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mariadb/sql/sql_prepare.cc
unknown 34e6098403 Merge bk-internal:/home/bk/mysql-4.1/ 
into serg.mylan:/usr/home/serg/Abk/mysql-4.1


sql/sql_prepare.cc:
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2004-04-06 12:32:02 +02:00

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/* Copyright (C) 1995-2002 MySQL 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 contains the implementation of prepare and executes.
Prepare:
- Server gets the query from client with command 'COM_PREPARE';
in the following format:
[COM_PREPARE:1] [query]
- Parse the query and recognize any parameter markers '?' and
store its information list in lex->param_list
- Allocate a new statement for this prepare; and keep this in
'thd->prepared_statements' pool.
- Without executing the query, return back to client the total
number of parameters along with result-set metadata information
(if any) in the following format:
[STMT_ID:4]
[Column_count:2]
[Param_count:2]
[Columns meta info] (if Column_count > 0)
[Params meta info] (if Param_count > 0 ) (TODO : 4.1.1)
Prepare-execute:
- Server gets the command 'COM_EXECUTE' to execute the
previously prepared query. If there is any param markers; then client
will send the data in the following format:
[COM_EXECUTE:1]
[STMT_ID:4]
[NULL_BITS:(param_count+7)/8)]
[TYPES_SUPPLIED_BY_CLIENT(0/1):1]
[[length]data]
[[length]data] .. [[length]data].
(Note: Except for string/binary types; all other types will not be
supplied with length field)
- Replace the param items with this new data. If it is a first execute
or types altered by client; then setup the conversion routines.
- Execute the query without re-parsing and send back the results
to client
Long data handling:
- Server gets the long data in pieces with command type 'COM_LONG_DATA'.
- The packet recieved will have the format as:
[COM_LONG_DATA:1][STMT_ID:4][parameter_number:2][type:2][data]
- Checks if the type is specified by client, and if yes reads the type,
and stores the data in that format.
- It's up to the client to check for read data ended. The server doesn't
care; and also server doesn't notify to the client that it got the
data or not; if there is any error; then during execute; the error
will be returned
***********************************************************************/
#include "mysql_priv.h"
#include "sql_acl.h"
#include "sql_select.h" // for JOIN
#include <m_ctype.h> // for isspace()
#ifdef EMBEDDED_LIBRARY
/* include MYSQL_BIND headers */
#include <mysql.h>
#endif
const String my_null_string("NULL", 4, default_charset_info);
/******************************************************************************
Prepared_statement: statement which can contain placeholders
******************************************************************************/
class Prepared_statement: public Statement
{
public:
THD *thd;
Item_param **param_array;
uint param_count;
uint last_errno;
char last_error[MYSQL_ERRMSG_SIZE];
bool get_longdata_error;
bool long_data_used;
bool log_full_query;
#ifndef EMBEDDED_LIBRARY
bool (*set_params)(Prepared_statement *st, uchar *data, uchar *data_end,
uchar *read_pos);
#else
bool (*set_params_data)(Prepared_statement *st);
#endif
public:
Prepared_statement(THD *thd_arg);
virtual ~Prepared_statement();
virtual Statement::Type type() const;
};
/******************************************************************************
Implementation
******************************************************************************/
inline bool is_param_null(const uchar *pos, ulong param_no)
{
return pos[param_no/8] & (1 << (param_no & 7));
}
enum { STMT_QUERY_LOG_LENGTH= 8192 };
enum enum_send_error { DONT_SEND_ERROR= 0, SEND_ERROR };
/*
Seek prepared statement in statement map by id: returns zero if statement
was not found, pointer otherwise.
*/
static Prepared_statement *
find_prepared_statement(THD *thd, ulong id, const char *where,
enum enum_send_error se)
{
Statement *stmt= thd->stmt_map.find(id);
if (stmt == 0 || stmt->type() != Statement::PREPARED_STATEMENT)
{
my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), id, where);
if (se == SEND_ERROR)
send_error(thd);
return 0;
}
return (Prepared_statement *) stmt;
}
/*
Send prepared stmt info to client after prepare
*/
#ifndef EMBEDDED_LIBRARY
static bool send_prep_stmt(Prepared_statement *stmt, uint columns)
{
NET *net= &stmt->thd->net;
char buff[9];
buff[0]= 0; /* OK packet indicator */
int4store(buff+1, stmt->id);
int2store(buff+5, columns);
int2store(buff+7, stmt->param_count);
/*
Send types and names of placeholders to the client
XXX: fix this nasty upcast from List<Item_param> to List<Item>
*/
return my_net_write(net, buff, sizeof(buff)) ||
(stmt->param_count &&
stmt->thd->protocol_simple.send_fields((List<Item> *)
&stmt->lex->param_list, 0)) ||
net_flush(net);
return 0;
}
#else
static bool send_prep_stmt(Prepared_statement *stmt,
uint columns __attribute__((unused)))
{
THD *thd= stmt->thd;
thd->client_stmt_id= stmt->id;
thd->client_param_count= stmt->param_count;
thd->net.last_errno= 0;
return 0;
}
#endif /*!EMBEDDED_LIBRARY*/
/*
Read the length of the parameter data and return back to
caller by positing the pointer to param data.
*/
#ifndef EMBEDDED_LIBRARY
static ulong get_param_length(uchar **packet, ulong len)
{
reg1 uchar *pos= *packet;
if (len < 1)
return 0;
if (*pos < 251)
{
(*packet)++;
return (ulong) *pos;
}
if (len < 3)
return 0;
if (*pos == 252)
{
(*packet)+=3;
return (ulong) uint2korr(pos+1);
}
if (len < 4)
return 0;
if (*pos == 253)
{
(*packet)+=4;
return (ulong) uint3korr(pos+1);
}
if (len < 5)
return 0;
(*packet)+=9; // Must be 254 when here
/* TODO: why uint4korr here? (should be uint8korr) */
return (ulong) uint4korr(pos+1);
}
#else
#define get_param_length(packet, len) len
#endif /*!EMBEDDED_LIBRARY*/
/*
Data conversion routines
SYNOPSIS
set_param_xx()
param parameter item
pos input data buffer
len length of data in the buffer
All these functions read the data from pos, convert it to requested type
and assign to param; pos is advanced to predefined length.
Make a note that the NULL handling is examined at first execution
(i.e. when input types altered) and for all subsequent executions
we don't read any values for this.
RETURN VALUE
none
*/
void set_param_tiny(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 1)
return;
#endif
param->set_int((longlong)(**pos));
*pos+= 1;
}
void set_param_short(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 2)
return;
#endif
param->set_int((longlong)sint2korr(*pos));
*pos+= 2;
}
void set_param_int32(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 4)
return;
#endif
param->set_int((longlong)sint4korr(*pos));
*pos+= 4;
}
void set_param_int64(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 8)
return;
#endif
param->set_int((longlong)sint8korr(*pos));
*pos+= 8;
}
void set_param_float(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 4)
return;
#endif
float data;
float4get(data,*pos);
param->set_double((double) data);
*pos+= 4;
}
void set_param_double(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 8)
return;
#endif
double data;
float8get(data,*pos);
param->set_double((double) data);
*pos+= 8;
}
void set_param_time(Item_param *param, uchar **pos, ulong len)
{
ulong length;
if ((length= get_param_length(pos, len)) >= 8)
{
uchar *to= *pos;
TIME tm;
/* TODO: why length is compared with 8 here? */
tm.second_part= (length > 8 ) ? (ulong) sint4korr(to+7): 0;
tm.day= (ulong) sint4korr(to+1);
tm.hour= (uint) to[5];
tm.minute= (uint) to[6];
tm.second= (uint) to[7];
tm.year= tm.month= 0;
tm.neg= (bool)to[0];
param->set_time(&tm, TIMESTAMP_TIME);
}
*pos+= length;
}
void set_param_datetime(Item_param *param, uchar **pos, ulong len)
{
uint length;
if ((length= get_param_length(pos, len)) >= 4)
{
uchar *to= *pos;
TIME tm;
tm.second_part= (length > 7 ) ? (ulong) sint4korr(to+7): 0;
if (length > 4)
{
tm.hour= (uint) to[4];
tm.minute= (uint) to[5];
tm.second= (uint) to[6];
}
else
tm.hour= tm.minute= tm.second= 0;
tm.year= (uint) sint2korr(to);
tm.month= (uint) to[2];
tm.day= (uint) to[3];
tm.neg= 0;
param->set_time(&tm, TIMESTAMP_DATETIME);
}
*pos+= length;
}
void set_param_date(Item_param *param, uchar **pos, ulong len)
{
ulong length;
if ((length= get_param_length(pos, len)) >= 4)
{
uchar *to= *pos;
TIME tm;
tm.year= (uint) sint2korr(to);
tm.month= (uint) to[2];
tm.day= (uint) to[3];
tm.hour= tm.minute= tm.second= 0;
tm.second_part= 0;
tm.neg= 0;
param->set_time(&tm, TIMESTAMP_DATE);
}
*pos+= length;
}
void set_param_str(Item_param *param, uchar **pos, ulong len)
{
ulong length= get_param_length(pos, len);
param->set_value((const char *)*pos, length);
*pos+= length;
}
static void setup_one_conversion_function(Item_param *param, uchar param_type)
{
switch (param_type) {
case FIELD_TYPE_TINY:
param->set_param_func= set_param_tiny;
param->item_result_type= INT_RESULT;
break;
case FIELD_TYPE_SHORT:
param->set_param_func= set_param_short;
param->item_result_type= INT_RESULT;
break;
case FIELD_TYPE_LONG:
param->set_param_func= set_param_int32;
param->item_result_type= INT_RESULT;
break;
case FIELD_TYPE_LONGLONG:
param->set_param_func= set_param_int64;
param->item_result_type= INT_RESULT;
break;
case FIELD_TYPE_FLOAT:
param->set_param_func= set_param_float;
param->item_result_type= REAL_RESULT;
break;
case FIELD_TYPE_DOUBLE:
param->set_param_func= set_param_double;
param->item_result_type= REAL_RESULT;
break;
case FIELD_TYPE_TIME:
param->set_param_func= set_param_time;
param->item_result_type= STRING_RESULT;
break;
case FIELD_TYPE_DATE:
param->set_param_func= set_param_date;
param->item_result_type= STRING_RESULT;
break;
case MYSQL_TYPE_DATETIME:
case MYSQL_TYPE_TIMESTAMP:
param->set_param_func= set_param_datetime;
param->item_result_type= STRING_RESULT;
break;
default:
param->set_param_func= set_param_str;
param->item_result_type= STRING_RESULT;
}
}
#ifndef EMBEDDED_LIBRARY
/*
Update the parameter markers by reading data from client packet
and if binary/update log is set, generate the valid query.
*/
static bool insert_params_withlog(Prepared_statement *stmt, uchar *null_array,
uchar *read_pos, uchar *data_end)
{
THD *thd= stmt->thd;
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
uint32 length= 0;
String str, query;
const String *res;
DBUG_ENTER("insert_params_withlog");
if (query.copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
if (param->long_data_supplied)
res= param->query_val_str(&str);
else
{
if (is_param_null(null_array, it - begin))
{
param->maybe_null= param->null_value= 1;
res= &my_null_string;
}
else
{
param->maybe_null= param->null_value= 0;
if (read_pos >= data_end)
DBUG_RETURN(1);
param->set_param_func(param, &read_pos, data_end - read_pos);
res= param->query_val_str(&str);
}
}
if (query.replace(param->pos_in_query+length, 1, *res))
DBUG_RETURN(1);
length+= res->length()-1;
}
if (alloc_query(thd, (char *)query.ptr(), query.length()+1))
DBUG_RETURN(1);
DBUG_RETURN(0);
}
static bool insert_params(Prepared_statement *stmt, uchar *null_array,
uchar *read_pos, uchar *data_end)
{
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
DBUG_ENTER("insert_params");
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
if (!param->long_data_supplied)
{
if (is_param_null(null_array, it - begin))
param->maybe_null= param->null_value= 1;
else
{
param->maybe_null= param->null_value= 0;
if (read_pos >= data_end)
DBUG_RETURN(1);
param->set_param_func(param, &read_pos, data_end - read_pos);
}
}
}
DBUG_RETURN(0);
}
static bool setup_conversion_functions(Prepared_statement *stmt,
uchar **data, uchar *data_end)
{
/* skip null bits */
uchar *read_pos= *data + (stmt->param_count+7) / 8;
DBUG_ENTER("setup_conversion_functions");
if (*read_pos++) //types supplied / first execute
{
/*
First execute or types altered by the client, setup the
conversion routines for all parameters (one time)
*/
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
for (; it < end; ++it)
{
if (read_pos >= data_end)
DBUG_RETURN(1);
setup_one_conversion_function(*it, *read_pos);
read_pos+= 2;
}
}
*data= read_pos;
DBUG_RETURN(0);
}
#else
static bool emb_insert_params(Prepared_statement *stmt)
{
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
MYSQL_BIND *client_param= stmt->thd->client_params;
DBUG_ENTER("emb_insert_params");
for (; it < end; ++it, ++client_param)
{
Item_param *param= *it;
setup_one_conversion_function(param, client_param->buffer_type);
if (!param->long_data_supplied)
{
if (*client_param->is_null)
param->maybe_null= param->null_value= 1;
else
{
uchar *buff= (uchar*)client_param->buffer;
param->maybe_null= param->null_value= 0;
param->set_param_func(param, &buff,
client_param->length ?
*client_param->length :
client_param->buffer_length);
}
}
}
DBUG_RETURN(0);
}
static bool emb_insert_params_withlog(Prepared_statement *stmt)
{
THD *thd= stmt->thd;
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
MYSQL_BIND *client_param= thd->client_params;
String str, query;
const String *res;
uint32 length= 0;
DBUG_ENTER("emb_insert_params_withlog");
if (query.copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (; it < end; ++it, ++client_param)
{
Item_param *param= *it;
setup_one_conversion_function(param, client_param->buffer_type);
if (param->long_data_supplied)
res= param->query_val_str(&str);
else
{
if (*client_param->is_null)
{
param->maybe_null= param->null_value= 1;
res= &my_null_string;
}
else
{
uchar *buff= (uchar*)client_param->buffer;
param->maybe_null= param->null_value= 0;
param->set_param_func(param, &buff,
client_param->length ?
*client_param->length :
client_param->buffer_length);
res= param->query_val_str(&str);
}
}
if (query.replace(param->pos_in_query+length, 1, *res))
DBUG_RETURN(1);
length+= res->length()-1;
}
if (alloc_query(thd, (char *) query.ptr(), query.length()+1))
DBUG_RETURN(1);
DBUG_RETURN(0);
}
#endif /*!EMBEDDED_LIBRARY*/
/*
Validate the following information for INSERT statement:
- field existence
- fields count
SYNOPSIS
mysql_test_insert_fields()
RETURN VALUE
0 ok
1 error, sent to the client
-1 error, not sent to client
*/
static int mysql_test_insert_fields(Prepared_statement *stmt,
TABLE_LIST *table_list,
List<Item> &fields,
List<List_item> &values_list)
{
THD *thd= stmt->thd;
TABLE *table;
List_iterator_fast<List_item> its(values_list);
List_item *values;
DBUG_ENTER("mysql_test_insert_fields");
#ifndef NO_EMBEDDED_ACCESS_CHECKS
my_bool update=(stmt->lex->value_list.elements ? UPDATE_ACL : 0);
ulong privilege= (stmt->lex->duplicates == DUP_REPLACE ?
INSERT_ACL | DELETE_ACL : INSERT_ACL | update);
if (check_access(thd,privilege,table_list->db,
&table_list->grant.privilege,0,0) ||
(grant_option && check_grant(thd,privilege,table_list,0,0)))
DBUG_RETURN(1);
#endif
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (open_and_lock_tables(thd, table_list))
{
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(-1);
}
table= table_list->table;
if ((values= its++))
{
uint value_count;
ulong counter= 0;
if (check_insert_fields(thd,table,fields,*values,1))
{
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(-1);
}
thd->free_temporary_memory_pool_for_ps_preparing();
value_count= values->elements;
its.rewind();
while ((values= its++))
{
counter++;
if (values->elements != value_count)
{
my_printf_error(ER_WRONG_VALUE_COUNT_ON_ROW,
ER(ER_WRONG_VALUE_COUNT_ON_ROW),
MYF(0), counter);
DBUG_RETURN(-1);
}
}
}
else
{
thd->free_temporary_memory_pool_for_ps_preparing();
}
DBUG_RETURN(0);
}
/*
Validate the following information:
UPDATE - set and where clause
DELETE - where clause
SYNOPSIS
mysql_test_upd_fields()
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_upd_fields(Prepared_statement *stmt,
TABLE_LIST *table_list,
List<Item> &fields, List<Item> &values,
COND *conds)
{
THD *thd= stmt->thd;
DBUG_ENTER("mysql_test_upd_fields");
#ifndef NO_EMBEDDED_ACCESS_CHECKS
if (check_access(thd,UPDATE_ACL,table_list->db,
&table_list->grant.privilege,0,0) ||
(grant_option && check_grant(thd,UPDATE_ACL,table_list,0,0)))
DBUG_RETURN(1);
#endif
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (open_and_lock_tables(thd, table_list))
goto err;
if (setup_tables(table_list) ||
setup_fields(thd, 0, table_list, fields, 1, 0, 0) ||
setup_conds(thd, table_list, &conds) || thd->net.report_error)
goto err;
thd->free_temporary_memory_pool_for_ps_preparing();
/* TODO: here we should send types of placeholders to the client. */
DBUG_RETURN(0);
err:
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(-1);
}
/*
Validate the following information:
SELECT - column list
- where clause
- order clause
- having clause
- group by clause
- if no column spec i.e. '*', then setup all fields
In case of success, if this query is not EXPLAIN, send column list info
back to client.
SYNOPSIS
mysql_test_select_fields()
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_select_fields(Prepared_statement *stmt,
TABLE_LIST *tables,
uint wild_num,
List<Item> &fields, COND *conds,
uint og_num, ORDER *order, ORDER *group,
Item *having, ORDER *proc,
ulong select_options,
SELECT_LEX_UNIT *unit,
SELECT_LEX *select_lex)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
DBUG_ENTER("mysql_test_select_fields");
#ifndef NO_EMBEDDED_ACCESS_CHECKS
ulong privilege= lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL;
if (tables)
{
if (check_table_access(thd, privilege, tables,0))
DBUG_RETURN(1);
}
else if (check_access(thd, privilege, any_db,0,0,0))
DBUG_RETURN(1);
#endif
if ((&lex->select_lex != lex->all_selects_list &&
lex->unit.create_total_list(thd, lex, &tables)))
DBUG_RETURN(1);
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (open_and_lock_tables(thd, tables))
{
send_error(thd);
goto err;
}
if (lex->describe)
{
if (send_prep_stmt(stmt, 0))
goto err;
}
else
{
select_result *result= lex->result;
if (!result && !(result= new select_send()))
{
send_error(thd, ER_OUT_OF_RESOURCES);
goto err;
}
thd->used_tables= 0; // Updated by setup_fields
if (unit->prepare(thd, result, 0))
{
send_error(thd);
goto err_prep;
}
if (send_prep_stmt(stmt, fields.elements) ||
thd->protocol_simple.send_fields(&fields, 0)
#ifndef EMBEDDED_LIBRARY
|| net_flush(&thd->net)
#endif
)
goto err_prep;
unit->cleanup();
}
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(0);
err_prep:
unit->cleanup();
err:
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(1);
}
/*
Send the prepare query results back to client
SYNOPSIS
send_prepare_results()
stmt prepared statement
RETURN VALUE
0 success
1 error, sent to client
*/
static int send_prepare_results(Prepared_statement *stmt)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX *select_lex= &lex->select_lex;
TABLE_LIST *tables=(TABLE_LIST*) select_lex->table_list.first;
enum enum_sql_command sql_command= lex->sql_command;
int res;
DBUG_ENTER("send_prepare_results");
DBUG_PRINT("enter",("command: %d, param_count: %ld",
sql_command, stmt->param_count));
switch (sql_command) {
case SQLCOM_INSERT:
if ((res= mysql_test_insert_fields(stmt, tables, lex->field_list,
lex->many_values)))
goto error;
break;
case SQLCOM_UPDATE:
/* XXX: fallthrough */
case SQLCOM_DELETE:
if ((res= mysql_test_upd_fields(stmt, tables, select_lex->item_list,
lex->value_list, select_lex->where)))
goto error;
break;
case SQLCOM_SELECT:
if ((res= mysql_test_select_fields(stmt, tables, select_lex->with_wild,
select_lex->item_list,
select_lex->where,
select_lex->order_list.elements +
select_lex->group_list.elements,
(ORDER*) select_lex->order_list.first,
(ORDER*) select_lex->group_list.first,
select_lex->having,
(ORDER*)lex->proc_list.first,
select_lex->options | thd->options,
&(lex->unit), select_lex)))
goto error;
/* Statement and field info has already been sent */
DBUG_RETURN(0);
default:
/*
Rest fall through to default category, no parsing
for non-DML statements
*/
break;
}
DBUG_RETURN(send_prep_stmt(stmt, 0));
error:
if (res < 0)
send_error(thd, thd->killed ? ER_SERVER_SHUTDOWN : 0);
DBUG_RETURN(1);
}
/*
Initialize array of parametes in statement from LEX.
(We need to have quick access to items by number in mysql_send_longdata).
This is to avoid using malloc/realloc in the parser.
*/
static bool init_param_array(Prepared_statement *stmt)
{
LEX *lex= stmt->lex;
if ((stmt->param_count= lex->param_list.elements))
{
Item_param **to;
List_iterator<Item_param> param_iterator(lex->param_list);
/* Use thd->mem_root as it points at statement mem_root */
stmt->param_array= (Item_param **)
alloc_root(&stmt->thd->mem_root,
sizeof(Item_param*) * stmt->param_count);
if (!stmt->param_array)
{
send_error(stmt->thd, ER_OUT_OF_RESOURCES);
return 1;
}
for (to= stmt->param_array;
to < stmt->param_array + stmt->param_count;
++to)
{
*to= param_iterator++;
}
}
return 0;
}
/*
Parse the query and send the total number of parameters
and resultset metadata information back to client (if any),
without executing the query i.e. without any log/disk
writes. This will allow the queries to be re-executed
without re-parsing during execute.
If parameter markers are found in the query, then store
the information using Item_param along with maintaining a
list in lex->param_array, so that a fast and direct
retrieval can be made without going through all field
items.
*/
void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
{
LEX *lex;
Prepared_statement *stmt= new Prepared_statement(thd);
int error;
DBUG_ENTER("mysql_stmt_prepare");
if (stmt == 0)
{
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_VOID_RETURN;
}
if (thd->stmt_map.insert(stmt))
{
delete stmt;
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_VOID_RETURN;
}
thd->stmt_backup.set_statement(thd);
thd->stmt_backup.set_item_arena(thd);
thd->set_statement(stmt);
thd->set_item_arena(stmt);
if (alloc_query(thd, packet, packet_length))
{
stmt->set_statement(thd);
stmt->set_item_arena(thd);
thd->set_statement(&thd->stmt_backup);
thd->set_item_arena(&thd->stmt_backup);
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_VOID_RETURN;
}
mysql_log.write(thd, COM_PREPARE, "%s", packet);
thd->current_statement= stmt;
lex= lex_start(thd, (uchar *) thd->query, thd->query_length);
mysql_init_query(thd);
lex->safe_to_cache_query= 0;
error= yyparse((void *)thd) || thd->is_fatal_error ||
init_param_array(stmt) ||
send_prepare_results(stmt);
/* restore to WAIT_PRIOR: QUERY_PRIOR is set inside alloc_query */
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),WAIT_PRIOR);
lex_end(lex);
stmt->set_statement(thd);
stmt->set_item_arena(thd);
thd->set_statement(&thd->stmt_backup);
thd->set_item_arena(&thd->stmt_backup);
thd->current_statement= 0;
if (error)
{
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
/* error is sent inside yyparse/send_prepare_results */
}
else
{
SELECT_LEX *sl= stmt->lex->all_selects_list;
/*
Save WHERE clause pointers, because they may be changed during query
optimisation.
*/
for (; sl; sl= sl->next_select_in_list())
{
sl->prep_where= sl->where;
}
}
DBUG_VOID_RETURN;
}
/* Reinit statement before execution */
static void reset_stmt_for_execute(Prepared_statement *stmt)
{
THD *thd= stmt->thd;
SELECT_LEX *sl= stmt->lex->all_selects_list;
for (; sl; sl= sl->next_select_in_list())
{
/*
Copy WHERE clause pointers to avoid damaging they by optimisation
*/
if (sl->prep_where)
sl->where= sl->prep_where->copy_andor_structure(thd);
DBUG_ASSERT(sl->join == 0);
ORDER *order;
/* Fix GROUP list */
for (order=(ORDER *)sl->group_list.first ; order ; order=order->next)
order->item= (Item **)(order+1);
/* Fix ORDER list */
for (order=(ORDER *)sl->order_list.first ; order ; order=order->next)
order->item= (Item **)(order+1);
/*
TODO: When the new table structure is ready, then have a status bit
to indicate the table is altered, and re-do the setup_*
and open the tables back.
*/
for (TABLE_LIST *tables= (TABLE_LIST*) sl->table_list.first;
tables;
tables= tables->next)
{
/*
Reset old pointers to TABLEs: they are not valid since the tables
were closed in the end of previous prepare or execute call.
*/
tables->table= 0;
tables->table_list= 0;
}
{
SELECT_LEX_UNIT *unit= sl->master_unit();
unit->unclean();
unit->types.empty();
/* for derived tables & PS (which can't be reset by Item_subquery) */
unit->reinit_exec_mechanism();
}
}
}
/*
Executes previously prepared query.
If there is any parameters, then replace markers with the data supplied
from client, and then execute the query.
SYNOPSYS
mysql_stmt_execute()
*/
void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
{
ulong stmt_id= uint4korr(packet);
#ifndef EMBEDDED_LIBRARY
uchar *packet_end= (uchar *) packet + packet_length - 1;
#endif
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_execute");
packet+= 9; /* stmt_id + 5 bytes of flags */
if (!(stmt= find_prepared_statement(thd, stmt_id, "execute", SEND_ERROR)))
DBUG_VOID_RETURN;
/* Check if we got an error when sending long data */
if (stmt->get_longdata_error)
{
send_error(thd, stmt->last_errno, stmt->last_error);
DBUG_VOID_RETURN;
}
thd->stmt_backup.set_statement(thd);
thd->set_statement(stmt);
reset_stmt_for_execute(stmt);
#ifndef EMBEDDED_LIBRARY
if (stmt->param_count)
{
uchar *null_array= (uchar *) packet;
if (setup_conversion_functions(stmt, (uchar **) &packet, packet_end) ||
stmt->set_params(stmt, null_array, (uchar *) packet, packet_end))
goto set_params_data_err;
}
#else
/*
In embedded library we re-install conversion routines each time
we set params, and also we don't need to parse packet.
So we do it in one function.
*/
if (stmt->param_count && stmt->set_params_data(stmt))
goto set_params_data_err;
#endif
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),QUERY_PRIOR);
/*
TODO:
Also, have checks on basic executions such as mysql_insert(),
mysql_delete(), mysql_update() and mysql_select() to not to
have re-check on setup_* and other things ..
*/
thd->protocol= &thd->protocol_prep; // Switch to binary protocol
mysql_execute_command(thd);
thd->protocol= &thd->protocol_simple; // Use normal protocol
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(), WAIT_PRIOR);
cleanup_items(stmt->free_list);
close_thread_tables(thd); // to close derived tables
thd->set_statement(&thd->stmt_backup);
DBUG_VOID_RETURN;
set_params_data_err:
thd->set_statement(&thd->stmt_backup);
my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_execute");
send_error(thd);
DBUG_VOID_RETURN;
}
/*
Reset a prepared statement, in case there was an error in send_longdata.
Note: we don't send any reply to that command.
SYNOPSIS
mysql_stmt_reset()
thd Thread handle
packet Packet with stmt id
DESCRIPTION
This function is useful when one gets an error after calling
mysql_stmt_getlongdata() and wants to reset the handle
so that one can call execute again.
See also bug #1664
*/
void mysql_stmt_reset(THD *thd, char *packet)
{
/* There is always space for 4 bytes in buffer */
ulong stmt_id= uint4korr(packet);
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_reset");
if (!(stmt= find_prepared_statement(thd, stmt_id, "reset", DONT_SEND_ERROR)))
DBUG_VOID_RETURN;
stmt->get_longdata_error= 0;
/* Free long data if used */
if (stmt->long_data_used)
{
Item_param **item= stmt->param_array;
Item_param **end= item + stmt->param_count;
stmt->long_data_used= 0;
for (; item < end ; item++)
(**item).reset();
}
DBUG_VOID_RETURN;
}
/*
Delete a prepared statement from memory.
Note: we don't send any reply to that command.
*/
void mysql_stmt_free(THD *thd, char *packet)
{
/* There is always space for 4 bytes in packet buffer */
ulong stmt_id= uint4korr(packet);
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_free");
if (!(stmt= find_prepared_statement(thd, stmt_id, "close", DONT_SEND_ERROR)))
DBUG_VOID_RETURN;
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
DBUG_VOID_RETURN;
}
/*
Long data in pieces from client
SYNOPSIS
mysql_stmt_get_longdata()
thd Thread handle
pos String to append
packet_length Length of string
DESCRIPTION
Get a part of a long data.
To make the protocol efficient, we are not sending any return packages
here.
If something goes wrong, then we will send the error on 'execute'
We assume that the client takes care of checking that all parts are sent
to the server. (No checking that we get a 'end of column' in the server)
*/
void mysql_stmt_get_longdata(THD *thd, char *pos, ulong packet_length)
{
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_get_longdata");
#ifndef EMBEDDED_LIBRARY
/* The following should never happen */
if (packet_length < MYSQL_LONG_DATA_HEADER+1)
{
my_error(ER_WRONG_ARGUMENTS, MYF(0), "get_longdata");
DBUG_VOID_RETURN;
}
#endif
ulong stmt_id= uint4korr(pos);
uint param_number= uint2korr(pos+4);
if (!(stmt=find_prepared_statement(thd, stmt_id, "get_longdata",
DONT_SEND_ERROR)))
DBUG_VOID_RETURN;
#ifndef EMBEDDED_LIBRARY
if (param_number >= stmt->param_count)
{
/* Error will be sent in execute call */
stmt->get_longdata_error= 1;
stmt->last_errno= ER_WRONG_ARGUMENTS;
sprintf(stmt->last_error, ER(ER_WRONG_ARGUMENTS), "get_longdata");
DBUG_VOID_RETURN;
}
pos+= MYSQL_LONG_DATA_HEADER; // Point to data
#endif
Item_param *param= stmt->param_array[param_number];
#ifndef EMBEDDED_LIBRARY
param->set_longdata(pos, packet_length-MYSQL_LONG_DATA_HEADER-1);
#else
param->set_longdata(thd->extra_data, thd->extra_length);
#endif
stmt->long_data_used= 1;
DBUG_VOID_RETURN;
}
Prepared_statement::Prepared_statement(THD *thd_arg)
:Statement(thd_arg),
thd(thd_arg),
param_array(0),
param_count(0),
last_errno(0),
get_longdata_error(0),
long_data_used(0),
log_full_query(0)
{
*last_error= '\0';
if (mysql_bin_log.is_open())
{
log_full_query= 1;
#ifndef EMBEDDED_LIBRARY
set_params= insert_params_withlog;
#else
set_params_data= emb_insert_params_withlog;
#endif
}
else
#ifndef EMBEDDED_LIBRARY
set_params= insert_params;
#else
set_params_data= emb_insert_params;
#endif
}
Prepared_statement::~Prepared_statement()
{
free_items(free_list);
}
Statement::Type Prepared_statement::type() const
{
return PREPARED_STATEMENT;
}
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