Bz2 Delphi DLL Reference Documentation

Bz2

Current Version: 10.1.0

Requires Chilkat Bundle License

Provides the ability to create and unzip .bz2 compressed files using the BZip2 compression algorithm.

Create/Dispose

var
myObject: HCkBz2;

begin
myObject := CkBz2_Create();

// ...

CkBz2_Dispose(myObject);
end;

function CkBz2_Create: HCkBz2; stdcall;

Creates an instance of the HCkBz2 object and returns a handle (i.e. a Pointer). The handle is passed in the 1st argument for the functions listed on this page.

procedure CkBz2_Dispose(handle: HCkBz2); stdcall;

Objects created by calling CkBz2_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function.

Properties

AbortCurrent

function CkBz2_getAbortCurrent(objHandle: HCkBz2): wordbool; stdcall;
procedure CkBz2_putAbortCurrent(objHandle: HCkBz2; newPropVal: wordbool); stdcall;

Introduced in version 9.5.0.58

When set to True, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to False when the next method is called. When the abort occurs, this property is reset to False. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

DebugLogFilePath

procedure CkBz2_getDebugLogFilePath(objHandle: HCkBz2; outPropVal: HCkString); stdcall;
procedure CkBz2_putDebugLogFilePath(objHandle: HCkBz2; newPropVal: PWideChar); stdcall;
function CkBz2__debugLogFilePath(objHandle: HCkBz2): PWideChar; stdcall;

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

A timeout property set to 0, indicating an infinite timeout.
A hang occurring within an event callback in the application code.
An internal bug in the Chilkat code causing the hang.

See the notes about PWideChar memory ownership and validity.

More Information and Examples

Example showing how to use DebugLogFilePath.

HeartbeatMs

function CkBz2_getHeartbeatMs(objHandle: HCkBz2): Integer; stdcall;
procedure CkBz2_putHeartbeatMs(objHandle: HCkBz2; newPropVal: Integer); stdcall;

This is the number of milliseconds between each AbortCheck event callback. The AbortCheck callback allows an application to abort any compress or decompress operation prior to completion. If HeartbeatMs is 0, no AbortCheck event callbacks will occur.

LastErrorHtml

procedure CkBz2_getLastErrorHtml(objHandle: HCkBz2; outPropVal: HCkString); stdcall;
function CkBz2__lastErrorHtml(objHandle: HCkBz2): PWideChar; stdcall;

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

See the notes about PWideChar memory ownership and validity.

LastErrorText

procedure CkBz2_getLastErrorText(objHandle: HCkBz2; outPropVal: HCkString); stdcall;
function CkBz2__lastErrorText(objHandle: HCkBz2): PWideChar; stdcall;

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

See the notes about PWideChar memory ownership and validity.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

procedure CkBz2_getLastErrorXml(objHandle: HCkBz2; outPropVal: HCkString); stdcall;
function CkBz2__lastErrorXml(objHandle: HCkBz2): PWideChar; stdcall;

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

See the notes about PWideChar memory ownership and validity.

LastMethodSuccess

function CkBz2_getLastMethodSuccess(objHandle: HCkBz2): wordbool; stdcall;
procedure CkBz2_putLastMethodSuccess(objHandle: HCkBz2; newPropVal: wordbool); stdcall;

Indicates the success or failure of the most recent method call: True means success, False means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages.

VerboseLogging

function CkBz2_getVerboseLogging(objHandle: HCkBz2): wordbool; stdcall;
procedure CkBz2_putVerboseLogging(objHandle: HCkBz2; newPropVal: wordbool); stdcall;

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version

procedure CkBz2_getVersion(objHandle: HCkBz2; outPropVal: HCkString); stdcall;
function CkBz2__version(objHandle: HCkBz2): PWideChar; stdcall;

Version of the component/library, such as "10.1.0"

See the notes about PWideChar memory ownership and validity.

More Information and Examples

How to get the Chilkat version at runtime.

Methods

CompressFile

function CkBz2_CompressFile(objHandle: HCkBz2;
inFilename: PWideChar;
toPath: PWideChar): wordbool; stdcall;

Compresses a file to create a BZip2 compressed file (.bz2).

Note: Both inFilename and toPath should be relative or absolute file paths (not just a path to a directory). For example "someDir1/someDir2/myFile.txt" or "c:/someDir1/myFile.bz2".

Returns True for success, False for failure.

More Information and Examples

bz2 Compress File

CompressFileAsync ⁽¹⁾

function CkBz2_CompressFileAsync(objHandle: HCkBz2;
inFilename: PWideChar;
toPath: PWideChar): HCkTask; stdcall;

Creates an asynchronous task to call the CompressFile method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

CompressFileToMem

function CkBz2_CompressFileToMem(objHandle: HCkBz2;
inFilename: PWideChar;
outBytes: HCkByteData): wordbool; stdcall;

BZip2 compresses a file to an in-memory image of a .bz2 file.

Returns True for success, False for failure.

CompressFileToMemAsync ⁽¹⁾

function CkBz2_CompressFileToMemAsync(objHandle: HCkBz2;
inFilename: PWideChar): HCkTask; stdcall;

Creates an asynchronous task to call the CompressFileToMem method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

CompressMemory

function CkBz2_CompressMemory(objHandle: HCkBz2;
inData: HCkByteData;
outBytes: HCkByteData): wordbool; stdcall;

Compresses in-memory data to an in-memory image of a .bz2 file.

Returns True for success, False for failure.

CompressMemoryAsync ⁽¹⁾

function CkBz2_CompressMemoryAsync(objHandle: HCkBz2;
inData: HCkByteData): HCkTask; stdcall;

Creates an asynchronous task to call the CompressMemory method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

CompressMemToFile

function CkBz2_CompressMemToFile(objHandle: HCkBz2;
inData: HCkByteData;
toPath: PWideChar): wordbool; stdcall;

BZip2 compresses and creates a .bz2 file from in-memory data.

Returns True for success, False for failure.

CompressMemToFileAsync ⁽¹⁾

function CkBz2_CompressMemToFileAsync(objHandle: HCkBz2;
inData: HCkByteData;
toPath: PWideChar): HCkTask; stdcall;

Creates an asynchronous task to call the CompressMemToFile method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

LoadTaskCaller

function CkBz2_LoadTaskCaller(objHandle: HCkBz2;
task: HCkTask): wordbool; stdcall;

Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns True for success, False for failure.

UncompressFile

function CkBz2_UncompressFile(objHandle: HCkBz2;
inFilename: PWideChar;
toPath: PWideChar): wordbool; stdcall;

Unzips a .bz2 file.

Returns True for success, False for failure.

UncompressFileAsync ⁽¹⁾

function CkBz2_UncompressFileAsync(objHandle: HCkBz2;
inFilename: PWideChar;
toPath: PWideChar): HCkTask; stdcall;

Creates an asynchronous task to call the UncompressFile method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

UncompressFileToMem

function CkBz2_UncompressFileToMem(objHandle: HCkBz2;
inFilename: PWideChar;
outBytes: HCkByteData): wordbool; stdcall;

Unzips a .bz2 file directly to memory.

Returns True for success, False for failure.

UncompressFileToMemAsync ⁽¹⁾

function CkBz2_UncompressFileToMemAsync(objHandle: HCkBz2;
inFilename: PWideChar): HCkTask; stdcall;

Creates an asynchronous task to call the UncompressFileToMem method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

UncompressMemory

function CkBz2_UncompressMemory(objHandle: HCkBz2;
inData: HCkByteData;
outBytes: HCkByteData): wordbool; stdcall;

Unzips from an in-memory image of a .bz2 file directly into memory.

Returns True for success, False for failure.

UncompressMemoryAsync ⁽¹⁾

function CkBz2_UncompressMemoryAsync(objHandle: HCkBz2;
inData: HCkByteData): HCkTask; stdcall;

Creates an asynchronous task to call the UncompressMemory method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

UncompressMemToFile

function CkBz2_UncompressMemToFile(objHandle: HCkBz2;
inData: HCkByteData;
toPath: PWideChar): wordbool; stdcall;

Unzips from an in-memory image of a .bz2 file to a file.

Returns True for success, False for failure.

UncompressMemToFileAsync ⁽¹⁾

function CkBz2_UncompressMemToFileAsync(objHandle: HCkBz2;
inData: HCkByteData;
toPath: PWideChar): HCkTask; stdcall;

Creates an asynchronous task to call the UncompressMemToFile method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

Events

AbortCheck

function MyAbortCheck(): Integer; cdecl;

Introduced in version 9.5.0.82

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200. Return True to abort; return False to continue (not abort)

More Information and Examples

Delphi DLL AbortCheck Event Callback Example

PercentDone

function MyPercentDone(pctDone: Integer): Integer; cdecl;

Introduced in version 9.5.0.82

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

Return True to abort; return False to continue (not abort)

More Information and Examples

Delphi DLL PercentDone Event Callback Example

ProgressInfo

procedure MyProgressInfo(name: PWideChar; value: PWideChar) cdecl;

Introduced in version 9.5.0.82

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

More Information and Examples

Delphi DLL ProgressInfo Event Callback Example

TaskCompleted

procedure MyTaskCompleted(task: HCkTask) cdecl;

Introduced in version 9.5.0.82

Called in the background thread when an asynchronous task completes.

More Information and Examples

Delphi DLL TaskCompleted Event Callback Example

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