THYAutoUpdateService

Overview

The THYAutoUpdateService service implements the basic functionality of an auto update service. Please refere to this article for more information.

Location


 

FileSearchInfo

Stores the list of directories that are used by servers and clients to generate their file lists.

property FileSearchInfo: THYFileSearchInfoCollection read write

GetFileData  protected

Reads data from a file with given parameters.

function GetFileData(const UpdateInfo: THYFileUpdateInfo; const Offset: Integer; const Count: Integer; out Data: Binary): Integer

Parameters:

  • UpdateInfo: Reference to the update info that stores information about file.
  • Offset: Defines starting position.
  • Count: Number of bytes to read.
  • Data: Output data.

GetUpdatesInfo  protected

Scans for a server files and compares them to a client files. Returns an array of items that needs to be updated.

function GetUpdatesInfo(const UpdateID: string; const ClientFiles: THYFileUpdateInfoArray): THYFileUpdateInfoArray

Parameters:

  • UpdateID: User-defined identificator of update.
  • ClientFiles: Array that holds description of a client files.

OnCompareUpdates

This event is invoked when service needs to compare to files. Please note that this event if fired only when UpdateComparisonMethod is set to ucmUserDefined.

property OnCompareUpdates: THYUpdateComparisonEvent read write
delegate: procedure OnCompareUpdates(Sender: TObject; aFileInfo: THYFileUpdateInfo; anUpdate: THYFileUpdateInfo; var FileInfoIsUpToDate: Boolean)

OnGetFileData

Service fires this event when he reads data of a file.

property OnGetFileData: THYGetFileDataEvent read write
delegate: procedure OnGetFileData(Sender: THYAutoUpdateService; FileName: string; Offset: Integer; Count: Integer; ActualData: Binary)

OnGetUpdatesInfo

This event if fired after service finished to process updated info.

property OnGetUpdatesInfo: THYGetUpdatesInfoEvent read write
delegate: procedure OnGetUpdatesInfo(Sender: THYAutoUpdateService; ClientFileList: THYFileUpdateInfoArray; UpdatesList: THYFileUpdateInfoArray)

OnVerifyUpdateStatus

Handle this event to process calls to a VerifyUpdateStatus.

property OnVerifyUpdateStatus: THYVerifyUpdateStatusEvent read write
delegate: procedure OnVerifyUpdateStatus(Sender: THYAutoUpdateService; const LastUpdateID: string; var UpdateStatus: THYUpdateStatus; var CurrentUpdateID: string; var UserData: string)

UpdateComparisonMethod

Gets or sets the method of file comparison.

property UpdateComparisonMethod: THYUpdateComparisonMethod read write

VerifyUpdateStatus  protected

This method can be called to check the update status based on a user-defined identifiers. By default service returns usNeedsUpdate or fires OnVerifyUpdateStatus event.

function VerifyUpdateStatus(const LastUpdateID: string; out CurrentUpdateID: string; out UserData: string): THYUpdateStatus

Parameters:

  • LastUpdateID: User-defined identifier of update on a client side.
  • CurrentUpdateID: User-defined identifier of current update on a server side.
  • UserData: Custom data.

 

FileSearchInfo

Stores the list of directories that are used by servers and clients to generate their file lists.

property FileSearchInfo: THYFileSearchInfoCollection read write

UpdateComparisonMethod

Gets or sets the method of file comparison.

property UpdateComparisonMethod: THYUpdateComparisonMethod read write

 

GetFileData  protected

Reads data from a file with given parameters.

function GetFileData(const UpdateInfo: THYFileUpdateInfo; const Offset: Integer; const Count: Integer; out Data: Binary): Integer

Parameters:

  • UpdateInfo: Reference to the update info that stores information about file.
  • Offset: Defines starting position.
  • Count: Number of bytes to read.
  • Data: Output data.

GetUpdatesInfo  protected

Scans for a server files and compares them to a client files. Returns an array of items that needs to be updated.

function GetUpdatesInfo(const UpdateID: string; const ClientFiles: THYFileUpdateInfoArray): THYFileUpdateInfoArray

Parameters:

  • UpdateID: User-defined identificator of update.
  • ClientFiles: Array that holds description of a client files.

VerifyUpdateStatus  protected

This method can be called to check the update status based on a user-defined identifiers. By default service returns usNeedsUpdate or fires OnVerifyUpdateStatus event.

function VerifyUpdateStatus(const LastUpdateID: string; out CurrentUpdateID: string; out UserData: string): THYUpdateStatus

Parameters:

  • LastUpdateID: User-defined identifier of update on a client side.
  • CurrentUpdateID: User-defined identifier of current update on a server side.
  • UserData: Custom data.

 

OnCompareUpdates

This event is invoked when service needs to compare to files. Please note that this event if fired only when UpdateComparisonMethod is set to ucmUserDefined.

property OnCompareUpdates: THYUpdateComparisonEvent read write
delegate: procedure OnCompareUpdates(Sender: TObject; aFileInfo: THYFileUpdateInfo; anUpdate: THYFileUpdateInfo; var FileInfoIsUpToDate: Boolean)

OnGetFileData

Service fires this event when he reads data of a file.

property OnGetFileData: THYGetFileDataEvent read write
delegate: procedure OnGetFileData(Sender: THYAutoUpdateService; FileName: string; Offset: Integer; Count: Integer; ActualData: Binary)

OnGetUpdatesInfo

This event if fired after service finished to process updated info.

property OnGetUpdatesInfo: THYGetUpdatesInfoEvent read write
delegate: procedure OnGetUpdatesInfo(Sender: THYAutoUpdateService; ClientFileList: THYFileUpdateInfoArray; UpdatesList: THYFileUpdateInfoArray)

OnVerifyUpdateStatus

Handle this event to process calls to a VerifyUpdateStatus.

property OnVerifyUpdateStatus: THYVerifyUpdateStatusEvent read write
delegate: procedure OnVerifyUpdateStatus(Sender: THYAutoUpdateService; const LastUpdateID: string; var UpdateStatus: THYUpdateStatus; var CurrentUpdateID: string; var UserData: string)

 

Implements