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/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2009 Sun Microsystems
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef PLUGIN_INFORMATION_ENGINE_INFORMATION_CURSOR_H
#define PLUGIN_INFORMATION_ENGINE_INFORMATION_CURSOR_H
#include <drizzled/server_includes.h>
#include <drizzled/cursor.h>
#include <mysys/thr_lock.h>
#include <drizzled/plugin/info_schema_table.h>
#include <plugin/information_engine/information_engine.h>
class InformationCursor: public Cursor
{
private:
THR_LOCK_DATA lock; /* MySQL lock */
InformationEngine::Share *share;
drizzled::plugin::InfoSchemaTable::Rows::iterator iter;
public:
InformationCursor(drizzled::plugin::StorageEngine &engine, TableShare &table_arg);
~InformationCursor() {}
int open(const char *name, int mode, uint32_t test_if_locked);
int close(void);
int rnd_init(bool scan);
/* get the next row and copy it into buf */
int rnd_next(unsigned char *buf);
/* locate row pointed to by pos, copy it into buf */
int rnd_pos(unsigned char *buf, unsigned char *pos);
/* record position of a record for reordering */
void position(const unsigned char *record);
int info(uint32_t flag);
/**
* @return an upper bound estimate for the number of rows in the table
*/
ha_rows estimate_rows_upper_bound()
{
if (share)
{
drizzled::plugin::InfoSchemaTable *sch_table= share->getInfoSchemaTable();
if (sch_table)
{
if (! sch_table->getRows().empty())
{
/* we multiply by 3 here to ensure enough memory is allocated for sort buffers */
return (3 * sch_table->getRows().size());
}
}
}
return HA_POS_ERROR;
}
};
#endif /* PLUGIN_INFORMATION_ENGINE_INFORMATION_CURSOR_H */
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