Bz2 Xojo Plugin 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.

Object Creation

Dim bz2 As New Chilkat.Bz2

Properties

AbortCurrent

AbortCurrent As Boolean

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

DebugLogFilePath As String

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.

More Information and Examples

Example showing how to use DebugLogFilePath.

HeartbeatMs

HeartbeatMs As Int32

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

LastErrorHtml As String (read-only)

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.

LastErrorText

LastErrorText As String (read-only)

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.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

LastErrorXml As String (read-only)

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.

LastMethodSuccess

LastMethodSuccess As Boolean

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

VerboseLogging As Boolean

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

Version As String (read-only)

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

More Information and Examples

How to get the Chilkat version at runtime.

Methods

CompressFile

Function CompressFile(inFilename As String, toPath As String) As Boolean

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 CompressFileAsync(inFilename As String, toPath As String) As Chilkat.Task

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 CompressFileToMem(inFilename As String) As MemoryBlock

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

Returns Nil on failure

CompressFileToMemAsync ⁽¹⁾

Function CompressFileToMemAsync(inFilename As String) As Chilkat.Task

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 CompressMemory(inData As MemoryBlock) As MemoryBlock

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

Returns Nil on failure

CompressMemoryAsync ⁽¹⁾

Function CompressMemoryAsync(inData As MemoryBlock) As Chilkat.Task

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 CompressMemToFile(inData As MemoryBlock, toPath As String) As Boolean

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

Returns True for success, False for failure.

CompressMemToFileAsync ⁽¹⁾

Function CompressMemToFileAsync(inData As MemoryBlock, toPath As String) As Chilkat.Task

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 LoadTaskCaller(task As Chilkat.Task) As Boolean

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 UncompressFile(inFilename As String, toPath As String) As Boolean

Unzips a .bz2 file.

Returns True for success, False for failure.

UncompressFileAsync ⁽¹⁾

Function UncompressFileAsync(inFilename As String, toPath As String) As Chilkat.Task

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 UncompressFileToMem(inFilename As String) As MemoryBlock

Unzips a .bz2 file directly to memory.

Returns Nil on failure

UncompressFileToMemAsync ⁽¹⁾

Function UncompressFileToMemAsync(inFilename As String) As Chilkat.Task

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 UncompressMemory(inData As MemoryBlock) As MemoryBlock

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

Returns Nil on failure

UncompressMemoryAsync ⁽¹⁾

Function UncompressMemoryAsync(inData As MemoryBlock) As Chilkat.Task

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 UncompressMemToFile(inData As MemoryBlock, toPath As String) As Boolean

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

Returns True for success, False for failure.

UncompressMemToFileAsync ⁽¹⁾

Function UncompressMemToFileAsync(inData As MemoryBlock, toPath As String) As Chilkat.Task

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

To implement events, your application would define and implement a class that is a subclass of Chilkat.Bz2. Your custom class would implement (i.e. override) some or all of the event methods.

For example:

class MyBz2
    Inherits Chilkat.Bz2

    Function AbortCheck() As Boolean

    Function PercentDone(pctDone As Int32) As Boolean

    Sub ProgressInfo(name As String, value As String)

    Sub TaskCompleted(task As Chilkat.Task)


End Class

AbortCheck

Function AbortCheck() As Boolean

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.

PercentDone

Function PercentDone(pctDone As Int32) As Boolean

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.

The abort output argument provides a means for aborting the operation. Setting it to True will cause the method to abort and return a failed status (or whatever return value indicates failure).

ProgressInfo

Sub ProgressInfo(name As String, value As String)

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

Sub TaskCompleted(task As Chilkat.Task)

Called in the background thread when an asynchronous task completes.

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