TDiskPartitioner

Return to Unit Filesystem

Description

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To be documented

Class definitions

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TDiskPartitioner = class(TObject)

constructor Create(ADriver:TFileSysDriver; ARecognizer:TRecognizer);
destructor Destroy; override;
private
FLock:TSynchronizerHandle;
FLocalLock:TMutexHandle;
protected
FDriver:TFileSysDriver;
FRecognizer:TRecognizer;
FInitChar:Byte;	Character to initialize sectors when adding partitions
function AcquireLock:Boolean;
function ReleaseLock:Boolean;
function CheckLogical(ADevice:TDiskDevice; AParent:TDiskPartition; APartitionId:Byte):Boolean; virtual;
function CheckExtended(ADevice:TDiskDevice; AParent:TDiskPartition; APartitionId:Byte):Boolean; virtual;
function GetLogicalChild(ADevice:TDiskDevice; APartition:TDiskPartition; ALock:Boolean; AState:LongWord):TDiskPartition;
function GetExtendedSibling(ADevice:TDiskDevice; AParent:TDiskPartition; ALock:Boolean; AState:LongWord):TDiskPartition;
function GetExtendedParent(ADevice:TDiskDevice; AParent:TDiskPartition; AStart:LongWord; ALock:Boolean; AState:LongWord):TDiskPartition;
function GetEndCHS(ADevice:TDiskDevice; AStart,ACount:LongWord; var ACylinder,AHead,ASector:Word):Boolean; virtual;
function GetStartCHS(ADevice:TDiskDevice; AStart,ACount:LongWord; var ACylinder,AHead,ASector:Word):Boolean; virtual;
function GetSectorCount(ADevice:TDiskDevice; AStart,ACount:LongWord):LongWord; virtual;
function GetStartSector(ADevice:TDiskDevice; AExtended,ALogical:Boolean; AStart:LongWord; var ACount:LongWord):LongWord; virtual;
function GetSectorOffset(ADevice:TDiskDevice; AParent:TDiskPartition; AExtended:Boolean; AStart:LongWord):LongWord; virtual;
function GetPartitionId(ADevice:TDiskDevice; AParent:TDiskPartition; AStart,ACount:LongWord; APartitionId:Byte):Byte; virtual;
function InitPartition(ADevice:TDiskDevice; AParent:TDiskPartition; AStart,ACount:LongWord; APartitionId:Byte):Boolean; virtual;
function CreatePartitionRecord(ADevice:TDiskDevice; ARecord:PPartitionRecord):Boolean;
function CreatePartitionEntry(ADevice:TDiskDevice; AStart,ACount,AOffset:LongWord; APartitionId:Byte; AActive:Boolean; var AEntry:TPartitionEntry):Boolean;
function FillSectors(ADevice:TDiskDevice; APartition:TDiskPartition; ASector,ACount:LongWord; AValue:Byte):Boolean;
function ReadSectors(ADevice:TDiskDevice; APartition:TDiskPartition; ASector,ACount:LongWord; var ABuffer):Boolean;
function WriteSectors(ADevice:TDiskDevice; APartition:TDiskPartition; ASector,ACount:LongWord; const ABuffer):Boolean;
public
property InitChar:Byte read FInitChar write FInitChar;
function ReaderLock:Boolean;
function ReaderUnlock:Boolean;
function WriterLock:Boolean;
function WriterUnlock:Boolean;
function AcceptPartition(ADevice:TDiskDevice; APartition,AParent:TDiskPartition; APartitionId:Byte):Boolean; virtual;
function CreatePartition(ADevice:TDiskDevice; AParent:TDiskPartition; APartitionId:Byte; ACount:LongWord; AActive:Boolean):Boolean; virtual;
function DeletePartition(APartition:TDiskPartition):Boolean; virtual;
function ModifyPartition(APartition:TDiskPartition; APartitionId:Byte; AOverride:Boolean):Boolean; virtual;
function ActivatePartition(APartition:TDiskPartition; AActive:Boolean):Boolean; virtual;

Function declarations

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constructor TDiskPartitioner.Create(ADriver:TFileSysDriver; ARecognizer:TRecognizer);

Description: To be documented

Note	None documented

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destructor TDiskPartitioner.Destroy;

Description: To be documented

Note	None documented

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function TDiskPartitioner.AcquireLock:Boolean;

Description: To be documented

Note	None documented

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function TDiskPartitioner.ReleaseLock:Boolean;

Description: To be documented

Note	None documented

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function TDiskPartitioner.CheckLogical(ADevice:TDiskDevice; AParent:TDiskPartition; APartitionId:Byte):Boolean;

Description: Check if the Partition is of a Logical type

Note	Caller must hold the device and partition lock

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function TDiskPartitioner.CheckExtended(ADevice:TDiskDevice; AParent:TDiskPartition; APartitionId:Byte):Boolean;

Description: Check if the Partition is of an Extended type

Note	Caller must hold the device and partition lock

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function TDiskPartitioner.GetLogicalChild(ADevice:TDiskDevice; APartition:TDiskPartition; ALock:Boolean; AState:LongWord):TDiskPartition;

Description: Get the logical Child for an extended partition based on Parent

Note	Used to find the logical child of a Partition being deleted Caller must hold the device and partition lock

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function TDiskPartitioner.GetExtendedSibling(ADevice:TDiskDevice; AParent:TDiskPartition; ALock:Boolean; AState:LongWord):TDiskPartition;

Description: Get the next Sibling for an extended partition based on Parent

Note	Passed Parent should be the actual Parent Also used to find the next sibling of a Partition being deleted Caller must hold the device and partition lock

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function TDiskPartitioner.GetExtendedParent(ADevice:TDiskDevice; AParent:TDiskPartition; AStart:LongWord; ALock:Boolean; AState:LongWord):TDiskPartition;

Description: Get the actual Parent for an extended partition based on Start sector

Note	Passed Parent should be the Root extended Caller must hold the device and partition lock

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function TDiskPartitioner.GetEndCHS(ADevice:TDiskDevice; AStart,ACount:LongWord; var ACylinder,AHead,ASector:Word):Boolean;

Description: Get the End CHS values or dummy values if larger than 8GB

Note	Start and Count must be Cylinder aligned when passed Caller must hold the device lock

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function TDiskPartitioner.GetStartCHS(ADevice:TDiskDevice; AStart,ACount:LongWord; var ACylinder,AHead,ASector:Word):Boolean;

Description: Get the Start CHS values or dummy values if larger than 8GB

Note	Start and Count must be Cylinder aligned when passed Caller must hold the device lock

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function TDiskPartitioner.GetSectorCount(ADevice:TDiskDevice; AStart,ACount:LongWord):LongWord;

Description: Determine the actual sector Count given an actual Start sector and nominal sector Count

Start	Start must be Cylinder aligned when passed
Note	The actual result will be a Count that is aligned to a Cylinder boundary Caller must hold the device lock

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function TDiskPartitioner.GetStartSector(ADevice:TDiskDevice; AExtended,ALogical:Boolean; AStart:LongWord; var ACount:LongWord):LongWord;

Description: Determine the actual Start sector given a nominal Start sector

Note	The actual result will be a Start that is aligned to a Cylinder boundary For first Partition (not Extended) and Logical the Start is aligned to a Head boundary Caller must hold the device lock

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function TDiskPartitioner.GetSectorOffset(ADevice:TDiskDevice; AParent:TDiskPartition; AExtended:Boolean; AStart:LongWord):LongWord;

Description: Determine the actual sector Offset given an actual Start sector

Start	Start must be Cylinder aligned when passed
Note	Accounts for Offset behaviour of second level extended and logical partitions Caller must hold the device and partition lock

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function TDiskPartitioner.GetPartitionId(ADevice:TDiskDevice; AParent:TDiskPartition; AStart,ACount:LongWord; APartitionId:Byte):Byte;

Description: Determine the actual partition Type given a Start, Count and nominal Type

Note	Caller must hold the device and partition lock

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function TDiskPartitioner.InitPartition(ADevice:TDiskDevice; AParent:TDiskPartition; AStart,ACount:LongWord; APartitionId:Byte):Boolean;

Description: Perform any initialization of a new partition such as filling the boot sector etc

Start	Start is the absolute start sector on the device
Note	Caller must hold the device and partition lock

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function TDiskPartitioner.CreatePartitionRecord(ADevice:TDiskDevice; ARecord:PPartitionRecord):Boolean;

Description: Check for a valid Partition record (or Master Boot Record)

Note	Create an empty Partition record (or Master Boot Record) if not valid Caller must hold the device lock

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function TDiskPartitioner.CreatePartitionEntry(ADevice:TDiskDevice; AStart,ACount,AOffset:LongWord; APartitionId:Byte; AActive:Boolean; var AEntry:TPartitionEntry):Boolean;

Description: Fill the Partitition entry with the supplied values

Note	Caller must hold the device lock

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function TDiskPartitioner.FillSectors(ADevice:TDiskDevice; APartition:TDiskPartition; ASector,ACount:LongWord; AValue:Byte):Boolean;

Description: Fill specified number of sectors with the supplied value

Sector	Sector is relative to the StartSector of the Partition
Note	Caller must hold the device and partition lock

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function TDiskPartitioner.ReadSectors(ADevice:TDiskDevice; APartition:TDiskPartition; ASector,ACount:LongWord; var ABuffer):Boolean;

Description: Read Sectors from the Device or Partition using Cache

Sector	Sector is relative to the StartSector of the Device or Partition
Note	Caller must hold the device and partition lock, cache will serialize access to device.

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function TDiskPartitioner.WriteSectors(ADevice:TDiskDevice; APartition:TDiskPartition; ASector,ACount:LongWord; const ABuffer):Boolean;

Description: Write Sectors to the Device or Partition using Cache

Sector	Sector is relative to the StartSector of the Device or Partition
Note	Caller must hold the device and partition lock, cache will serialize access to device.

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function TDiskPartitioner.ReaderLock:Boolean;

Description: To be documented

Note	None documented

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function TDiskPartitioner.ReaderUnlock:Boolean;

Description: To be documented

Note	None documented

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function TDiskPartitioner.WriterLock:Boolean;

Description: To be documented

Note	None documented

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function TDiskPartitioner.WriterUnlock:Boolean;

Description: To be documented

Note	None documented

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function TDiskPartitioner.AcceptPartition(ADevice:TDiskDevice; APartition,AParent:TDiskPartition; APartitionId:Byte):Boolean;

Description: Check if the Partition can be accepted for Create, Delete, Modify, Activate

Note	Caller must hold the device and partition and parent lock

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function TDiskPartitioner.CreatePartition(ADevice:TDiskDevice; AParent:TDiskPartition; APartitionId:Byte; ACount:LongWord; AActive:Boolean):Boolean;

Description: Create a new Partition on the specified Device with the specified Parent (Optional)

Note	When creating Logical partitions the passed Parent must be the Root Extended Caller must hold the device and parent writer locks

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function TDiskPartitioner.DeletePartition(APartition:TDiskPartition):Boolean;

Description: Delete the specified Partition from the specified Device

Note	Caller must hold the device and partition writer locks

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function TDiskPartitioner.ModifyPartition(APartition:TDiskPartition; APartitionId:Byte; AOverride:Boolean):Boolean;

Description: Modify the type of the specified Partition

Note	Override disables the normalisation of PartitionId to suit size and type and also disables dismount and remount of any volumes and drives etc Caller must hold the partition writer lock

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function TDiskPartitioner.ActivatePartition(APartition:TDiskPartition; AActive:Boolean):Boolean;

Description: Make the specified Partition active and all siblings inactive

Note	Also allows making the specified Partition inactive No need to check for Extended as AcceptPartition does Caller must hold the partition writer lock

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