ClickHouse/dbms/include/DB/Databases/DatabaseMemory.h
2016-11-09 22:05:35 +03:00

64 lines
1.8 KiB
C++

#pragma once
#include <DB/Databases/IDatabase.h>
namespace DB
{
/** A non-persistent database to store temporary data.
* It doesn't make any manipulations with filesystem.
* All tables are created by calling code.
* TODO: Maybe DatabaseRuntime is more suitable class name.
*/
class DatabaseMemory : public IDatabase
{
protected:
const String name;
mutable std::mutex mutex;
Tables tables;
Logger * log;
public:
DatabaseMemory(const String & name_) : name(name_) {}
String getEngineName() const override { return "Memory"; }
void loadTables(Context & context, ThreadPool * thread_pool, bool has_force_restore_data_flag) override;
bool isTableExist(const String & table_name) const override;
StoragePtr tryGetTable(const String & table_name) override;
DatabaseIteratorPtr getIterator() override;
bool empty() const override;
void createTable(const String & table_name, const StoragePtr & table, const ASTPtr & query, const String & engine) override;
void removeTable(const String & table_name) override;
void attachTable(const String & table_name, const StoragePtr & table) override;
StoragePtr detachTable(const String & table_name) override;
void renameTable(const Context & context, const String & table_name, IDatabase & to_database, const String & to_table_name) override;
time_t getTableMetadataModificationTime(const String & table_name) override;
ASTPtr getCreateQuery(const String & table_name) const override;
void shutdown() override;
void drop() override;
void alterTable(
const Context & context,
const String & name,
const NamesAndTypesList & columns,
const NamesAndTypesList & materialized_columns,
const NamesAndTypesList & alias_columns,
const ColumnDefaults & column_defaults,
const ASTModifier & engine_modifier) override;
};
}