This class is responsible for managing the large, short lived tables produced by CARMA. More...

#include <carma/dbms/TableManager.h>

Public Member Functions
virtual int	createMonitorDataTable (const carma::dbms::MonitorAverageType &averageType, const carma::dbms::MonitorAggregateType &aggType, const unsigned &requiredSpace, std::string &tableName, const std::string &tag)
	create a monitor data table table More...

void	loadConfigurationInformation ()
	(re)load config info regarding partitions from the db this is called by the constructor and can be called periodically after construction to check for configuration changes More...

	TableManager (const bool &persistentConnection=true, DBConfigurator *dbconf=NULL)
	constructor More...

void	updateMonitorIndexTable (const std::string &tableName, const MonitorAverageType &averageType)
	insert the max and min frame counts into the specified row in the volatile tables table. More...

Protected Member Functions
void	closeDBConnection ()
	close the DBConnection More...

void	closeDBConnectionIfNecessary ()
	close the db connection and delete the db connection object if !persistentConnection_ More...

void	dropTable (const std::string &tableName) const
	removes a table from the db and removes its entry in MONITOR_INDEX_TABLE Callers from this class must already have opened a DBConnection More...

virtual int	getAvailablePartition (const int &requiredSpace, const bool &connectionIsOpen)
	find a partition on which a new table can be created. More...

std::map< int, Partition >	getEmptyPartitions (const bool &connectionIsOpen)
	get the partitions which do not have any volatile tables on them This method queries the database to determine this; it does not interrogate the filesystem the returned map has partition IDs as its keys and Partition objects as its values More...

unsigned	getFreeMB (const std::string &partition) const
	get the available space (for normal users) in MB of the specified partition More...

unsigned	getTotalMB (const std::string &partition) const
	get the total (used+free) size, in megabytes, of the specified partition More...

void	openDBConnectionIfNecessary ()
	open a connection to the database if one is not currently established More...

Protected Attributes
carma::dbms::DBConnection *	dbc_

DBConfigurator *	dbconf_

std::map< int, Partition >	partitions_

bool	persistentConnection_

std::string	rdbms_

bool	useProductionDB_

Static Protected Attributes
static int	minimumCorrelRetentionFrames_

static int	minimumFrameRetentionFrames_

static int	minimumMinuteRetentionFrames_

Detailed Description

This class is responsible for managing the large, short lived tables produced by CARMA.

Examples of such tables are the monitor data tables and the log tables. All requests to create new tables therefore must be submitted via this class. An object of this class maintains a map of partitions where tables can be located. Once partitions fill up, this class will drop old tables as it receives create table requests.

Todo:: it would be nice to have paritition/minimum space info in a config file, rather than hardcoded in the header file, which is read as necessary (ie, without having to restart the app should this file be updated).

Definition at line 34 of file TableManager.h.

Constructor & Destructor Documentation

carma::dbms::TableManager::TableManager	(	const bool &	persistentConnection = `true`,
		DBConfigurator *	dbconf = `NULL`
	)

constructor

Parameters

persistentConnection	maintain a persistent connection to the db for the life of this object?
dbconf	DBConfigurator object used to configure the DBConnection objects this class creates. To guard against the caller deleting this pointer after a TableManager has been created, this constructor creates a copy of the dbconf object which is pointed to

Exceptions

DBConnectionException

Member Function Documentation

void carma::dbms::TableManager::closeDBConnection ( )

protected

close the DBConnection

void carma::dbms::TableManager::closeDBConnectionIfNecessary ( )

protected

close the db connection and delete the db connection object if !persistentConnection_

virtual int carma::dbms::TableManager::createMonitorDataTable	(	const carma::dbms::MonitorAverageType &	averageType,
		const carma::dbms::MonitorAggregateType &	aggType,
		const unsigned &	requiredSpace,
		std::string &	tableName,
		const std::string &	tag
	)

virtual

create a monitor data table table

Parameters

averageType	[in] averageType the average type of the table
aggType	[in] dataType the type of data that will be loaded into the table
requiredSpace	[in] requiredSpace the space required for the table, in MB
tableName	[out] tableName the name of the created table which will have the tag parameter at the end
tag	[in] tag string to append to the end of the table base name to assure that the table name is unique

Returns: the partition ID of the partition on which the table was created or < 0 if the table couldn't be created

Exceptions

DBConnectionException

void carma::dbms::TableManager::dropTable ( const std::string & tableName ) const

protected

removes a table from the db and removes its entry in MONITOR_INDEX_TABLE Callers from this class must already have opened a DBConnection

Parameters

tableName the table to be removed

Exceptions

DBConnectionException

virtual int carma::dbms::TableManager::getAvailablePartition	(	const int &	requiredSpace,
		const bool &	connectionIsOpen
	)

protectedvirtual

find a partition on which a new table can be created.

This method will delete tables to free up the specified amount of disk space if necessary. The target partition will be the partition with the oldest table which contains at least the required amount of space when empty

Parameters

requiredSpace	the amount of space (in MB) above the minimum allowed space that must be made available
connectionIsOpen	the caller (a method from this class) has already opened the connection to the database

Returns: partition ID for the partition on which the table should be created

Exceptions

TableManagerException if no available partition can be found

std::map<int, Partition> carma::dbms::TableManager::getEmptyPartitions ( const bool & connectionIsOpen )

protected

get the partitions which do not have any volatile tables on them This method queries the database to determine this; it does not interrogate the filesystem the returned map has partition IDs as its keys and Partition objects as its values

Parameters

connectionIsOpen the caller (a method from this class) has already opened the connection to the database

Returns: map of partitionIDs -> partition objects for partitions with no volatile tables on them

unsigned carma::dbms::TableManager::getFreeMB ( const std::string & partition ) const

protected

get the available space (for normal users) in MB of the specified partition

Parameters

partition the partition for which to get the available space

Returns: available space, in MB

unsigned carma::dbms::TableManager::getTotalMB ( const std::string & partition ) const

protected

get the total (used+free) size, in megabytes, of the specified partition

Parameters

partition the partition for which to get the total size

Returns: the total partition size in megabytes

void carma::dbms::TableManager::loadConfigurationInformation ( )

(re)load config info regarding partitions from the db this is called by the constructor and can be called periodically after construction to check for configuration changes

Exceptions

DBConnectionException

void carma::dbms::TableManager::openDBConnectionIfNecessary ( )

protected

open a connection to the database if one is not currently established

Exceptions

DBConnectionException