Bz2 Delphi DLL Reference Documentation
Bz2
Current Version: 10.1.0
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.)
topDebugLogFilePath
procedure CkBz2_putDebugLogFilePath(objHandle: HCkBz2; newPropVal: PWideChar); stdcall;
function CkBz2__debugLogFilePath(objHandle: HCkBz2): PWideChar; stdcall;
If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.
This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:
- a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
- the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
- there is an internal problem (bug) in the Chilkat code that causes the hang.
See the notes about PWideChar memory ownership and validity.
HeartbeatMs
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.
topLastErrorHtml
function CkBz2__lastErrorHtml(objHandle: HCkBz2): PWideChar; stdcall;
Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.
See the notes about PWideChar memory ownership and validity.
topLastErrorText
function CkBz2__lastErrorText(objHandle: HCkBz2): PWideChar; stdcall;
Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.
See the notes about PWideChar memory ownership and validity.
LastErrorXml
function CkBz2__lastErrorXml(objHandle: HCkBz2): PWideChar; stdcall;
Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.
See the notes about PWideChar memory ownership and validity.
topLastMethodSuccess
procedure CkBz2_putLastMethodSuccess(objHandle: HCkBz2; newPropVal: wordbool); stdcall;
Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:
- Any method that returns a string.
- Any method returning a Chilkat object, binary bytes, or a date/time.
- Any method returning a standard boolean status value where success = True and failure = False.
- Any method returning an integer where failure is defined by a return value less than zero.
Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.
topVerboseLogging
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.
topVersion
function CkBz2__version(objHandle: HCkBz2): PWideChar; stdcall;
Version of the component/library, such as "9.5.0.94"
See the notes about PWideChar memory ownership and validity.
Methods
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. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topCompressFileToMem
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 (1)
Creates an asynchronous task to call the CompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topCompressMemory
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 (1)
Creates an asynchronous task to call the CompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topCompressMemToFile
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 (1)
inData: HCkByteData;
toPath: PWideChar): HCkTask; stdcall;
Creates an asynchronous task to call the CompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topLoadTaskCaller
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. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topUncompressFileToMem
inFilename: PWideChar;
outBytes: HCkByteData): wordbool; stdcall;
UncompressFileToMemAsync (1)
inFilename: PWideChar): HCkTask; stdcall;
Creates an asynchronous task to call the UncompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topUncompressMemory
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 (1)
Creates an asynchronous task to call the UncompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topUncompressMemToFile
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 (1)
inData: HCkByteData;
toPath: PWideChar): HCkTask; stdcall;
Creates an asynchronous task to call the UncompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)
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
topEvents
Chilkat supports event callbacks for the Delphi DLL starting in version 9.5.0.82.
AbortCheck
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)
PercentDone
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)
ProgressInfo
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.
TaskCompleted
Called in the background thread when an asynchronous task completes.