Bz2 Delphi DLL Reference Documentation
Bz2
Current Version: 11.1.0
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;
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.
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
procedure CkBz2_putAbortCurrent(objHandle: HCkBz2; newPropVal: wordbool); stdcall;
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_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.
HeartbeatMs
procedure CkBz2_putHeartbeatMs(objHandle: HCkBz2; newPropVal: Integer); stdcall;
The interval in milliseconds between each AbortCheck
event callback, which enables an application to abort certain method calls before they complete. By default, HeartbeatMs is set to 0
, meaning no AbortCheck event callbacks will trigger.
LastErrorHtml
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.
topLastErrorText
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.
LastErrorXml
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.
topLastMethodSuccess
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
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
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.
Methods
CompressBd
BZ2 compress the contents of bd. After compression, the bd contains the binary content of a .bz2 file, which is slightly different than simple BZIP2 compressed data because a .bz2
file contains:
- Header
- Compressed blocks
- End-of-stream trailer
Returns True for success, False for failure.
topCompressBdAsync (1)
Creates an asynchronous task to call the CompressBd 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
CompressFile
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.
CompressFileAsync (1)
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
LoadTaskCaller
UncompressBd
BZ2 uncompress the contents of bd, which initially should contain the bytes of a .bz2 file. After uncompressing, the bd contains the original uncompressed content.
Returns True for success, False for failure.
topUncompressBdAsync (1)
Creates an asynchronous task to call the UncompressBd 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
UncompressFile
inFilename: PWideChar;
toPath: PWideChar): wordbool; stdcall;
UncompressFileAsync (1)
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
Events
AbortCheck
Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs
property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second. Return True
to abort; return False
to continue (not abort)
PercentDone
This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pctDone argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pctDone equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).
The PercentDone callback also acts as an AbortCheck
event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.
Return True
to abort; return False
to continue (not abort)
ProgressInfo
This event callback provides tag name
/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.
TaskCompleted
Called from the background thread when an asynchronous task completes.
Deprecated
CompressFileToMem Deprecated
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.
topCompressFileToMemAsync Deprecated (1)
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 Deprecated
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.
topCompressMemoryAsync Deprecated (1)
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 Deprecated
inData: HCkByteData;
toPath: PWideChar): wordbool; stdcall;
BZip2 compresses and creates a .bz2 file from in-memory data.
Returns True for success, False for failure.
topCompressMemToFileAsync Deprecated (1)
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
UncompressFileToMem Deprecated
inFilename: PWideChar;
outBytes: HCkByteData): wordbool; stdcall;
UncompressFileToMemAsync Deprecated (1)
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 Deprecated
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.
topUncompressMemoryAsync Deprecated (1)
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 Deprecated
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.
topUncompressMemToFileAsync Deprecated (1)
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