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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008-2009 Sun Microsystems, Inc.
*
* 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
*/
#include <config.h>
#include <drizzled/session.h>
#include <drizzled/util/functors.h>
#include <drizzled/optimizer/range.h>
#include <drizzled/optimizer/quick_range_select.h>
#include <drizzled/optimizer/quick_ror_union_select.h>
#include <drizzled/table.h>
#include <drizzled/system_variables.h>
#include <vector>
#include <algorithm>
using namespace std;
namespace drizzled {
optimizer::QuickRorUnionSelect::QuickRorUnionSelect(Session *session_param,
Table *table)
:
session(session_param),
scans_inited(false)
{
index= MAX_KEY;
head= table;
rowid_length= table->cursor->ref_length;
record= head->record[0];
memory::init_sql_alloc(&alloc, session->variables.range_alloc_block_size, 0);
session_param->mem_root= &alloc;
}
/*
* Function object that is used as the comparison function
* for the priority queue in the QuickRorUnionSelect
* class.
*/
class optimizer::compare_functor
{
optimizer::QuickRorUnionSelect *self;
public:
compare_functor(optimizer::QuickRorUnionSelect *in_arg)
: self(in_arg) { }
inline bool operator()(const optimizer::QuickSelectInterface *i, const optimizer::QuickSelectInterface *j) const
{
int val= self->head->cursor->cmp_ref(i->last_rowid,
j->last_rowid);
return (val >= 0);
}
};
int optimizer::QuickRorUnionSelect::init()
{
queue=
new priority_queue<optimizer::QuickSelectInterface *,
vector<optimizer::QuickSelectInterface *>,
optimizer::compare_functor >(optimizer::compare_functor(this));
if (! (cur_rowid= (unsigned char*) alloc.alloc_root(2 * head->cursor->ref_length)))
{
return 0;
}
prev_rowid= cur_rowid + head->cursor->ref_length;
return 0;
}
int optimizer::QuickRorUnionSelect::reset()
{
int error;
have_prev_rowid= false;
if (! scans_inited)
{
for (vector<optimizer::QuickSelectInterface *>::iterator it= quick_selects.begin();
it != quick_selects.end();
++it)
{
if ((*it)->init_ror_merged_scan(false))
{
return 0;
}
}
scans_inited= true;
}
while (! queue->empty())
{
queue->pop();
}
/*
Initialize scans for merged quick selects and put all merged quick
selects into the queue.
*/
for (vector<optimizer::QuickSelectInterface *>::iterator it= quick_selects.begin();
it != quick_selects.end();
++it)
{
if ((*it)->reset())
{
return 0;
}
error= (*it)->get_next();
if (error)
{
if (error == HA_ERR_END_OF_FILE)
{
continue;
}
}
(*it)->save_last_pos();
queue->push(*it);
}
if (head->cursor->startTableScan(1))
{
return 0;
}
return 0;
}
bool
optimizer::QuickRorUnionSelect::push_quick_back(QuickSelectInterface *quick_sel_range)
{
quick_selects.push_back(quick_sel_range);
return false;
}
optimizer::QuickRorUnionSelect::~QuickRorUnionSelect()
{
while (! queue->empty())
{
queue->pop();
}
delete queue;
for_each(quick_selects.begin(),
quick_selects.end(),
DeletePtr());
quick_selects.clear();
if (head->cursor->inited != Cursor::NONE)
{
head->cursor->endTableScan();
}
alloc.free_root(MYF(0));
}
bool optimizer::QuickRorUnionSelect::is_keys_used(const boost::dynamic_bitset<>& fields)
{
for (vector<optimizer::QuickSelectInterface *>::iterator it= quick_selects.begin();
it != quick_selects.end();
++it)
{
if ((*it)->is_keys_used(fields))
{
return true;
}
}
return false;
}
int optimizer::QuickRorUnionSelect::get_next()
{
int error;
int dup_row;
optimizer::QuickSelectInterface *quick= NULL;
unsigned char *tmp= NULL;
do
{
do
{
if (queue->empty())
return HA_ERR_END_OF_FILE;
/* Ok, we have a queue with >= 1 scans */
quick= queue->top();
memcpy(cur_rowid, quick->last_rowid, rowid_length);
/* put into queue rowid from the same stream as top element */
if ((error= quick->get_next()))
{
if (error != HA_ERR_END_OF_FILE)
return(error);
queue->pop();
}
else
{
quick->save_last_pos();
queue->pop();
queue->push(quick);
}
if (!have_prev_rowid)
{
/* No rows have been returned yet */
dup_row= false;
have_prev_rowid= true;
}
else
dup_row= ! head->cursor->cmp_ref(cur_rowid, prev_rowid);
} while (dup_row);
tmp= cur_rowid;
cur_rowid= prev_rowid;
prev_rowid= tmp;
error= head->cursor->rnd_pos(quick->record, prev_rowid);
} while (error == HA_ERR_RECORD_DELETED);
return error;
}
void optimizer::QuickRorUnionSelect::add_info_string(string *str)
{
bool first= true;
str->append("union(");
for (vector<optimizer::QuickSelectInterface *>::iterator it= quick_selects.begin();
it != quick_selects.end();
++it)
{
if (! first)
str->append(",");
else
first= false;
(*it)->add_info_string(str);
}
str->append(")");
}
void optimizer::QuickRorUnionSelect::add_keys_and_lengths(string *key_names,
string *used_lengths)
{
bool first= true;
for (vector<optimizer::QuickSelectInterface *>::iterator it= quick_selects.begin();
it != quick_selects.end();
++it)
{
if (first)
{
first= false;
}
else
{
used_lengths->append(",");
key_names->append(",");
}
(*it)->add_keys_and_lengths(key_names, used_lengths);
}
}
} /* namespace drizzled */
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