init();
/* Initialize sub structures */
init_alloc_root(&warn_root, WARN_ALLOC_BLOCK_SIZE, WARN_ALLOC_PREALLOC_SIZE);
user_connect=(USER_CONN *)0;
hash_init(&user_vars, &my_charset_bin, USER_VARS_HASH_SIZE, 0, 0,
(hash_get_key) get_var_key,
(hash_free_key) free_user_var,0);
/* For user vars replication*/
if (opt_bin_log)
my_init_dynamic_array(&user_var_events,
sizeof(BINLOG_USER_VAR_EVENT *),
16,
16);
else
bzero((char*) &user_var_events, sizeof(user_var_events));
/* Protocol */
protocol= &protocol_simple; // Default protocol
protocol_simple.init(this);
protocol_prep.init(this);
tablespace_op=FALSE;
#ifdef USING_TRANSACTIONS
bzero((char*) &transaction,sizeof(transaction));
/*
Binlog is always open (if needed) before a THD is created (including
bootstrap).
*/
if (opt_using_transactions && mysql_bin_log.is_open())
{
if (open_cached_file(&transaction.trans_log,
mysql_tmpdir, LOG_PREFIX, binlog_cache_size,
MYF(MY_WME)))
killed=1;
transaction.trans_log.end_of_file= max_binlog_cache_size;
}
#endif
init_alloc_root(&transaction.mem_root, ALLOC_ROOT_MIN_BLOCK_SIZE, 0);
{
ulong tmp=sql_rnd_with_mutex();
randominit(&rand, tmp + (ulong) &rand, tmp + (ulong) ::query_id);
}
}
/*
Init common variables that has to be reset on start and on change_user
*/
void THD::init(void)
{
pthread_mutex_lock(&LOCK_global_system_variables);
variables= global_system_variables;
variables.time_format= date_time_format_copy((THD*) 0,
variables.time_format);
variables.date_format= date_time_format_copy((THD*) 0,
variables.date_format);
variables.datetime_format= date_time_format_copy((THD*) 0,
variables.datetime_format);
pthread_mutex_unlock(&LOCK_global_system_variables);
server_status= SERVER_STATUS_AUTOCOMMIT;
options= thd_startup_options;
open_options=ha_open_options;
update_lock_default= (variables.low_priority_updates ?
TL_WRITE_LOW_PRIORITY :
TL_WRITE);
session_tx_isolation= (enum_tx_isolation) variables.tx_isolation;
warn_list.empty();
bzero((char*) warn_count, sizeof(warn_count));
total_warn_count= 0;
update_charset();
}
/*
Init THD for query processing.
This has to be called once before we call mysql_parse.
See also comments in sql_class.h.
*/
void THD::init_for_queries()
{
ha_enable_transaction(this,TRUE);
reset_root_defaults(&mem_root, variables.query_alloc_block_size,
variables.query_prealloc_size);
reset_root_defaults(&transaction.mem_root,
variables.trans_alloc_block_size,
variables.trans_prealloc_size);
}
/*
Do what's needed when one invokes change user
SYNOPSIS
change_user()
IMPLEMENTATION
Reset all resources that are connection specific
*/
void THD::change_user(void)
{
cleanup();
cleanup_done= 0;
init();
stmt_map.reset();
hash_init(&user_vars, &my_charset_bin, USER_VARS_HASH_SIZE, 0, 0,
(hash_get_key) get_var_key,
(hash_free_key) free_user_var, 0);
}
/* Do operations that may take a long time */
void THD::cleanup(void)
{
DBUG_ENTER("THD::cleanup");
ha_rollback(this);
if (locked_tables)
{
lock=locked_tables; locked_tables=0;
close_thread_tables(this);
}
mysql_ha_flush(this, (TABLE_LIST*) 0,
MYSQL_HA_CLOSE_FINAL | MYSQL_HA_FLUSH_ALL);
hash_free(&handler_tables_hash);
close_temporary_tables(this);
my_free((char*) variables.time_format, MYF(MY_ALLOW_ZERO_PTR));
my_free((char*) variables.date_format, MYF(MY_ALLOW_ZERO_PTR));
my_free((char*) variables.datetime_format, MYF(MY_ALLOW_ZERO_PTR));
delete_dynamic(&user_var_events);
hash_free(&user_vars);
if (global_read_lock)
unlock_global_read_lock(this);
if (ull)
{
pthread_mutex_lock(&LOCK_user_locks);
item_user_lock_release(ull);
pthread_mutex_unlock(&LOCK_user_locks);
ull= 0;
}
cleanup_done=1;
DBUG_VOID_RETURN;
}
THD::~THD()
{
THD_CHECK_SENTRY(this);
DBUG_ENTER("~THD()");
/* Ensure that no one is using THD */
pthread_mutex_lock(&LOCK_delete);
pthread_mutex_unlock(&LOCK_delete);
/* Close connection */
#ifndef EMBEDDED_LIBRARY
if (net.vio)
{
vio_delete(net.vio);
net_end(&net);
}
#endif
if (!cleanup_done)
cleanup();
#ifdef USING_TRANSACTIONS
if (opt_using_transactions)
{
close_cached_file(&transaction.trans_log);
ha_close_connection(this);
}
#endif
DBUG_PRINT("info", ("freeing host"));
if (host != my_localhost) // If not pointer to constant
safeFree(host);
if (user != delayed_user)
safeFree(user);
safeFree(ip);
safeFree(db);
free_root(&warn_root,MYF(0));
free_root(&transaction.mem_root,MYF(0));
mysys_var=0; // Safety (shouldn't be needed)
pthread_mutex_destroy(&LOCK_delete);
#ifndef DBUG_OFF
dbug_sentry = THD_SENTRY_GONE;
#endif
/* Reset stmt_backup.mem_root to not double-free memory from thd.mem_root */
clear_alloc_root(&stmt_backup.mem_root);
DBUG_VOID_RETURN;
}
void THD::awake(bool prepare_to_die)
{
THD_CHECK_SENTRY(this);
safe_mutex_assert_owner(&LOCK_delete);
if (prepare_to_die)
killed = 1;
thr_alarm_kill(real_id);
#ifdef SIGNAL_WITH_VIO_CLOSE
close_active_vio();
#endif
if (mysys_var)
{
pthread_mutex_lock(&mysys_var->mutex);
if (!system_thread) // Don't abort locks
mysys_var->abort=1;
/*
This broadcast could be up in the air if the victim thread
exits the cond in the time between read and broadcast, but that is
ok since all we want to do is to make the victim thread get out
of waiting on current_cond.
If we see a non-zero current_cond: it cannot be an old value (because
then exit_cond() should have run and it can't because we have mutex); so
it is the true value but maybe current_mutex is not yet non-zero (we're
in the middle of enter_cond() and there is a "memory order
inversion"). So we test the mutex too to not lock 0.
Note that there is a small chance we fail to kill. If victim has locked
current_mutex, but hasn't yet entered enter_cond() (which means that
current_cond and current_mutex are 0), then the victim will not get
a signal and it may wait "forever" on the cond (until
we issue a second KILL or the status it's waiting for happens).
It's true that we have set its thd->killed but it may not
see it immediately and so may have time to reach the cond_wait().
*/
if (mysys_var->current_cond && mysys_var->current_mutex)
{
pthread_mutex_lock(mysys_var->current_mutex);
pthread_cond_broadcast(mysys_var->current_cond);
pthread_mutex_unlock(mysys_var->current_mutex);
}
pthread_mutex_unlock(&mysys_var->mutex);
}
}
/*
Remember the location of thread info, the structure needed for
sql_alloc() and the structure for the net buffer
*/
bool THD::store_globals()
{
if (my_pthread_setspecific_ptr(THR_THD, this) ||
my_pthread_setspecific_ptr(THR_MALLOC, &mem_root))
return 1;
mysys_var=my_thread_var;
dbug_thread_id=my_thread_id();
/*
By default 'slave_proxy_id' is 'thread_id'. They may later become different
if this is the slave SQL thread.
*/
variables.pseudo_thread_id= thread_id;
return 0;
}
/*
Convert a string to another character set
SYNOPSIS
convert_string()
to Store new allocated string here
to_cs New character set for allocated string
from String to convert
from_length Length of string to convert
from_cs Original character set
NOTES
to will be 0-terminated to make it easy to pass to system funcs
RETURN
0 ok
1 End of memory.
In this case to->str will point to 0 and to->length will be 0.
*/
bool THD::convert_string(LEX_STRING *to, CHARSET_INFO *to_cs,
const char *from, uint from_length,
CHARSET_INFO *from_cs)
{
DBUG_ENTER("convert_string");
size_s new_length= to_cs->mbmaxlen * from_length;
if (!(to->str= alloc(new_length+1)))
{
to->length= 0; // Safety fix
DBUG_RETURN(1); // EOM
}
to->length= copy_and_convert((char*) to->str, new_length, to_cs,
from, from_length, from_cs);
to->str[to->length]=0; // Safety
DBUG_RETURN(0);
}
/*
Convert string from source character set to target character set inplace.
SYNOPSIS
THD::convert_string
DESCRIPTION
Convert string using convert_buffer - buffer for character set
conversion shared between all protocols.
RETURN
0 ok
!0 out of memory
*/
bool THD::convert_string(String *s, CHARSET_INFO *from_cs, CHARSET_INFO *to_cs)
{
if (convert_buffer.copy(s->ptr(), s->length(), from_cs, to_cs))
return TRUE;
/* If convert_buffer >> s copying is more efficient long term */
if (convert_buffer.alloced_length() >= convert_buffer.length() * 2 ||
!s->is_alloced())
{
return s->copy(convert_buffer);
}
s->swap(convert_buffer);
return FALSE;
}
/*
Update some cache variables when character set changes
*/
void THD::update_charset()
{
uint32 not_used;
charset_is_system_charset= !String::needs_conversion(0,charset(),
system_charset_info,
&not_used);
charset_is_collation_connection=
!String::needs_conversion(0,charset(),variables.collation_connection,
&not_used);
}
/* routings to adding tables to list of changed in transaction tables */
inline static void list_include(CHANGED_TABLE_LIST** prev,
CHANGED_TABLE_LIST* curr,
CHANGED_TABLE_LIST* new_table)
{
if (new_table)
{
*prev = new_table;
(*prev)->next = curr;
}
}
/* add table to list of changed in transaction tables */
void THD::add_changed_table(TABLE *table)
{
DBUG_ENTER("THD::add_changed_table(table)");
DBUG_ASSERT((options & (OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN)) &&
table->file->has_transactions());
add_changed_table(table->table_cache_key, table->key_length);
DBUG_VOID_RETURN;
}
void THD::add_changed_table(const char *key, long key_length)
{
DBUG_ENTER("THD::add_changed_table(key)");
CHANGED_TABLE_LIST **prev_changed = &transaction.changed_tables;
CHANGED_TABLE_LIST *curr = transaction.changed_tables;
for (; curr; prev_changed = &(curr->next), curr = curr->next)
{
int cmp = (long)curr->key_length - (long)key_length;
if (cmp < 0)
{
list_include(prev_changed, curr, changed_table_dup(key, key_length));
DBUG_PRINT("info",
("key_length %u %u", key_length, (*prev_changed)->key_length));
DBUG_VOID_RETURN;
}
else if (cmp == 0)
{
cmp = memcmp(curr->key, key, curr->key_length);
if (cmp < 0)
{
list_include(prev_changed, curr, changed_table_dup(key, key_length));
DBUG_PRINT("info",
("key_length %u %u", key_length,
(*prev_changed)->key_length));
DBUG_VOID_RETURN;
}
else if (cmp == 0)
{
DBUG_PRINT("info", ("already in list"));
DBUG_VOID_RETURN;
}
}
}
*prev_changed = changed_table_dup(key, key_length);
DBUG_PRINT("info", ("key_length %u %u", key_length,
(*prev_changed)->key_length));
DBUG_VOID_RETURN;
}
CHANGED_TABLE_LIST* THD::changed_table_dup(const char *key, long key_length)
{
CHANGED_TABLE_LIST* new_table =
(CHANGED_TABLE_LIST*) trans_alloc(ALIGN_SIZE(sizeof(CHANGED_TABLE_LIST))+
key_length + 1);
if (!new_table)
{
my_error(EE_OUTOFMEMORY, MYF(ME_BELL),
ALIGN_SIZE(sizeof(TABLE_LIST)) + key_length + 1);
killed= 1;
return 0;
}
new_table->key = (char *) (((byte*)new_table)+
ALIGN_SIZE(sizeof(CHANGED_TABLE_LIST)));
new_table->next = 0;
new_table->key_length = key_length;
::memcpy(new_table->key, key, key_length);
return new_table;
}
int THD::send_explain_fields(select_result *result)
{
List<Item> field_list;
Item *item;
CHARSET_INFO *cs= system_charset_info;
field_list.push_back(new Item_return_int("id",3, MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_empty_string("select_type", 19, cs));
field_list.push_back(new Item_empty_string("table", NAME_LEN, cs));
field_list.push_back(new Item_empty_string("type", 10, cs));
field_list.push_back(item=new Item_empty_string("possible_keys",
NAME_LEN*MAX_KEY, cs));
item->maybe_null=1;
field_list.push_back(item=new Item_empty_string("key", NAME_LEN, cs));
item->maybe_null=1;
field_list.push_back(item=new Item_return_int("key_len",3,
MYSQL_TYPE_LONGLONG));
item->maybe_null=1;
field_list.push_back(item=new Item_empty_string("ref",
NAME_LEN*MAX_REF_PARTS, cs));
item->maybe_null=1;
field_list.push_back(new Item_return_int("rows", 10, MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_empty_string("Extra", 255, cs));
return (result->send_fields(field_list,1));
}
#ifdef SIGNAL_WITH_VIO_CLOSE
void THD::close_active_vio()
{
DBUG_ENTER("close_active_vio");
safe_mutex_assert_owner(&LOCK_delete);
#ifndef EMBEDDED_LIBRARY
if (active_vio)
{
vio_close(active_vio);
active_vio = 0;
}
#endif
DBUG_VOID_RETURN;
}
#endif
struct Item_change_record: public ilink
{
Item **place;
Item *old_value;
/* Placement new was hidden by `new' in ilink (TODO: check): */
static void *operator new(size_t size, void *mem) { return mem; }
};
/*
Register an item tree tree transformation, performed by the query
optimizer. We need a pointer to runtime_memroot because it may be !=
thd->mem_root (due to possible set_n_backup_item_arena called for thd).
*/
void THD::nocheck_register_item_tree_change(Item **place, Item *old_value,
MEM_ROOT *runtime_memroot)
{
Item_change_record *change;
/*
Now we use one node per change, which adds some memory overhead,
but still is rather fast as we use alloc_root for allocations.
A list of item tree changes of an average query should be short.
*/
void *change_mem= alloc_root(runtime_memroot, sizeof(*change));
if (change_mem == 0)
{
fatal_error();
return;
}
change= new (change_mem) Item_change_record;
change->place= place;
change->old_value= old_value;
change_list.append(change);
}
void THD::rollback_item_tree_changes()
{
I_List_iterator<Item_change_record> it(change_list);
Item_change_record *change;
while ((change= it++))
*change->place= change->old_value;
/* We can forget about changes memory: it's allocated in runtime memroot */
change_list.empty();
}
/*****************************************************************************
** Functions to provide a interface to select results
*****************************************************************************/
select_result::select_result()
{
thd=current_thd;
}
void select_result::send_error(uint errcode,const char *err)
{
::send_error(thd, errcode, err);
}
void select_result::cleanup()
{
/* do nothing */
}
static String default_line_term("\n",default_charset_info);
static String default_escaped("\\",default_charset_info);
static String default_field_term("\t",default_charset_info);
sql_exchange::sql_exchange(char *name,bool flag)
:file_name(name), opt_enclosed(0), dumpfile(flag), skip_lines(0)
{
field_term= &default_field_term;
enclosed= line_start= &my_empty_string;
line_term= &default_line_term;
escaped= &default_escaped;
}
bool select_send::send_fields(List<Item> &list,uint flag)
{
return thd->protocol->send_fields(&list,flag);
}
/* Send data to client. Returns 0 if ok */
bool select_send::send_data(List<Item> &items)
{
if (unit->offset_limit_cnt)
{ // using limit offset,count
unit->offset_limit_cnt--;
return 0;
}
#ifdef HAVE_INNOBASE_DB
/*
We may be passing the control from mysqld to the client: release the
InnoDB adaptive hash S-latch to avoid thread deadlocks if it was reserved
by thd
*/
if (thd->transaction.all.innobase_tid)
ha_release_temporary_latches(thd);
#endif
List_iterator_fast<Item> li(items);
Protocol *protocol= thd->protocol;
char buff[MAX_FIELD_WIDTH];
String buffer(buff, sizeof(buff), &my_charset_bin);
DBUG_ENTER("send_data");
protocol->prepare_for_resend();
Item *item;
while ((item=li++))
{
if (item->send(protocol, &buffer))
{
protocol->free(); // Free used buffer
my_message(ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES), MYF(0));
break;
}
}
thd->sent_row_count++;
if (!thd->vio_ok())
DBUG_RETURN(0);
if (!thd->net.report_error)
DBUG_RETURN(protocol->write());
DBUG_RETURN(1);
}
bool select_send::send_eof()
{
#ifdef HAVE_INNOBASE_DB
/* We may be passing the control from mysqld to the client: release the
InnoDB adaptive hash S-latch to avoid thread deadlocks if it was reserved
by thd */
if (thd->transaction.all.innobase_tid)
ha_release_temporary_latches(thd);
#endif
/* Unlock tables before sending packet to gain some speed */
if (thd->lock)
{
mysql_unlock_tables(thd, thd->lock); thd->lock=0;
}
if (!thd->net.report_error)
{
::send_eof(thd);
return 0;
}
else
return 1;
}
/************************************************************************
Handling writing to file
************************************************************************/
void select_to_file::send_error(uint errcode,const char *err)
{
::send_error(thd,errcode,err);
if (file > 0)
{
(void) end_io_cache(&cache);
(void) my_close(file,MYF(0));
(void) my_delete(path,MYF(0)); // Delete file on error
file= -1;
}
}
bool select_to_file::send_eof()
{
int error= test(end_io_cache(&cache));
if (my_close(file,MYF(MY_WME)))
error= 1;
if (!error)
::send_ok(thd,row_count);
file= -1;
return error;
}
void select_to_file::cleanup()
{
/* In case of error send_eof() may be not called: close the file here. */
if (file >= 0)
{
(void) end_io_cache(&cache);
(void) my_close(file,MYF(0));
file= -1;
}
path[0]= '\0';
row_count= 0;
}
select_to_file::~select_to_file()
{
if (file >= 0)
{ // This only happens in case of error
(void) end_io_cache(&cache);
(void) my_close(file,MYF(0));
file= -1;
}
}
/***************************************************************************
** Export of select to textfile
***************************************************************************/
select_export::~select_export()
{
thd->sent_row_count=row_count;
}
/*
Create file with IO cache
SYNOPSIS
create_file()
thd Thread handle
path File name
exchange Excange class
cache IO cache
RETURN
>= 0 File handle
-1 Error
*/
static File create_file(THD *thd, char *path, sql_exchange *exchange,
IO_CACHE *cache)
{
File file;
uint option= MY_UNPACK_FILENAME;
#ifdef DONT_ALLOW_FULL_LOAD_DATA_PATHS
option|= MY_REPLACE_DIR; // Force use of db directory
#endif
if (!dirname_length(exchange->file_name))
{
strxnmov(path, FN_REFLEN, mysql_real_data_home, thd->db ? thd->db : "", NullS);
(void) fn_format(path, exchange->file_name, path, "", option);
}
else
(void) fn_format(path, exchange->file_name, mysql_real_data_home, "", option);
if (!access(path, F_OK))
{
my_error(ER_FILE_EXISTS_ERROR, MYF(0), exchange->file_name);
return -1;
}
/* Create the file world readable */
if ((file= my_create(path, 0666, O_WRONLY, MYF(MY_WME))) < 0)
return file;
#ifdef HAVE_FCHMOD
(void) fchmod(file, 0666); // Because of umask()
#else
(void) chmod(path, 0666);
#endif
if (init_io_cache(cache, file, 0L, WRITE_CACHE, 0L, 1, MYF(MY_WME)))
{
my_close(file, MYF(0));
my_delete(path, MYF(0)); // Delete file on error, it was just created
return -1;
}
return file;
}
int
select_export::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
{
bool blob_flag=0;
unit= u;
if ((uint) strlen(exchange->file_name) + NAME_LEN >= FN_REFLEN)
strmake(path,exchange->file_name,FN_REFLEN-1);
if ((file= create_file(thd, path, exchange, &cache)) < 0)
return 1;
/* Check if there is any blobs in data */
{
List_iterator_fast<Item> li(list);
Item *item;
while ((item=li++))
{
if (item->max_length >= MAX_BLOB_WIDTH)
{
blob_flag=1;
break;
}
}
}
field_term_length=exchange->field_term->length();
if (!exchange->line_term->length())
exchange->line_term=exchange->field_term; // Use this if it exists
field_sep_char= (exchange->enclosed->length() ? (*exchange->enclosed)[0] :
field_term_length ? (*exchange->field_term)[0] : INT_MAX);
escape_char= (exchange->escaped->length() ? (*exchange->escaped)[0] : -1);
line_sep_char= (exchange->line_term->length() ?
(*exchange->line_term)[0] : INT_MAX);
if (!field_term_length)
exchange->opt_enclosed=0;
if (!exchange->enclosed->length())
exchange->opt_enclosed=1; // A little quicker loop
fixed_row_size= (!field_term_length && !exchange->enclosed->length() &&
!blob_flag);
return 0;
}
bool select_export::send_data(List<Item> &items)
{
DBUG_ENTER("send_data");
char buff[MAX_FIELD_WIDTH],null_buff[2],space[MAX_FIELD_WIDTH];
bool space_inited=0;
String tmp(buff,sizeof(buff),&my_charset_bin),*res;
tmp.length(0);
if (unit->offset_limit_cnt)
{ // using limit offset,count
unit->offset_limit_cnt--;
DBUG_RETURN(0);
}
row_count++;
Item *item;
char *buff_ptr=buff;
uint used_length=0,items_left=items.elements;
List_iterator_fast<Item> li(items);
if (my_b_write(&cache,(byte*) exchange->line_start->ptr(),
exchange->line_start->length()))
goto err;
while ((item=li++))
{
Item_result result_type=item->result_type();
res=item->str_result(&tmp);
if (res && (!exchange->opt_enclosed || result_type == STRING_RESULT))
{
if (my_b_write(&cache,(byte*) exchange->enclosed->ptr(),
exchange->enclosed->length()))
goto err;
}
if (!res)
{ // NULL
if (!fixed_row_size)
{
if (escape_char != -1) // Use \N syntax
{
null_buff[0]=escape_char;
null_buff[1]='N';
if (my_b_write(&cache,(byte*) null_buff,2))
goto err;
}
else if (my_b_write(&cache,(byte*) "NULL",4))
goto err;
}
else
{
used_length=0; // Fill with space
}
}
else
{
if (fixed_row_size)
used_length=min(res->length(),item->max_length);
else
used_length=res->length();
if (result_type == STRING_RESULT && escape_char != -1)
{
char *pos,*start,*end;
for (start=pos=(char*) res->ptr(),end=pos+used_length ;
pos != end ;
pos++)
{
#ifdef USE_MB
CHARSET_INFO *res_charset=res->charset();
if (use_mb(res_charset))
{
int l;
if ((l=my_ismbchar(res_charset, pos, end)))
{
pos += l-1;
continue;
}
}
#endif
if ((int) *pos == escape_char || (int) *pos == field_sep_char ||
(int) *pos == line_sep_char || !*pos)
{
char tmp_buff[2];
tmp_buff[0]= escape_char;
tmp_buff[1]= *pos ? *pos : '0';
if (my_b_write(&cache,(byte*) start,(uint) (pos-start)) ||
my_b_write(&cache,(byte*) tmp_buff,2))
goto err;
start=pos+1;
}
}
if (my_b_write(&cache,(byte*) start,(uint) (pos-start)))
goto err;
}
else if (my_b_write(&cache,(byte*) res->ptr(),used_length))
goto err;
}
if (fixed_row_size)
{ // Fill with space
if (item->max_length > used_length)
{
/* QQ: Fix by adding a my_b_fill() function */
if (!space_inited)
{
space_inited=1;
bfill(space,sizeof(space),' ');
}
uint length=item->max_length-used_length;
for (; length > sizeof(space) ; length-=sizeof(space))
{
if (my_b_write(&cache,(byte*) space,sizeof(space)))
goto err;
}
if (my_b_write(&cache,(byte*) space,length))
goto err;
}
}
buff_ptr=buff; // Place separators here
if (res && (!exchange->opt_enclosed || result_type == STRING_RESULT))
{
memcpy(buff_ptr,exchange->enclosed->ptr(),exchange->enclosed->length());
buff_ptr+=exchange->enclosed->length();
}
if (--items_left)
{
memcpy(buff_ptr,exchange->field_term->ptr(),field_term_length);
buff_ptr+=field_term_length;
}
if (my_b_write(&cache,(byte*) buff,(uint) (buff_ptr-buff)))
goto err;
}
if (my_b_write(&cache,(byte*) exchange->line_term->ptr(),
exchange->line_term->length()))
goto err;
DBUG_RETURN(0);
err:
DBUG_RETURN(1);
}
/***************************************************************************
** Dump of select to a binary file
***************************************************************************/
int
select_dump::prepare(List<Item> &list __attribute__((unused)),
SELECT_LEX_UNIT *u)
{
unit= u;
return (int) ((file= create_file(thd, path, exchange, &cache)) < 0);
}
bool select_dump::send_data(List<Item> &items)
{
List_iterator_fast<Item> li(items);
char buff[MAX_FIELD_WIDTH];
String tmp(buff,sizeof(buff),&my_charset_bin),*res;
tmp.length(0);
Item *item;
DBUG_ENTER("send_data");
if (unit->offset_limit_cnt)
{ // using limit offset,count
unit->offset_limit_cnt--;
DBUG_RETURN(0);
}
if (row_count++ > 1)
{
my_error(ER_TOO_MANY_ROWS, MYF(0));
goto err;
}
while ((item=li++))
{
res=item->str_result(&tmp);
if (!res) // If NULL
{
if (my_b_write(&cache,(byte*) "",1))
goto err;
}
else if (my_b_write(&cache,(byte*) res->ptr(),res->length()))
{
my_error(ER_ERROR_ON_WRITE,MYF(0), path, my_errno);
goto err;
}
}
DBUG_RETURN(0);
err:
DBUG_RETURN(1);
}
select_subselect::select_subselect(Item_subselect *item_arg)
{
item= item_arg;
}
bool select_singlerow_subselect::send_data(List<Item> &items)
{
DBUG_ENTER("select_singlerow_subselect::send_data");
Item_singlerow_subselect *it= (Item_singlerow_subselect *)item;
if (it->assigned())
{
my_message(ER_SUBQUERY_NO_1_ROW, ER(ER_SUBQUERY_NO_1_ROW), MYF(0));
DBUG_RETURN(1);
}
if (unit->offset_limit_cnt)
{ // Using limit offset,count
unit->offset_limit_cnt--;
DBUG_RETURN(0);
}
List_iterator_fast<Item> li(items);
Item *val_item;
for (uint i= 0; (val_item= li++); i++)
it->store(i, val_item);
it->assigned(1);
DBUG_RETURN(0);
}
bool select_max_min_finder_subselect::send_data(List<Item> &items)
{
DBUG_ENTER("select_max_min_finder_subselect::send_data");
Item_singlerow_subselect *it= (Item_singlerow_subselect *)item;
List_iterator_fast<Item> li(items);
Item *val_item= li++;
if (it->assigned())
{
cache->store(val_item);
if ((this->*op)())
it->store(0, cache);
}
else
{
if (!cache)
{
cache= Item_cache::get_cache(val_item->result_type());
switch (val_item->result_type())
{
case REAL_RESULT:
op= &select_max_min_finder_subselect::cmp_real;
break;
case INT_RESULT:
op= &select_max_min_finder_subselect::cmp_int;
break;
case STRING_RESULT:
op= &select_max_min_finder_subselect::cmp_str;
break;
case ROW_RESULT:
// This case should never be choosen
DBUG_ASSERT(0);
op= 0;
}
}
cache->store(val_item);
it->store(0, cache);
}
it->assigned(1);
DBUG_RETURN(0);
}
bool select_max_min_finder_subselect::cmp_real()
{
Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
double val1= cache->val(), val2= maxmin->val();
if (fmax)
return (cache->null_value && !maxmin->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 > val2);
else
return (maxmin->null_value && !cache->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 < val2);
}
bool select_max_min_finder_subselect::cmp_int()
{
Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
longlong val1= cache->val_int(), val2= maxmin->val_int();
if (fmax)
return (cache->null_value && !maxmin->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 > val2);
else
return (maxmin->null_value && !cache->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 < val2);
}
bool select_max_min_finder_subselect::cmp_str()
{
String *val1, *val2, buf1, buf2;
Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
/*
as far as both operand is Item_cache buf1 & buf2 will not be used,
but added for safety
*/
val1= cache->val_str(&buf1);
val2= maxmin->val_str(&buf1);
if (fmax)
return (cache->null_value && !maxmin->null_value) ||
(!cache->null_value && !maxmin->null_value &&
sortcmp(val1, val2, cache->collation.collation) > 0) ;
else
return (maxmin->null_value && !cache->null_value) ||
(!cache->null_value && !maxmin->null_value &&
sortcmp(val1, val2, cache->collation.collation) < 0);
}
bool select_exists_subselect::send_data(List<Item> &items)
{
DBUG_ENTER("select_exists_subselect::send_data");
Item_exists_subselect *it= (Item_exists_subselect *)item;
if (unit->offset_limit_cnt)
{ // Using limit offset,count
unit->offset_limit_cnt--;
DBUG_RETURN(0);
}
it->value= 1;
it->assigned(1);
DBUG_RETURN(0);
}
/***************************************************************************
Dump of select to variables
***************************************************************************/
int select_dumpvar::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
{
List_iterator_fast<Item> li(list);
List_iterator_fast<LEX_STRING> gl(var_list);
Item *item;
LEX_STRING *ls;
if (var_list.elements != list.elements)
{
my_error(ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT, MYF(0));
return 1;
}
unit=u;
while ((item=li++))
{
ls= gl++;
Item_func_set_user_var *xx = new Item_func_set_user_var(*ls,item);
/*
Item_func_set_user_var can't substitute something else on its place =>
0 can be passed as last argument (reference on item)
*/
xx->fix_fields(thd,(TABLE_LIST*) thd->lex->select_lex.table_list.first,
0);
xx->fix_length_and_dec();
vars.push_back(xx);
}
return 0;
}
void select_dumpvar::cleanup()
{
vars.empty();
row_count=0;
}
/*
Create arena for already constructed THD.
SYNOPSYS
Item_arena()
thd - thread for which arena is created
DESCRIPTION
Create arena for already existing THD using its variables as parameters
for memory root initialization.
*/
Item_arena::Item_arena(THD* thd)
:free_list(0),
state(INITIALIZED)
{
init_sql_alloc(&mem_root,
thd->variables.query_alloc_block_size,
thd->variables.query_prealloc_size);
}
/*
Create arena and optionally initialize memory root.
SYNOPSYS
Item_arena()
init_mem_root - whenever we need to initialize memory root
DESCRIPTION
Create arena and optionally initialize memory root with minimal
possible parameters.
NOTE
We use this constructor when arena is part of THD, but reinitialize
its memory root in THD::init_for_queries() before execution of real
statements.
*/
Item_arena::Item_arena(bool init_mem_root)
:free_list(0),
state(CONVENTIONAL_EXECUTION)
{
if (init_mem_root)
init_alloc_root(&mem_root, ALLOC_ROOT_MIN_BLOCK_SIZE, 0);
}
Item_arena::Type Item_arena::type() const
{
DBUG_ASSERT("Item_arena::type()" == "abstract");
return STATEMENT;
}
/*
Statement functions
*/
Statement::Statement(THD *thd)
:Item_arena(thd),
id(++thd->statement_id_counter),
set_query_id(1),
allow_sum_func(0),
lex(&main_lex),
query(0),
query_length(0)
{
name.str= NULL;
}
/*
This constructor is called when statement is a subobject of THD:
Some variables are initialized in THD::init due to locking problems
This statement object will be used to
*/
Statement::Statement()
:Item_arena((bool)TRUE),
id(0),
set_query_id(1),
allow_sum_func(0), /* initialized later */
lex(&main_lex),
query(0), /* these two are set */
query_length(0) /* in alloc_query() */
{
}
Item_arena::Type Statement::type() const
{
return STATEMENT;
}
void Statement::set_statement(Statement *stmt)
{
id= stmt->id;
set_query_id= stmt->set_query_id;
allow_sum_func= stmt->allow_sum_func;
lex= stmt->lex;
query= stmt->query;
query_length= stmt->query_length;
}
void
Statement::set_n_backup_statement(Statement *stmt, Statement *backup)
{
backup->set_statement(this);
set_statement(stmt);
}
void Statement::restore_backup_statement(Statement *stmt, Statement *backup)
{
stmt->set_statement(this);
set_statement(backup);
}
void THD::end_statement()
{
/* Cleanup SQL processing state to resuse this statement in next query. */
lex_end(lex);
delete lex->result;
lex->result= 0;
free_items(free_list);
free_list= 0;
/*
Don't free mem_root, as mem_root is freed in the end of dispatch_command
(once for any command).
*/
}
void Item_arena::set_n_backup_item_arena(Item_arena *set, Item_arena *backup)
{
backup->set_item_arena(this);
set_item_arena(set);
}
void Item_arena::restore_backup_item_arena(Item_arena *set, Item_arena *backup)
{
set->set_item_arena(this);
set_item_arena(backup);
#ifdef NOT_NEEDED_NOW
/*
Reset backup mem_root to avoid its freeing.
Since Item_arena's mem_root is freed only when it is part of Statement
we need this only if we use some Statement's arena as backup storage.
But we do this only with THD::stmt_backup and this Statement is specially
handled in this respect. So this code is not really needed now.
*/
clear_alloc_root(&backup->mem_root);
#endif
}
void Item_arena::set_item_arena(Item_arena *set)
{
mem_root= set->mem_root;
free_list= set->free_list;
state= set->state;
}
Statement::~Statement()
{
free_root(&mem_root, MYF(0));
}
C_MODE_START
static byte *
get_statement_id_as_hash_key(const byte *record, uint *key_length,
my_bool not_used __attribute__((unused)))
{
const Statement *statement= (const Statement *) record;
*key_length= sizeof(statement->id);
return (byte *) &((const Statement *) statement)->id;
}
static void delete_statement_as_hash_key(void *key)
{
delete (Statement *) key;
}
static byte *get_stmt_name_hash_key(Statement *entry, uint *length,
my_bool not_used __attribute__((unused)))
{
*length=(uint) entry->name.length;
return (byte*) entry->name.str;
}
C_MODE_END
Statement_map::Statement_map() :
last_found_statement(0)
{
enum
{
START_STMT_HASH_SIZE = 16,
START_NAME_HASH_SIZE = 16
};
hash_init(&st_hash, &my_charset_bin, START_STMT_HASH_SIZE, 0, 0,
get_statement_id_as_hash_key,
delete_statement_as_hash_key, MYF(0));
hash_init(&names_hash, system_charset_info, START_NAME_HASH_SIZE, 0, 0,
(hash_get_key) get_stmt_name_hash_key,
NULL,MYF(0));
}
int Statement_map::insert(Statement *statement)
{
int rc= my_hash_insert(&st_hash, (byte *) statement);
if (rc == 0)
last_found_statement= statement;
if (statement->name.str)
{
/*
If there is a statement with the same name, remove it. It is ok to
remove old and fail to insert new one at the same time.
*/
Statement *old_stmt;
if ((old_stmt= find_by_name(&statement->name)))
erase(old_stmt);
if ((rc= my_hash_insert(&names_hash, (byte*)statement)))
hash_delete(&st_hash, (byte*)statement);
}
return rc;
}
bool select_dumpvar::send_data(List<Item> &items)
{
List_iterator_fast<Item_func_set_user_var> li(vars);
Item_func_set_user_var *xx;
DBUG_ENTER("send_data");
if (unit->offset_limit_cnt)
{ // Using limit offset,count
unit->offset_limit_cnt--;
DBUG_RETURN(0);
}
if (row_count++)
{
my_error(ER_TOO_MANY_ROWS, MYF(0));
DBUG_RETURN(1);
}
while ((xx=li++))
{
xx->check();
xx->update();
}
DBUG_RETURN(0);
}
bool select_dumpvar::send_eof()
{
if (row_count)
{
::send_ok(thd,row_count);
return 0;
}
else
{
my_error(ER_EMPTY_QUERY,MYF(0));
return 1;
}
}
/****************************************************************************
TMP_TABLE_PARAM
****************************************************************************/
void TMP_TABLE_PARAM::init()
{
field_count= sum_func_count= func_count= hidden_field_count= 0;
group_parts= group_length= group_null_parts= 0;
quick_group= 1;
}
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