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mariadb/sql/item_sum.cc
Alexander Barkov ab297744b7 Merge remote-tracking branch 'origin/10.3' into 10.4
2018-06-05 10:50:08 +04:00

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/* Copyright (c) 2000, 2015, Oracle and/or its affiliates.
Copyright (c) 2008, 2015, MariaDB
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; version 2 of the License.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/**
@file
@brief
Sum functions (COUNT, MIN...)
*/
#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation // gcc: Class implementation
#endif
#include "mariadb.h"
#include "sql_priv.h"
#include "sql_select.h"
#include "uniques.h"
#include "sp_rcontext.h"
#include "sp.h"
#include "sql_parse.h"
#include "sp_head.h"
/**
Calculate the affordable RAM limit for structures like TREE or Unique
used in Item_sum_*
*/
size_t Item_sum::ram_limitation(THD *thd)
{
return (size_t)MY_MIN(thd->variables.tmp_memory_table_size,
thd->variables.max_heap_table_size);
}
/**
Prepare an aggregate function item for checking context conditions.
The function initializes the members of the Item_sum object created
for a set function that are used to check validity of the set function
occurrence.
If the set function is not allowed in any subquery where it occurs
an error is reported immediately.
@param thd reference to the thread context info
@note
This function is to be called for any item created for a set function
object when the traversal of trees built for expressions used in the query
is performed at the phase of context analysis. This function is to
be invoked at the descent of this traversal.
@retval
TRUE if an error is reported
@retval
FALSE otherwise
*/
bool Item_sum::init_sum_func_check(THD *thd)
{
SELECT_LEX *curr_sel= thd->lex->current_select;
if (!curr_sel->name_visibility_map)
{
for (SELECT_LEX *sl= curr_sel; sl; sl= sl->context.outer_select())
{
curr_sel->name_visibility_map|= (1 << sl-> nest_level);
}
}
if (!(thd->lex->allow_sum_func & curr_sel->name_visibility_map))
{
my_message(ER_INVALID_GROUP_FUNC_USE, ER_THD(thd, ER_INVALID_GROUP_FUNC_USE),
MYF(0));
return TRUE;
}
/* Set a reference to the nesting set function if there is any */
in_sum_func= thd->lex->in_sum_func;
/* Save a pointer to object to be used in items for nested set functions */
thd->lex->in_sum_func= this;
nest_level= thd->lex->current_select->nest_level;
ref_by= 0;
aggr_level= -1;
aggr_sel= NULL;
max_arg_level= -1;
max_sum_func_level= -1;
outer_fields.empty();
return FALSE;
}
/**
Check constraints imposed on a usage of a set function.
The method verifies whether context conditions imposed on a usage
of any set function are met for this occurrence.
The function first checks if we are using any window functions as
arguments to the set function. In that case it returns an error.
Afterwards, it checks whether the set function occurs in the position where it
can be aggregated and, when it happens to occur in argument of another
set function, the method checks that these two functions are aggregated in
different subqueries.
If the context conditions are not met the method reports an error.
If the set function is aggregated in some outer subquery the method
adds it to the chain of items for such set functions that is attached
to the the st_select_lex structure for this subquery.
A number of designated members of the object are used to check the
conditions. They are specified in the comment before the Item_sum
class declaration.
Additionally a bitmap variable called allow_sum_func is employed.
It is included into the thd->lex structure.
The bitmap contains 1 at n-th position if the set function happens
to occur under a construct of the n-th level subquery where usage
of set functions are allowed (i.e either in the SELECT list or
in the HAVING clause of the corresponding subquery)
Consider the query:
@code
SELECT SUM(t1.b) FROM t1 GROUP BY t1.a
HAVING t1.a IN (SELECT t2.c FROM t2 WHERE AVG(t1.b) > 20) AND
t1.a > (SELECT MIN(t2.d) FROM t2);
@endcode
allow_sum_func will contain:
- for SUM(t1.b) - 1 at the first position
- for AVG(t1.b) - 1 at the first position, 0 at the second position
- for MIN(t2.d) - 1 at the first position, 1 at the second position.
@param thd reference to the thread context info
@param ref location of the pointer to this item in the embedding expression
@note
This function is to be called for any item created for a set function
object when the traversal of trees built for expressions used in the query
is performed at the phase of context analysis. This function is to
be invoked at the ascent of this traversal.
@retval
TRUE if an error is reported
@retval
FALSE otherwise
*/
bool Item_sum::check_sum_func(THD *thd, Item **ref)
{
SELECT_LEX *curr_sel= thd->lex->current_select;
nesting_map allow_sum_func= (thd->lex->allow_sum_func &
curr_sel->name_visibility_map);
bool invalid= FALSE;
DBUG_ASSERT(curr_sel->name_visibility_map); // should be set already
/*
Window functions can not be used as arguments to sum functions.
Aggregation happes before window function computation, so there
are no values to aggregate over.
*/
if (with_window_func)
{
my_message(ER_SUM_FUNC_WITH_WINDOW_FUNC_AS_ARG,
ER_THD(thd, ER_SUM_FUNC_WITH_WINDOW_FUNC_AS_ARG),
MYF(0));
return TRUE;
}
if (window_func_sum_expr_flag)
return false;
/*
The value of max_arg_level is updated if an argument of the set function
contains a column reference resolved against a subquery whose level is
greater than the current value of max_arg_level.
max_arg_level cannot be greater than nest level.
nest level is always >= 0
*/
if (nest_level == max_arg_level)
{
/*
The function must be aggregated in the current subquery,
If it is there under a construct where it is not allowed
we report an error.
*/
invalid= !(allow_sum_func & ((nesting_map)1 << max_arg_level));
}
else if (max_arg_level >= 0 ||
!(allow_sum_func & ((nesting_map)1 << nest_level)))
{
/*
The set function can be aggregated only in outer subqueries.
Try to find a subquery where it can be aggregated;
If we fail to find such a subquery report an error.
*/
if (register_sum_func(thd, ref))
return TRUE;
invalid= aggr_level < 0 &&
!(allow_sum_func & ((nesting_map)1 << nest_level));
if (!invalid && thd->variables.sql_mode & MODE_ANSI)
invalid= aggr_level < 0 && max_arg_level < nest_level;
}
if (!invalid && aggr_level < 0)
{
aggr_level= nest_level;
aggr_sel= curr_sel;
}
/*
By this moment we either found a subquery where the set function is
to be aggregated and assigned a value that is >= 0 to aggr_level,
or set the value of 'invalid' to TRUE to report later an error.
*/
/*
Additionally we have to check whether possible nested set functions
are acceptable here: they are not, if the level of aggregation of
some of them is less than aggr_level.
*/
if (!invalid)
invalid= aggr_level <= max_sum_func_level;
if (invalid)
{
my_message(ER_INVALID_GROUP_FUNC_USE,
ER_THD(thd, ER_INVALID_GROUP_FUNC_USE),
MYF(0));
return TRUE;
}
if (in_sum_func)
{
/*
If the set function is nested adjust the value of
max_sum_func_level for the nesting set function.
We take into account only enclosed set functions that are to be
aggregated on the same level or above of the nest level of
the enclosing set function.
But we must always pass up the max_sum_func_level because it is
the maximum nested level of all directly and indirectly enclosed
set functions. We must do that even for set functions that are
aggregated inside of their enclosing set function's nest level
because the enclosing function may contain another enclosing
function that is to be aggregated outside or on the same level
as its parent's nest level.
*/
if (in_sum_func->nest_level >= aggr_level)
set_if_bigger(in_sum_func->max_sum_func_level, aggr_level);
set_if_bigger(in_sum_func->max_sum_func_level, max_sum_func_level);
}
/*
Check that non-aggregated fields and sum functions aren't mixed in the
same select in the ONLY_FULL_GROUP_BY mode.
*/
if (outer_fields.elements)
{
Item_field *field;
/*
Here we compare the nesting level of the select to which an outer field
belongs to with the aggregation level of the sum function. All fields in
the outer_fields list are checked.
If the nesting level is equal to the aggregation level then the field is
aggregated by this sum function.
If the nesting level is less than the aggregation level then the field
belongs to an outer select. In this case if there is an embedding sum
function add current field to functions outer_fields list. If there is
no embedding function then the current field treated as non aggregated
and the select it belongs to is marked accordingly.
If the nesting level is greater than the aggregation level then it means
that this field was added by an inner sum function.
Consider an example:
select avg ( <-- we are here, checking outer.f1
select (
select sum(outer.f1 + inner.f1) from inner
) from outer)
from most_outer;
In this case we check that no aggregate functions are used in the
select the field belongs to. If there are some then an error is
raised.
*/
List_iterator<Item_field> of(outer_fields);
while ((field= of++))
{
SELECT_LEX *sel= field->field->table->pos_in_table_list->select_lex;
if (sel->nest_level < aggr_level)
{
if (in_sum_func)
{
/*
Let upper function decide whether this field is a non
aggregated one.
*/
in_sum_func->outer_fields.push_back(field, thd->mem_root);
}
else
sel->set_non_agg_field_used(true);
}
if (sel->nest_level > aggr_level &&
(sel->agg_func_used()) &&
!sel->group_list.elements)
{
my_message(ER_MIX_OF_GROUP_FUNC_AND_FIELDS,
ER_THD(thd, ER_MIX_OF_GROUP_FUNC_AND_FIELDS), MYF(0));
return TRUE;
}
}
}
aggr_sel->set_agg_func_used(true);
if (sum_func() == SP_AGGREGATE_FUNC)
aggr_sel->set_custom_agg_func_used(true);
update_used_tables();
thd->lex->in_sum_func= in_sum_func;
return FALSE;
}
/**
Attach a set function to the subquery where it must be aggregated.
The function looks for an outer subquery where the set function must be
aggregated. If it finds such a subquery then aggr_level is set to
the nest level of this subquery and the item for the set function
is added to the list of set functions used in nested subqueries
inner_sum_func_list defined for each subquery. When the item is placed
there the field 'ref_by' is set to ref.
@note
Now we 'register' only set functions that are aggregated in outer
subqueries. Actually it makes sense to link all set function for
a subquery in one chain. It would simplify the process of 'splitting'
for set functions.
@param thd reference to the thread context info
@param ref location of the pointer to this item in the embedding expression
@retval
FALSE if the executes without failures (currently always)
@retval
TRUE otherwise
*/
bool Item_sum::register_sum_func(THD *thd, Item **ref)
{
SELECT_LEX *sl;
nesting_map allow_sum_func= thd->lex->allow_sum_func;
for (sl= thd->lex->current_select->context.outer_select() ;
sl && sl->nest_level > max_arg_level;
sl= sl->context.outer_select())
{
if (aggr_level < 0 &&
(allow_sum_func & ((nesting_map)1 << sl->nest_level)))
{
/* Found the most nested subquery where the function can be aggregated */
aggr_level= sl->nest_level;
aggr_sel= sl;
}
}
if (sl && (allow_sum_func & ((nesting_map)1 << sl->nest_level)))
{
/*
We reached the subquery of level max_arg_level and checked
that the function can be aggregated here.
The set function will be aggregated in this subquery.
*/
aggr_level= sl->nest_level;
aggr_sel= sl;
}
if (aggr_level >= 0)
{
ref_by= ref;
/* Add the object to the list of registered objects assigned to aggr_sel */
if (!aggr_sel->inner_sum_func_list)
next= this;
else
{
next= aggr_sel->inner_sum_func_list->next;
aggr_sel->inner_sum_func_list->next= this;
}
aggr_sel->inner_sum_func_list= this;
aggr_sel->with_sum_func= 1;
/*
Mark Item_subselect(s) as containing aggregate function all the way up
to aggregate function's calculation context.
Note that we must not mark the Item of calculation context itself
because with_sum_func on the calculation context st_select_lex is
already set above.
with_sum_func being set for an Item means that this Item refers
(somewhere in it, e.g. one of its arguments if it's a function) directly
or through intermediate items to an aggregate function that is calculated
in a context "outside" of the Item (e.g. in the current or outer select).
with_sum_func being set for an st_select_lex means that this st_select_lex
has aggregate functions directly referenced (i.e. not through a sub-select).
*/
for (sl= thd->lex->current_select;
sl && sl != aggr_sel && sl->master_unit()->item;
sl= sl->master_unit()->outer_select() )
sl->master_unit()->item->with_sum_func= 1;
}
thd->lex->current_select->mark_as_dependent(thd, aggr_sel, NULL);
if ((thd->lex->describe & DESCRIBE_EXTENDED) && aggr_sel)
{
push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
ER_WARN_AGGFUNC_DEPENDENCE,
ER_THD(thd, ER_WARN_AGGFUNC_DEPENDENCE),
func_name(),
thd->lex->current_select->select_number,
aggr_sel->select_number);
}
return FALSE;
}
bool Item_sum::collect_outer_ref_processor(void *param)
{
Collect_deps_prm *prm= (Collect_deps_prm *)param;
SELECT_LEX *ds;
if ((ds= depended_from()) &&
ds->nest_level_base == prm->nest_level_base &&
ds->nest_level < prm->nest_level)
{
if (prm->collect)
prm->parameters->add_unique(this, &cmp_items);
else
prm->count++;
}
return FALSE;
}
Item_sum::Item_sum(THD *thd, List<Item> &list): Item_func_or_sum(thd, list)
{
if (!(orig_args= (Item **) thd->alloc(sizeof(Item *) * arg_count)))
{
args= NULL;
}
mark_as_sum_func();
init_aggregator();
list.empty(); // Fields are used
}
/**
Constructor used in processing select with temporary tebles.
*/
Item_sum::Item_sum(THD *thd, Item_sum *item):
Item_func_or_sum(thd, item),
aggr_sel(item->aggr_sel),
nest_level(item->nest_level), aggr_level(item->aggr_level),
quick_group(item->quick_group),
orig_args(NULL)
{
if (arg_count <= 2)
{
orig_args=tmp_orig_args;
}
else
{
if (!(orig_args= (Item**) thd->alloc(sizeof(Item*)*arg_count)))
return;
}
memcpy(orig_args, item->orig_args, sizeof(Item*)*arg_count);
init_aggregator();
with_distinct= item->with_distinct;
if (item->aggr)
set_aggregator(item->aggr->Aggrtype());
}
void Item_sum::mark_as_sum_func()
{
SELECT_LEX *cur_select= current_thd->lex->current_select;
cur_select->n_sum_items++;
cur_select->with_sum_func= 1;
const_item_cache= false;
with_sum_func= 1;
with_field= 0;
window_func_sum_expr_flag= false;
}
void Item_sum::print(String *str, enum_query_type query_type)
{
/* orig_args is not filled with valid values until fix_fields() */
Item **pargs= fixed ? orig_args : args;
str->append(func_name());
/*
TODO:
The fact that func_name() may return a name with an extra '('
is really annoying. This shoud be fixed.
*/
if (!is_aggr_sum_func())
str->append('(');
for (uint i=0 ; i < arg_count ; i++)
{
if (i)
str->append(',');
pargs[i]->print(str, query_type);
}
str->append(')');
}
void Item_sum::fix_num_length_and_dec()
{
decimals=0;
for (uint i=0 ; i < arg_count ; i++)
set_if_bigger(decimals,args[i]->decimals);
max_length=float_length(decimals);
}
Item *Item_sum::get_tmp_table_item(THD *thd)
{
Item_sum* sum_item= (Item_sum *) copy_or_same(thd);
if (sum_item && sum_item->result_field) // If not a const sum func
{
Field *result_field_tmp= sum_item->result_field;
for (uint i=0 ; i < sum_item->arg_count ; i++)
{
Item *arg= sum_item->args[i];
if (!arg->const_item())
{
if (arg->type() == Item::FIELD_ITEM)
((Item_field*) arg)->field= result_field_tmp++;
else
sum_item->args[i]= new (thd->mem_root) Item_temptable_field(thd, result_field_tmp++);
}
}
}
return sum_item;
}
void Item_sum::update_used_tables ()
{
if (!Item_sum::const_item())
{
used_tables_cache= 0;
for (uint i=0 ; i < arg_count ; i++)
{
args[i]->update_used_tables();
used_tables_cache|= args[i]->used_tables();
}
/*
MariaDB: don't run the following {
used_tables_cache&= PSEUDO_TABLE_BITS;
// the aggregate function is aggregated into its local context
used_tables_cache|= ((table_map)1 << aggr_sel->join->tables) - 1;
} because if we do it, table elimination will assume that
- constructs like "COUNT(*)" use columns from all tables
- so, it is not possible to eliminate any table
our solution for COUNT(*) is that it has
item->used_tables() == 0 && !item->const_item()
*/
}
}
Item *Item_sum::set_arg(uint i, THD *thd, Item *new_val)
{
thd->change_item_tree(args + i, new_val);
return new_val;
}
int Item_sum::set_aggregator(Aggregator::Aggregator_type aggregator)
{
/*
Dependent subselects may be executed multiple times, making
set_aggregator to be called multiple times. The aggregator type
will be the same, but it needs to be reset so that it is
reevaluated with the new dependent data.
This function may also be called multiple times during query optimization.
In this case, the type may change, so we delete the old aggregator,
and create a new one.
*/
if (aggr && aggregator == aggr->Aggrtype())
{
aggr->clear();
return FALSE;
}
delete aggr;
switch (aggregator)
{
case Aggregator::DISTINCT_AGGREGATOR:
aggr= new Aggregator_distinct(this);
break;
case Aggregator::SIMPLE_AGGREGATOR:
aggr= new Aggregator_simple(this);
break;
};
return aggr ? FALSE : TRUE;
}
void Item_sum::cleanup()
{
if (aggr)
{
delete aggr;
aggr= NULL;
}
Item_result_field::cleanup();
const_item_cache= false;
}
Item *Item_sum::result_item(THD *thd, Field *field)
{
return new (thd->mem_root) Item_field(thd, field);
}
bool Item_sum::check_vcol_func_processor(void *arg)
{
return mark_unsupported_function(func_name(),
is_aggr_sum_func() ? ")" : "()",
arg, VCOL_IMPOSSIBLE);
}
/**
Compare keys consisting of single field that cannot be compared as binary.
Used by the Unique class to compare keys. Will do correct comparisons
for all field types.
@param arg Pointer to the relevant Field class instance
@param key1 left key image
@param key2 right key image
@return comparison result
@retval < 0 if key1 < key2
@retval = 0 if key1 = key2
@retval > 0 if key1 > key2
*/
int simple_str_key_cmp(void* arg, uchar* key1, uchar* key2)
{
Field *f= (Field*) arg;
return f->cmp(key1, key2);
}
C_MODE_START
int count_distinct_walk(void *elem, element_count count, void *arg)
{
(*((ulonglong*)arg))++;
return 0;
}
C_MODE_END
/**
Correctly compare composite keys.
Used by the Unique class to compare keys. Will do correct comparisons
for composite keys with various field types.
@param arg Pointer to the relevant Aggregator_distinct instance
@param key1 left key image
@param key2 right key image
@return comparison result
@retval <0 if key1 < key2
@retval =0 if key1 = key2
@retval >0 if key1 > key2
*/
int Aggregator_distinct::composite_key_cmp(void* arg, uchar* key1, uchar* key2)
{
Aggregator_distinct *aggr= (Aggregator_distinct *) arg;
Field **field = aggr->table->field;
Field **field_end= field + aggr->table->s->fields;
uint32 *lengths=aggr->field_lengths;
for (; field < field_end; ++field)
{
Field* f = *field;
int len = *lengths++;
int res = f->cmp(key1, key2);
if (res)
return res;
key1 += len;
key2 += len;
}
return 0;
}
/***************************************************************************/
C_MODE_START
/* Declarations for auxilary C-callbacks */
int simple_raw_key_cmp(void* arg, const void* key1, const void* key2)
{
return memcmp(key1, key2, *(uint *) arg);
}
static int item_sum_distinct_walk_for_count(void *element,
element_count num_of_dups,
void *item)
{
return ((Aggregator_distinct*) (item))->unique_walk_function_for_count(element);
}
static int item_sum_distinct_walk(void *element, element_count num_of_dups,
void *item)
{
return ((Aggregator_distinct*) (item))->unique_walk_function(element);
}
C_MODE_END
/***************************************************************************/
/**
Called before feeding the first row. Used to allocate/setup
the internal structures used for aggregation.
@param thd Thread descriptor
@return status
@retval FALSE success
@retval TRUE faliure
Prepares Aggregator_distinct to process the incoming stream.
Creates the temporary table and the Unique class if needed.
Called by Item_sum::aggregator_setup()
*/
bool Aggregator_distinct::setup(THD *thd)
{
endup_done= FALSE;
/*
Setup can be called twice for ROLLUP items. This is a bug.
Please add DBUG_ASSERT(tree == 0) here when it's fixed.
*/
if (tree || table || tmp_table_param)
return FALSE;
if (item_sum->setup(thd))
return TRUE;
if (item_sum->sum_func() == Item_sum::COUNT_FUNC ||
item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC)
{
List<Item> list;
SELECT_LEX *select_lex= thd->lex->current_select;
if (!(tmp_table_param= new TMP_TABLE_PARAM))
return TRUE;
/* Create a table with an unique key over all parameters */
for (uint i=0; i < item_sum->get_arg_count() ; i++)
{
Item *item=item_sum->get_arg(i);
if (list.push_back(item, thd->mem_root))
return TRUE; // End of memory
if (item->const_item() && item->is_null())
always_null= true;
}
if (always_null)
return FALSE;
count_field_types(select_lex, tmp_table_param, list, 0);
tmp_table_param->force_copy_fields= item_sum->has_force_copy_fields();
DBUG_ASSERT(table == 0);
/*
Make create_tmp_table() convert BIT columns to BIGINT.
This is needed because BIT fields store parts of their data in table's
null bits, and we don't have methods to compare two table records, which
is needed by Unique which is used when HEAP table is used.
*/
{
List_iterator_fast<Item> li(list);
Item *item;
while ((item= li++))
{
if (item->type() == Item::FIELD_ITEM &&
((Item_field*)item)->field->type() == FIELD_TYPE_BIT)
item->marker=4;
}
}
if (!(table= create_tmp_table(thd, tmp_table_param, list, (ORDER*) 0, 1,
0,
(select_lex->options | thd->variables.option_bits),
HA_POS_ERROR, &empty_clex_str)))
return TRUE;
table->file->extra(HA_EXTRA_NO_ROWS); // Don't update rows
table->no_rows=1;
if (table->s->db_type() == heap_hton)
{
/*
No blobs, otherwise it would have been MyISAM: set up a compare
function and its arguments to use with Unique.
*/
qsort_cmp2 compare_key;
void* cmp_arg;
Field **field= table->field;
Field **field_end= field + table->s->fields;
bool all_binary= TRUE;
for (tree_key_length= 0; field < field_end; ++field)
{
Field *f= *field;
enum enum_field_types type= f->type();
tree_key_length+= f->pack_length();
if ((type == MYSQL_TYPE_VARCHAR) ||
(!f->binary() && (type == MYSQL_TYPE_STRING ||
type == MYSQL_TYPE_VAR_STRING)))
{
all_binary= FALSE;
break;
}
}
if (all_binary)
{
cmp_arg= (void*) &tree_key_length;
compare_key= (qsort_cmp2) simple_raw_key_cmp;
}
else
{
if (table->s->fields == 1)
{
/*
If we have only one field, which is the most common use of
count(distinct), it is much faster to use a simpler key
compare method that can take advantage of not having to worry
about other fields.
*/
compare_key= (qsort_cmp2) simple_str_key_cmp;
cmp_arg= (void*) table->field[0];
/* tree_key_length has been set already */
}
else
{
uint32 *length;
compare_key= (qsort_cmp2) composite_key_cmp;
cmp_arg= (void*) this;
field_lengths= (uint32*) thd->alloc(table->s->fields * sizeof(uint32));
for (tree_key_length= 0, length= field_lengths, field= table->field;
field < field_end; ++field, ++length)
{
*length= (*field)->pack_length();
tree_key_length+= *length;
}
}
}
DBUG_ASSERT(tree == 0);
tree= new Unique(compare_key, cmp_arg, tree_key_length,
item_sum->ram_limitation(thd));
/*
The only time tree_key_length could be 0 is if someone does
count(distinct) on a char(0) field - stupid thing to do,
but this has to be handled - otherwise someone can crash
the server with a DoS attack
*/
if (! tree)
return TRUE;
}
return FALSE;
}
else
{
Item *arg;
DBUG_ENTER("Aggregator_distinct::setup");
/* It's legal to call setup() more than once when in a subquery */
if (tree)
DBUG_RETURN(FALSE);
/*
Virtual table and the tree are created anew on each re-execution of
PS/SP. Hence all further allocations are performed in the runtime
mem_root.
*/
item_sum->null_value= item_sum->maybe_null= 1;
item_sum->quick_group= 0;
DBUG_ASSERT(item_sum->get_arg(0)->fixed);
arg= item_sum->get_arg(0);
if (arg->const_item())
{
(void) arg->is_null();
if (arg->null_value)
always_null= true;
}
if (always_null)
DBUG_RETURN(FALSE);
Field *field= arg->type_handler()->
make_num_distinct_aggregator_field(thd->mem_root, arg);
if (!field || !(table= create_virtual_tmp_table(thd, field)))
DBUG_RETURN(TRUE);
/* XXX: check that the case of CHAR(0) works OK */
tree_key_length= table->s->reclength - table->s->null_bytes;
/*
Unique handles all unique elements in a tree until they can't fit
in. Then the tree is dumped to the temporary file. We can use
simple_raw_key_cmp because the table contains numbers only; decimals
are converted to binary representation as well.
*/
tree= new Unique(simple_raw_key_cmp, &tree_key_length, tree_key_length,
item_sum->ram_limitation(thd));
DBUG_RETURN(tree == 0);
}
}
/**
Invalidate calculated value and clear the distinct rows.
Frees space used by the internal data structures.
Removes the accumulated distinct rows. Invalidates the calculated result.
*/
void Aggregator_distinct::clear()
{
endup_done= FALSE;
item_sum->clear();
if (tree)
tree->reset();
/* tree and table can be both null only if always_null */
if (item_sum->sum_func() == Item_sum::COUNT_FUNC ||
item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC)
{
if (!tree && table)
{
table->file->extra(HA_EXTRA_NO_CACHE);
table->file->ha_delete_all_rows();
table->file->extra(HA_EXTRA_WRITE_CACHE);
}
}
else
{
item_sum->null_value= 1;
}
}
/**
Process incoming row.
Add it to Unique/temp hash table if it's unique. Skip the row if
not unique.
Prepare Aggregator_distinct to process the incoming stream.
Create the temporary table and the Unique class if needed.
Called by Item_sum::aggregator_add().
To actually get the result value in item_sum's buffers
Aggregator_distinct::endup() must be called.
@return status
@retval FALSE success
@retval TRUE failure
*/
bool Aggregator_distinct::add()
{
if (always_null)
return 0;
if (item_sum->sum_func() == Item_sum::COUNT_FUNC ||
item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC)
{
int error;
copy_fields(tmp_table_param);
if (copy_funcs(tmp_table_param->items_to_copy, table->in_use))
return TRUE;
for (Field **field=table->field ; *field ; field++)
if ((*field)->is_real_null(0))
return 0; // Don't count NULL
if (tree)
{
/*
The first few bytes of record (at least one) are just markers
for deleted and NULLs. We want to skip them since they will
bloat the tree without providing any valuable info. Besides,
key_length used to initialize the tree didn't include space for them.
*/
return tree->unique_add(table->record[0] + table->s->null_bytes);
}
if (unlikely((error= table->file->ha_write_tmp_row(table->record[0]))) &&
table->file->is_fatal_error(error, HA_CHECK_DUP))
return TRUE;
return FALSE;
}
else
{
item_sum->get_arg(0)->save_in_field(table->field[0], FALSE);
if (table->field[0]->is_null())
return 0;
DBUG_ASSERT(tree);
item_sum->null_value= 0;
/*
'0' values are also stored in the tree. This doesn't matter
for SUM(DISTINCT), but is important for AVG(DISTINCT)
*/
return tree->unique_add(table->field[0]->ptr);
}
}
/**
Calculate the aggregate function value.
Since Distinct_aggregator::add() just collects the distinct rows,
we must go over the distinct rows and feed them to the aggregation
function before returning its value.
This is what endup () does. It also sets the result validity flag
endup_done to TRUE so it will not recalculate the aggregate value
again if the Item_sum hasn't been reset.
*/
void Aggregator_distinct::endup()
{
/* prevent consecutive recalculations */
if (endup_done)
return;
/* we are going to calculate the aggregate value afresh */
item_sum->clear();
/* The result will definitely be null : no more calculations needed */
if (always_null)
return;
if (item_sum->sum_func() == Item_sum::COUNT_FUNC ||
item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC)
{
DBUG_ASSERT(item_sum->fixed == 1);
Item_sum_count *sum= (Item_sum_count *)item_sum;
if (tree && tree->elements == 0)
{
/* everything fits in memory */
sum->count= (longlong) tree->elements_in_tree();
endup_done= TRUE;
}
if (!tree)
{
/* there were blobs */
table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
sum->count= table->file->stats.records;
endup_done= TRUE;
}
}
/*
We don't have a tree only if 'setup()' hasn't been called;
this is the case of sql_executor.cc:return_zero_rows.
*/
if (tree && !endup_done)
{
/*
All tree's values are not NULL.
Note that value of field is changed as we walk the tree, in
Aggregator_distinct::unique_walk_function, but it's always not NULL.
*/
table->field[0]->set_notnull();
/* go over the tree of distinct keys and calculate the aggregate value */
use_distinct_values= TRUE;
tree_walk_action func;
if (item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC)
func= item_sum_distinct_walk_for_count;
else
func= item_sum_distinct_walk;
tree->walk(table, func, (void*) this);
use_distinct_values= FALSE;
}
/* prevent consecutive recalculations */
endup_done= TRUE;
}
String *
Item_sum_num::val_str(String *str)
{
return val_string_from_real(str);
}
my_decimal *Item_sum_num::val_decimal(my_decimal *decimal_value)
{
return val_decimal_from_real(decimal_value);
}
String *
Item_sum_int::val_str(String *str)
{
return val_string_from_int(str);
}
my_decimal *Item_sum_int::val_decimal(my_decimal *decimal_value)
{
return val_decimal_from_int(decimal_value);
}
bool
Item_sum_num::fix_fields(THD *thd, Item **ref)
{
DBUG_ASSERT(fixed == 0);
if (init_sum_func_check(thd))
return TRUE;
decimals=0;
maybe_null= sum_func() != COUNT_FUNC;
for (uint i=0 ; i < arg_count ; i++)
{
if (args[i]->fix_fields_if_needed_for_scalar(thd, &args[i]))
return TRUE;
set_if_bigger(decimals, args[i]->decimals);
m_with_subquery|= args[i]->with_subquery();
with_param|= args[i]->with_param;
with_window_func|= args[i]->with_window_func;
}
result_field=0;
max_length=float_length(decimals);
null_value=1;
fix_length_and_dec();
if (check_sum_func(thd, ref))
return TRUE;
memcpy (orig_args, args, sizeof (Item *) * arg_count);
fixed= 1;
return FALSE;
}
bool
Item_sum_hybrid::fix_fields(THD *thd, Item **ref)
{
DBUG_ENTER("Item_sum_hybrid::fix_fields");
DBUG_ASSERT(fixed == 0);
if (init_sum_func_check(thd))
DBUG_RETURN(TRUE);
// 'item' can be changed during fix_fields
if (args[0]->fix_fields_if_needed_for_scalar(thd, &args[0]))
DBUG_RETURN(TRUE);
m_with_subquery= args[0]->with_subquery();
with_param= args[0]->with_param;
with_window_func|= args[0]->with_window_func;
fix_length_and_dec();
if (!is_window_func_sum_expr())
setup_hybrid(thd, args[0], NULL);
result_field=0;
if (check_sum_func(thd, ref))
DBUG_RETURN(TRUE);
orig_args[0]= args[0];
fixed= 1;
DBUG_RETURN(FALSE);
}
void Item_sum_hybrid::fix_length_and_dec()
{
DBUG_ASSERT(args[0]->field_type() == args[0]->real_item()->field_type());
DBUG_ASSERT(args[0]->result_type() == args[0]->real_item()->result_type());
(void) args[0]->type_handler()->Item_sum_hybrid_fix_length_and_dec(this);
}
/**
MIN/MAX function setup.
@param item argument of MIN/MAX function
@param value_arg calculated value of MIN/MAX function
@details
Setup cache/comparator of MIN/MAX functions. When called by the
copy_or_same function value_arg parameter contains calculated value
of the original MIN/MAX object and it is saved in this object's cache.
We mark the value and arg_cache with 'RAND_TABLE_BIT' to ensure
that Arg_comparator::compare_datetime() doesn't allocate new
item inside of Arg_comparator. This would cause compare_datetime()
and Item_sum_min::add() to use different values!
*/
void Item_sum_hybrid::setup_hybrid(THD *thd, Item *item, Item *value_arg)
{
DBUG_ENTER("Item_sum_hybrid::setup_hybrid");
if (!(value= item->get_cache(thd)))
DBUG_VOID_RETURN;
value->setup(thd, item);
value->store(value_arg);
/* Don't cache value, as it will change */
if (!item->const_item())
value->set_used_tables(RAND_TABLE_BIT);
if (!(arg_cache= item->get_cache(thd)))
DBUG_VOID_RETURN;
arg_cache->setup(thd, item);
/* Don't cache value, as it will change */
if (!item->const_item())
arg_cache->set_used_tables(RAND_TABLE_BIT);
cmp= new Arg_comparator();
if (cmp)
cmp->set_cmp_func(this, (Item**)&arg_cache, (Item**)&value, FALSE);
DBUG_VOID_RETURN;
}
Field *Item_sum_hybrid::create_tmp_field(bool group, TABLE *table)
{
DBUG_ENTER("Item_sum_hybrid::create_tmp_field");
if (args[0]->type() == Item::FIELD_ITEM)
{
Field *field= ((Item_field*) args[0])->field;
if ((field= field->create_tmp_field(table->in_use->mem_root, table, true)))
{
DBUG_ASSERT((field->flags & NOT_NULL_FLAG) == 0);
field->field_name= name;
}
DBUG_RETURN(field);
}
DBUG_RETURN(tmp_table_field_from_field_type(table));
}
/***********************************************************************
** Item_sum_sp class
***********************************************************************/
Item_sum_sp::Item_sum_sp(THD *thd, Name_resolution_context *context_arg,
sp_name *name_arg, sp_head *sp, List<Item> &list)
:Item_sum(thd, list), Item_sp(thd, context_arg, name_arg)
{
maybe_null= 1;
quick_group= 0;
m_sp= sp;
}
Item_sum_sp::Item_sum_sp(THD *thd, Name_resolution_context *context_arg,
sp_name *name_arg, sp_head *sp)
:Item_sum(thd), Item_sp(thd, context_arg, name_arg)
{
maybe_null= 1;
quick_group= 0;
m_sp= sp;
}
Item_sum_sp::Item_sum_sp(THD *thd, Item_sum_sp *item):
Item_sum(thd, item), Item_sp(thd, item)
{
maybe_null= item->maybe_null;
quick_group= item->quick_group;
}
bool
Item_sum_sp::fix_fields(THD *thd, Item **ref)
{
DBUG_ASSERT(fixed == 0);
if (init_sum_func_check(thd))
return TRUE;
decimals= 0;
m_sp= m_sp ? m_sp : sp_handler_function.sp_find_routine(thd, m_name, true);
if (!m_sp)
{
my_missing_function_error(m_name->m_name, ErrConvDQName(m_name).ptr());
context->process_error(thd);
return TRUE;
}
if (init_result_field(thd, max_length, maybe_null, &null_value, &name))
return TRUE;
for (uint i= 0 ; i < arg_count ; i++)
{
if (args[i]->fix_fields_if_needed_for_scalar(thd, &args[i]))
return TRUE;
set_if_bigger(decimals, args[i]->decimals);
m_with_subquery|= args[i]->with_subquery();
with_window_func|= args[i]->with_window_func;
}
result_field= NULL;
max_length= float_length(decimals);
null_value= 1;
fix_length_and_dec();
if (check_sum_func(thd, ref))
return TRUE;
memcpy(orig_args, args, sizeof(Item *) * arg_count);
fixed= 1;
return FALSE;
}
/**
Execute function to store value in result field.
This is called when we need the value to be returned for the function.
Here we send a signal in form of the server status that all rows have been
fetched and now we have to exit from the function with the return value.
@return Function returns error status.
@retval FALSE on success.
@retval TRUE if an error occurred.
*/
bool
Item_sum_sp::execute()
{
THD *thd= current_thd;
bool res;
uint old_server_status= thd->server_status;
/* We set server status so we can send a signal to exit from the
function with the return value. */
thd->server_status= SERVER_STATUS_LAST_ROW_SENT;
res= Item_sp::execute(thd, &null_value, args, arg_count);
thd->server_status= old_server_status;
return res;
}
/**
Handles the aggregation of the values.
@note: See class description for more details on how and why this is done.
@return The error state.
@retval FALSE on success.
@retval TRUE if an error occurred.
*/
bool
Item_sum_sp::add()
{
return execute_impl(current_thd, args, arg_count);
}
void
Item_sum_sp::clear()
{
delete func_ctx;
func_ctx= NULL;
sp_query_arena->free_items();
free_root(&sp_mem_root, MYF(0));
}
const Type_handler *Item_sum_sp::type_handler() const
{
DBUG_ENTER("Item_sum_sp::type_handler");
DBUG_PRINT("info", ("m_sp = %p", (void *) m_sp));
DBUG_ASSERT(sp_result_field);
// This converts ENUM/SET to STRING
const Type_handler *handler= sp_result_field->type_handler();
DBUG_RETURN(handler->type_handler_for_item_field());
}
void
Item_sum_sp::cleanup()
{
Item_sp::cleanup();
Item_sum::cleanup();
}
/**
Initialize local members with values from the Field interface.
@note called from Item::fix_fields.
*/
void
Item_sum_sp::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_sp::fix_length_and_dec");
DBUG_ASSERT(sp_result_field);
Type_std_attributes::set(sp_result_field->type_std_attributes());
Item_sum::fix_length_and_dec();
DBUG_VOID_RETURN;
}
const char *
Item_sum_sp::func_name() const
{
THD *thd= current_thd;
return Item_sp::func_name(thd);
}
Item* Item_sum_sp::copy_or_same(THD *thd)
{
Item_sum_sp *copy_item= new (thd->mem_root) Item_sum_sp(thd, this);
copy_item->init_result_field(thd, max_length, maybe_null,
&copy_item->null_value, &copy_item->name);
return copy_item;
}
/***********************************************************************
** reset and add of sum_func
***********************************************************************/
/**
@todo
check if the following assignments are really needed
*/
Item_sum_sum::Item_sum_sum(THD *thd, Item_sum_sum *item)
:Item_sum_num(thd, item),
Type_handler_hybrid_field_type(item),
direct_added(FALSE), direct_reseted_field(FALSE),
curr_dec_buff(item->curr_dec_buff),
count(item->count)
{
/* TODO: check if the following assignments are really needed */
if (result_type() == DECIMAL_RESULT)
{
my_decimal2decimal(item->dec_buffs, dec_buffs);
my_decimal2decimal(item->dec_buffs + 1, dec_buffs + 1);
}
else
sum= item->sum;
}
Item *Item_sum_sum::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_sum(thd, this);
}
void Item_sum_sum::cleanup()
{
DBUG_ENTER("Item_sum_sum::cleanup");
direct_added= direct_reseted_field= FALSE;
Item_sum_num::cleanup();
DBUG_VOID_RETURN;
}
void Item_sum_sum::clear()
{
DBUG_ENTER("Item_sum_sum::clear");
null_value=1;
count= 0;
if (result_type() == DECIMAL_RESULT)
{
curr_dec_buff= 0;
my_decimal_set_zero(dec_buffs);
}
else
sum= 0.0;
DBUG_VOID_RETURN;
}
void Item_sum_sum::fix_length_and_dec_double()
{
set_handler(&type_handler_double); // Change FLOAT to DOUBLE
decimals= args[0]->decimals;
sum= 0.0;
}
void Item_sum_sum::fix_length_and_dec_decimal()
{
set_handler(&type_handler_newdecimal); // Change temporal to new DECIMAL
decimals= args[0]->decimals;
/* SUM result can't be longer than length(arg) + length(MAX_ROWS) */
int precision= args[0]->decimal_precision() + DECIMAL_LONGLONG_DIGITS;
max_length= my_decimal_precision_to_length_no_truncation(precision,
decimals,
unsigned_flag);
curr_dec_buff= 0;
my_decimal_set_zero(dec_buffs);
}
void Item_sum_sum::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_sum::fix_length_and_dec");
maybe_null=null_value=1;
args[0]->cast_to_int_type_handler()->Item_sum_sum_fix_length_and_dec(this);
DBUG_PRINT("info", ("Type: %s (%d, %d)", type_handler()->name().ptr(),
max_length, (int) decimals));
DBUG_VOID_RETURN;
}
void Item_sum_sum::direct_add(my_decimal *add_sum_decimal)
{
DBUG_ENTER("Item_sum_sum::direct_add");
DBUG_PRINT("info", ("add_sum_decimal: %p", add_sum_decimal));
direct_added= TRUE;
direct_reseted_field= FALSE;
if (add_sum_decimal)
{
direct_sum_is_null= FALSE;
direct_sum_decimal= *add_sum_decimal;
}
else
{
direct_sum_is_null= TRUE;
direct_sum_decimal= decimal_zero;
}
DBUG_VOID_RETURN;
}
void Item_sum_sum::direct_add(double add_sum_real, bool add_sum_is_null)
{
DBUG_ENTER("Item_sum_sum::direct_add");
DBUG_PRINT("info", ("add_sum_real: %f", add_sum_real));
direct_added= TRUE;
direct_reseted_field= FALSE;
direct_sum_is_null= add_sum_is_null;
direct_sum_real= add_sum_real;
DBUG_VOID_RETURN;
}
bool Item_sum_sum::add()
{
DBUG_ENTER("Item_sum_sum::add");
add_helper(false);
DBUG_RETURN(0);
}
void Item_sum_sum::add_helper(bool perform_removal)
{
DBUG_ENTER("Item_sum_sum::add_helper");
if (result_type() == DECIMAL_RESULT)
{
if (unlikely(direct_added))
{
/* Add value stored by Item_sum_sum::direct_add */
DBUG_ASSERT(!perform_removal);
direct_added= FALSE;
if (likely(!direct_sum_is_null))
{
my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs + (curr_dec_buff^1),
&direct_sum_decimal, dec_buffs + curr_dec_buff);
curr_dec_buff^= 1;
null_value= 0;
}
}
else
{
direct_reseted_field= FALSE;
my_decimal value;
const my_decimal *val= aggr->arg_val_decimal(&value);
if (!aggr->arg_is_null(true))
{
if (perform_removal)
{
if (count > 0)
{
my_decimal_sub(E_DEC_FATAL_ERROR, dec_buffs + (curr_dec_buff ^ 1),
dec_buffs + curr_dec_buff, val);
count--;
}
else
DBUG_VOID_RETURN;
}
else
{
count++;
my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs + (curr_dec_buff ^ 1),
val, dec_buffs + curr_dec_buff);
}
curr_dec_buff^= 1;
null_value= (count > 0) ? 0 : 1;
}
}
}
else
{
if (unlikely(direct_added))
{
/* Add value stored by Item_sum_sum::direct_add */
DBUG_ASSERT(!perform_removal);
direct_added= FALSE;
if (!direct_sum_is_null)
{
sum+= direct_sum_real;
null_value= 0;
}
}
else
{
direct_reseted_field= FALSE;
if (perform_removal && count > 0)
sum-= aggr->arg_val_real();
else
sum+= aggr->arg_val_real();
if (!aggr->arg_is_null(true))
{
if (perform_removal)
{
if (count > 0)
{
count--;
}
}
else
count++;
null_value= (count > 0) ? 0 : 1;
}
}
}
DBUG_VOID_RETURN;
}
longlong Item_sum_sum::val_int()
{
DBUG_ASSERT(fixed == 1);
if (aggr)
aggr->endup();
if (result_type() == DECIMAL_RESULT)
{
longlong result;
my_decimal2int(E_DEC_FATAL_ERROR, dec_buffs + curr_dec_buff, unsigned_flag,
&result);
return result;
}
return val_int_from_real();
}
double Item_sum_sum::val_real()
{
DBUG_ASSERT(fixed == 1);
if (aggr)
aggr->endup();
if (result_type() == DECIMAL_RESULT)
my_decimal2double(E_DEC_FATAL_ERROR, dec_buffs + curr_dec_buff, &sum);
return sum;
}
String *Item_sum_sum::val_str(String *str)
{
if (aggr)
aggr->endup();
if (result_type() == DECIMAL_RESULT)
return val_string_from_decimal(str);
return val_string_from_real(str);
}
my_decimal *Item_sum_sum::val_decimal(my_decimal *val)
{
if (aggr)
aggr->endup();
if (result_type() == DECIMAL_RESULT)
return null_value ? NULL : (dec_buffs + curr_dec_buff);
return val_decimal_from_real(val);
}
void Item_sum_sum::remove()
{
DBUG_ENTER("Item_sum_sum::remove");
add_helper(true);
DBUG_VOID_RETURN;
}
/**
Aggregate a distinct row from the distinct hash table.
Called for each row into the hash table 'Aggregator_distinct::table'.
Includes the current distinct row into the calculation of the
aggregate value. Uses the Field classes to get the value from the row.
This function is used for AVG/SUM(DISTINCT). For COUNT(DISTINCT)
it's called only when there are no blob arguments and the data don't
fit into memory (so Unique makes persisted trees on disk).
@param element pointer to the row data.
@return status
@retval FALSE success
@retval TRUE failure
*/
bool Aggregator_distinct::unique_walk_function(void *element)
{
memcpy(table->field[0]->ptr, element, tree_key_length);
item_sum->add();
return 0;
}
/*
A variant of unique_walk_function() that is to be used with Item_sum_count.
COUNT is a special aggregate function: it doesn't need the values, it only
needs to count them. COUNT needs to know the values are not NULLs, but NULL
values are not put into the Unique, so we don't need to check for NULLs here.
*/
bool Aggregator_distinct::unique_walk_function_for_count(void *element)
{
Item_sum_count *sum= (Item_sum_count *)item_sum;
sum->count++;
return 0;
}
Aggregator_distinct::~Aggregator_distinct()
{
if (tree)
{
delete tree;
tree= NULL;
}
if (table)
{
free_tmp_table(table->in_use, table);
table=NULL;
}
if (tmp_table_param)
{
delete tmp_table_param;
tmp_table_param= NULL;
}
}
my_decimal *Aggregator_simple::arg_val_decimal(my_decimal *value)
{
return item_sum->args[0]->val_decimal(value);
}
double Aggregator_simple::arg_val_real()
{
return item_sum->args[0]->val_real();
}
bool Aggregator_simple::arg_is_null(bool use_null_value)
{
Item **item= item_sum->args;
const uint item_count= item_sum->arg_count;
if (use_null_value)
{
for (uint i= 0; i < item_count; i++)
{
if (item[i]->null_value)
return true;
}
}
else
{
for (uint i= 0; i < item_count; i++)
{
if (item[i]->maybe_null && item[i]->is_null())
return true;
}
}
return false;
}
my_decimal *Aggregator_distinct::arg_val_decimal(my_decimal * value)
{
return use_distinct_values ? table->field[0]->val_decimal(value) :
item_sum->args[0]->val_decimal(value);
}
double Aggregator_distinct::arg_val_real()
{
return use_distinct_values ? table->field[0]->val_real() :
item_sum->args[0]->val_real();
}
bool Aggregator_distinct::arg_is_null(bool use_null_value)
{
if (use_distinct_values)
{
const bool rc= table->field[0]->is_null();
DBUG_ASSERT(!rc); // NULLs are never stored in 'tree'
return rc;
}
return use_null_value ?
item_sum->args[0]->null_value :
(item_sum->args[0]->maybe_null && item_sum->args[0]->is_null());
}
Item *Item_sum_count::copy_or_same(THD* thd)
{
DBUG_ENTER("Item_sum_count::copy_or_same");
DBUG_RETURN(new (thd->mem_root) Item_sum_count(thd, this));
}
void Item_sum_count::direct_add(longlong add_count)
{
DBUG_ENTER("Item_sum_count::direct_add");
DBUG_PRINT("info", ("add_count: %lld", add_count));
direct_counted= TRUE;
direct_reseted_field= FALSE;
direct_count= add_count;
DBUG_VOID_RETURN;
}
void Item_sum_count::clear()
{
DBUG_ENTER("Item_sum_count::clear");
count= 0;
DBUG_VOID_RETURN;
}
bool Item_sum_count::add()
{
DBUG_ENTER("Item_sum_count::add");
if (direct_counted)
{
direct_counted= FALSE;
count+= direct_count;
}
else
{
direct_reseted_field= FALSE;
if (aggr->arg_is_null(false))
DBUG_RETURN(0);
count++;
}
DBUG_RETURN(0);
}
/*
Remove a row. This is used by window functions.
*/
void Item_sum_count::remove()
{
DBUG_ASSERT(aggr->Aggrtype() == Aggregator::SIMPLE_AGGREGATOR);
if (aggr->arg_is_null(false))
return;
if (count > 0)
count--;
}
longlong Item_sum_count::val_int()
{
DBUG_ENTER("Item_sum_count::val_int");
DBUG_ASSERT(fixed == 1);
if (aggr)
aggr->endup();
DBUG_RETURN((longlong)count);
}
void Item_sum_count::cleanup()
{
DBUG_ENTER("Item_sum_count::cleanup");
count= 0;
direct_counted= FALSE;
direct_reseted_field= FALSE;
Item_sum_int::cleanup();
DBUG_VOID_RETURN;
}
/*
Avgerage
*/
void Item_sum_avg::fix_length_and_dec_decimal()
{
Item_sum_sum::fix_length_and_dec_decimal();
int precision= args[0]->decimal_precision() + prec_increment;
decimals= MY_MIN(args[0]->decimals + prec_increment, DECIMAL_MAX_SCALE);
max_length= my_decimal_precision_to_length_no_truncation(precision,
decimals,
unsigned_flag);
f_precision= MY_MIN(precision+DECIMAL_LONGLONG_DIGITS, DECIMAL_MAX_PRECISION);
f_scale= args[0]->decimals;
dec_bin_size= my_decimal_get_binary_size(f_precision, f_scale);
}
void Item_sum_avg::fix_length_and_dec_double()
{
Item_sum_sum::fix_length_and_dec_double();
decimals= MY_MIN(args[0]->decimals + prec_increment,
FLOATING_POINT_DECIMALS);
max_length= MY_MIN(args[0]->max_length + prec_increment, float_length(decimals));
}
void Item_sum_avg::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_avg::fix_length_and_dec");
prec_increment= current_thd->variables.div_precincrement;
maybe_null=null_value=1;
args[0]->cast_to_int_type_handler()->Item_sum_avg_fix_length_and_dec(this);
DBUG_PRINT("info", ("Type: %s (%d, %d)", type_handler()->name().ptr(),
max_length, (int) decimals));
DBUG_VOID_RETURN;
}
Item *Item_sum_avg::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_avg(thd, this);
}
Field *Item_sum_avg::create_tmp_field(bool group, TABLE *table)
{
if (group)
{
/*
We must store both value and counter in the temporary table in one field.
The easiest way is to do this is to store both value in a string
and unpack on access.
*/
Field *field= new (table->in_use->mem_root)
Field_string(((result_type() == DECIMAL_RESULT) ?
dec_bin_size : sizeof(double)) + sizeof(longlong),
0, &name, &my_charset_bin);
if (field)
field->init(table);
return field;
}
return tmp_table_field_from_field_type(table);
}
void Item_sum_avg::clear()
{
Item_sum_sum::clear();
count=0;
}
bool Item_sum_avg::add()
{
if (Item_sum_sum::add())
return TRUE;
if (!aggr->arg_is_null(true))
count++;
return FALSE;
}
void Item_sum_avg::remove()
{
Item_sum_sum::remove();
if (!aggr->arg_is_null(true))
{
if (count > 0)
count--;
}
}
double Item_sum_avg::val_real()
{
DBUG_ASSERT(fixed == 1);
if (aggr)
aggr->endup();
if (!count)
{
null_value=1;
return 0.0;
}
return Item_sum_sum::val_real() / ulonglong2double(count);
}
my_decimal *Item_sum_avg::val_decimal(my_decimal *val)
{
my_decimal cnt;
const my_decimal *sum_dec;
DBUG_ASSERT(fixed == 1);
if (aggr)
aggr->endup();
if (!count)
{
null_value=1;
return NULL;
}
/*
For non-DECIMAL result_type() the division will be done in
Item_sum_avg::val_real().
*/
if (result_type() != DECIMAL_RESULT)
return val_decimal_from_real(val);
sum_dec= dec_buffs + curr_dec_buff;
int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &cnt);
my_decimal_div(E_DEC_FATAL_ERROR, val, sum_dec, &cnt, prec_increment);
return val;
}
String *Item_sum_avg::val_str(String *str)
{
if (aggr)
aggr->endup();
if (result_type() == DECIMAL_RESULT)
return val_string_from_decimal(str);
return val_string_from_real(str);
}
/*
Standard deviation
*/
double Item_sum_std::val_real()
{
DBUG_ASSERT(fixed == 1);
double nr= Item_sum_variance::val_real();
if (std::isinf(nr))
return DBL_MAX;
DBUG_ASSERT(nr >= 0.0);
return sqrt(nr);
}
Item *Item_sum_std::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_std(thd, this);
}
Item *Item_sum_std::result_item(THD *thd, Field *field)
{
return new (thd->mem_root) Item_std_field(thd, this);
}
/*
Variance
*/
/**
Variance implementation for floating-point implementations, without
catastrophic cancellation, from Knuth's _TAoCP_, 3rd ed, volume 2, pg232.
This alters the value at m, s, and increments count.
*/
/*
These two functions are used by the Item_sum_variance and the
Item_variance_field classes, which are unrelated, and each need to calculate
variance. The difference between the two classes is that the first is used
for a mundane SELECT, while the latter is used in a GROUPing SELECT.
*/
static void variance_fp_recurrence_next(double *m, double *s, ulonglong *count, double nr)
{
*count += 1;
if (*count == 1)
{
*m= nr;
*s= 0;
}
else
{
double m_kminusone= *m;
*m= m_kminusone + (nr - m_kminusone) / (double) *count;
*s= *s + (nr - m_kminusone) * (nr - *m);
}
}
static double variance_fp_recurrence_result(double s, ulonglong count, bool is_sample_variance)
{
if (count == 1)
return 0.0;
if (is_sample_variance)
return s / (count - 1);
/* else, is a population variance */
return s / count;
}
Item_sum_variance::Item_sum_variance(THD *thd, Item_sum_variance *item):
Item_sum_num(thd, item),
count(item->count), sample(item->sample),
prec_increment(item->prec_increment)
{
recurrence_m= item->recurrence_m;
recurrence_s= item->recurrence_s;
}
void Item_sum_variance::fix_length_and_dec_double()
{
DBUG_ASSERT(Item_sum_variance::type_handler() == &type_handler_double);
decimals= MY_MIN(args[0]->decimals + 4, FLOATING_POINT_DECIMALS);
}
void Item_sum_variance::fix_length_and_dec_decimal()
{
DBUG_ASSERT(Item_sum_variance::type_handler() == &type_handler_double);
int precision= args[0]->decimal_precision() * 2 + prec_increment;
decimals= MY_MIN(args[0]->decimals + prec_increment,
FLOATING_POINT_DECIMALS - 1);
max_length= my_decimal_precision_to_length_no_truncation(precision,
decimals,
unsigned_flag);
}
void Item_sum_variance::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_variance::fix_length_and_dec");
maybe_null= null_value= 1;
prec_increment= current_thd->variables.div_precincrement;
/*
According to the SQL2003 standard (Part 2, Foundations; sec 10.9,
aggregate function; paragraph 7h of Syntax Rules), "the declared
type of the result is an implementation-defined aproximate numeric
type.
*/
args[0]->type_handler()->Item_sum_variance_fix_length_and_dec(this);
DBUG_PRINT("info", ("Type: %s (%d, %d)", type_handler()->name().ptr(),
max_length, (int)decimals));
DBUG_VOID_RETURN;
}
Item *Item_sum_variance::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_variance(thd, this);
}
/**
Create a new field to match the type of value we're expected to yield.
If we're grouping, then we need some space to serialize variables into, to
pass around.
*/
Field *Item_sum_variance::create_tmp_field(bool group, TABLE *table)
{
Field *field;
if (group)
{
/*
We must store both value and counter in the temporary table in one field.
The easiest way is to do this is to store both value in a string
and unpack on access.
*/
field= new Field_string(sizeof(double)*2 + sizeof(longlong), 0,
&name, &my_charset_bin);
}
else
field= new Field_double(max_length, maybe_null, &name, decimals,
TRUE);
if (field != NULL)
field->init(table);
return field;
}
void Item_sum_variance::clear()
{
count= 0;
}
bool Item_sum_variance::add()
{
/*
Why use a temporary variable? We don't know if it is null until we
evaluate it, which has the side-effect of setting null_value .
*/
double nr= args[0]->val_real();
if (!args[0]->null_value)
variance_fp_recurrence_next(&recurrence_m, &recurrence_s, &count, nr);
return 0;
}
double Item_sum_variance::val_real()
{
DBUG_ASSERT(fixed == 1);
/*
'sample' is a 1/0 boolean value. If it is 1/true, id est this is a sample
variance call, then we should set nullness when the count of the items
is one or zero. If it's zero, i.e. a population variance, then we only
set nullness when the count is zero.
Another way to read it is that 'sample' is the numerical threshhold, at and
below which a 'count' number of items is called NULL.
*/
DBUG_ASSERT((sample == 0) || (sample == 1));
if (count <= sample)
{
null_value=1;
return 0.0;
}
null_value=0;
return variance_fp_recurrence_result(recurrence_s, count, sample);
}
my_decimal *Item_sum_variance::val_decimal(my_decimal *dec_buf)
{
DBUG_ASSERT(fixed == 1);
return val_decimal_from_real(dec_buf);
}
void Item_sum_variance::reset_field()
{
double nr;
uchar *res= result_field->ptr;
nr= args[0]->val_real(); /* sets null_value as side-effect */
if (args[0]->null_value)
bzero(res,sizeof(double)*2+sizeof(longlong));
else
{
/* Serialize format is (double)m, (double)s, (longlong)count */
ulonglong tmp_count;
double tmp_s;
float8store(res, nr); /* recurrence variable m */
tmp_s= 0.0;
float8store(res + sizeof(double), tmp_s);
tmp_count= 1;
int8store(res + sizeof(double)*2, tmp_count);
}
}
void Item_sum_variance::update_field()
{
ulonglong field_count;
uchar *res=result_field->ptr;
double nr= args[0]->val_real(); /* sets null_value as side-effect */
if (args[0]->null_value)
return;
/* Serialize format is (double)m, (double)s, (longlong)count */
double field_recurrence_m, field_recurrence_s;
float8get(field_recurrence_m, res);
float8get(field_recurrence_s, res + sizeof(double));
field_count=sint8korr(res+sizeof(double)*2);
variance_fp_recurrence_next(&field_recurrence_m, &field_recurrence_s, &field_count, nr);
float8store(res, field_recurrence_m);
float8store(res + sizeof(double), field_recurrence_s);
res+= sizeof(double)*2;
int8store(res,field_count);
}
Item *Item_sum_variance::result_item(THD *thd, Field *field)
{
return new (thd->mem_root) Item_variance_field(thd, this);
}
/* min & max */
void Item_sum_hybrid::clear()
{
DBUG_ENTER("Item_sum_hybrid::clear");
value->clear();
null_value= 1;
DBUG_VOID_RETURN;
}
bool
Item_sum_hybrid::get_date(MYSQL_TIME *ltime, ulonglong fuzzydate)
{
DBUG_ASSERT(fixed == 1);
if (null_value)
return true;
bool retval= value->get_date(ltime, fuzzydate);
if ((null_value= value->null_value))
DBUG_ASSERT(retval == true);
return retval;
}
void Item_sum_hybrid::direct_add(Item *item)
{
DBUG_ENTER("Item_sum_hybrid::direct_add");
DBUG_PRINT("info", ("item: %p", item));
direct_added= TRUE;
direct_item= item;
DBUG_VOID_RETURN;
}
double Item_sum_hybrid::val_real()
{
DBUG_ENTER("Item_sum_hybrid::val_real");
DBUG_ASSERT(fixed == 1);
if (null_value)
DBUG_RETURN(0.0);
double retval= value->val_real();
if ((null_value= value->null_value))
DBUG_ASSERT(retval == 0.0);
DBUG_RETURN(retval);
}
longlong Item_sum_hybrid::val_int()
{
DBUG_ENTER("Item_sum_hybrid::val_int");
DBUG_ASSERT(fixed == 1);
if (null_value)
DBUG_RETURN(0);
longlong retval= value->val_int();
if ((null_value= value->null_value))
DBUG_ASSERT(retval == 0);
DBUG_RETURN(retval);
}
my_decimal *Item_sum_hybrid::val_decimal(my_decimal *val)
{
DBUG_ENTER("Item_sum_hybrid::val_decimal");
DBUG_ASSERT(fixed == 1);
if (null_value)
DBUG_RETURN(0);
my_decimal *retval= value->val_decimal(val);
if ((null_value= value->null_value))
DBUG_ASSERT(retval == NULL);
DBUG_RETURN(retval);
}
String *
Item_sum_hybrid::val_str(String *str)
{
DBUG_ENTER("Item_sum_hybrid::val_str");
DBUG_ASSERT(fixed == 1);
if (null_value)
DBUG_RETURN(0);
String *retval= value->val_str(str);
if ((null_value= value->null_value))
DBUG_ASSERT(retval == NULL);
DBUG_RETURN(retval);
}
void Item_sum_hybrid::cleanup()
{
DBUG_ENTER("Item_sum_hybrid::cleanup");
Item_sum::cleanup();
if (cmp)
delete cmp;
cmp= 0;
/*
by default it is TRUE to avoid TRUE reporting by
Item_func_not_all/Item_func_nop_all if this item was never called.
no_rows_in_result() set it to FALSE if was not results found.
If some results found it will be left unchanged.
*/
was_values= TRUE;
DBUG_VOID_RETURN;
}
void Item_sum_hybrid::no_rows_in_result()
{
DBUG_ENTER("Item_sum_hybrid::no_rows_in_result");
/* We may be called here twice in case of ref field in function */
if (was_values)
{
was_values= FALSE;
was_null_value= value->null_value;
clear();
}
DBUG_VOID_RETURN;
}
void Item_sum_hybrid::restore_to_before_no_rows_in_result()
{
if (!was_values)
{
was_values= TRUE;
null_value= value->null_value= was_null_value;
}
}
Item *Item_sum_min::copy_or_same(THD* thd)
{
DBUG_ENTER("Item_sum_min::copy_or_same");
Item_sum_min *item= new (thd->mem_root) Item_sum_min(thd, this);
item->setup_hybrid(thd, args[0], value);
DBUG_RETURN(item);
}
bool Item_sum_min::add()
{
Item *UNINIT_VAR(tmp_item);
DBUG_ENTER("Item_sum_min::add");
DBUG_PRINT("enter", ("this: %p", this));
if (unlikely(direct_added))
{
/* Change to use direct_item */
tmp_item= arg_cache->get_item();
arg_cache->store(direct_item);
}
DBUG_PRINT("info", ("null_value: %s", null_value ? "TRUE" : "FALSE"));
/* args[0] < value */
arg_cache->cache_value();
if (!arg_cache->null_value &&
(null_value || cmp->compare() < 0))
{
value->store(arg_cache);
value->cache_value();
null_value= 0;
}
if (unlikely(direct_added))
{
/* Restore original item */
direct_added= FALSE;
arg_cache->store(tmp_item);
}
DBUG_RETURN(0);
}
Item *Item_sum_max::copy_or_same(THD* thd)
{
Item_sum_max *item= new (thd->mem_root) Item_sum_max(thd, this);
item->setup_hybrid(thd, args[0], value);
return item;
}
bool Item_sum_max::add()
{
Item * UNINIT_VAR(tmp_item);
DBUG_ENTER("Item_sum_max::add");
DBUG_PRINT("enter", ("this: %p", this));
if (unlikely(direct_added))
{
/* Change to use direct_item */
tmp_item= arg_cache->get_item();
arg_cache->store(direct_item);
}
/* args[0] > value */
arg_cache->cache_value();
DBUG_PRINT("info", ("null_value: %s", null_value ? "TRUE" : "FALSE"));
if (!arg_cache->null_value &&
(null_value || cmp->compare() > 0))
{
value->store(arg_cache);
value->cache_value();
null_value= 0;
}
if (unlikely(direct_added))
{
/* Restore original item */
direct_added= FALSE;
arg_cache->store(tmp_item);
}
DBUG_RETURN(0);
}
/* bit_or and bit_and */
longlong Item_sum_bit::val_int()
{
DBUG_ASSERT(fixed == 1);
return (longlong) bits;
}
void Item_sum_bit::clear()
{
bits= reset_bits;
if (as_window_function)
clear_as_window();
}
Item *Item_sum_or::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_or(thd, this);
}
bool Item_sum_bit::clear_as_window()
{
memset(bit_counters, 0, sizeof(bit_counters));
num_values_added= 0;
set_bits_from_counters();
return 0;
}
bool Item_sum_bit::remove_as_window(ulonglong value)
{
DBUG_ASSERT(as_window_function);
if (num_values_added == 0)
return 0; // Nothing to remove.
for (int i= 0; i < NUM_BIT_COUNTERS; i++)
{
if (!bit_counters[i])
{
// Don't attempt to remove values that were never added.
DBUG_ASSERT((value & (1ULL << i)) == 0);
continue;
}
bit_counters[i]-= (value & (1ULL << i)) ? 1 : 0;
}
// Prevent overflow;
num_values_added = MY_MIN(num_values_added, num_values_added - 1);
set_bits_from_counters();
return 0;
}
bool Item_sum_bit::add_as_window(ulonglong value)
{
DBUG_ASSERT(as_window_function);
for (int i= 0; i < NUM_BIT_COUNTERS; i++)
{
bit_counters[i]+= (value & (1ULL << i)) ? 1 : 0;
}
// Prevent overflow;
num_values_added = MY_MAX(num_values_added, num_values_added + 1);
set_bits_from_counters();
return 0;
}
void Item_sum_or::set_bits_from_counters()
{
ulonglong value= 0;
for (int i= 0; i < NUM_BIT_COUNTERS; i++)
{
value|= bit_counters[i] > 0 ? (1 << i) : 0;
}
bits= value | reset_bits;
}
bool Item_sum_or::add()
{
ulonglong value= (ulonglong) args[0]->val_int();
if (!args[0]->null_value)
{
if (as_window_function)
return add_as_window(value);
bits|=value;
}
return 0;
}
void Item_sum_xor::set_bits_from_counters()
{
ulonglong value= 0;
for (int i= 0; i < NUM_BIT_COUNTERS; i++)
{
value|= (bit_counters[i] % 2) ? (1 << i) : 0;
}
bits= value ^ reset_bits;
}
Item *Item_sum_xor::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_xor(thd, this);
}
bool Item_sum_xor::add()
{
ulonglong value= (ulonglong) args[0]->val_int();
if (!args[0]->null_value)
{
if (as_window_function)
return add_as_window(value);
bits^=value;
}
return 0;
}
void Item_sum_and::set_bits_from_counters()
{
ulonglong value= 0;
if (!num_values_added)
{
bits= reset_bits;
return;
}
for (int i= 0; i < NUM_BIT_COUNTERS; i++)
{
// We've only added values of 1 for this bit.
if (bit_counters[i] == num_values_added)
value|= (1ULL << i);
}
bits= value & reset_bits;
}
Item *Item_sum_and::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_and(thd, this);
}
bool Item_sum_and::add()
{
ulonglong value= (ulonglong) args[0]->val_int();
if (!args[0]->null_value)
{
if (as_window_function)
return add_as_window(value);
bits&=value;
}
return 0;
}
/************************************************************************
** reset result of a Item_sum with is saved in a tmp_table
*************************************************************************/
void Item_sum_num::reset_field()
{
double nr= args[0]->val_real();
uchar *res=result_field->ptr;
if (maybe_null)
{
if (args[0]->null_value)
{
nr=0.0;
result_field->set_null();
}
else
result_field->set_notnull();
}
float8store(res,nr);
}
void Item_sum_hybrid::reset_field()
{
Item *UNINIT_VAR(tmp_item), *arg0;
DBUG_ENTER("Item_sum_hybrid::reset_field");
arg0= args[0];
if (unlikely(direct_added))
{
/* Switch to use direct item */
tmp_item= value->get_item();
value->store(direct_item);
arg0= direct_item;
}
switch(result_type()) {
case STRING_RESULT:
{
char buff[MAX_FIELD_WIDTH];
String tmp(buff,sizeof(buff),result_field->charset()),*res;
res= arg0->val_str(&tmp);
if (arg0->null_value)
{
result_field->set_null();
result_field->reset();
}
else
{
result_field->set_notnull();
result_field->store(res->ptr(),res->length(),tmp.charset());
}
break;
}
case INT_RESULT:
{
longlong nr= arg0->val_int();
if (maybe_null)
{
if (arg0->null_value)
{
nr=0;
result_field->set_null();
}
else
result_field->set_notnull();
}
DBUG_PRINT("info", ("nr: %lld", nr));
result_field->store(nr, unsigned_flag);
break;
}
case REAL_RESULT:
{
double nr= arg0->val_real();
if (maybe_null)
{
if (arg0->null_value)
{
nr=0.0;
result_field->set_null();
}
else
result_field->set_notnull();
}
result_field->store(nr);
break;
}
case DECIMAL_RESULT:
{
my_decimal value_buff, *arg_dec= arg0->val_decimal(&value_buff);
if (maybe_null)
{
if (arg0->null_value)
result_field->set_null();
else
result_field->set_notnull();
}
/*
We must store zero in the field as we will use the field value in
add()
*/
if (!arg_dec) // Null
arg_dec= &decimal_zero;
result_field->store_decimal(arg_dec);
break;
}
case ROW_RESULT:
case TIME_RESULT:
DBUG_ASSERT(0);
}
if (unlikely(direct_added))
{
direct_added= FALSE;
value->store(tmp_item);
}
DBUG_VOID_RETURN;
}
void Item_sum_sum::reset_field()
{
my_bool null_flag;
DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR);
if (result_type() == DECIMAL_RESULT)
{
my_decimal value, *arg_val;
if (unlikely(direct_added))
arg_val= &direct_sum_decimal;
else
{
if (!(arg_val= args[0]->val_decimal(&value)))
arg_val= &decimal_zero; // Null
}
result_field->store_decimal(arg_val);
}
else
{
DBUG_ASSERT(result_type() == REAL_RESULT);
double nr= likely(!direct_added) ? args[0]->val_real() : direct_sum_real;
float8store(result_field->ptr, nr);
}
if (unlikely(direct_added))
{
direct_added= FALSE;
direct_reseted_field= TRUE;
null_flag= direct_sum_is_null;
}
else
null_flag= args[0]->null_value;
if (null_flag)
result_field->set_null();
else
result_field->set_notnull();
}
void Item_sum_count::reset_field()
{
DBUG_ENTER("Item_sum_count::reset_field");
uchar *res=result_field->ptr;
longlong nr=0;
DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR);
if (unlikely(direct_counted))
{
nr= direct_count;
direct_counted= FALSE;
direct_reseted_field= TRUE;
}
else if (!args[0]->maybe_null || !args[0]->is_null())
nr= 1;
DBUG_PRINT("info", ("nr: %lld", nr));
int8store(res,nr);
DBUG_VOID_RETURN;
}
void Item_sum_avg::reset_field()
{
uchar *res=result_field->ptr;
DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR);
if (result_type() == DECIMAL_RESULT)
{
longlong tmp;
my_decimal value, *arg_dec= args[0]->val_decimal(&value);
if (args[0]->null_value)
{
arg_dec= &decimal_zero;
tmp= 0;
}
else
tmp= 1;
my_decimal2binary(E_DEC_FATAL_ERROR, arg_dec, res, f_precision, f_scale);
res+= dec_bin_size;
int8store(res, tmp);
}
else
{
double nr= args[0]->val_real();
if (args[0]->null_value)
bzero(res,sizeof(double)+sizeof(longlong));
else
{
longlong tmp= 1;
float8store(res,nr);
res+=sizeof(double);
int8store(res,tmp);
}
}
}
void Item_sum_bit::reset_field()
{
reset_and_add();
int8store(result_field->ptr, bits);
}
void Item_sum_bit::update_field()
{
// We never call update_field when computing the function as a window
// function. Setting bits to a random value invalidates the bits counters and
// the result of the bit function becomes erroneous.
DBUG_ASSERT(!as_window_function);
uchar *res=result_field->ptr;
bits= uint8korr(res);
add();
int8store(res, bits);
}
/**
calc next value and merge it with field_value.
*/
void Item_sum_sum::update_field()
{
DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR);
if (result_type() == DECIMAL_RESULT)
{
my_decimal value, *arg_val;
my_bool null_flag;
if (unlikely(direct_added || direct_reseted_field))
{
direct_added= direct_reseted_field= FALSE;
arg_val= &direct_sum_decimal;
null_flag= direct_sum_is_null;
}
else
{
arg_val= args[0]->val_decimal(&value);
null_flag= args[0]->null_value;
}
if (!null_flag)
{
if (!result_field->is_null())
{
my_decimal field_value;
my_decimal *field_val= result_field->val_decimal(&field_value);
my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs, arg_val, field_val);
result_field->store_decimal(dec_buffs);
}
else
{
result_field->store_decimal(arg_val);
result_field->set_notnull();
}
}
}
else
{
double old_nr,nr;
uchar *res= result_field->ptr;
my_bool null_flag;
float8get(old_nr,res);
if (unlikely(direct_added || direct_reseted_field))
{
direct_added= direct_reseted_field= FALSE;
null_flag= direct_sum_is_null;
nr= direct_sum_real;
}
else
{
nr= args[0]->val_real();
null_flag= args[0]->null_value;
}
if (!null_flag)
{
old_nr+=nr;
result_field->set_notnull();
}
float8store(res,old_nr);
}
}
void Item_sum_count::update_field()
{
DBUG_ENTER("Item_sum_count::update_field");
longlong nr;
uchar *res=result_field->ptr;
nr=sint8korr(res);
if (unlikely(direct_counted || direct_reseted_field))
{
direct_counted= direct_reseted_field= FALSE;
nr+= direct_count;
}
else if (!args[0]->maybe_null || !args[0]->is_null())
nr++;
DBUG_PRINT("info", ("nr: %lld", nr));
int8store(res,nr);
DBUG_VOID_RETURN;
}
void Item_sum_avg::update_field()
{
longlong field_count;
uchar *res=result_field->ptr;
DBUG_ASSERT (aggr->Aggrtype() != Aggregator::DISTINCT_AGGREGATOR);
if (result_type() == DECIMAL_RESULT)
{
my_decimal value, *arg_val= args[0]->val_decimal(&value);
if (!args[0]->null_value)
{
binary2my_decimal(E_DEC_FATAL_ERROR, res,
dec_buffs + 1, f_precision, f_scale);
field_count= sint8korr(res + dec_bin_size);
my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs, arg_val, dec_buffs + 1);
my_decimal2binary(E_DEC_FATAL_ERROR, dec_buffs,
res, f_precision, f_scale);
res+= dec_bin_size;
field_count++;
int8store(res, field_count);
}
}
else
{
double nr;
nr= args[0]->val_real();
if (!args[0]->null_value)
{
double old_nr;
float8get(old_nr, res);
field_count= sint8korr(res + sizeof(double));
old_nr+= nr;
float8store(res,old_nr);
res+= sizeof(double);
field_count++;
int8store(res, field_count);
}
}
}
Item *Item_sum_avg::result_item(THD *thd, Field *field)
{
return
result_type() == DECIMAL_RESULT ?
(Item_avg_field*) new (thd->mem_root) Item_avg_field_decimal(thd, this) :
(Item_avg_field*) new (thd->mem_root) Item_avg_field_double(thd, this);
}
void Item_sum_hybrid::update_field()
{
DBUG_ENTER("Item_sum_hybrid::update_field");
Item *UNINIT_VAR(tmp_item);
if (unlikely(direct_added))
{
tmp_item= args[0];
args[0]= direct_item;
}
switch (result_type()) {
case STRING_RESULT:
min_max_update_str_field();
break;
case INT_RESULT:
min_max_update_int_field();
break;
case DECIMAL_RESULT:
min_max_update_decimal_field();
break;
default:
min_max_update_real_field();
}
if (unlikely(direct_added))
{
direct_added= FALSE;
args[0]= tmp_item;
}
DBUG_VOID_RETURN;
}
void
Item_sum_hybrid::min_max_update_str_field()
{
DBUG_ENTER("Item_sum_hybrid::min_max_update_str_field");
DBUG_ASSERT(cmp);
String *res_str=args[0]->val_str(&cmp->value1);
if (!args[0]->null_value)
{
result_field->val_str(&cmp->value2);
if (result_field->is_null() ||
(cmp_sign * sortcmp(res_str,&cmp->value2,collation.collation)) < 0)
result_field->store(res_str->ptr(),res_str->length(),res_str->charset());
result_field->set_notnull();
}
DBUG_VOID_RETURN;
}
void
Item_sum_hybrid::min_max_update_real_field()
{
double nr,old_nr;
DBUG_ENTER("Item_sum_hybrid::min_max_update_real_field");
old_nr=result_field->val_real();
nr= args[0]->val_real();
if (!args[0]->null_value)
{
if (result_field->is_null(0) ||
(cmp_sign > 0 ? old_nr > nr : old_nr < nr))
old_nr=nr;
result_field->set_notnull();
}
else if (result_field->is_null(0))
result_field->set_null();
result_field->store(old_nr);
DBUG_VOID_RETURN;
}
void
Item_sum_hybrid::min_max_update_int_field()
{
longlong nr,old_nr;
DBUG_ENTER("Item_sum_hybrid::min_max_update_int_field");
old_nr=result_field->val_int();
nr=args[0]->val_int();
if (!args[0]->null_value)
{
if (result_field->is_null(0))
old_nr=nr;
else
{
bool res=(unsigned_flag ?
(ulonglong) old_nr > (ulonglong) nr :
old_nr > nr);
/* (cmp_sign > 0 && res) || (!(cmp_sign > 0) && !res) */
if ((cmp_sign > 0) ^ (!res))
old_nr=nr;
}
result_field->set_notnull();
}
else if (result_field->is_null(0))
result_field->set_null();
DBUG_PRINT("info", ("nr: %lld", old_nr));
result_field->store(old_nr, unsigned_flag);
DBUG_VOID_RETURN;
}
/**
@todo
optimize: do not get result_field in case of args[0] is NULL
*/
void
Item_sum_hybrid::min_max_update_decimal_field()
{
DBUG_ENTER("Item_sum_hybrid::min_max_update_decimal_field");
my_decimal old_val, nr_val;
const my_decimal *old_nr;
const my_decimal *nr= args[0]->val_decimal(&nr_val);
if (!args[0]->null_value)
{
if (result_field->is_null(0))
old_nr=nr;
else
{
old_nr= result_field->val_decimal(&old_val);
bool res= my_decimal_cmp(old_nr, nr) > 0;
/* (cmp_sign > 0 && res) || (!(cmp_sign > 0) && !res) */
if ((cmp_sign > 0) ^ (!res))
old_nr=nr;
}
result_field->set_notnull();
result_field->store_decimal(old_nr);
}
else if (result_field->is_null(0))
result_field->set_null();
DBUG_VOID_RETURN;
}
double Item_avg_field_double::val_real()
{
// fix_fields() never calls for this Item
double nr;
longlong count;
uchar *res;
float8get(nr,field->ptr);
res= (field->ptr+sizeof(double));
count= sint8korr(res);
if ((null_value= !count))
return 0.0;
return nr/(double) count;
}
my_decimal *Item_avg_field_decimal::val_decimal(my_decimal *dec_buf)
{
// fix_fields() never calls for this Item
longlong count= sint8korr(field->ptr + dec_bin_size);
if ((null_value= !count))
return 0;
my_decimal dec_count, dec_field;
binary2my_decimal(E_DEC_FATAL_ERROR,
field->ptr, &dec_field, f_precision, f_scale);
int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &dec_count);
my_decimal_div(E_DEC_FATAL_ERROR, dec_buf,
&dec_field, &dec_count, prec_increment);
return dec_buf;
}
double Item_std_field::val_real()
{
double nr;
// fix_fields() never calls for this Item
nr= Item_variance_field::val_real();
DBUG_ASSERT(nr >= 0.0);
return sqrt(nr);
}
double Item_variance_field::val_real()
{
// fix_fields() never calls for this Item
double recurrence_s;
ulonglong count;
float8get(recurrence_s, (field->ptr + sizeof(double)));
count=sint8korr(field->ptr+sizeof(double)*2);
if ((null_value= (count <= sample)))
return 0.0;
return variance_fp_recurrence_result(recurrence_s, count, sample);
}
/****************************************************************************
** Functions to handle dynamic loadable aggregates
** Original source by: Alexis Mikhailov <root@medinf.chuvashia.su>
** Adapted for UDAs by: Andreas F. Bobak <bobak@relog.ch>.
** Rewritten by: Monty.
****************************************************************************/
#ifdef HAVE_DLOPEN
void Item_udf_sum::clear()
{
DBUG_ENTER("Item_udf_sum::clear");
udf.clear();
DBUG_VOID_RETURN;
}
bool Item_udf_sum::add()
{
my_bool tmp_null_value;
DBUG_ENTER("Item_udf_sum::add");
udf.add(&tmp_null_value);
null_value= tmp_null_value;
DBUG_RETURN(0);
}
void Item_udf_sum::cleanup()
{
/*
udf_handler::cleanup() nicely handles case when we have not
original item but one created by copy_or_same() method.
*/
udf.cleanup();
Item_sum::cleanup();
}
void Item_udf_sum::print(String *str, enum_query_type query_type)
{
str->append(func_name());
str->append('(');
for (uint i=0 ; i < arg_count ; i++)
{
if (i)
str->append(',');
args[i]->print(str, query_type);
}
str->append(')');
}
Item *Item_sum_udf_float::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_float(thd, this);
}
double Item_sum_udf_float::val_real()
{
my_bool tmp_null_value;
double res;
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_sum_udf_float::val");
DBUG_PRINT("enter",("result_type: %d arg_count: %d",
args[0]->result_type(), arg_count));
res= udf.val(&tmp_null_value);
null_value= tmp_null_value;
DBUG_RETURN(res);
}
String *Item_sum_udf_float::val_str(String *str)
{
return val_string_from_real(str);
}
my_decimal *Item_sum_udf_float::val_decimal(my_decimal *dec)
{
return val_decimal_from_real(dec);
}
String *Item_sum_udf_decimal::val_str(String *str)
{
return val_string_from_decimal(str);
}
double Item_sum_udf_decimal::val_real()
{
return val_real_from_decimal();
}
longlong Item_sum_udf_decimal::val_int()
{
return val_int_from_decimal();
}
my_decimal *Item_sum_udf_decimal::val_decimal(my_decimal *dec_buf)
{
my_decimal *res;
my_bool tmp_null_value;
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_func_udf_decimal::val_decimal");
DBUG_PRINT("enter",("result_type: %d arg_count: %d",
args[0]->result_type(), arg_count));
res= udf.val_decimal(&tmp_null_value, dec_buf);
null_value= tmp_null_value;
DBUG_RETURN(res);
}
Item *Item_sum_udf_decimal::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_decimal(thd, this);
}
Item *Item_sum_udf_int::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_int(thd, this);
}
longlong Item_sum_udf_int::val_int()
{
my_bool tmp_null_value;
longlong res;
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_sum_udf_int::val_int");
DBUG_PRINT("enter",("result_type: %d arg_count: %d",
args[0]->result_type(), arg_count));
res= udf.val_int(&tmp_null_value);
null_value= tmp_null_value;
DBUG_RETURN(res);
}
String *Item_sum_udf_int::val_str(String *str)
{
return val_string_from_int(str);
}
my_decimal *Item_sum_udf_int::val_decimal(my_decimal *dec)
{
return val_decimal_from_int(dec);
}
/** Default max_length is max argument length. */
void Item_sum_udf_str::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_udf_str::fix_length_and_dec");
max_length=0;
for (uint i = 0; i < arg_count; i++)
set_if_bigger(max_length,args[i]->max_length);
DBUG_VOID_RETURN;
}
Item *Item_sum_udf_str::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_str(thd, this);
}
my_decimal *Item_sum_udf_str::val_decimal(my_decimal *dec)
{
return val_decimal_from_string(dec);
}
String *Item_sum_udf_str::val_str(String *str)
{
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_sum_udf_str::str");
String *res=udf.val_str(str,&str_value);
null_value = !res;
DBUG_RETURN(res);
}
#endif /* HAVE_DLOPEN */
/*****************************************************************************
GROUP_CONCAT function
SQL SYNTAX:
GROUP_CONCAT([DISTINCT] expr,... [ORDER BY col [ASC|DESC],...]
[SEPARATOR str_const])
concat of values from "group by" operation
BUGS
Blobs doesn't work with DISTINCT or ORDER BY
*****************************************************************************/
/**
Compares the values for fields in expr list of GROUP_CONCAT.
@note
GROUP_CONCAT([DISTINCT] expr [,expr ...]
[ORDER BY {unsigned_integer | col_name | expr}
[ASC | DESC] [,col_name ...]]
[SEPARATOR str_val])
@return
@retval -1 : key1 < key2
@retval 0 : key1 = key2
@retval 1 : key1 > key2
*/
extern "C"
int group_concat_key_cmp_with_distinct(void* arg, const void* key1,
const void* key2)
{
Item_func_group_concat *item_func= (Item_func_group_concat*)arg;
for (uint i= 0; i < item_func->arg_count_field; i++)
{
Item *item= item_func->args[i];
/*
If item is a const item then either get_tmp_table_field returns 0
or it is an item over a const table.
*/
if (item->const_item())
continue;
/*
We have to use get_tmp_table_field() instead of
real_item()->get_tmp_table_field() because we want the field in
the temporary table, not the original field
*/
Field *field= item->get_tmp_table_field();
if (!field)
continue;
uint offset= (field->offset(field->table->record[0]) -
field->table->s->null_bytes);
int res= field->cmp((uchar*)key1 + offset, (uchar*)key2 + offset);
if (res)
return res;
}
return 0;
}
/**
function of sort for syntax: GROUP_CONCAT(expr,... ORDER BY col,... )
*/
extern "C"
int group_concat_key_cmp_with_order(void* arg, const void* key1,
const void* key2)
{
Item_func_group_concat* grp_item= (Item_func_group_concat*) arg;
ORDER **order_item, **end;
for (order_item= grp_item->order, end=order_item+ grp_item->arg_count_order;
order_item < end;
order_item++)
{
Item *item= *(*order_item)->item;
/*
If field_item is a const item then either get_tmp_table_field returns 0
or it is an item over a const table.
*/
if (item->const_item())
continue;
/*
If item is a const item then either get_tmp_table_field returns 0
or it is an item over a const table.
*/
if (item->const_item())
continue;
/*
We have to use get_tmp_table_field() instead of
real_item()->get_tmp_table_field() because we want the field in
the temporary table, not the original field
Note that for the case of ROLLUP, field may point to another table
tham grp_item->table. This is however ok as the table definitions are
the same.
*/
Field *field= item->get_tmp_table_field();
if (!field)
continue;
uint offset= (field->offset(field->table->record[0]) -
field->table->s->null_bytes);
int res= field->cmp((uchar*)key1 + offset, (uchar*)key2 + offset);
if (res)
return ((*order_item)->direction == ORDER::ORDER_ASC) ? res : -res;
}
/*
We can't return 0 because in that case the tree class would remove this
item as double value. This would cause problems for case-changes and
if the returned values are not the same we do the sort on.
*/
return 1;
}
/**
Append data from current leaf to item->result.
*/
extern "C"
int dump_leaf_key(void* key_arg, element_count count __attribute__((unused)),
void* item_arg)
{
Item_func_group_concat *item= (Item_func_group_concat *) item_arg;
TABLE *table= item->table;
uint max_length= (uint)table->in_use->variables.group_concat_max_len;
String tmp((char *)table->record[1], table->s->reclength,
default_charset_info);
String tmp2;
uchar *key= (uchar *) key_arg;
String *result= &item->result;
Item **arg= item->args, **arg_end= item->args + item->arg_count_field;
uint old_length= result->length();
ulonglong *offset_limit= &item->copy_offset_limit;
ulonglong *row_limit = &item->copy_row_limit;
if (item->limit_clause && !(*row_limit))
return 1;
if (item->no_appended)
item->no_appended= FALSE;
else
result->append(*item->separator);
tmp.length(0);
if (item->limit_clause && (*offset_limit))
{
item->row_count++;
item->no_appended= TRUE;
(*offset_limit)--;
return 0;
}
for (; arg < arg_end; arg++)
{
String *res;
/*
We have to use get_tmp_table_field() instead of
real_item()->get_tmp_table_field() because we want the field in
the temporary table, not the original field
We also can't use table->field array to access the fields
because it contains both order and arg list fields.
*/
if ((*arg)->const_item())
res= (*arg)->val_str(&tmp);
else
{
Field *field= (*arg)->get_tmp_table_field();
if (field)
{
uint offset= (field->offset(field->table->record[0]) -
table->s->null_bytes);
DBUG_ASSERT(offset < table->s->reclength);
res= field->val_str(&tmp, key + offset);
}
else
res= (*arg)->val_str(&tmp);
}
if (res)
result->append(*res);
}
if (item->limit_clause)
(*row_limit)--;
item->row_count++;
/* stop if length of result more than max_length */
if (result->length() > max_length)
{
CHARSET_INFO *cs= item->collation.collation;
const char *ptr= result->ptr();
THD *thd= current_thd;
/*
It's ok to use item->result.length() as the fourth argument
as this is never used to limit the length of the data.
Cut is done with the third argument.
*/
size_t add_length= Well_formed_prefix(cs,
ptr + old_length,
ptr + max_length,
result->length()).length();
result->length(old_length + add_length);
item->warning_for_row= TRUE;
push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
ER_CUT_VALUE_GROUP_CONCAT,
ER_THD(thd, ER_CUT_VALUE_GROUP_CONCAT),
item->row_count);
/**
To avoid duplicated warnings in Item_func_group_concat::val_str()
*/
if (table && table->blob_storage)
table->blob_storage->set_truncated_value(false);
return 1;
}
return 0;
}
/**
Constructor of Item_func_group_concat.
@param distinct_arg distinct
@param select_list list of expression for show values
@param order_list list of sort columns
@param separator_arg string value of separator.
*/
Item_func_group_concat::
Item_func_group_concat(THD *thd, Name_resolution_context *context_arg,
bool distinct_arg, List<Item> *select_list,
const SQL_I_List<ORDER> &order_list,
String *separator_arg, bool limit_clause,
Item *row_limit_arg, Item *offset_limit_arg)
:Item_sum(thd), tmp_table_param(0), separator(separator_arg), tree(0),
unique_filter(NULL), table(0),
order(0), context(context_arg),
arg_count_order(order_list.elements),
arg_count_field(select_list->elements),
row_count(0),
distinct(distinct_arg),
warning_for_row(FALSE),
force_copy_fields(0), row_limit(NULL),
offset_limit(NULL), limit_clause(limit_clause),
copy_offset_limit(0), copy_row_limit(0), original(0)
{
Item *item_select;
Item **arg_ptr;
quick_group= FALSE;
arg_count= arg_count_field + arg_count_order;
/*
We need to allocate:
args - arg_count_field+arg_count_order
(for possible order items in temporary tables)
order - arg_count_order
*/
if (!(args= (Item**) thd->alloc(sizeof(Item*) * arg_count * 2 +
sizeof(ORDER*)*arg_count_order)))
return;
order= (ORDER**)(args + arg_count);
/* fill args items of show and sort */
List_iterator_fast<Item> li(*select_list);
for (arg_ptr=args ; (item_select= li++) ; arg_ptr++)
*arg_ptr= item_select;
if (arg_count_order)
{
ORDER **order_ptr= order;
for (ORDER *order_item= order_list.first;
order_item != NULL;
order_item= order_item->next)
{
(*order_ptr++)= order_item;
*arg_ptr= *order_item->item;
order_item->item= arg_ptr++;
}
}
/* orig_args is only used for print() */
orig_args= (Item**) (order + arg_count_order);
memcpy(orig_args, args, sizeof(Item*) * arg_count);
if (limit_clause)
{
row_limit= row_limit_arg;
offset_limit= offset_limit_arg;
}
}
Item_func_group_concat::Item_func_group_concat(THD *thd,
Item_func_group_concat *item)
:Item_sum(thd, item),
tmp_table_param(item->tmp_table_param),
separator(item->separator),
tree(item->tree),
unique_filter(item->unique_filter),
table(item->table),
context(item->context),
arg_count_order(item->arg_count_order),
arg_count_field(item->arg_count_field),
row_count(item->row_count),
distinct(item->distinct),
warning_for_row(item->warning_for_row),
always_null(item->always_null),
force_copy_fields(item->force_copy_fields),
row_limit(item->row_limit), offset_limit(item->offset_limit),
limit_clause(item->limit_clause),copy_offset_limit(item->copy_offset_limit),
copy_row_limit(item->copy_row_limit), original(item)
{
quick_group= item->quick_group;
result.set_charset(collation.collation);
/*
Since the ORDER structures pointed to by the elements of the 'order' array
may be modified in find_order_in_list() called from
Item_func_group_concat::setup(), create a copy of those structures so that
such modifications done in this object would not have any effect on the
object being copied.
*/
ORDER *tmp;
if (!(tmp= (ORDER *) thd->alloc(sizeof(ORDER *) * arg_count_order +
sizeof(ORDER) * arg_count_order)))
return;
order= (ORDER **)(tmp + arg_count_order);
for (uint i= 0; i < arg_count_order; i++, tmp++)
{
/*
Compiler generated copy constructor is used to
to copy all the members of ORDER struct.
It's also necessary to update ORDER::next pointer
so that it points to new ORDER element.
*/
new (tmp) st_order(*(item->order[i]));
tmp->next= (i + 1 == arg_count_order) ? NULL : (tmp + 1);
order[i]= tmp;
}
}
void Item_func_group_concat::cleanup()
{
DBUG_ENTER("Item_func_group_concat::cleanup");
Item_sum::cleanup();
/*
Free table and tree if they belong to this item (if item have not pointer
to original item from which was made copy => it own its objects )
*/
if (!original)
{
delete tmp_table_param;
tmp_table_param= 0;
if (table)
{
THD *thd= table->in_use;
if (table->blob_storage)
delete table->blob_storage;
free_tmp_table(thd, table);
table= 0;
if (tree)
{
delete_tree(tree, 0);
tree= 0;
}
if (unique_filter)
{
delete unique_filter;
unique_filter= NULL;
}
}
DBUG_ASSERT(tree == 0);
}
/*
As the ORDER structures pointed to by the elements of the
'order' array may be modified in find_order_in_list() called
from Item_func_group_concat::setup() to point to runtime
created objects, we need to reset them back to the original
arguments of the function.
*/
ORDER **order_ptr= order;
for (uint i= 0; i < arg_count_order; i++)
{
(*order_ptr)->item= &args[arg_count_field + i];
order_ptr++;
}
DBUG_VOID_RETURN;
}
Item *Item_func_group_concat::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_func_group_concat(thd, this);
}
void Item_func_group_concat::clear()
{
result.length(0);
result.copy();
null_value= TRUE;
warning_for_row= FALSE;
no_appended= TRUE;
if (offset_limit)
copy_offset_limit= offset_limit->val_int();
if (row_limit)
copy_row_limit= row_limit->val_int();
if (tree)
reset_tree(tree);
if (unique_filter)
unique_filter->reset();
if (table && table->blob_storage)
table->blob_storage->reset();
/* No need to reset the table as we never call write_row */
}
bool Item_func_group_concat::add()
{
if (always_null)
return 0;
copy_fields(tmp_table_param);
if (copy_funcs(tmp_table_param->items_to_copy, table->in_use))
return TRUE;
for (uint i= 0; i < arg_count_field; i++)
{
Item *show_item= args[i];
if (show_item->const_item())
continue;
Field *field= show_item->get_tmp_table_field();
if (field && field->is_null_in_record((const uchar*) table->record[0]))
return 0; // Skip row if it contains null
}
null_value= FALSE;
bool row_eligible= TRUE;
if (distinct)
{
/* Filter out duplicate rows. */
uint count= unique_filter->elements_in_tree();
unique_filter->unique_add(table->record[0] + table->s->null_bytes);
if (count == unique_filter->elements_in_tree())
row_eligible= FALSE;
}
TREE_ELEMENT *el= 0; // Only for safety
if (row_eligible && tree)
{
el= tree_insert(tree, table->record[0] + table->s->null_bytes, 0,
tree->custom_arg);
/* check if there was enough memory to insert the row */
if (!el)
return 1;
}
/*
If the row is not a duplicate (el->count == 1)
we can dump the row here in case of GROUP_CONCAT(DISTINCT...)
instead of doing tree traverse later.
*/
if (row_eligible && !warning_for_row &&
(!tree || (el->count == 1 && distinct && !arg_count_order)))
dump_leaf_key(table->record[0] + table->s->null_bytes, 1, this);
return 0;
}
bool
Item_func_group_concat::fix_fields(THD *thd, Item **ref)
{
uint i; /* for loop variable */
DBUG_ASSERT(fixed == 0);
if (init_sum_func_check(thd))
return TRUE;
maybe_null= 1;
/*
Fix fields for select list and ORDER clause
*/
for (i=0 ; i < arg_count ; i++)
{
if (args[i]->fix_fields_if_needed_for_scalar(thd, &args[i]))
return TRUE;
m_with_subquery|= args[i]->with_subquery();
with_param|= args[i]->with_param;
with_window_func|= args[i]->with_window_func;
}
/* skip charset aggregation for order columns */
if (agg_arg_charsets_for_string_result(collation,
args, arg_count - arg_count_order))
return 1;
result.set_charset(collation.collation);
result_field= 0;
null_value= 1;
max_length= (uint32)(thd->variables.group_concat_max_len
/ collation.collation->mbminlen
* collation.collation->mbmaxlen);
uint32 offset;
if (separator->needs_conversion(separator->length(), separator->charset(),
collation.collation, &offset))
{
uint32 buflen= collation.collation->mbmaxlen * separator->length();
uint errors, conv_length;
char *buf;
String *new_separator;
if (!(buf= (char*) thd->stmt_arena->alloc(buflen)) ||
!(new_separator= new(thd->stmt_arena->mem_root)
String(buf, buflen, collation.collation)))
return TRUE;
conv_length= copy_and_convert(buf, buflen, collation.collation,
separator->ptr(), separator->length(),
separator->charset(), &errors);
new_separator->length(conv_length);
separator= new_separator;
}
if (check_sum_func(thd, ref))
return TRUE;
fixed= 1;
return FALSE;
}
bool Item_func_group_concat::setup(THD *thd)
{
List<Item> list;
SELECT_LEX *select_lex= thd->lex->current_select;
const bool order_or_distinct= MY_TEST(arg_count_order > 0 || distinct);
DBUG_ENTER("Item_func_group_concat::setup");
/*
Currently setup() can be called twice. Please add
assertion here when this is fixed.
*/
if (table || tree)
DBUG_RETURN(FALSE);
if (!(tmp_table_param= new TMP_TABLE_PARAM))
DBUG_RETURN(TRUE);
/* Push all not constant fields to the list and create a temp table */
always_null= 0;
for (uint i= 0; i < arg_count_field; i++)
{
Item *item= args[i];
if (list.push_back(item, thd->mem_root))
DBUG_RETURN(TRUE);
if (item->const_item())
{
if (item->is_null())
{
always_null= 1;
DBUG_RETURN(FALSE);
}
}
}
List<Item> all_fields(list);
/*
Try to find every ORDER expression in the list of GROUP_CONCAT
arguments. If an expression is not found, prepend it to
"all_fields". The resulting field list is used as input to create
tmp table columns.
*/
if (arg_count_order)
{
uint n_elems= arg_count_order + all_fields.elements;
ref_pointer_array= static_cast<Item**>(thd->alloc(sizeof(Item*) * n_elems));
if (!ref_pointer_array)
DBUG_RETURN(TRUE);
memcpy(ref_pointer_array, args, arg_count * sizeof(Item*));
if (setup_order(thd, Ref_ptr_array(ref_pointer_array, n_elems),
context->table_list, list, all_fields, *order))
DBUG_RETURN(TRUE);
}
count_field_types(select_lex, tmp_table_param, all_fields, 0);
tmp_table_param->force_copy_fields= force_copy_fields;
DBUG_ASSERT(table == 0);
if (order_or_distinct)
{
/*
Force the create_tmp_table() to convert BIT columns to INT
as we cannot compare two table records containg BIT fields
stored in the the tree used for distinct/order by.
Moreover we don't even save in the tree record null bits
where BIT fields store parts of their data.
*/
List_iterator_fast<Item> li(all_fields);
Item *item;
while ((item= li++))
{
if (item->type() == Item::FIELD_ITEM &&
((Item_field*) item)->field->type() == FIELD_TYPE_BIT)
item->marker= 4;
}
}
/*
We have to create a temporary table to get descriptions of fields
(types, sizes and so on).
Note that in the table, we first have the ORDER BY fields, then the
field list.
*/
if (!(table= create_tmp_table(thd, tmp_table_param, all_fields,
(ORDER*) 0, 0, TRUE,
(select_lex->options |
thd->variables.option_bits),
HA_POS_ERROR, &empty_clex_str)))
DBUG_RETURN(TRUE);
table->file->extra(HA_EXTRA_NO_ROWS);
table->no_rows= 1;
/**
Initialize blob_storage if GROUP_CONCAT is used
with ORDER BY | DISTINCT and BLOB field count > 0.
*/
if (order_or_distinct && table->s->blob_fields)
table->blob_storage= new Blob_mem_storage();
/*
Need sorting or uniqueness: init tree and choose a function to sort.
Don't reserve space for NULLs: if any of gconcat arguments is NULL,
the row is not added to the result.
*/
uint tree_key_length= table->s->reclength - table->s->null_bytes;
if (arg_count_order)
{
tree= &tree_base;
/*
Create a tree for sorting. The tree is used to sort (according to the
syntax of this function). If there is no ORDER BY clause, we don't
create this tree.
*/
init_tree(tree, (size_t)MY_MIN(thd->variables.max_heap_table_size,
thd->variables.sortbuff_size/16), 0,
tree_key_length,
group_concat_key_cmp_with_order, NULL, (void*) this,
MYF(MY_THREAD_SPECIFIC));
}
if (distinct)
unique_filter= new Unique(group_concat_key_cmp_with_distinct,
(void*)this,
tree_key_length,
ram_limitation(thd));
if ((row_limit && row_limit->cmp_type() != INT_RESULT) ||
(offset_limit && offset_limit->cmp_type() != INT_RESULT))
{
my_error(ER_INVALID_VALUE_TO_LIMIT, MYF(0));
DBUG_RETURN(TRUE);
}
DBUG_RETURN(FALSE);
}
/* This is used by rollup to create a separate usable copy of the function */
void Item_func_group_concat::make_unique()
{
tmp_table_param= 0;
table=0;
original= 0;
force_copy_fields= 1;
tree= 0;
}
String* Item_func_group_concat::val_str(String* str)
{
DBUG_ASSERT(fixed == 1);
if (null_value)
return 0;
if (no_appended && tree)
/* Tree is used for sorting as in ORDER BY */
tree_walk(tree, &dump_leaf_key, this, left_root_right);
if (table && table->blob_storage &&
table->blob_storage->is_truncated_value())
{
warning_for_row= true;
push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN,
ER_CUT_VALUE_GROUP_CONCAT, ER(ER_CUT_VALUE_GROUP_CONCAT),
row_count);
}
return &result;
}
void Item_func_group_concat::print(String *str, enum_query_type query_type)
{
str->append(STRING_WITH_LEN("group_concat("));
if (distinct)
str->append(STRING_WITH_LEN("distinct "));
for (uint i= 0; i < arg_count_field; i++)
{
if (i)
str->append(',');
orig_args[i]->print(str, query_type);
}
if (arg_count_order)
{
str->append(STRING_WITH_LEN(" order by "));
for (uint i= 0 ; i < arg_count_order ; i++)
{
if (i)
str->append(',');
orig_args[i + arg_count_field]->print(str, query_type);
if (order[i]->direction == ORDER::ORDER_ASC)
str->append(STRING_WITH_LEN(" ASC"));
else
str->append(STRING_WITH_LEN(" DESC"));
}
}
str->append(STRING_WITH_LEN(" separator \'"));
str->append_for_single_quote(separator->ptr(), separator->length());
str->append(STRING_WITH_LEN("\')"));
}
Item_func_group_concat::~Item_func_group_concat()
{
if (!original && unique_filter)
delete unique_filter;
}
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