KCompressionDevice Class Reference

#include <KCompressionDevice>

Inheritance diagram for KCompressionDevice:

Public Types
enum	CompressionType {   GZip, BZip2, Xz, None,   Zstd }
Public Types inherited from QIODevice
enum	OpenModeFlag

Public Member Functions
	KCompressionDevice (const QString &fileName)
	KCompressionDevice (const QString &fileName, CompressionType type)
	KCompressionDevice (QIODevice *inputDevice, bool autoDeleteInputDevice, CompressionType type)
	~KCompressionDevice () override
bool	atEnd () const override
void	close () override
CompressionType	compressionType () const
QFileDevice::FileError	error () const
bool	open (QIODevice::OpenMode mode) override
bool	seek (qint64) override
void	setOrigFileName (const QByteArray &fileName)
void	setSkipHeaders ()
Public Member Functions inherited from QIODevice
	QIODevice (QObject *parent)
void	aboutToClose ()
virtual qint64	bytesAvailable () const const
virtual qint64	bytesToWrite () const const
void	bytesWritten (qint64 bytes)
virtual bool	canReadLine () const const
void	channelBytesWritten (int channel, qint64 bytes)
void	channelReadyRead (int channel)
void	commitTransaction ()
int	currentReadChannel () const const
int	currentWriteChannel () const const
QString	errorString () const const
bool	getChar (char *c)
bool	isOpen () const const
bool	isReadable () const const
virtual bool	isSequential () const const
bool	isTextModeEnabled () const const
bool	isTransactionStarted () const const
bool	isWritable () const const
QIODevice::OpenMode	openMode () const const
qint64	peek (char *data, qint64 maxSize)
QByteArray	peek (qint64 maxSize)
virtual qint64	pos () const const
bool	putChar (char c)
qint64	read (char *data, qint64 maxSize)
QByteArray	read (qint64 maxSize)
QByteArray	readAll ()
int	readChannelCount () const const
void	readChannelFinished ()
qint64	readLine (char *data, qint64 maxSize)
QByteArray	readLine (qint64 maxSize)
void	readyRead ()
virtual bool	reset ()
void	rollbackTransaction ()
void	setCurrentReadChannel (int channel)
void	setCurrentWriteChannel (int channel)
void	setTextModeEnabled (bool enabled)
virtual qint64	size () const const
qint64	skip (qint64 maxSize)
void	startTransaction ()
void	ungetChar (char c)
virtual bool	waitForBytesWritten (int msecs)
virtual bool	waitForReadyRead (int msecs)
qint64	write (const char *data)
qint64	write (const char *data, qint64 maxSize)
qint64	write (const QByteArray &byteArray)
int	writeChannelCount () const const
Public Member Functions inherited from QObject
	QObject (QObject *parent)
bool	blockSignals (bool block)
const QObjectList &	children () const const
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const char *method, Qt::ConnectionType type) const const
void	deleteLater ()
void	destroyed (QObject *obj)
bool	disconnect (const char *signal, const QObject *receiver, const char *method) const const
bool	disconnect (const QObject *receiver, const char *method) const const
void	dumpObjectInfo ()
void	dumpObjectInfo () const const
void	dumpObjectTree ()
void	dumpObjectTree () const const
QList< QByteArray >	dynamicPropertyNames () const const
virtual bool	event (QEvent *e)
virtual bool	eventFilter (QObject *watched, QEvent *event)
T	findChild (const QString &name, Qt::FindChildOptions options) const const
QList< T >	findChildren (const QRegExp &regExp, Qt::FindChildOptions options) const const
QList< T >	findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const
QList< T >	findChildren (const QString &name, Qt::FindChildOptions options) const const
bool	inherits (const char *className) const const
void	installEventFilter (QObject *filterObj)
bool	isWidgetType () const const
bool	isWindowType () const const
void	killTimer (int id)
virtual const QMetaObject *	metaObject () const const
void	moveToThread (QThread *targetThread)
QString	objectName () const const
void	objectNameChanged (const QString &objectName)
QObject *	parent () const const
QVariant	property (const char *name) const const
	Q_CLASSINFO (Name, Value)
	Q_DISABLE_COPY (Class)
	Q_DISABLE_COPY_MOVE (Class)
	Q_DISABLE_MOVE (Class)
	Q_EMIT Q_EMIT
	Q_ENUM (...)
	Q_ENUM_NS (...)
	Q_ENUMS (...)
	Q_FLAG (...)
	Q_FLAG_NS (...)
	Q_FLAGS (...)
	Q_GADGET Q_GADGET
	Q_INTERFACES (...)
	Q_INVOKABLE Q_INVOKABLE
	Q_NAMESPACE Q_NAMESPACE
	Q_NAMESPACE_EXPORT (EXPORT_MACRO)
	Q_OBJECT Q_OBJECT
	Q_PROPERTY (...)
	Q_REVISION Q_REVISION
	Q_SET_OBJECT_NAME (Object)
	Q_SIGNAL Q_SIGNAL
	Q_SIGNALS Q_SIGNALS
	Q_SLOT Q_SLOT
	Q_SLOTS Q_SLOTS
T	qFindChild (const QObject *obj, const QString &name)
QList< T >	qFindChildren (const QObject *obj, const QRegExp &regExp)
QList< T >	qFindChildren (const QObject *obj, const QString &name)
T	qobject_cast (const QObject *object)
T	qobject_cast (QObject *object)
	QT_NO_NARROWING_CONVERSIONS_IN_CONNECT QT_NO_NARROWING_CONVERSIONS_IN_CONNECT
void	removeEventFilter (QObject *obj)
void	setObjectName (const QString &name)
void	setParent (QObject *parent)
bool	setProperty (const char *name, const QVariant &value)
bool	signalsBlocked () const const
int	startTimer (int interval, Qt::TimerType timerType)
int	startTimer (std::chrono::milliseconds time, Qt::TimerType timerType)
QThread *	thread () const const

Static Public Member Functions
static CompressionType	compressionTypeForMimeType (const QString &mimetype)
static KFilterBase *	filterForCompressionType (CompressionType type)
Static Public Member Functions inherited from QObject
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, const QObject *context, Functor functor, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)
bool	disconnect (const QMetaObject::Connection &connection)
bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *method)
bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method)
bool	disconnect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method)
QString	tr (const char *sourceText, const char *disambiguation, int n)
QString	trUtf8 (const char *sourceText, const char *disambiguation, int n)

Protected Member Functions
KFilterBase *	filterBase ()
qint64	readData (char *data, qint64 maxlen) override
qint64	writeData (const char *data, qint64 len) override
Protected Member Functions inherited from QIODevice
virtual qint64	readLineData (char *data, qint64 maxSize)
void	setErrorString (const QString &str)
void	setOpenMode (QIODevice::OpenMode openMode)
Protected Member Functions inherited from QObject
virtual void	childEvent (QChildEvent *event)
virtual void	connectNotify (const QMetaMethod &signal)
virtual void	customEvent (QEvent *event)
virtual void	disconnectNotify (const QMetaMethod &signal)
bool	isSignalConnected (const QMetaMethod &signal) const const
int	receivers (const char *signal) const const
QObject *	sender () const const
int	senderSignalIndex () const const
virtual void	timerEvent (QTimerEvent *event)

Additional Inherited Members
Properties inherited from QObject
	objectName
Public Attributes inherited from QIODevice
	Append
	ExistingOnly
	NewOnly
	NotOpen
typedef	OpenMode
	ReadOnly
	ReadWrite
	Text
	Truncate
	Unbuffered
	WriteOnly
Public Attributes inherited from QObject
typedef	QObjectList

Detailed Description

A class for reading and writing compressed data onto a device (e.g. file, but other usages are possible, like a buffer or a socket).

Use this class to read/write compressed files.

Definition at line 30 of file kcompressiondevice.h.

Member Enumeration Documentation

CompressionType

enum KCompressionDevice::CompressionType

Enumerator
Zstd	Since 5.82

Definition at line 34 of file kcompressiondevice.h.

Constructor & Destructor Documentation

KCompressionDevice() [1/3]

KCompressionDevice::KCompressionDevice	(	QIODevice *	inputDevice,
		bool	autoDeleteInputDevice,
		CompressionType	type
	)

Constructs a KCompressionDevice for a given CompressionType (e.g.

GZip, BZip2 etc.).

Parameters

inputDevice	input device.
autoDeleteInputDevice	if true, inputDevice will be deleted automatically
type	the CompressionType to use.

Definition at line 187 of file kcompressiondevice.cpp.

KCompressionDevice() [2/3]

KCompressionDevice::KCompressionDevice	(	const QString &	fileName,
		CompressionType	type
	)

Constructs a KCompressionDevice for a given CompressionType (e.g.

GZip, BZip2 etc.).

Parameters

fileName	the name of the file to filter.
type	the CompressionType to use.

Definition at line 198 of file kcompressiondevice.cpp.

KCompressionDevice() [3/3]

KCompressionDevice::KCompressionDevice

(

const QString &

fileName

)

Constructs a KCompressionDevice for a given fileName.

Parameters

fileName

the name of the file to filter.

Since

5.85

Definition at line 211 of file kcompressiondevice.cpp.

~KCompressionDevice()

KCompressionDevice::~KCompressionDevice ( )

override

Destructs the KCompressionDevice.

Calls close() if the filter device is still open.

Definition at line 216 of file kcompressiondevice.cpp.

Member Function Documentation

close()

void KCompressionDevice::close ( )

overridevirtual

Close after reading or writing.

Reimplemented from QIODevice.

Definition at line 265 of file kcompressiondevice.cpp.

compressionType()

KCompressionDevice::CompressionType KCompressionDevice::compressionType

(

)

const

The compression actually used by this device.

If the support for the compression requested in the constructor is not available, then the device will use None.

Definition at line 225 of file kcompressiondevice.cpp.

compressionTypeForMimeType()

KCompressionDevice::CompressionType KCompressionDevice::compressionTypeForMimeType ( const QString &  mimetype )

static

Returns the compression type for the given MIME type, if possible.

Otherwise returns None. This handles simple cases like application/gzip, but also application/x-compressed-tar, and inheritance.

Since

5.85

Definition at line 105 of file kcompressiondevice.cpp.

error()

QFileDevice::FileError KCompressionDevice::error

(

)

const

Returns the error code from the last failing operation.

This is especially useful after calling close(), which unfortunately returns void (see https://bugreports.qt.io/browse/QTBUG-70033), to see if the flushing done by close was able to write all the data to disk.

Definition at line 287 of file kcompressiondevice.cpp.

filterForCompressionType()

KFilterBase * KCompressionDevice::filterForCompressionType ( KCompressionDevice::CompressionType  type )

static

Call this to create the appropriate filter for the CompressionType named type.

Parameters

type	the type of the compression filter

Returns

the filter for the type, or 0 if not found

Definition at line 160 of file kcompressiondevice.cpp.

open()

bool KCompressionDevice::open ( QIODevice::OpenMode  mode )

overridevirtual

Open for reading or writing.

Reimplemented from QIODevice.

Definition at line 230 of file kcompressiondevice.cpp.

seek()

bool KCompressionDevice::seek ( qint64  pos )

overridevirtual

That one can be quite slow, when going back.

Use with care.

Reimplemented from QIODevice.

Definition at line 292 of file kcompressiondevice.cpp.

setOrigFileName()

void KCompressionDevice::setOrigFileName

(

const QByteArray &

fileName

)

For writing gzip compressed files only: set the name of the original file, to be used in the gzip header.

Parameters

fileName

the name of the original file

Definition at line 502 of file kcompressiondevice.cpp.

setSkipHeaders()

void KCompressionDevice::setSkipHeaders

(

)

Call this let this device skip the gzip headers when reading/writing.

This way KCompressionDevice (with gzip filter) can be used as a direct wrapper around zlib - this is used by KZip.

Definition at line 507 of file kcompressiondevice.cpp.

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The documentation for this class was generated from the following files:

• kcompressiondevice.h
• kcompressiondevice.cpp