A subclass of VFS_datastore_cache_entry, used for disk access. More...

#include <VFS_hd.h>

Inheritance diagram for VFS_HD_cache_entry:

Public Member Functions
	VFS_HD_cache_entry (QString path, bool debug, int flushInterval, int expireInterval, bool create=false, bool container=false, bool raw=false, bool watch=false)

virtual	~VFS_HD_cache_entry ()
	VFS_HD_cache_entry destructor. More...

virtual bool	valid (QString &reason)
	If the file or directory does not exist or is not readable, _valid is set to false. More...

Public Member Functions inherited from VFS_datastore_cache_entry
	VFS_datastore_cache_entry (bool debug, int flushInterval, int expireInterval, bool raw=false)
	Construct the cache entry. More...

virtual	~VFS_datastore_cache_entry ()
	Destroy the cache entry. More...

virtual QJsonDocument	getData ()
	Return the data from an entry. More...

virtual QByteArray	getRawData ()
	Return the data from an entry. More...

virtual void	setData (QByteArray data)
	Write raw data to the entry. More...

virtual void	setData (QJsonObject json)
	Write data to the entry. More...

quint64	size ()

Protected Member Functions
virtual void	flush ()
	Actually write the file to disk. More...

Protected Member Functions inherited from VFS_datastore_cache_entry
virtual void	touch ()
	Reset the expiration timer. More...

Protected Attributes
QFileInfo	_info
	An info object, useful for type and metadata information. More...

QString	_path
	The actual file path. More...

QFileSystemWatcher	_watcher
	Watches for changes to the file or directory, and expires the entry on change. More...

Protected Attributes inherited from VFS_datastore_cache_entry
QJsonDocument	_data
	The actual cache data. More...

bool	_debug
	Debug flag, for verbose output. More...

bool	_dirty
	Changes have occurred but they are not commited to storage yet. More...

int	_expireID
	Timer ID for expire events. More...

int	_expireInterval
	Expire interval, in milliseconds. More...

QBasicTimer	_expireTimer
	The expiration timer. More...

int	_flushID
	Timer ID for flush events. More...

int	_flushInterval
	Flush interval, in milliseconds. More...

bool	_raw
	A convenience flag used in subclasses. Not used by this class. More...

QByteArray	_rawData
	Raw binary data. Used if _raw=true. More...

QString	_reason
	The reason this may be invalid. Set by a subclass. More...

quint64	_size
	The size of the data. Always initialized to zero. Must be set in a subclass. More...

bool	_valid
	Defaults to false. A subclass will determine if _valid is true, like for instance if an underlying file doesn't exist. More...

Private Slots
void	modified (const QString &path)
	A slot for when the _watcher detects that there has been a change. More...

Friends
class	VFS_HD

Additional Inherited Members
Public Slots inherited from VFS_datastore_cache_entry
virtual void	timerEvent (QTimerEvent *e)
	Either a flush or expire has happened. More...

Signals inherited from VFS_datastore_cache_entry
void	expired (VFS_datastore_cache_entry *)
	Signal emitted when a cache entry has expired and is no longer in use. More...

void	touched ()
	Signal emitted when a cache entry has made a change and should climb the cache queue. More...

Public Attributes inherited from VFS_datastore_cache_entry
QString	_key
	The cache entry key. More...

Detailed Description

A subclass of VFS_datastore_cache_entry, used for disk access.

See also: VFS_datastore_cache_entry

Definition at line 14 of file VFS_hd.h.

Constructor & Destructor Documentation

◆ VFS_HD_cache_entry()

VFS_HD_cache_entry::VFS_HD_cache_entry	(	QString	path,
		bool	debug,
		int	flushInterval,
		int	expireInterval,
		bool	create = `false`,
		bool	container = `false`,
		bool	raw = `false`,
		bool	watch = `false`
	)

explicit

Parameters

path	The filesystem path of the file resource, which may be relative to the VFS executable or absolute
debug	Verbose debug mode
flushInterval	Interval to flush to disk, in milliseconds.
expireInterval	Interval to expire the cache entry, in milliseconds.
create	If the filesystem path doesn't exist and it's not a container, create an empty json object: `{}`.
container	When true, and create is true, create an empty directory instead
raw	Set the raw flag on this entry.
watch	Set the watch flag on this entry, which will expire an entry if a change happens outside of the VFS

Warning: DOCME: describe the logic here more thoroughly

Definition at line 112 of file VFS_hd.cpp.

◆ ~VFS_HD_cache_entry()

VFS_HD_cache_entry::~VFS_HD_cache_entry ( )

virtual

VFS_HD_cache_entry destructor.

Will call flush() if _dirty and _valid are true.

See also: VFS_datastore_cache_entry::~VFS_datastore_cache_entry()

Definition at line 288 of file VFS_hd.cpp.

Member Function Documentation

◆ flush()

void VFS_HD_cache_entry::flush ( )

protectedvirtual

Actually write the file to disk.

If the entry is not _dirty, this immediately returns. If data cannot be written to disk, the entry is left _dirty and a _reason is recorded.

If a partial file is written, a VFS::CRITICAL() message is sent, on suspicion that the disk is full.

On write success, _dirty is set to false, and the _size of the entry is updated.

Note: FIXME: The data size consumed in the cache should also be updated, but this is currently unimplemented.

Implements VFS_datastore_cache_entry.

Definition at line 354 of file VFS_hd.cpp.

◆ modified

void VFS_HD_cache_entry::modified ( const QString & path )

privateslot

A slot for when the _watcher detects that there has been a change.

Parameters

path	The changed path, which should be this path

This will emit expired() to remove this entry, as it needs to be re-cached.

Note: On a watched cache entry, flush() will cause the _watcher to see a change and will un-cache the entry. Have to think of a solution for this.

Definition at line 307 of file VFS_hd.cpp.

◆ valid()

bool VFS_HD_cache_entry::valid ( QString & reason )

virtual

If the file or directory does not exist or is not readable, _valid is set to false.

Parameters

reason If invalid, the reason will be written to this string.

Returns: The _valid flag value

This uses values in VFS_HD_cache_entry::_info. An attempt is made to not continuously hit the disk by checking if _valid is already true, however in a production environment this optimization may be invalid.

Reimplemented from VFS_datastore_cache_entry.

Definition at line 326 of file VFS_hd.cpp.

Friends And Related Function Documentation

◆ VFS_HD

friend class VFS_HD

friend

Definition at line 18 of file VFS_hd.h.

Member Data Documentation

◆ _info

QFileInfo VFS_HD_cache_entry::_info

protected

An info object, useful for type and metadata information.

Definition at line 28 of file VFS_hd.h.

◆ _path

QString VFS_HD_cache_entry::_path

protected

The actual file path.

Definition at line 27 of file VFS_hd.h.

◆ _watcher

QFileSystemWatcher VFS_HD_cache_entry::_watcher

protected

Watches for changes to the file or directory, and expires the entry on change.

Definition at line 29 of file VFS_hd.h.

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

Public Member Functions

Protected Member Functions

Protected Attributes

Private Slots

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ VFS_HD_cache_entry()

◆ ~VFS_HD_cache_entry()

Member Function Documentation

◆ flush()

◆ modified

◆ valid()

Friends And Related Function Documentation

◆ VFS_HD

Member Data Documentation

◆ _info

◆ _path

◆ _watcher