Package org.yamcs.yarch

Interface StorageEngine

All Known Implementing Classes:

RdbStorageEngine

public interface StorageEngine

Method Summary

Modifier and Type	Method	Description
void	createTable(YarchDatabaseInstance ydb, TableDefinition tblDef)	Create a new table based on definition.
void	dropTable(YarchDatabaseInstance ydb, TableDefinition tblDef)	Drop the table (removing all data)
BucketDatabase	getBucketDatabase(YarchDatabaseInstance yarchDatabaseInstance)
HistogramIterator	getHistogramIterator(YarchDatabaseInstance ydb, TableDefinition tblDef, String columnName, TimeInterval interval)
PartitionManager	getPartitionManager(YarchDatabaseInstance ydb, TableDefinition tblDef)
ProtobufDatabase	getProtobufDatabase(YarchDatabaseInstance ydb)
Sequence	getSequence(YarchDatabaseInstance ydb, String name, boolean create)	Returns a sequence with the given name if it exists or first create it and returns it if create is true.
List<SequenceInfo>	getSequencesInfo(YarchDatabaseInstance ydb)	Gets the list of sequences togehter with their latest values
List<TableDefinition>	loadTables(YarchDatabaseInstance ydb)	Loads the table definitions from the disk for all the tables belonging to the instance.
default void	migrateTableDefinition(YarchDatabaseInstance ydb, TableDefinition tblDef)	In Yamcs version 4 the table definitions were stored in yaml serialized format (in the /storage/yamcs-data/<instance-name>/<table-name>.def)
TableWalker	newSecondaryIndexTableWalker(YarchDatabaseInstance ydb, TableDefinition tableDefinition, boolean ascending, boolean follow)
TableWalker	newTableWalker(ExecutionContext ctx, TableDefinition tblDef, boolean ascending, boolean follow)	Creates a new table iterator.
TableWriter	newTableWriter(YarchDatabaseInstance ydb, TableDefinition tblDef, TableWriter.InsertMode insertMode)	Creates a new table writer
void	renameTable(YarchDatabaseInstance ydb, TableDefinition tblDef, String newName)	rename the table
void	saveTableDefinition(YarchDatabaseInstance ydb, TableDefinition tblDef, List<TableColumnDefinition> keyColumns, List<TableColumnDefinition> valueColumns)	Persist the table definition to diks (called when the table definition modifies)

Method Details

loadTables

List<TableDefinition> loadTables(YarchDatabaseInstance ydb)
                          throws YarchException

Loads the table definitions from the disk for all the tables belonging to the instance.

called at startup.

Parameters:

ydb -

Throws:

YarchException

createTable

void createTable(YarchDatabaseInstance ydb,
 TableDefinition tblDef)
          throws YarchException

Create a new table based on definition.

Parameters:

ydb -

tblDef -

Throws:

YarchException

saveTableDefinition

void saveTableDefinition(YarchDatabaseInstance ydb,
 TableDefinition tblDef,
 List<TableColumnDefinition> keyColumns,
 List<TableColumnDefinition> valueColumns)
                  throws YarchException

Persist the table definition to diks (called when the table definition modifies)

The general table properties should be read from the tblDef argument but the column properties should be read from the extra arguments This is because the method is called with modified column content which is not reflected in the table definition until the data is saved in the database.

Parameters:

ydb -

tblDef -

Throws:

YarchException

dropTable

void dropTable(YarchDatabaseInstance ydb,
 TableDefinition tblDef)
        throws YarchException

Drop the table (removing all data)

Parameters:

ydb -

tblDef -

Throws:

YarchException

newTableWriter

TableWriter newTableWriter(YarchDatabaseInstance ydb,
 TableDefinition tblDef,
 TableWriter.InsertMode insertMode)
                    throws YarchException

Creates a new table writer

Parameters:

ydb -

tblDef -

insertMode -

Returns:

Throws:

YarchException

newTableWalker

TableWalker newTableWalker(ExecutionContext ctx,
 TableDefinition tblDef,
 boolean ascending,
 boolean follow)

Creates a new table iterator.

Parameters:

ctx -

tblDef -

getHistogramIterator

HistogramIterator getHistogramIterator(YarchDatabaseInstance ydb,
 TableDefinition tblDef,
 String columnName,
 TimeInterval interval)
                                throws YarchException

Throws:

YarchException

getBucketDatabase

BucketDatabase getBucketDatabase(YarchDatabaseInstance yarchDatabaseInstance)
                          throws YarchException

Throws:

YarchException

getProtobufDatabase

ProtobufDatabase getProtobufDatabase(YarchDatabaseInstance ydb)
                              throws YarchException

Throws:

YarchException

getPartitionManager

PartitionManager getPartitionManager(YarchDatabaseInstance ydb,
 TableDefinition tblDef)

migrateTableDefinition

default void migrateTableDefinition(YarchDatabaseInstance ydb,
 TableDefinition tblDef)
                             throws YarchException

In Yamcs version 4 the table definitions were stored in yaml serialized format (in the /storage/yamcs-data/<instance-name>/<table-name>.def)

This function is called to migrate them inside the storage engine where they are stored starting with Yamcs 5

Throws:

YarchException

getSequence

Sequence getSequence(YarchDatabaseInstance ydb,
 String name,
 boolean create)
              throws YarchException

Returns a sequence with the given name if it exists or first create it and returns it if create is true.

If create is false and the sequence does not exist, returns null.

Parameters:

name -

create -

Returns:

Throws:

YarchException

newSecondaryIndexTableWalker

TableWalker newSecondaryIndexTableWalker(YarchDatabaseInstance ydb,
 TableDefinition tableDefinition,
 boolean ascending,
 boolean follow)

getSequencesInfo

List<SequenceInfo> getSequencesInfo(YarchDatabaseInstance ydb)

Gets the list of sequences togehter with their latest values

renameTable

void renameTable(YarchDatabaseInstance ydb,
 TableDefinition tblDef,
 String newName)

rename the table