cutelyst  4.5.1
A C++ Web Framework built on top of Qt, using the simple approach of Catalyst (Perl) framework.
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Cutelyst::StaticCompressed Class Reference
Plugins

Serve static files compressed on the fly or pre-compressed. More...

#include <Cutelyst/Plugins/StaticCompressed/StaticCompressed>

Inheritance diagram for Cutelyst::StaticCompressed:
Inheritance graph
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Additional Inherited Members

- Public Member Functions inherited from Cutelyst::Plugin
 Plugin (Application *parent)
 
- Public Member Functions inherited from QObject
 QObject (QObject *parent)
 
QBindable< QString > bindableObjectName ()
 
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 () const const
 
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 QRegularExpression &re, Qt::FindChildOptions options) const const
 
QList< T > findChildren (const QString &name, Qt::FindChildOptions options) const const
 
QList< T > findChildren (Qt::FindChildOptions options) const const
 
bool inherits (const char *className) const const
 
void installEventFilter (QObject *filterObj)
 
bool isQuickItemType () const const
 
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_EMIT Q_EMIT
 
 Q_ENUM (...)
 
 Q_ENUM_NS (...)
 
 Q_ENUMS (...)
 
 Q_FLAG (...)
 
 Q_FLAG_NS (...)
 
 Q_FLAGS (...)
 
 Q_GADGET Q_GADGET
 
 Q_GADGET_EXPORT (EXPORT_MACRO)
 
 Q_INTERFACES (...)
 
 Q_INVOKABLE Q_INVOKABLE
 
 Q_MOC_INCLUDE Q_MOC_INCLUDE
 
 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 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 setObjectName (QAnyStringView name)
 
void setParent (QObject *parent)
 
bool setProperty (const char *name, const QVariant &value)
 
bool setProperty (const char *name, QVariant &&value)
 
bool signalsBlocked () const const
 
int startTimer (int interval, Qt::TimerType timerType)
 
int startTimer (std::chrono::milliseconds interval, Qt::TimerType timerType)
 
QThread * thread () const const
 
- 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)
 
- Public Attributes inherited from QObject
typedef QObjectList
 
- 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)
 
- Properties inherited from QObject
 objectName
 

Detailed Description

The StaticCompressed plugin for Cutelyst can be used to serve specific static files like CSS and JavaScript files compressed. It has built in support for gzip and DEFLATE compression format and can be extended by external libraries to support the Brotli and Zstandard (since Cutelyst 4.4.0) compression algorithms and to use Zopfli for gzip and deflate compression. Beside compressing the raw data on the fly and store the result in a cache directory, it supports pre-compressed files distinguished by file extension in the static source directories. The plugin uses the Accept-Encoding HTTP request header to determine the compression methods supported by the user agent. If you do not need this, use the StaticSimple plugin to serve your static files.

Beside serving the file content this will also set the respective HTTP header fields Content-Type, Content-Length, Last-Modified, Content-Encoding, Vary=Accept-Encoding and Cache-Control=public.

Compression formats

Support for gzip and DEFLATE compression format is built in by using the qCompress() function.

To enable suport for Brotli, build with -DPLUGIN_STATICCOMPRESSED_BROTLI:BOOL=ON and have the libbrotlienc development and header files available.

To enable support for Zstandard, build with -DPLUGIN_STATICCOMPRESSED_ZSTD:BOOL=ON and have the libzstd development and header files available.

To use Zopfli for the gzip and deflate compression, build with -DPLUGIN_STATICCOMPRESSED_ZOPFLI:BOOL=ON and have the libzopfli development and header files available. Also set the configuration key use_zopfli to true. Be aware that Zopfli gives better compression rate than default gzip and deflate but is also much slower. So Zopfli is disabled by default even if it is enabled at compilation time.

On the fly compression

Static files of the configured mime_types or with the configured suffixes can be compressed on the fly into a format that is accepted by the requesting user agent. The compressed data is saved into files in the cache_diretory specified in the configuration. The cache file name will be the MD5 hash sum of the original local file path together with the file extension indicating the compression format (.br for Brotli, .gz for gzip/Zopfli, .deflate for DEFLATE/Zopfli and .zst for Zstandard). If the modification time of the original file is newer than the modification time of the cached compressed file, the file will be compressed again. It is safe to clean the content of the cache directory - the files will then be recompressed on the next request. On the fly compression can be disabled by setting on_the_fly_compression to false in the configuration file.

Pre-compressed files

Beside the cached on the fly compression it is also possible to serve pre-compressed static files that are available from the same directories as the original files. The StaticCompressed plugin will try to find a compressed file at the same path as the original file appended by an extension indicating the compression method. So if you have for example boostrap.min.css and bootstrap.min.css.gz in your static files directory, the plugin will serve the compressed variant if the requesting user agent supports the gzip encoding. The delivery of pre-compressed files can be disabled by setting check_pre_compressed to false in the configuration file.

Used file extensions/suffixes

  • .br - Brotli compressed files
  • .gz - gzip/Zopfli compressed files
  • .deflate - DEFLATE compressed files
  • .zst - Zstandard compressed files (since Cutelyst 4.4.0)

Only serve for specific request paths

You can use setDirs() to set a list of directories/paths below your web root where files should always be served by this plugin. By default, the plugin also tries to serve files from other paths when they have a file extension when they do not start with one of these paths. You can set setServeDirsOnly() to true (since Cutelyst 4.0.0) to only serve files beginning with these paths. Have a look at setDirs() to learn more.

Runtime configuration

The plugin offers some configuration options that can be set in the application configuration file in the Cutelyst_StaticCompressed_Plugin section. You can override the defaults by setting a QVariantMap with selected default values to the constructor.

cache_directory

Type: string
Default: QStandardPaths::CacheLocation + /compressed-static

Sets the directory path where on the fly compressed data is saved.

mime_types

Type: string
Default: text/css,application/javascript,text/javascript

Comma separated list of MIME types that should be compressed.

suffixes

Type: string
Default: js.map,css.map,min.js.map,min.css.map

Comma separted list of file suffixes/extensions that should be compressed.

compression_format_order

Type: string
Default: br,zstd,gzip,deflate

Comma separated list of compression formats that will be used in order if supported by the user agent.

check_pre_compressed

Type: bool
Default: true

Enables or disables the check for pre compressed files.

on_the_fly_compression

Type: bool
Default: true

Enables or disables the compression on the fly.

zlib_compression_level

Type: integer
Default: 9

Compression level for built in zlib based compression between 0 and 9, with 9 corresponding to the best compression. Used for gzip and deflate compression format if use_zopfli is set to false.

brotli_quality_level

Type: integer
Default: 11

Quality level for Brotli compression between 0 and 11, with 11 corresponding to the best compression.

use_zopfli

Type: bool
Default: false

Enables the optional use of Zopfli for the gzip and @ deflate compression format. Note that Zopfli gives much better compression results for the cost of a slower compression.

zopfli_iterations

Type: integer
Default: 15

Number of iterations used for Zopfli compression, more gives better compression but is slower.

zstd_compression_level

Type: integer
Default: 9

Compression level used for Zstandard compression. Normally between 1 and 19, but can also use negative levels for faster compression or higher levels up to 22 for better/stronger compression.

Usage example

#include <Cutelyst/Plugins/StaticCompressed/StaticCompressed>
bool MyCutelystApp::init()
{
// other initialization stuff
// ...
// constructs a new plugin and sets the default value for
// the config file option use_zopfli to true
auto staticCompressed = new StaticCompressed(this, {{"use_zopfli", true}});
staticCompressed->setIncludePaths({QStringLiteral("/path/to/my/static/files")});
// maybe more initialization stuff
//...
}

Build configuration

Definition at line 199 of file staticcompressed.h.