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/* Copyright (C) 2005 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef PLUGIN_INFORMATION_ENGINE_INFORMATION_ENGINE_H
#define PLUGIN_INFORMATION_ENGINE_INFORMATION_ENGINE_H
#include <drizzled/server_includes.h>
#include <mysys/thr_lock.h>
#include <drizzled/plugin/info_schema_table.h>
static const char *information_exts[] = {
NULL
};
class InformationEngine : public drizzled::plugin::StorageEngine
{
public:
InformationEngine(const std::string &name_arg)
: drizzled::plugin::StorageEngine(name_arg,
HTON_ALTER_NOT_SUPPORTED |
HTON_HIDDEN |
HTON_NOT_USER_SELECTABLE |
HTON_TEMPORARY_NOT_SUPPORTED)
{
pthread_mutex_init(&mutex, NULL);
}
~InformationEngine()
{
pthread_mutex_destroy(&mutex);
}
class Share
{
private:
uint32_t count;
drizzled::plugin::InfoSchemaTable *table;
THR_LOCK lock;
public:
Share(const std::string &in_name) :
count(1)
{
thr_lock_init(&lock);
table= drizzled::plugin::InfoSchemaTable::getTable(in_name.c_str());
}
~Share()
{
thr_lock_delete(&lock);
}
/**
* Increment the counter which tracks how many instances of this share are
* currently open.
* @return the new counter value
*/
uint32_t incUseCount(void)
{
return ++count;
}
/**
* Decrement the count which tracks how many instances of this share are
* currently open.
* @return the new counter value
*/
uint32_t decUseCount(void)
{
return --count;
}
/**
* @ return the value of the use counter for this share
*/
uint32_t getUseCount() const
{
return count;
}
/**
* @return the table name associated with this share.
*/
const std::string &getName() const
{
return table->getTableName();
}
/**
* @return the I_S table associated with this share.
*/
drizzled::plugin::InfoSchemaTable *getInfoSchemaTable()
{
return table;
}
};
private:
typedef std::map<const std::string, Share> OpenTables;
typedef std::pair<const std::string, Share> Record;
OpenTables open_tables;
pthread_mutex_t mutex; // Mutext used in getShare() calls
public:
// Follow Two Methods are for "share"
Share *getShare(const std::string &name_arg);
void freeShare(Share *share);
int doCreateTable(Session *,
const char *,
Table&,
HA_CREATE_INFO&,
drizzled::message::Table&)
{
return EPERM;
}
int doDropTable(Session&, const std::string)
{
return EPERM;
}
virtual Cursor *create(TableShare &table, MEM_ROOT *mem_root);
const char **bas_ext() const
{
return information_exts;
}
void doGetTableNames(CachedDirectory&,
std::string &db,
std::set<std::string> &set_of_names);
int doGetTableDefinition(Session &session,
const char *path,
const char *db,
const char *table_name,
const bool is_tmp,
drizzled::message::Table *table_proto);
};
#endif /* PLUGIN_INFORMATION_ENGINE_INFORMATION_ENGINE_H */
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