KCompressionDevice Class
| Header: | #include <KCompressionDevice> |
| CMake: | find_package(KF6 REQUIRED COMPONENTS Archive)target_link_libraries(mytarget PRIVATE KF6::Archive) |
| Inherits: | QIODevice |
Public Types
| enum | CompressionType { GZip, BZip2, Xz, None, Zstd } |
Public Functions
(since 5.85) | KCompressionDevice(const QString &fileName) |
| KCompressionDevice(const QString &fileName, KCompressionDevice::CompressionType type) | |
| KCompressionDevice(QIODevice *inputDevice, bool autoDeleteInputDevice, KCompressionDevice::CompressionType type) | |
| virtual | ~KCompressionDevice() override |
| KCompressionDevice::CompressionType | compressionType() const |
| QFileDevice::FileError | error() const |
| void | setOrigFileName(const QByteArray &fileName) |
| void | setSkipHeaders() |
Reimplemented Public Functions
| virtual bool | seek(qint64) override |
Static Public Members
(since 5.85) KCompressionDevice::CompressionType | compressionTypeForMimeType(const QString &mimetype) |
| KFilterBase * | filterForCompressionType(KCompressionDevice::CompressionType type) |
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.
Member Type Documentation
enum KCompressionDevice::CompressionType
| Constant | Value |
|---|---|
KCompressionDevice::GZip | 0 |
KCompressionDevice::BZip2 | 1 |
KCompressionDevice::Xz | 2 |
KCompressionDevice::None | 3 |
KCompressionDevice::Zstd (since 5.82) | 4 |
Member Function Documentation
[explicit, since 5.85] KCompressionDevice::KCompressionDevice(const QString &fileName)
Constructs a KCompressionDevice for a given fileName.
fileName the name of the file to filter.
This function was introduced in 5.85.
KCompressionDevice::KCompressionDevice(const QString &fileName, KCompressionDevice::CompressionType type)
Constructs a KCompressionDevice for a given CompressionType (e.g. GZip, BZip2 etc.).
fileName the name of the file to filter.
type the CompressionType to use.
KCompressionDevice::KCompressionDevice(QIODevice *inputDevice, bool autoDeleteInputDevice, KCompressionDevice::CompressionType type)
Constructs a KCompressionDevice for a given CompressionType (e.g. GZip, BZip2 etc.).
inputDevice input device.
autoDeleteInputDevice if true, inputDevice will be deleted automatically
type the CompressionType to use.
[override virtual noexcept] KCompressionDevice::~KCompressionDevice()
Destructs the KCompressionDevice.
Calls close() if the filter device is still open.
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.
[static, since 5.85] KCompressionDevice::CompressionType KCompressionDevice::compressionTypeForMimeType(const QString &mimetype)
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.
This function was introduced in 5.85.
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.
[static] KFilterBase *KCompressionDevice::filterForCompressionType(KCompressionDevice::CompressionType type)
Call this to create the appropriate filter for the CompressionType named type.
type the type of the compression filter
Returns the filter for the type, or 0 if not found
[override virtual] bool KCompressionDevice::seek(qint64)
Reimplements: QIODevice::seek(qint64 pos).
That one can be quite slow, when going back. Use with care.
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.
fileName the name of the original file
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.