C# Class GSF.IO.FileStructure.Media.DiskIoSession

Provides a data IO session with the disk subsystem to perform basic read and write operations.

Inheritance: IDisposable

Show file Open project: GridProtectionAlliance/openHistorian Class Usage Examples

Public Properties

Property	Type	Description
CachedLookups	long
Lookups	long

Public Methods

Method	Description
Clear ( ) : void
DiskIoSession ( DiskIo diskIo, BinaryStreamIoSessionBase ioSession, FileHeaderBlock header, SubFileHeader file ) : System	Creates a new DiskIoSession that can be used to read from the disk subsystem.
Dispose ( ) : void	Releases all the resources used by the DiskIoSession object.
Read ( uint blockIndex, BlockType blockType, uint indexValue ) : void	Navigates to a block that will be only read and not modified.
ReadOld ( uint blockIndex, BlockType blockType, uint indexValue ) : void	Navigates to a block that will be only read and not modified.
WriteToExistingBlock ( uint blockIndex, BlockType blockType, uint indexValue ) : void	Navigates to a block that will be written to. This block must currently exist and have the correct parameters passed to this function In order to allow this block to be modified.
WriteToNewBlock ( uint blockIndex, BlockType blockType, uint indexValue ) : void	Navigates to a block that will be written to. This class does not check if overwriting an existing block. So be careful not to corrupt the file. This function will increase the size of the file if the block excedes the current size of the file.

Private Methods

Method	Description
ClearFooterData ( ) : void
IsFooterCurrentSnapshotAndValid ( ) : IoReadState
IsFooterValid ( ) : IoReadState
IsFooterValidFromOldBlock ( ) : IoReadState
ReadBlock ( bool requestWriteAccess ) : void	Tries to read data from the following file
WriteFooterData ( ) : void

Method Details

Clear() public method

public Clear ( ) : void
return	void

DiskIoSession() public method

Creates a new DiskIoSession that can be used to read from the disk subsystem.

public DiskIoSession ( DiskIo diskIo, BinaryStreamIoSessionBase ioSession, FileHeaderBlock header, SubFileHeader file ) : System
diskIo	DiskIo	owner of the disk
ioSession	GSF.IO.Unmanaged.BinaryStreamIoSessionBase	the base ioSession to use for this io session
header	FileHeaderBlock
file	SubFileHeader	The file that will be read from this diskIoSession
return	System

Dispose() public method

Releases all the resources used by the DiskIoSession object.

public Dispose ( ) : void
return	void

Read() public method

Navigates to a block that will be only read and not modified.

public Read ( uint blockIndex, BlockType blockType, uint indexValue ) : void
blockIndex	uint
blockType	BlockType	the type of this block.
indexValue	uint	a value put in the footer of the block designating the index of this block
return	void

ReadOld() public method

Navigates to a block that will be only read and not modified.

public ReadOld ( uint blockIndex, BlockType blockType, uint indexValue ) : void
blockIndex	uint
blockType	BlockType	the type of this block.
indexValue	uint	a value put in the footer of the block designating the index of this block
return	void

WriteToExistingBlock() public method

Navigates to a block that will be written to. This block must currently exist and have the correct parameters passed to this function In order to allow this block to be modified.

public WriteToExistingBlock ( uint blockIndex, BlockType blockType, uint indexValue ) : void
blockIndex	uint	the index value of this block
blockType	BlockType	the type of this block.
indexValue	uint	a value put in the footer of the block designating the index of this block
return	void

WriteToNewBlock() public method

Navigates to a block that will be written to. This class does not check if overwriting an existing block. So be careful not to corrupt the file.

This function will increase the size of the file if the block excedes the current size of the file.

public WriteToNewBlock ( uint blockIndex, BlockType blockType, uint indexValue ) : void
blockIndex	uint	the index value of this block
blockType	BlockType	the type of this block.
indexValue	uint	a value put in the footer of the block designating the index of this block
return	void

Property Details

CachedLookups public static property

public static long CachedLookups
return	long

Lookups public static property

public static long Lookups
return	long