C# Class GSF.IO.FileStructure.IndexParser

This class provides passthrough properties for the IndexMapper class as well follows the directions of the Index Mapper to find the data cluster that contains the point in question.

Inheritance: IndexMapper

Show file Open project: GridProtectionAlliance/openHistorian Class Usage Examples

Protected Properties

Property	Type	Description
DataClusterAddress	uint
FirstIndirectBlockAddress	uint
FourthIndirectBlockAddress	uint
SecondIndirectBlockAddress	uint
ThirdIndirectBlockAddress	uint

Public Methods

Method	Description
ClearIndexCache ( IndexParser mostRecentParser ) : void	Resets the index cache with the information from the supplied mostRecentParser
IndexParser ( SubFileDiskIoSessionPool ioSessions ) : GSF.IO.FileStructure.Media	Creates a new instance of this class.
SetPositionAndLookup ( uint positionIndex ) : void	Determines if the current sector contains the position passed. If not, it updates the current sector to the one that contains the passed position.
VirtualToPhysical ( uint positionIndex ) : uint	This function will also call IndexMapper.MapPosition so after it returns, the current block data will be updated.

Private Methods

Method	Description
GetBlockIndexValue ( uint blockIndex, int offset, BlockType blockType, uint blockBaseIndex ) : uint	This uses the (blockIndex,offset) values to determine what the next block index is. This also has consistency checks to determine if the file is inconsistent (potentially corruption)
UpdateBlockInformation ( ) : void	Looks up the physical/virtual block positions for the address given.

Method Details

ClearIndexCache() public method

Resets the index cache with the information from the supplied mostRecentParser

public ClearIndexCache ( IndexParser mostRecentParser ) : void
mostRecentParser	IndexParser
return	void

IndexParser() public method

Creates a new instance of this class.

public IndexParser ( SubFileDiskIoSessionPool ioSessions ) : GSF.IO.FileStructure.Media
ioSessions	SubFileDiskIoSessionPool	IoSessions to use to read from this disk
return	GSF.IO.FileStructure.Media

SetPositionAndLookup() public method

Determines if the current sector contains the position passed. If not, it updates the current sector to the one that contains the passed position.

public SetPositionAndLookup ( uint positionIndex ) : void
positionIndex	uint	The position to navigate to indexed to the block data block size.
return	void

VirtualToPhysical() public method

This function will also call IndexMapper.MapPosition so after it returns, the current block data will be updated.

public VirtualToPhysical ( uint positionIndex ) : uint
positionIndex	uint	The virtual index address.
return	uint

Property Details

DataClusterAddress protected property

The address of the first block of the data cluster.

protected uint DataClusterAddress
return	uint

FirstIndirectBlockAddress protected property

The address of the first indirect block

protected uint FirstIndirectBlockAddress
return	uint

FourthIndirectBlockAddress protected property

The address of the third indirect block

protected uint FourthIndirectBlockAddress
return	uint

SecondIndirectBlockAddress protected property

The address of the second indirect block

protected uint SecondIndirectBlockAddress
return	uint

ThirdIndirectBlockAddress protected property

The address of the third indirect block

protected uint ThirdIndirectBlockAddress
return	uint