mariadb/sql/sql_select.h
unknown d36c14f748 A fix and a test case for Bug#11172 "mysql_stmt_attr_set
CURSOR_TYPE_READ_ONLY date/datetime filter server crash".
The fix adds support for Item_change_list in cursors (proper rollback
of the modified item tree). 


sql/sql_class.cc:
  No need to call fatal_error() twice.
sql/sql_prepare.cc:
  - implement proper cleanup of the prepared statement in mysql_stmt_reset
    if there is a cursor.
  - take into account thd->change_list when fetching data through a
    cursor.
sql/sql_select.cc:
  - take into account thd->change_list when fetching data from a cursor:
    grab it when we open a cursor, and rollback the changes to the parsed
    tree when we close it.
sql/sql_select.h:
  - Cursor::change_list added
tests/mysql_client_test.c:
  - a test case for Bug#11172 "mysql_stmt_attr_set CURSOR_TYPE_READ_ONLY date/datetime
   filter server crash"
2005-07-01 15:47:45 +04:00

560 lines
18 KiB
C++

/* 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 */
/* classes to use when handling where clause */
#ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class implementation */
#endif
#include "procedure.h"
#include <myisam.h>
typedef struct keyuse_t {
TABLE *table;
Item *val; /* or value if no field */
table_map used_tables;
uint key, keypart, optimize;
key_part_map keypart_map;
ha_rows ref_table_rows;
/*
If true, the comparison this value was created from will not be
satisfied if val has NULL 'value'.
*/
bool null_rejecting;
} KEYUSE;
class store_key;
typedef struct st_table_ref
{
bool key_err;
uint key_parts; // num of ...
uint key_length; // length of key_buff
int key; // key no
byte *key_buff; // value to look for with key
byte *key_buff2; // key_buff+key_length
store_key **key_copy; //
Item **items; // val()'s for each keypart
/*
(null_rejecting & (1<<i)) means the condition is '=' and no matching
rows will be produced if items[i] IS NULL (see add_not_null_conds())
*/
key_part_map null_rejecting;
table_map depend_map; // Table depends on these tables.
byte *null_ref_key; // null byte position in the key_buf.
// used for REF_OR_NULL optimization.
} TABLE_REF;
/*
** CACHE_FIELD and JOIN_CACHE is used on full join to cache records in outer
** table
*/
typedef struct st_cache_field {
char *str;
uint length,blob_length;
Field_blob *blob_field;
bool strip;
} CACHE_FIELD;
typedef struct st_join_cache {
uchar *buff,*pos,*end;
uint records,record_nr,ptr_record,fields,length,blobs;
CACHE_FIELD *field,**blob_ptr;
SQL_SELECT *select;
} JOIN_CACHE;
/*
** The structs which holds the join connections and join states
*/
enum join_type { JT_UNKNOWN,JT_SYSTEM,JT_CONST,JT_EQ_REF,JT_REF,JT_MAYBE_REF,
JT_ALL, JT_RANGE, JT_NEXT, JT_FT, JT_REF_OR_NULL,
JT_UNIQUE_SUBQUERY, JT_INDEX_SUBQUERY, JT_INDEX_MERGE};
class JOIN;
enum enum_nested_loop_state
{
NESTED_LOOP_KILLED= -2, NESTED_LOOP_ERROR= -1,
NESTED_LOOP_OK= 0, NESTED_LOOP_NO_MORE_ROWS= 1,
NESTED_LOOP_QUERY_LIMIT= 3, NESTED_LOOP_CURSOR_LIMIT= 4
};
typedef enum_nested_loop_state
(*Next_select_func)(JOIN *, struct st_join_table *, bool);
typedef int (*Read_record_func)(struct st_join_table *tab);
typedef struct st_join_table {
TABLE *table;
KEYUSE *keyuse; /* pointer to first used key */
SQL_SELECT *select;
COND *select_cond;
QUICK_SELECT_I *quick;
Item **on_expr_ref; /* pointer to the associated on expression */
COND_EQUAL *cond_equal; /* multiple equalities for the on expression */
st_join_table *first_inner; /* first inner table for including outerjoin */
bool found; /* true after all matches or null complement */
bool not_null_compl;/* true before null complement is added */
st_join_table *last_inner; /* last table table for embedding outer join */
st_join_table *first_upper; /* first inner table for embedding outer join */
st_join_table *first_unmatched; /* used for optimization purposes only */
const char *info;
Read_record_func read_first_record;
Next_select_func next_select;
READ_RECORD read_record;
double worst_seeks;
key_map const_keys; /* Keys with constant part */
key_map checked_keys; /* Keys checked in find_best */
key_map needed_reg;
key_map keys; /* all keys with can be used */
ha_rows records,found_records,read_time;
table_map dependent,key_dependent;
uint use_quick,index;
uint status; // Save status for cache
uint used_fields,used_fieldlength,used_blobs;
enum join_type type;
bool cached_eq_ref_table,eq_ref_table,not_used_in_distinct;
TABLE_REF ref;
JOIN_CACHE cache;
JOIN *join;
void cleanup();
} JOIN_TAB;
typedef struct st_position /* Used in find_best */
{
double records_read;
double read_time;
JOIN_TAB *table;
KEYUSE *key;
} POSITION;
typedef struct st_rollup
{
enum State { STATE_NONE, STATE_INITED, STATE_READY };
State state;
Item_null_result **null_items;
Item ***ref_pointer_arrays;
List<Item> *fields;
} ROLLUP;
class JOIN :public Sql_alloc
{
public:
JOIN_TAB *join_tab,**best_ref;
JOIN_TAB **map2table; // mapping between table indexes and JOIN_TABs
JOIN_TAB *join_tab_save; // saved join_tab for subquery reexecution
TABLE **table,**all_tables,*sort_by_table;
uint tables,const_tables;
uint send_group_parts;
bool sort_and_group,first_record,full_join,group, no_field_update;
bool do_send_rows;
/*
TRUE when we want to resume nested loop iterations when
fetching data from a cursor
*/
bool resume_nested_loop;
table_map const_table_map,found_const_table_map,outer_join;
ha_rows send_records,found_records,examined_rows,row_limit, select_limit;
/*
Used to fetch no more than given amount of rows per one
fetch operation of server side cursor.
The value is checked in end_send and end_send_group in fashion, similar
to offset_limit_cnt:
- fetch_limit= HA_POS_ERROR if there is no cursor.
- when we open a cursor, we set fetch_limit to 0,
- on each fetch iteration we add num_rows to fetch to fetch_limit
*/
ha_rows fetch_limit;
POSITION positions[MAX_TABLES+1],best_positions[MAX_TABLES+1];
double best_read;
List<Item> *fields;
List<Cached_item> group_fields, group_fields_cache;
TABLE *tmp_table;
// used to store 2 possible tmp table of SELECT
TABLE *exec_tmp_table1, *exec_tmp_table2;
THD *thd;
Item_sum **sum_funcs, ***sum_funcs_end;
/* second copy of sumfuncs (for queries with 2 temporary tables */
Item_sum **sum_funcs2, ***sum_funcs_end2;
Procedure *procedure;
Item *having;
Item *tmp_having; // To store having when processed temporary table
Item *having_history; // Store having for explain
uint select_options;
select_result *result;
TMP_TABLE_PARAM tmp_table_param;
MYSQL_LOCK *lock;
// unit structure (with global parameters) for this select
SELECT_LEX_UNIT *unit;
// select that processed
SELECT_LEX *select_lex;
JOIN *tmp_join; // copy of this JOIN to be used with temporary tables
ROLLUP rollup; // Used with rollup
bool select_distinct; // Set if SELECT DISTINCT
/*
simple_xxxxx is set if ORDER/GROUP BY doesn't include any references
to other tables than the first non-constant table in the JOIN.
It's also set if ORDER/GROUP BY is empty.
*/
bool simple_order, simple_group;
/*
Is set only in case if we have a GROUP BY clause
and no ORDER BY after constant elimination of 'order'.
*/
bool no_order;
/* Is set if we have a GROUP BY and we have ORDER BY on a constant. */
bool skip_sort_order;
bool need_tmp, hidden_group_fields, buffer_result;
DYNAMIC_ARRAY keyuse;
Item::cond_result cond_value;
List<Item> all_fields; // to store all fields that used in query
//Above list changed to use temporary table
List<Item> tmp_all_fields1, tmp_all_fields2, tmp_all_fields3;
//Part, shared with list above, emulate following list
List<Item> tmp_fields_list1, tmp_fields_list2, tmp_fields_list3;
List<Item> &fields_list; // hold field list passed to mysql_select
int error;
ORDER *order, *group_list, *proc_param; //hold parameters of mysql_select
COND *conds; // ---"---
Item *conds_history; // store WHERE for explain
TABLE_LIST *tables_list; //hold 'tables' parameter of mysql_select
List<TABLE_LIST> *join_list; // list of joined tables in reverse order
COND_EQUAL *cond_equal;
SQL_SELECT *select; //created in optimisation phase
JOIN_TAB *return_tab; //used only for outer joins
Item **ref_pointer_array; //used pointer reference for this select
// Copy of above to be used with different lists
Item **items0, **items1, **items2, **items3, **current_ref_pointer_array;
uint ref_pointer_array_size; // size of above in bytes
const char *zero_result_cause; // not 0 if exec must return zero result
bool union_part; // this subselect is part of union
bool optimized; // flag to avoid double optimization in EXPLAIN
JOIN(THD *thd_arg, List<Item> &fields_arg, ulong select_options_arg,
select_result *result_arg)
:fields_list(fields_arg)
{
init(thd_arg, fields_arg, select_options_arg, result_arg);
}
void init(THD *thd_arg, List<Item> &fields_arg, ulong select_options_arg,
select_result *result_arg)
{
join_tab= join_tab_save= 0;
table= 0;
tables= 0;
const_tables= 0;
join_list= 0;
sort_and_group= 0;
first_record= 0;
do_send_rows= 1;
resume_nested_loop= FALSE;
send_records= 0;
found_records= 0;
fetch_limit= HA_POS_ERROR;
examined_rows= 0;
exec_tmp_table1= 0;
exec_tmp_table2= 0;
thd= thd_arg;
sum_funcs= sum_funcs2= 0;
procedure= 0;
having= tmp_having= having_history= 0;
select_options= select_options_arg;
result= result_arg;
lock= thd_arg->lock;
select_lex= 0; //for safety
tmp_join= 0;
select_distinct= test(select_options & SELECT_DISTINCT);
no_order= 0;
simple_order= 0;
simple_group= 0;
skip_sort_order= 0;
need_tmp= 0;
hidden_group_fields= 0; /*safety*/
buffer_result= test(select_options & OPTION_BUFFER_RESULT) &&
!test(select_options & OPTION_FOUND_ROWS);
error= 0;
select= 0;
return_tab= 0;
ref_pointer_array= items0= items1= items2= items3= 0;
ref_pointer_array_size= 0;
zero_result_cause= 0;
optimized= 0;
cond_equal= 0;
all_fields= fields_arg;
fields_list= fields_arg;
bzero((char*) &keyuse,sizeof(keyuse));
tmp_table_param.copy_field=0;
tmp_table_param.end_write_records= HA_POS_ERROR;
rollup.state= ROLLUP::STATE_NONE;
}
int prepare(Item ***rref_pointer_array, TABLE_LIST *tables, uint wind_num,
COND *conds, uint og_num, ORDER *order, ORDER *group,
Item *having, ORDER *proc_param, SELECT_LEX *select,
SELECT_LEX_UNIT *unit);
int optimize();
int reinit();
void exec();
int destroy();
void restore_tmp();
bool alloc_func_list();
bool make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields,
bool before_group_by, bool recompute= FALSE);
inline void set_items_ref_array(Item **ptr)
{
memcpy((char*) ref_pointer_array, (char*) ptr, ref_pointer_array_size);
current_ref_pointer_array= ptr;
}
inline void init_items_ref_array()
{
items0= ref_pointer_array + all_fields.elements;
memcpy(items0, ref_pointer_array, ref_pointer_array_size);
current_ref_pointer_array= items0;
}
bool rollup_init();
bool rollup_make_fields(List<Item> &all_fields, List<Item> &fields,
Item_sum ***func);
int rollup_send_data(uint idx);
int rollup_write_data(uint idx, TABLE *table);
bool test_in_subselect(Item **where);
/*
Release memory and, if possible, the open tables held by this execution
plan (and nested plans). It's used to release some tables before
the end of execution in order to increase concurrency and reduce
memory consumption.
*/
void join_free(bool full);
/* Cleanup this JOIN, possibly for reuse */
void cleanup(bool full);
void clear();
bool save_join_tab();
bool send_row_on_empty_set()
{
return (do_send_rows && tmp_table_param.sum_func_count != 0 &&
!group_list);
}
bool change_result(select_result *result);
};
/*
Server-side cursor (now stands only for basic read-only cursor)
See class implementation in sql_select.cc
A cursor has its own runtime state - list of used items and memory root of
used memory - which is different from Prepared statement runtime: it must
be different at least for the purpose of reusing the same prepared
statement for many cursors.
*/
class Cursor: public Sql_alloc, public Query_arena
{
MEM_ROOT main_mem_root;
JOIN *join;
SELECT_LEX_UNIT *unit;
TABLE *open_tables;
MYSQL_LOCK *lock;
TABLE *derived_tables;
/* List of items created during execution */
query_id_t query_id;
public:
Item_change_list change_list;
select_send result;
/* Temporary implementation as now we replace THD state by value */
/* Save THD state into cursor */
void init_from_thd(THD *thd);
/* bzero cursor state in THD */
void reset_thd(THD *thd);
int open(JOIN *join);
void fetch(ulong num_rows);
void reset() { join= 0; }
bool is_open() const { return join != 0; }
void close(bool is_active);
void set_unit(SELECT_LEX_UNIT *unit_arg) { unit= unit_arg; }
Cursor(THD *thd);
~Cursor();
};
typedef struct st_select_check {
uint const_ref,reg_ref;
} SELECT_CHECK;
extern const char *join_type_str[];
void TEST_join(JOIN *join);
/* Extern functions in sql_select.cc */
bool store_val_in_field(Field *field,Item *val);
TABLE *create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
ORDER *group, bool distinct, bool save_sum_fields,
ulong select_options, ha_rows rows_limit,
char* alias);
TABLE *create_virtual_tmp_table(THD *thd, List<create_field> &field_list);
void free_tmp_table(THD *thd, TABLE *entry);
void count_field_types(TMP_TABLE_PARAM *param, List<Item> &fields,
bool reset_with_sum_func);
bool setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
Item **ref_pointer_array,
List<Item> &new_list1, List<Item> &new_list2,
uint elements, List<Item> &fields);
void copy_fields(TMP_TABLE_PARAM *param);
void copy_funcs(Item **func_ptr);
bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
int error, bool ignore_last_dupp_error);
uint find_shortest_key(TABLE *table, const key_map *usable_keys);
Field* create_tmp_field_from_field(THD *thd, Field* org_field,
const char *name, TABLE *table,
Item_field *item, uint convert_blob_length);
/* functions from opt_sum.cc */
bool simple_pred(Item_func *func_item, Item **args, bool *inv_order);
int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds);
/* from sql_delete.cc, used by opt_range.cc */
extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b);
/* class to copying an field/item to a key struct */
class store_key :public Sql_alloc
{
protected:
Field *to_field; // Store data here
char *null_ptr;
char err;
public:
enum store_key_result { STORE_KEY_OK, STORE_KEY_FATAL, STORE_KEY_CONV };
store_key(THD *thd, Field *field_arg, char *ptr, char *null, uint length)
:null_ptr(null),err(0)
{
if (field_arg->type() == FIELD_TYPE_BLOB)
{
/* Key segments are always packed with a 2 byte length prefix */
to_field=new Field_varstring(ptr, length, 2, (uchar*) null, 1,
Field::NONE, field_arg->field_name,
field_arg->table, field_arg->charset());
}
else
to_field=field_arg->new_key_field(thd->mem_root, field_arg->table,
ptr, (uchar*) null, 1);
}
virtual ~store_key() {} /* Not actually needed */
virtual enum store_key_result copy()=0;
virtual const char *name() const=0;
};
class store_key_field: public store_key
{
Copy_field copy_field;
const char *field_name;
public:
store_key_field(THD *thd, Field *to_field_arg, char *ptr, char *null_ptr_arg,
uint length, Field *from_field, const char *name_arg)
:store_key(thd, to_field_arg,ptr,
null_ptr_arg ? null_ptr_arg : from_field->maybe_null() ? &err
: NullS,length), field_name(name_arg)
{
if (to_field)
{
copy_field.set(to_field,from_field,0);
}
}
enum store_key_result copy()
{
copy_field.do_copy(&copy_field);
return err != 0 ? STORE_KEY_FATAL : STORE_KEY_OK;
}
const char *name() const { return field_name; }
};
class store_key_item :public store_key
{
protected:
Item *item;
public:
store_key_item(THD *thd, Field *to_field_arg, char *ptr, char *null_ptr_arg,
uint length, Item *item_arg)
:store_key(thd, to_field_arg,ptr,
null_ptr_arg ? null_ptr_arg : item_arg->maybe_null ?
&err : NullS, length), item(item_arg)
{}
enum store_key_result copy()
{
int res= item->save_in_field(to_field, 1);
return (err != 0 || res > 2 ? STORE_KEY_FATAL : (store_key_result) res);
}
const char *name() const { return "func"; }
};
class store_key_const_item :public store_key_item
{
bool inited;
public:
store_key_const_item(THD *thd, Field *to_field_arg, char *ptr,
char *null_ptr_arg, uint length,
Item *item_arg)
:store_key_item(thd, to_field_arg,ptr,
null_ptr_arg ? null_ptr_arg : item_arg->maybe_null ?
&err : NullS, length, item_arg), inited(0)
{
}
enum store_key_result copy()
{
int res;
if (!inited)
{
inited=1;
if ((res= item->save_in_field(to_field, 1)))
{
if (!err)
err= res;
}
}
return (err > 2 ? STORE_KEY_FATAL : (store_key_result) err);
}
const char *name() const { return "const"; }
};
bool cp_buffer_from_ref(THD *thd, TABLE_REF *ref);
bool error_if_full_join(JOIN *join);
int report_error(TABLE *table, int error);
int safe_index_read(JOIN_TAB *tab);