MySQL 5.1: mysql/src/5.1-dbg/sql/sql_cursor.cc File Reference

mysql/src/5.1-dbg/sql/sql_cursor.cc File Reference

#include "mysql_priv.h"
#include "sql_cursor.h"
#include "sql_select.h"

Include dependency graph for sql_cursor.cc:


Classes
class	Sensitive_cursor
struct	Sensitive_cursor::Engine_info
class	Materialized_cursor
class	Select_materialize
Functions
int	mysql_open_cursor (THD thd, uint flags, select_result result, Server_side_cursor **pcursor)

Function Documentation

int mysql_open_cursor	(	THD *	thd,
		uint	flags,
		select_result *	result,
		Server_side_cursor **	pcursor
	)

Definition at line 138 of file sql_cursor.cc.

References ALWAYS_MATERIALIZED_CURSOR, DBUG_ASSERT, free_tmp_table(), Sensitive_cursor::get_lock_id(), Sensitive_cursor::is_open(), st_table::mem_root, mysql_execute_command(), Materialized_cursor::open(), and Sensitive_cursor::post_open().

Referenced by Prepared_statement::execute(), and sp_cursor::open().

00140 {
00141   Sensitive_cursor *sensitive_cursor;
00142   select_result *save_result;
00143   Select_materialize *result_materialize;
00144   LEX *lex= thd->lex;
00145   int rc;
00146 
00147   /*
00148     The lifetime of the sensitive cursor is the same or less as the
00149     lifetime of the runtime memory of the statement it's opened for.
00150   */
00151   if (! (result_materialize= new (thd->mem_root) Select_materialize(result)))
00152     return 1;
00153 
00154   if (! (sensitive_cursor= new (thd->mem_root) Sensitive_cursor(thd, result)))
00155   {
00156     delete result;
00157     return 1;
00158   }
00159 
00160   save_result= lex->result;
00161 
00162   lex->result= result_materialize;
00163   if (! (flags & (uint) ALWAYS_MATERIALIZED_CURSOR))
00164   {
00165     thd->lock_id= sensitive_cursor->get_lock_id();
00166     thd->cursor= sensitive_cursor;
00167   }
00168 
00169   rc= mysql_execute_command(thd);
00170 
00171   lex->result= save_result;
00172   thd->lock_id= &thd->main_lock_id;
00173   thd->cursor= 0;
00174 
00175   /*
00176     Possible options here:
00177     - a sensitive cursor is open. In this case rc is 0 and
00178       result_materialize->table is NULL, or
00179     - a materialized cursor is open. In this case rc is 0 and
00180       result_materialize->table is not NULL
00181     - an error occured during materializaton.
00182       result_materialize->table is not NULL, but rc != 0
00183     - successful completion of mysql_execute_command without
00184       a cursor: rc is 0, result_materialize->table is NULL,
00185       sensitive_cursor is not open.
00186       This is possible if some command writes directly to the
00187       network, bypassing select_result mechanism. An example of
00188       such command is SHOW VARIABLES or SHOW STATUS.
00189   */
00190   if (rc)
00191     goto err_open;
00192 
00193   if (sensitive_cursor->is_open())
00194   {
00195     DBUG_ASSERT(!result_materialize->table);
00196     /*
00197       It's safer if we grab THD state after mysql_execute_command
00198       is finished and not in Sensitive_cursor::open(), because
00199       currently the call to Sensitive_cursor::open is buried deep
00200       in JOIN::exec of the top level join.
00201     */
00202     sensitive_cursor->post_open(thd);
00203     *pcursor= sensitive_cursor;
00204     goto end;
00205   }
00206   else if (result_materialize->table)
00207   {
00208     Materialized_cursor *materialized_cursor;
00209     TABLE *table= result_materialize->table;
00210     MEM_ROOT *mem_root= &table->mem_root;
00211 
00212     if (!(materialized_cursor= new (mem_root)
00213                                Materialized_cursor(result, table)))
00214     {
00215       rc= 1;
00216       goto err_open;
00217     }
00218 
00219     if ((rc= materialized_cursor->open(0)))
00220     {
00221       delete materialized_cursor;
00222       goto err_open;
00223     }
00224 
00225     *pcursor= materialized_cursor;
00226     thd->stmt_arena->cleanup_stmt();
00227     goto end;
00228   }
00229 
00230 err_open:
00231   DBUG_ASSERT(! (sensitive_cursor && sensitive_cursor->is_open()));
00232   delete sensitive_cursor;
00233   if (result_materialize->table)
00234     free_tmp_table(thd, result_materialize->table);
00235 end:
00236   delete result_materialize;
00237   return rc;
00238 }

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Generated on Sat Sep 9 02:59:06 2006 for MySQL 5.1 by

1.4.7

mysql/src/5.1-dbg/sql/sql_cursor.cc File Reference

Classes

Functions

Function Documentation