Bzip2 Class

Properties   Methods   Events   Config Settings   Errors  

The Bzip2 class implements a bzip2 compressor and decompressor. It is compliant with bzip2 specification.

Syntax

Bzip2

Remarks

The bzip2 file format is typically used only to archive a single file. Accordingly, the operation of the class is simpler than that of the other classs.

To compress with the class, set ArchiveFile to the name of the bzip2 file to be created, and FileDecompressedName to the name of the file to be compressed. Finally, invoke Compress. To extract the file, set ArchiveFile to the bzip2 archive and FileDecompressedName to the file where the class should extract. Finally, invoke the Extract or Compress method.

Example (Creating a Bzip2 File)

ZipControl.ArchiveFile = "c:\test.bz2" ZipControl.FileDecompressedName = "c:\test.txt" ZipControl.Compress() Example (Extracting from a Bzip2 File)

ZipControl.ArchiveFile = "c:\test.bz2" ZipControl.FileDecompressedName = "c:\test.txt" ZipControl.Extract()

This class is an implementation based on Julian Seward's bzip2 library (http://www.bzip.org).

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

ArchiveFile Property (Bzip2 Class)

The name of the zip, gzip, tar, or jar archive.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetArchiveFile();
int SetArchiveFile(const char* lpszArchiveFile);

Unicode (Windows)
LPWSTR GetArchiveFile();
INT SetArchiveFile(LPCWSTR lpszArchiveFile);

char* ipworkszip_bzip2_getarchivefile(void* lpObj);
int ipworkszip_bzip2_setarchivefile(void* lpObj, const char* lpszArchiveFile);

QString GetArchiveFile();
int SetArchiveFile(QString qsArchiveFile);

Default Value

""

Remarks

This property specifies the name of the archive to be read or written. This property is required when extracting files.

When Scan, Extract, or ExtractAll is invoked, the file specified by ArchiveFile will be opened for read. If the file does not exist, a trappable error will be generated.

When Compress is called, the file named by ArchiveFile will be written; if a file of this name already exists the Overwrite event will be fired. If ArchiveFile is set to the empty string (""), the archive will not be written to disk, and will be provided only through the Progress event.

The filename may be specified with or without a path. Paths may be relative or absolute, and should be specified in the format native to the host operating system. The filename should be specified with the appropriate extension (such as "zip"); an extension will not automatically be appended by the class.

If the file cannot be read, or written, as appropriate, a trappable error will be generated.

Example (Creating an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Compress()

Note: an archive already open for read may be closed by setting ArchiveFile to the empty string ("").

Data Type

String

Bzip2Data Property (Bzip2 Class)

(Decompression only) The bzip2 file contents as a byte array.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int SetBzip2Data(const char* lpBzip2Data, int lenBzip2Data);

Unicode (Windows)
INT SetBzip2Data(LPCSTR lpBzip2Data, INT lenBzip2Data);

int ipworkszip_bzip2_setbzip2data(void* lpObj, const char* lpBzip2Data, int lenBzip2Data);

int SetBzip2Data(QByteArray qbaBzip2Data);

Default Value

""

Remarks

Normally you should set ArchiveFile before invoking Scan or Extract. If you prefer to read the bzip2 file from memory you may set Bzip2Data instead. Bzip2Data should be set to the entire contents of the bzip2 file; this will allow you to read from the bzip2 without writing any temporary files to disk.

If you would like to extract data from the archive without ever writing to disk you should also set WriteToProgressEvent to true, and after invoking Scan, you should set the value of FileDecompressedName to an empty string. Then, when you invoke Extract (or ExtractAll) the data will be provided in the Progress event.

This property is write-only. Note that modifying a bzip2 file stored in Bzip2Data is not supported, so Append will throw exceptions.

This property is write-only and not available at design time.

Data Type

Binary String

ExtractToPath Property (Bzip2 Class)

A base path to decompress to.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetExtractToPath();
int SetExtractToPath(const char* lpszExtractToPath);

Unicode (Windows)
LPWSTR GetExtractToPath();
INT SetExtractToPath(LPCWSTR lpszExtractToPath);

char* ipworkszip_bzip2_getextracttopath(void* lpObj);
int ipworkszip_bzip2_setextracttopath(void* lpObj, const char* lpszExtractToPath);

QString GetExtractToPath();
int SetExtractToPath(QString qsExtractToPath);

Default Value

""

Remarks

Setting the ExtractToPath property affects the operation of the Extract and ExtractAll methods. Setting this property to a nonempty string will cause all decompressed files to be written to the specified path. If pathnames are given in the values of FileDecompressedName they will be regarded as relative to ExtractToPath.

If the specified directory does not exist, it will be created when extraction is done.

ExtractToPath should always be specified in the format native to the host operating system, and with a trailing slash or backslash. If the path is specified otherwise, it will be immediately converted and stored in the converted format. For example, "/temp" would be immediately converted to "\temp\" on a Windows system.

Data Type

String

FileDecompressedName Property (Bzip2 Class)

File name to decompress to, or compress from.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetFileDecompressedName();
int SetFileDecompressedName(const char* lpszFileDecompressedName);

Unicode (Windows)
LPWSTR GetFileDecompressedName();
INT SetFileDecompressedName(LPCWSTR lpszFileDecompressedName);

char* ipworkszip_bzip2_getfiledecompressedname(void* lpObj);
int ipworkszip_bzip2_setfiledecompressedname(void* lpObj, const char* lpszFileDecompressedName);

QString GetFileDecompressedName();
int SetFileDecompressedName(QString qsFileDecompressedName);

Default Value

""

Remarks

FileDecompressedName contains the name of the file in the archive, as stored on the file system, outside the archive.

When compressing a file, this property should be specified with a path, if necessary, to allow the file to be found by the class. If the file cannot be found when Compress is called, a trappable error will be generated, and the archive will not be correctly written.

When decompressing files, this property may be set prior to calling Extract. If this property is set to the empty string when Extract is called, Extract will automatically set this property to an appropriate value.

Paths on the local file system should be specified in the format native to the host operating system. They may also be specified in standard (UNIX) format, in which case they will be immediately converted.

Data Type

String

FileInputData Property (Bzip2 Class)

The data of the file to be compressed.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetFileInputData(char* &lpFileInputData, int &lenFileInputData);
int SetFileInputData(const char* lpFileInputData, int lenFileInputData);

Unicode (Windows)
INT GetFileInputData(LPSTR &lpFileInputData, INT &lenFileInputData);
INT SetFileInputData(LPCSTR lpFileInputData, INT lenFileInputData);

int ipworkszip_bzip2_getfileinputdata(void* lpObj, char** lpFileInputData, int* lenFileInputData);
int ipworkszip_bzip2_setfileinputdata(void* lpObj, const char* lpFileInputData, int lenFileInputData);

QByteArray GetFileInputData();
int SetFileInputData(QByteArray qbaFileInputData);

Default Value

""

Remarks

When this property is set, the class will read in the data from this property instead of reading from the file contained in the FileDecompressedName property.

This property is not available at design time.

Data Type

Binary String

HasMoreData Property (Bzip2 Class)

Shows whether or not there is more data in the bzip2 archive.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetHasMoreData();

Unicode (Windows)
BOOL GetHasMoreData();

int ipworkszip_bzip2_gethasmoredata(void* lpObj);

bool GetHasMoreData();

Default Value

FALSE

Remarks

The bzip2 format allows multiple bzip2 data members to be concatenated into a single file. However, due to the nature of the algorithm it is impossible to determine the number of data members until after the entire archive has been decompressed. The HasMoreData property can be used to cycle through the archive and extract each file.

Simply set the ArchiveFile and ExtractToPath properties, then call Extract as long as the class has available data.

Note: the class will not update FileDecompressedName unless you manually set FileDecompressedName on each loop before calling Extract.

Example (Extracting Multiple Files)

ZipControl.ArchiveFile = "c:\temp.bz2" ZipControl.ExtractToPath = "c:\extracted\" Do //here you may set the file name in FileDecompressedName prior to extraction ZipControl.Extract() While ZipControl.HasMoreData

This property is read-only.

Data Type

Boolean

Abort Method (Bzip2 Class)

Aborts the current operation.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Abort();

Unicode (Windows)
INT Abort();

int ipworkszip_bzip2_abort(void* lpObj);

int Abort();

Remarks

Abort may be used to immediately interrupt compression or decompression. Any files partially written by the class will be deleted.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Append Method (Bzip2 Class)

Adds specified file to an existing archive.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Append();

Unicode (Windows)
INT Append();

int ipworkszip_bzip2_append(void* lpObj);

int Append();

Remarks

The file contained in the FileDecompressedName property will be appended to the archive specified by ArchiveFile.

This method may only be used to add files to an existing archive. To add files to a new archive, Compress method should be used.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Compress Method (Bzip2 Class)

Creates the compressed bzip2 archive.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Compress();

Unicode (Windows)
INT Compress();

int ipworkszip_bzip2_compress(void* lpObj);

int Compress();

Remarks

Invoking Compress creates the archive specified by ArchiveFile. When the method is called, the file specified by FileDecompressedName will be opened, and the file specified by ArchiveFile will contain the compressed output.

As the data is compressed the Progress event will be fired at regular intervals. This event may be used to stream out the bzip2 file, or to display a progress bar to the user.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Config Method (Bzip2 Class)

Sets or retrieves a configuration setting.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* Config(const char* lpszConfigurationString);

Unicode (Windows)
LPWSTR Config(LPCWSTR lpszConfigurationString);

char* ipworkszip_bzip2_config(void* lpObj, const char* lpszConfigurationString);

QString Config(const QString& qsConfigurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Error Handling (C++)

This method returns a String value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Extract Method (Bzip2 Class)

Extracts the compressed file from the bzip2 archive.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Extract();

Unicode (Windows)
INT Extract();

int ipworkszip_bzip2_extract(void* lpObj);

int Extract();

Remarks

Invoking Extract decompresses the archive specified by ArchiveFile. The compressed file will be extracted, and written to disk.

If FileDecompressedName is set to a nonempty string the file will be written there. Otherwise the class will automatically set FileDecompressedName to an appropriate value:

If ArchiveFile ends in ".bz2", this filename, less the ".bz2" extension will be used.

If this condition does not hold, ".unzipped" will be appended to ArchiveFile.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ExtractAll Method (Bzip2 Class)

Extracts all files from the compressed archive.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int ExtractAll();

Unicode (Windows)
INT ExtractAll();

int ipworkszip_bzip2_extractall(void* lpObj);

int ExtractAll();

Remarks

ExtractAll extracts all files from the archive. The file(s) will be extracted to the directory specified by ExtractToPath, and given the names specified by FileDecompressedName.

The BeginFile and EndFile events will be fired before and after each file is extracted, and the Progress event will be fired as the data is extracted. If WriteToProgressEvent is set to true, the decompressed data will be streamed out through the Progress event.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Reset Method (Bzip2 Class)

Resets the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Reset();

Unicode (Windows)
INT Reset();

int ipworkszip_bzip2_reset(void* lpObj);

int Reset();

Remarks

Reset resets the state of the class. All properties will be set to their default values, and any files open will be closed.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Scan Method (Bzip2 Class)

Scans the compressed archive.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Scan();

Unicode (Windows)
INT Scan();

int ipworkszip_bzip2_scan(void* lpObj);

int Scan();

Remarks

This method will scan the bzip archive specified by ArchiveFile. The archive will be read, and the header will be checked.

Unlike in the Zip, Tar, and Jar classs, it is never necessary to invoke this method, and it will not be automatically invoked by Extract. Suggested uses for this method would be to check that the file is a bzip file.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

SetArchiveInputStream Method (Bzip2 Class)

The stream to read the zip, tar, jar, or gzip archive from.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int SetArchiveInputStream(IPWorksZipStream* sArchiveStream);

Unicode (Windows)
INT SetArchiveInputStream(IPWorksZipStream* sArchiveStream);

int ipworkszip_bzip2_setarchiveinputstream(void* lpObj, IPWorksZipStream* sArchiveStream);

int SetArchiveInputStream(IPWorksZipStream* sArchiveStream);

Remarks

This method should be set when the archive is to be read from a stream when Extract is called.

By default, and when this is set to null, the class will read from the file specified by ArchiveFile. However, when this is a valid stream, the data will be read from the stream.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

SetArchiveOutputStream Method (Bzip2 Class)

The stream to write the zip, tar, jar, or gzip archive to.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int SetArchiveOutputStream(IPWorksZipStream* sArchiveStream);

Unicode (Windows)
INT SetArchiveOutputStream(IPWorksZipStream* sArchiveStream);

int ipworkszip_bzip2_setarchiveoutputstream(void* lpObj, IPWorksZipStream* sArchiveStream);

int SetArchiveOutputStream(IPWorksZipStream* sArchiveStream);

Remarks

This method should be set when the archive is to be written to a stream when Compress is called.

By default, and when this is set to null, the class will write to the file specified by ArchiveFile. However, when this is a valid stream, the data will be written to the stream.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

BeginFile Event (Bzip2 Class)

Fired before a file is processed.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireBeginFile(Bzip2BeginFileEventParams *e);

typedef struct {
  int Index;
  int Skip;
  int reserved;
} Bzip2BeginFileEventParams;


Unicode (Windows)
virtual INT FireBeginFile(Bzip2BeginFileEventParams *e);

typedef struct {
  INT Index;
  BOOL Skip;
  INT reserved;
} Bzip2BeginFileEventParams;

#define EID_BZIP2_BEGINFILE 1

virtual INT IPWORKSZIP_CALL FireBeginFile(INT &iIndex, BOOL &bSkip);

class Bzip2BeginFileEventParams {
public:
  int Index();

  bool Skip();
  void SetSkip(bool bSkip);

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void BeginFile(Bzip2BeginFileEventParams *e);

// Or, subclass Bzip2 and override this emitter function.
virtual int FireBeginFile(Bzip2BeginFileEventParams *e) {...}

Remarks

BeginFile is fired before compression or decompression begins. Index will contain 0.

You may use the Skip parameter to tell the class to skip the file when appending or decompressing.

EndFile Event (Bzip2 Class)

Fired after a file is processed.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireEndFile(Bzip2EndFileEventParams *e);

typedef struct {
  int Index;
  int reserved;
} Bzip2EndFileEventParams;


Unicode (Windows)
virtual INT FireEndFile(Bzip2EndFileEventParams *e);

typedef struct {
  INT Index;
  INT reserved;
} Bzip2EndFileEventParams;

#define EID_BZIP2_ENDFILE 2

virtual INT IPWORKSZIP_CALL FireEndFile(INT &iIndex);

class Bzip2EndFileEventParams {
public:
  int Index();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void EndFile(Bzip2EndFileEventParams *e);

// Or, subclass Bzip2 and override this emitter function.
virtual int FireEndFile(Bzip2EndFileEventParams *e) {...}

Remarks

EndFile is fired when compression or decompression finishes. Index will contain 0.

Error Event (Bzip2 Class)

Information about non-fatal errors.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireError(Bzip2ErrorEventParams *e);

typedef struct {
  const char *Description;
  int ErrorCode;
  int Index;
  const char *Filename;
  int Ignore;
  int reserved;
} Bzip2ErrorEventParams;


Unicode (Windows)
virtual INT FireError(Bzip2ErrorEventParams *e);

typedef struct {
  LPCWSTR Description;
  INT ErrorCode;
  INT Index;
  LPCWSTR Filename;
  BOOL Ignore;
  INT reserved;
} Bzip2ErrorEventParams;

#define EID_BZIP2_ERROR 3

virtual INT IPWORKSZIP_CALL FireError(LPSTR &lpszDescription, INT &iErrorCode, INT &iIndex, LPSTR &lpszFilename, BOOL &bIgnore);

class Bzip2ErrorEventParams {
public:
  const QString &Description();

  int ErrorCode();

  int Index();

  const QString &Filename();

  bool Ignore();
  void SetIgnore(bool bIgnore);

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Error(Bzip2ErrorEventParams *e);

// Or, subclass Bzip2 and override this emitter function.
virtual int FireError(Bzip2ErrorEventParams *e) {...}

Remarks

The Error event is fired when non-fatal errors occur during compression or decompression. Note that if this event is fired during decompression this may indicate that the archive is corrupt.

By default these errors will cause the component to fail with an exception. The exception may be overridden by setting Ignore to true. This will cause the error to be ignored, the file will be skipped if necessary, and the class will continue operation.

ErrorCode will correspond to one of the following errors:

Description contains a textual description of the error. Index and Filename contain the array index (where appropriate) and filename of the file being processed at the time of the error.

Overwrite Event (Bzip2 Class)

Fired whenever a file exists and may be overwritten.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireOverwrite(Bzip2OverwriteEventParams *e);

typedef struct {
  char *Filename;
  int Overwrite;
  int reserved;
} Bzip2OverwriteEventParams;


Unicode (Windows)
virtual INT FireOverwrite(Bzip2OverwriteEventParams *e);

typedef struct {
  LPWSTR Filename;
  BOOL Overwrite;
  INT reserved;
} Bzip2OverwriteEventParams;

#define EID_BZIP2_OVERWRITE 4

virtual INT IPWORKSZIP_CALL FireOverwrite(LPSTR &lpszFilename, BOOL &bOverwrite);

class Bzip2OverwriteEventParams {
public:
  const QString &Filename();
  void SetFilename(const QString &qsFilename);

  bool Overwrite();
  void SetOverwrite(bool bOverwrite);

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Overwrite(Bzip2OverwriteEventParams *e);

// Or, subclass Bzip2 and override this emitter function.
virtual int FireOverwrite(Bzip2OverwriteEventParams *e) {...}

Remarks

Overwrite is fired when a file is about to be overwritten, and would overwrite an existing file. The event is fired during decompression.

Filename contains the full name of the file, specified with its pathname.

Overwrite specifies whether or not the file will be overwritten. For Zip, Jar, and Tar, this is equal by default to the value of the OverwriteFiles property. For Gzip, this value defaults to true.

Either of the parameters may be changed when the event is fired. Changing the value of Overwrite will override the default behavior of the class, and cause the file to be overwritten or not overwritten, depending on the value set. If Filename is changed, the value of Overwrite will be ignored, and the file will be written with the specified name. If a file of the new name also exists this file will be silently overwritten.

Progress Event (Bzip2 Class)

Fired as progress is made.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireProgress(Bzip2ProgressEventParams *e);

typedef struct {
  const char *Data;
  int lenData;
  const char *Filename;
  int64 BytesProcessed;
  int PercentProcessed;
  int reserved;
} Bzip2ProgressEventParams;


Unicode (Windows)
virtual INT FireProgress(Bzip2ProgressEventParams *e);

typedef struct {
  LPCSTR Data;
  INT lenData;
  LPCWSTR Filename;
  LONG64 BytesProcessed;
  INT PercentProcessed;
  INT reserved;
} Bzip2ProgressEventParams;

#define EID_BZIP2_PROGRESS 5

virtual INT IPWORKSZIP_CALL FireProgress(LPSTR &lpData, INT &lenData, LPSTR &lpszFilename, LONG64 &lBytesProcessed, INT &iPercentProcessed);

class Bzip2ProgressEventParams {
public:
  const QByteArray &Data();

  const QString &Filename();

  qint64 BytesProcessed();

  int PercentProcessed();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Progress(Bzip2ProgressEventParams *e);

// Or, subclass Bzip2 and override this emitter function.
virtual int FireProgress(Bzip2ProgressEventParams *e) {...}

Remarks

The Progress event is automatically fired as compression or decompression is performed. When WriteToProgressEvent is true, the output data is provided through the Data parameter, allowing for it to be streamed out.

Filename contains the name of the file being written. If no file is being written, Filename will contain an empty string, and the output data will be provided exclusively through this event.

BytesProcessed contains the total number of uncompressed bytes processed. PercentProcessed contains the percent of uncompressed bytes processed, corresponding roughly to the running time of the operation.

For Gzip extraction only, BytesProcessed and PercentProcessed will reflect the number of compressed bytes extracted, as it is generally impossible to predetermine the total uncompressed size.

If WriteToProgressEvent is false, Data will contain null.

IPWorksZipStream Type

Syntax

IPWorksZipStream (declared in ipworkszip.h)

Remarks

The Bzip2 class includes one or more API members that take a stream object as a parameter. To use such API members, create a concrete class that implements the IPWorksZipStream interface and pass the Bzip2 class an instance of that concrete class.

When implementing the IPWorksZipStream interface's properties and methods, they must behave as described below. If the concrete class's implementation does not behave as expected, undefined behavior may occur.

bool CanRead() { return true; }

bool CanSeek() { return true; }

bool CanWrite() { return true; }

int64 GetLength() = 0;

void Close() {}

int Flush() { return 0; }

int Read(void* buffer, int count) = 0;

int64 Seek(int64 offset, int seekOrigin) = 0;

int Write(const void* buffer, int count) = 0;

Config Settings (Bzip2 Class)

Bzip2 Config Settings

Base Config Settings

Trappable Errors (Bzip2 Class)

Error Handling (C++)

Call the GetLastErrorCode() method to obtain the last called method's result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. Known error codes are listed below. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

The following errors may be generated by the class. Note that frequently the error message will contain more specific information than what is listed here.

Note that some non-fatal errors may be trapped and explicitly ignored in the Error event. This will allow the class to continue operation even in case of error.

Bzip2 Errors