org.yamcs.yarch

Class YarchDatabaseInstance

java.lang.Object

org.yamcs.yarch.YarchDatabaseInstance

public class YarchDatabaseInstance
extends Object

Handles tables and streams for one Yamcs Instance Synchronisation policy: to avoid problems with stream disappearing when clients connect to them, all the creation/closing/subscription to streams/tables shall be done while acquiring a lock on the YarchDatabase object. This is done in the StreamSqlStatement.java Delivery of tuples does not require locking, this means subscription can change while delivering (for that a concurrent list is used in Stream.java)

Author:

nm

Field Summary

Fields

Modifier and Type	Field and Description
static String	RDB_ENGINE_NAME

Method Summary

Modifier and Type	Method and Description
void	addStream(AbstractStream stream) Adds a stream to the dictionary making it "official"
void	close()
void	createTable(TableDefinition def) add a table to the dictionary throws exception if a table or a stream with the same name already exist
void	dropTable(String tblName)
StreamSqlResult	execute(String query)
StorageEngine	getDefaultStorageEngine()
String	getDefaultStorageEngineName()
String	getName()
String	getRoot() Returns the root directory for this database instance.
StorageEngine	getStorageEngine(TableDefinition tbldef)
AbstractStream	getStream(String name)
Collection<AbstractStream>	getStreams()
TableDefinition	getTable(String name)
Collection<TableDefinition>	getTableDefinitions()
String	getYamcsInstance()
static boolean	instanceExistsOnDisk(String yamcsInstance)
void	removeStream(String name)
boolean	streamOrTableExists(String name)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

RDB_ENGINE_NAME

public static final String RDB_ENGINE_NAME

See Also:

Constant Field Values

Method Detail

instanceExistsOnDisk

public static boolean instanceExistsOnDisk(String yamcsInstance)

getName

public String getName()

Returns:

the instance name

getYamcsInstance

public String getYamcsInstance()

getDefaultStorageEngineName

public String getDefaultStorageEngineName()

getDefaultStorageEngine

public StorageEngine getDefaultStorageEngine()

createTable

public void createTable(TableDefinition def)
                 throws YarchException

add a table to the dictionary throws exception if a table or a stream with the same name already exist

Parameters:

def - - table definition

Throws:

YarchException - - thrown in case a table or a stream with the same name already exists or if there was an error in creating the table

addStream

public void addStream(AbstractStream stream)
               throws YarchException

Adds a stream to the dictionary making it "official"

Parameters:

stream -

Throws:

YarchException

getTable

public TableDefinition getTable(String name)

streamOrTableExists

public boolean streamOrTableExists(String name)

getStream

public AbstractStream getStream(String name)

dropTable

public void dropTable(String tblName)
               throws YarchException

Throws:

YarchException

removeStream

public void removeStream(String name)

getStorageEngine

public StorageEngine getStorageEngine(TableDefinition tbldef)

getStreams

public Collection<AbstractStream> getStreams()

getTableDefinitions

public Collection<TableDefinition> getTableDefinitions()

getRoot

public String getRoot()

Returns the root directory for this database instance. It is usually home/instance_name.

Returns:

the roor directory for this database instance

execute

public StreamSqlResult execute(String query)
                        throws StreamSqlException,
                               ParseException

Throws:

StreamSqlException

ParseException

close

public void close()