--- product: Chilkat product_version: 11.7.0 language: dataflex language_label: DataFlex class: Bz2 license: bundle deprecated: false reference_html: https://www.chilkatsoft.com/refdoc/dataflexBz2Ref.html --- # Chilkat Bz2 — DataFlex — v11.7.0 > Chilkat 11.7.0 · language=dataflex · class=Bz2 > Other versions: replace `11.7.0` in this URL. Other languages: `https://www.chilkatsoft.com/ai-docs/v/11.7.0//classes/Bz2.md`. > Language-wide rules (install, unlock, error model, strings/bytes): `https://www.chilkatsoft.com/ai-docs/v/11.7.0/dataflex/guide.md`. ## Purpose `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](https://www.chilkatsoft.com/bz2_class_overview.asp) ## Object creation, unlocking and error handling **Object Creation** ```dataflex // (Dataflex programs use the 32-bit Chilkat ActiveX) Handle hoBz2 Get Create(RefClass(cComChilkatBz2)) to hoBz2 ``` Call `Global.UnlockBundle` once at the start of the program, before using this or any other Chilkat class. Any string unlocks a fully functional 30-day trial; a purchased unlock code is used in production. See `guide.md` for the exact code in DataFlex. How failure is reported depends on the method's return type and is stated in the note under each method below. In every case the diagnostic text is in the `LastErrorText` property of the object whose method was called. ## Members common to every Chilkat class Documented once per language in `common-members.md`; listed here so this page is self-contained. | Property | Signature | Access | Meaning | |---|---|---|---| | `DebugLogFilePath` | `Function ComDebugLogFilePath Returns String Procedure Set ComDebugLogFilePath String value` | read/write | If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. | | `LastBinaryResult` | `Function ComLastBinaryResult Returns Variant` | read-only | This property is mainly used in SQL Server stored procedures to retrieve binary data from the last method call that returned binary data. | | `LastErrorHtml` | `Function ComLastErrorHtml Returns String` | read-only | Provides HTML-formatted information about the last called method or property. | | `LastErrorText` | `Function ComLastErrorText Returns String` | read-only | Provides plain text information about the last called method or property. | | `LastErrorXml` | `Function ComLastErrorXml Returns String` | read-only | Provides XML-formatted information about the last called method or property. | | `LastMethodSuccess` | `Function ComLastMethodSuccess Returns Boolean Procedure Set ComLastMethodSuccess Boolean value` | read/write | Indicates the success or failure of the most recent method call: `True` means success, `False` means failure. | | `LastStringResult` | `Function ComLastStringResult Returns String` | read-only | In SQL Server stored procedures, this property holds the string return value of the most recent method call that returns a string. | | `LastStringResultLen` | `Function ComLastStringResultLen Returns Integer` | read-only | The length, in characters, of the string contained in the LastStringResult property. | | `VerboseLogging` | `Function ComVerboseLogging Returns Boolean Procedure Set ComVerboseLogging Boolean value` | read/write | If set to `True`, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. | | `Version` | `Function ComVersion Returns String` | read-only | Version of the component/library, such as "10.1.0" | ## Member index | Member | Kind | Signature | |---|---|---| | `AbortCurrent` | property, read/write | `Function ComAbortCurrent Returns Boolean Procedure Set ComAbortCurrent Boolean value` | | `CompressBd` | method | `Function ComCompressBd cComChilkatBinData bd Returns Boolean` | | `CompressFile` | method | `Function ComCompressFile String inFilename String toPath Returns Boolean` | | `CompressFileToMem` | method | `Function ComCompressFileToMem String inFilename Returns Variant` | | `CompressMemory` | method | `Function ComCompressMemory Variant inData Returns Variant` | | `CompressMemToFile` | method | `Function ComCompressMemToFile Variant inData String toPath Returns Boolean` | | `LoadTaskCaller` | method | `Function ComLoadTaskCaller cComChilkatTask task Returns Boolean` | | `UncompressBd` | method | `Function ComUncompressBd cComChilkatBinData bd Returns Boolean` | | `UncompressFile` | method | `Function ComUncompressFile String inFilename String toPath Returns Boolean` | | `UncompressFileToMem` | method | `Function ComUncompressFileToMem String inFilename Returns Variant` | | `UncompressMemory` | method | `Function ComUncompressMemory Variant inData Returns Variant` | | `UncompressMemToFile` | method | `Function ComUncompressMemToFile Variant inData String toPath Returns Boolean` | ## Properties ### Bz2.AbortCurrent `Chilkat 11.7.0 · dataflex · Bz2 · AbortCurrent · property · read/write · since 9.5.0.58` ```dataflex Function ComAbortCurrent Returns Boolean Procedure Set ComAbortCurrent Boolean value ``` Set this property to `True` 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 `False`. 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. ## Methods ### Bz2.CompressBd `Chilkat 11.7.0 · dataflex · Bz2 · CompressBd · method · since 11.0.0` ```dataflex Function ComCompressBd cComChilkatBinData bd Returns Boolean ``` 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 True for success, False for failure. Async variant: `CompressBdAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.CompressFile `Chilkat 11.7.0 · dataflex · Bz2 · CompressFile · method` ```dataflex Function ComCompressFile String inFilename String toPath Returns Boolean ``` 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 True for success, False for failure. Async variant: `CompressFileAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.CompressFileToMem `Chilkat 11.7.0 · dataflex · Bz2 · CompressFileToMem · method` ```dataflex Function ComCompressFileToMem String inFilename Returns Variant ``` Reads the file at `inFilename`, compresses it with BZip2, and returns the complete `.bz2` byte stream in memory. Returns `null` on failure Async variant: `CompressFileToMemAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.CompressMemory `Chilkat 11.7.0 · dataflex · Bz2 · CompressMemory · method` ```dataflex Function ComCompressMemory Variant inData Returns Variant ``` Compresses the bytes in `inData` and returns the complete standard BZip2 stream as an in-memory byte array. Returns `null` on failure Async variant: `CompressMemoryAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.CompressMemToFile `Chilkat 11.7.0 · dataflex · Bz2 · CompressMemToFile · method` ```dataflex Function ComCompressMemToFile Variant inData String toPath Returns Boolean ``` Compresses the bytes in `inData` and writes the resulting standard BZip2 stream to the file at `toPath`. Returns True for success, False for failure. Async variant: `CompressMemToFileAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.LoadTaskCaller `Chilkat 11.7.0 · dataflex · Bz2 · LoadTaskCaller · method · since 9.5.0.80` ```dataflex Function ComLoadTaskCaller cComChilkatTask task Returns Boolean ``` 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 True for success, False for failure. ### Bz2.UncompressBd `Chilkat 11.7.0 · dataflex · Bz2 · UncompressBd · method · since 11.0.0` ```dataflex Function ComUncompressBd cComChilkatBinData bd Returns Boolean ``` 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 True for success, False for failure. Async variant: `UncompressBdAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.UncompressFile `Chilkat 11.7.0 · dataflex · Bz2 · UncompressFile · method` ```dataflex Function ComUncompressFile String inFilename String toPath Returns Boolean ``` 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 True for success, False for failure. Async variant: `UncompressFileAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.UncompressFileToMem `Chilkat 11.7.0 · dataflex · Bz2 · UncompressFileToMem · method` ```dataflex Function ComUncompressFileToMem String inFilename Returns Variant ``` Reads and decompresses the BZip2 stream in the file at `inFilename`, returning the original uncompressed bytes in memory. Returns `null` on failure Async variant: `UncompressFileToMemAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.UncompressMemory `Chilkat 11.7.0 · dataflex · Bz2 · UncompressMemory · method` ```dataflex Function ComUncompressMemory Variant inData Returns Variant ``` Interprets `inData` as a complete BZip2 stream and returns the decompressed bytes in memory. Returns `null` on failure Async variant: `UncompressMemoryAsync` — same arguments, returns a `Task` (see Async variants below). ### Bz2.UncompressMemToFile `Chilkat 11.7.0 · dataflex · Bz2 · UncompressMemToFile · method` ```dataflex Function ComUncompressMemToFile Variant inData String toPath Returns Boolean ``` Interprets `inData` as a complete BZip2 stream, decompresses it, and writes the original bytes to the file at `toPath`. Returns True for success, False for failure. Async variant: `UncompressMemToFileAsync` — same arguments, returns a `Task` (see Async variants below). ## Events and callbacks This binding has no event callbacks. For progress, percent-done or cancellation use the `*Async` variant of a method and poll the returned `Task` (`PercentDone`, `Finished`, `Cancel`). ## Async variants Each returns a `Task` instead of the result and takes the same arguments as the synchronous method; run the task, wait for `Finished`, then read the result from the task. No new Async methods are added from 11.7.0 on. ```dataflex Function ComCompressBdAsync cComChilkatBinData bd Returns cComChilkatTask Function ComCompressFileAsync String inFilename String toPath Returns cComChilkatTask Function ComCompressFileToMemAsync String inFilename Returns cComChilkatTask Function ComCompressMemoryAsync Variant inData Returns cComChilkatTask Function ComCompressMemToFileAsync Variant inData String toPath Returns cComChilkatTask Function ComUncompressBdAsync cComChilkatBinData bd Returns cComChilkatTask Function ComUncompressFileAsync String inFilename String toPath Returns cComChilkatTask Function ComUncompressFileToMemAsync String inFilename Returns cComChilkatTask Function ComUncompressMemoryAsync Variant inData Returns cComChilkatTask Function ComUncompressMemToFileAsync Variant inData String toPath Returns cComChilkatTask ``` ## Related classes [`BinData`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/dataflex/classes/BinData.md), [`Task`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/dataflex/classes/Task.md)