273 lines
6.6 KiB
C++
273 lines
6.6 KiB
C++
/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
|
|
|
|
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,
|
|
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
|
|
|
|
|
|
/**
|
|
@file
|
|
|
|
@brief
|
|
Buffers to save and compare item values
|
|
*/
|
|
|
|
#include "sql_class.h" // THD
|
|
#include "item.h" // Cached_item, Cached_item_field, ...
|
|
#include "json_dom.h" // Json_wrapper
|
|
|
|
using std::min;
|
|
using std::max;
|
|
|
|
/**
|
|
Create right type of Cached_item for an item.
|
|
*/
|
|
|
|
Cached_item *new_Cached_item(THD *thd, Item *item, bool use_result_field)
|
|
{
|
|
if (item->real_item()->type() == Item::FIELD_ITEM &&
|
|
!(((Item_field *) (item->real_item()))->field->flags & BLOB_FLAG))
|
|
{
|
|
Item_field *real_item= (Item_field *) item->real_item();
|
|
Field *cached_field= use_result_field ? real_item->result_field :
|
|
real_item->field;
|
|
return new Cached_item_field(cached_field);
|
|
}
|
|
switch (item->result_type()) {
|
|
case STRING_RESULT:
|
|
if (item->is_temporal())
|
|
return new Cached_item_temporal((Item_field *) item);
|
|
if (item->field_type() == MYSQL_TYPE_JSON)
|
|
return new Cached_item_json(item);
|
|
return new Cached_item_str(thd, (Item_field *) item);
|
|
case INT_RESULT:
|
|
return new Cached_item_int((Item_field *) item);
|
|
case REAL_RESULT:
|
|
return new Cached_item_real(item);
|
|
case DECIMAL_RESULT:
|
|
return new Cached_item_decimal(item);
|
|
case ROW_RESULT:
|
|
default:
|
|
DBUG_ASSERT(0);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
Cached_item::~Cached_item() {}
|
|
|
|
/**
|
|
Compare with old value and replace value with new value.
|
|
|
|
@return
|
|
Return true if values have changed
|
|
*/
|
|
|
|
Cached_item_str::Cached_item_str(THD *thd, Item *arg)
|
|
:item(arg),
|
|
value_max_length(min<uint32>(arg->max_length, thd->variables.max_sort_length)),
|
|
value(value_max_length)
|
|
{}
|
|
|
|
bool Cached_item_str::cmp(void)
|
|
{
|
|
String *res;
|
|
bool tmp;
|
|
|
|
DBUG_ENTER("Cached_item_str::cmp");
|
|
DBUG_ASSERT(!item->is_temporal());
|
|
DBUG_ASSERT(item->field_type() != MYSQL_TYPE_JSON);
|
|
if ((res=item->val_str(&tmp_value)))
|
|
res->length(min(res->length(), static_cast<size_t>(value_max_length)));
|
|
DBUG_PRINT("info", ("old: %s, new: %s",
|
|
value.c_ptr_safe(), res ? res->c_ptr_safe() : ""));
|
|
if (null_value != item->null_value)
|
|
{
|
|
if ((null_value= item->null_value))
|
|
DBUG_RETURN(TRUE); // New value was null
|
|
tmp=TRUE;
|
|
}
|
|
else if (null_value)
|
|
DBUG_RETURN(0); // new and old value was null
|
|
else
|
|
tmp= sortcmp(&value,res,item->collation.collation) != 0;
|
|
if (tmp)
|
|
value.copy(*res); // Remember for next cmp
|
|
DBUG_RETURN(tmp);
|
|
}
|
|
|
|
Cached_item_str::~Cached_item_str()
|
|
{
|
|
item=0; // Safety
|
|
}
|
|
|
|
|
|
Cached_item_json::Cached_item_json(Item *item)
|
|
: m_item(item), m_value(new Json_wrapper())
|
|
{}
|
|
|
|
|
|
Cached_item_json::~Cached_item_json()
|
|
{
|
|
delete m_value;
|
|
}
|
|
|
|
|
|
/**
|
|
Compare the new JSON value in m_item with the previous value.
|
|
@retval true if the new value is different from the previous value,
|
|
or if there is no previously cached value
|
|
@retval false if the new value is the same as the already cached value
|
|
*/
|
|
bool Cached_item_json::cmp()
|
|
{
|
|
Json_wrapper wr;
|
|
if (m_item->val_json(&wr))
|
|
{
|
|
null_value= true; /* purecov: inspected */
|
|
return true; /* purecov: inspected */
|
|
}
|
|
if (null_value != m_item->null_value)
|
|
{
|
|
null_value= m_item->null_value;
|
|
if (null_value)
|
|
return true; // New value is null.
|
|
}
|
|
else if (null_value)
|
|
{
|
|
return false; // New and old are null.
|
|
}
|
|
else if (!m_value->empty() && m_value->compare(wr) == 0)
|
|
{
|
|
return false; // New and old are equal.
|
|
}
|
|
|
|
/*
|
|
Otherwise, old and new are not equal, and new is not null.
|
|
Remember the current value till the next time we're called.
|
|
*/
|
|
m_value->steal(&wr);
|
|
|
|
/*
|
|
The row buffer may change, which would garble the JSON binary
|
|
representation pointed to by m_value. Convert to DOM so that we
|
|
own the copy.
|
|
*/
|
|
m_value->to_dom();
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
bool Cached_item_real::cmp(void)
|
|
{
|
|
DBUG_ENTER("Cached_item_real::cmp");
|
|
double nr= item->val_real();
|
|
DBUG_PRINT("info", ("old: %f, new: %f", value, nr));
|
|
if (null_value != item->null_value || nr != value)
|
|
{
|
|
null_value= item->null_value;
|
|
value=nr;
|
|
DBUG_RETURN(TRUE);
|
|
}
|
|
DBUG_RETURN(FALSE);
|
|
}
|
|
|
|
bool Cached_item_int::cmp(void)
|
|
{
|
|
DBUG_ENTER("Cached_item_int::cmp");
|
|
longlong nr=item->val_int();
|
|
DBUG_PRINT("info", ("old: %lld, new: %lld", value, nr));
|
|
if (null_value != item->null_value || nr != value)
|
|
{
|
|
null_value= item->null_value;
|
|
value=nr;
|
|
DBUG_RETURN(TRUE);
|
|
}
|
|
DBUG_RETURN(FALSE);
|
|
}
|
|
|
|
|
|
bool Cached_item_temporal::cmp(void)
|
|
{
|
|
DBUG_ENTER("Cached_item_temporal::cmp");
|
|
longlong nr= item->val_temporal_by_field_type();
|
|
DBUG_PRINT("info", ("old: %lld, new: %lld", value, nr));
|
|
if (null_value != item->null_value || nr != value)
|
|
{
|
|
null_value= item->null_value;
|
|
value= nr;
|
|
DBUG_RETURN(TRUE);
|
|
}
|
|
DBUG_RETURN(FALSE);
|
|
}
|
|
|
|
|
|
bool Cached_item_field::cmp(void)
|
|
{
|
|
DBUG_ENTER("Cached_item_field::cmp");
|
|
DBUG_EXECUTE("info", dbug_print(););
|
|
|
|
bool different= false;
|
|
|
|
if (field->is_null())
|
|
{
|
|
if (!null_value)
|
|
{
|
|
different= true;
|
|
null_value= true;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (null_value)
|
|
{
|
|
different= true;
|
|
null_value= false;
|
|
field->get_image(buff, length, field->charset());
|
|
}
|
|
else if (field->cmp(buff)) // Not a blob: cmp() is OK
|
|
{
|
|
different= true;
|
|
field->get_image(buff, length, field->charset());
|
|
}
|
|
}
|
|
|
|
DBUG_RETURN(different);
|
|
}
|
|
|
|
|
|
Cached_item_decimal::Cached_item_decimal(Item *it)
|
|
:item(it)
|
|
{
|
|
my_decimal_set_zero(&value);
|
|
}
|
|
|
|
|
|
bool Cached_item_decimal::cmp()
|
|
{
|
|
my_decimal tmp;
|
|
my_decimal *ptmp= item->val_decimal(&tmp);
|
|
if (null_value != item->null_value ||
|
|
(!item->null_value && my_decimal_cmp(&value, ptmp)))
|
|
{
|
|
null_value= item->null_value;
|
|
/* Save only not null values */
|
|
if (!null_value)
|
|
{
|
|
my_decimal2decimal(ptmp, &value);
|
|
return TRUE;
|
|
}
|
|
return FALSE;
|
|
}
|
|
return FALSE;
|
|
}
|