Bz2 Tcl Reference Documentation

Bz2

Current Version: 11.5.0

Requires Chilkat Bundle License

Chilkat.Bz2 provides BZip2 compression and decompression for files, memory buffers, and BinData. It can create standard .bz2 file images, decompress .bz2 content back to its original bytes, and support abortable long-running operations.

For an extended overview, see Bz2 Class Overview

Object Creation

# 'this' is not a keyword in Tcl. It can freely be used as a variable name.
set this [new CkBz2]

Properties

AbortCurrent

boolean 1/0
set boolVal [CkBz2_get_AbortCurrent $this]
CkBz2_put_AbortCurrent $this $boolVal

Introduced in version 9.5.0.58

Set this property to 1 to request cancellation of the compression or decompression operation currently executing on this object. Long-running operations check the request periodically; an operation that finishes quickly may complete before the request is observed.

A synchronous call can be cancelled by setting this property from another thread. After cancellation is processed, Chilkat resets the property to 0. If no operation is running, a previously set value is cleared when the next method begins.

Cancellation is cooperative: Setting this property requests an abort; it does not guarantee immediate termination. Check the method's return value and LastErrorText to determine the final outcome.

DebugLogFilePath

string
# ckStr is a CkString
CkBz2_get_DebugLogFilePath $this $ckStr
set strVal [CkBz2_get_debugLogFilePath $this]
CkBz2_put_DebugLogFilePath $this $strVal

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.

LastErrorHtml

string
# ckStr is a CkString
CkBz2_get_LastErrorHtml $this $ckStr
set strVal [CkBz2_get_lastErrorHtml $this]

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

string
# ckStr is a CkString
CkBz2_get_LastErrorText $this $ckStr
set strVal [CkBz2_get_lastErrorText $this]

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

string
# ckStr is a CkString
CkBz2_get_LastErrorXml $this $ckStr
set strVal [CkBz2_get_lastErrorXml $this]

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

boolean 1/0
set boolVal [CkBz2_get_LastMethodSuccess $this]
CkBz2_put_LastMethodSuccess $this $boolVal

Indicates the success or failure of the most recent method call: 1 means success, 0 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. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

Utf8

boolean 1/0
set boolVal [CkBz2_get_Utf8 $this]
CkBz2_put_Utf8 $this $boolVal

When set to 1, all string arguments and return values are interpreted as UTF-8 strings. When set to 0, they are interpreted as ANSI strings.

In Chilkat v11.0.0 and later, the default value is 1. Before v11.0.0, it was 0.

More Information and Examples

Strings in TCL: Encoding, UTF-8, and Source File Format Considerations

VerboseLogging

boolean 1/0
set boolVal [CkBz2_get_VerboseLogging $this]
CkBz2_put_VerboseLogging $this $boolVal

If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version

string
# ckStr is a CkString
CkBz2_get_Version $this $ckStr
set strVal [CkBz2_get_version $this]

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

More Information and Examples

How to get the Chilkat version at runtime.

Methods

CompressBd

# bd is a CkBinData
set status [CkBz2_CompressBd $this $bd]

Introduced in version 11.0.0

Compresses the current contents of bd in place. On success, the BinData no longer contains the original bytes; it contains the complete standard BZip2 stream that may be saved with a .bz2 extension.

In-place transformation: Preserve a copy of the original data if it is still needed after this call. A BZip2 stream contains a stream header, one or more compressed blocks with integrity checks, and an end-of-stream marker. It does not contain archive filenames or directory entries.

Returns 1 for success, 0 for failure.

CompressBdAsync ⁽¹⁾

# returns a CkTask
# bd is a CkBinData
set ret_task [CkBz2_CompressBdAsync $this $bd]

Introduced in version 11.0.0

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

Returns NULL on failure

CompressFile

# inFilename is a string
# toPath is a string
set status [CkBz2_CompressFile $this $inFilename $toPath]

Reads the file at inFilename and writes its compressed bytes as a standard BZip2 stream to the file at toPath. The output is conventionally given a .bz2 extension.

Both arguments must identify files, not directories. They may be absolute or relative paths, for example data/report.txt and data/report.txt.bz2.

BZip2 is a compressor, not an archive format: A .bz2 file represents one compressed byte stream. It does not store the original filename, directory path, timestamps, permissions, or multiple archive entries. Formats such as .tar.bz2 first combine files in a TAR archive and then compress that TAR stream with BZip2.

Returns 1 for success, 0 for failure.

More Information and Examples

bz2 Compress File

CompressFileAsync ⁽¹⁾

# returns a CkTask
# inFilename is a string
# toPath is a string
set ret_task [CkBz2_CompressFileAsync $this $inFilename $toPath]

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

Returns NULL on failure

LoadTaskCaller

# task is a CkTask
set status [CkBz2_LoadTaskCaller $this $task]

Introduced in version 9.5.0.80

Loads this Bz2 object with the caller state associated with the asynchronous operation represented by task.

Advanced async infrastructure: This method is used to recover the original caller object associated with a completed task. It is not normally needed by application code. Pass a Task created by a compatible Bz2 asynchronous method; an unrelated task cannot be loaded.

Returns 1 for success, 0 for failure.

UncompressBd

# bd is a CkBinData
set status [CkBz2_UncompressBd $this $bd]

Introduced in version 11.0.0

Decompresses the BZip2 stream currently contained in bd in place. On success, the BinData is replaced with the original uncompressed bytes.

Input requirement: bd must contain a complete, valid BZip2 stream, such as the bytes of a .bz2 file or the output of CompressBd. This method operates on binary data and does not perform character-set conversion.

Returns 1 for success, 0 for failure.

UncompressBdAsync ⁽¹⁾

# returns a CkTask
# bd is a CkBinData
set ret_task [CkBz2_UncompressBdAsync $this $bd]

Introduced in version 11.0.0

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

Returns NULL on failure

UncompressFile

# inFilename is a string
# toPath is a string
set status [CkBz2_UncompressFile $this $inFilename $toPath]

Reads the BZip2 stream from the file at inFilename, decompresses it, and writes the original uncompressed bytes to the file at toPath.

Both arguments must identify files, not directories. Chilkat does not derive the destination name from the .bz2 filename because the BZip2 stream does not contain the original filename.

Terminology: This method decompresses BZip2 data; it does not “unzip” a ZIP archive. A .bz2 file normally contains a single compressed byte stream rather than a collection of named files.

Returns 1 for success, 0 for failure.

UncompressFileAsync ⁽¹⁾

# returns a CkTask
# inFilename is a string
# toPath is a string
set ret_task [CkBz2_UncompressFileAsync $this $inFilename $toPath]

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

Returns NULL on failure

Deprecated

CompressFileToMem Deprecated

# inFilename is a string
# outBytes is a CkByteData (output)
set status [CkBz2_CompressFileToMem $this $inFilename $outData]

Reads the file at inFilename, compresses it with BZip2, and returns the complete .bz2 byte stream in memory.

Returns 1 for success, 0 for failure.

CompressFileToMemAsync Deprecated ⁽¹⁾

# returns a CkTask
# inFilename is a string
set ret_task [CkBz2_CompressFileToMemAsync $this $inFilename]

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

Returns NULL on failure

CompressMemory Deprecated

# inData is a CkByteData
# outBytes is a CkByteData (output)
set status [CkBz2_CompressMemory $this $inData $outData]

Compresses the bytes in inData and returns the complete standard BZip2 stream as an in-memory byte array.

Returns 1 for success, 0 for failure.

CompressMemoryAsync Deprecated ⁽¹⁾

# returns a CkTask
# inData is a CkByteData
set ret_task [CkBz2_CompressMemoryAsync $this $inData]

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

Returns NULL on failure

CompressMemToFile Deprecated

# inData is a CkByteData
# toPath is a string
set status [CkBz2_CompressMemToFile $this $inData $toPath]

Compresses the bytes in inData and writes the resulting standard BZip2 stream to the file at toPath.

Returns 1 for success, 0 for failure.

CompressMemToFileAsync Deprecated ⁽¹⁾

# returns a CkTask
# inData is a CkByteData
# toPath is a string
set ret_task [CkBz2_CompressMemToFileAsync $this $inData $toPath]

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

Returns NULL on failure

UncompressFileToMem Deprecated

# inFilename is a string
# outBytes is a CkByteData (output)
set status [CkBz2_UncompressFileToMem $this $inFilename $outData]

Reads and decompresses the BZip2 stream in the file at inFilename, returning the original uncompressed bytes in memory.

Returns 1 for success, 0 for failure.

UncompressFileToMemAsync Deprecated ⁽¹⁾

# returns a CkTask
# inFilename is a string
set ret_task [CkBz2_UncompressFileToMemAsync $this $inFilename]

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

Returns NULL on failure

UncompressMemory Deprecated

# inData is a CkByteData
# outBytes is a CkByteData (output)
set status [CkBz2_UncompressMemory $this $inData $outData]

Interprets inData as a complete BZip2 stream and returns the decompressed bytes in memory.

Returns 1 for success, 0 for failure.

UncompressMemoryAsync Deprecated ⁽¹⁾

# returns a CkTask
# inData is a CkByteData
set ret_task [CkBz2_UncompressMemoryAsync $this $inData]

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

Returns NULL on failure

UncompressMemToFile Deprecated

# inData is a CkByteData
# toPath is a string
set status [CkBz2_UncompressMemToFile $this $inData $toPath]

Interprets inData as a complete BZip2 stream, decompresses it, and writes the original bytes to the file at toPath.

Returns 1 for success, 0 for failure.

UncompressMemToFileAsync Deprecated ⁽¹⁾

# returns a CkTask
# inData is a CkByteData
# toPath is a string
set ret_task [CkBz2_UncompressMemToFileAsync $this $inData $toPath]

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

Returns NULL on failure