FX::QFile Class Reference
[File type i/o devices]

#include <QFile.h>

Inheritance diagram for FX::QFile:

[legend]

List of all members.

---

Detailed Description

An i/o device accessing the filing system directly (Qt compatible).

Not much to say about this - it works as you'd expect. It's also thread-safe so multiple threads can read and write from it (though the current file pointer is the same for both, so it probably doesn't help you much).

Most likely you'll prefer to use FX::QMemMap all the time as it offers superior performance and facilities in most cases. Indeed, QFile does no internal buffering as it is expected it will only be used rarely, mostly for small files with little i/o performed to them.

Like all file type i/o classes, QFile can perform automatic CR/LF translation as well as UTF-8 to UTF-16 and UTF-32 conversion. If you enable IO_Translate, the file data is probed and its unicode type determined such that the file unicode type is transparently converted into UTF-8 and back into its original form. This allows your code to work exclusively in UTF-8 using the standard FX::FXString functions. You can set the type of output using setUnicodeTranslation().

For speed, QFile maintains its own record of file length which it manages. This normally isn't a problem, but when multiple QFile's are working on the same file (either in-process or across processes) then the internal count can become desynchronised with the actual length. If you want to reset the length, call reloadSize().

One major difference is default security, especially on NT. QFile like all TnFOX sets very conservative permissions on all things it creates - see FX::FXACL::default_(). Note that until the file is opened, permissions() returns what will be applied to the file on open() rather than the file itself - if you want the latter, use the static method.

Warning:

Try not to call atEnd() too much. Because of limitations in POSIX it works by reading a byte which if successful means not EOF and a ungetch() or moving the file pointer back!

Public Types
enum	CRLFType { Default, Unix, MacOS, MSDOS }
enum	UnicodeType {   NoTranslation, UTF8, UTF16, UTF16LE,   UTF32, UTF32LE }
typedef FXfval	Offset
Public Member Functions
	QFile (const FXString &name)
const FXString &	name () const
void	setName (const FXString &name)
bool	exists () const
bool	remove ()
FXfval	reloadSize ()
virtual bool	open (FXuint mode)
virtual void	close ()
virtual void	flush ()
virtual FXfval	size () const
virtual void	truncate (FXfval size)
virtual FXfval	at () const
virtual bool	at (FXfval newpos)
virtual bool	atEnd () const
virtual const FXACL &	permissions () const
virtual void	setPermissions (const FXACL &perms)
virtual FXuval	readBlock (char *data, FXuval maxlen)
virtual FXuval	writeBlock (const char *data, FXuval maxlen)
virtual FXuval	readBlockFrom (char *data, FXuval maxlen, FXfval pos)
virtual FXuval	writeBlockTo (FXfval pos, const char *data, FXuval maxlen)
virtual int	ungetch (int c)
FXuint	flags () const
FXuint	mode () const
FXuint	state () const
CRLFType	crlfFormat () const
void	setCRLFFormat (CRLFType type)
UnicodeType	unicodeTranslation () const
void	setUnicodeTranslation (UnicodeType type)
bool	isBuffered () const
bool	isRaw () const
bool	isTranslated () const
bool	isUTF16Translated () const
bool	isUTF32Translated () const
bool	isReadable () const
bool	isWriteable () const
bool	isWritable () const
bool	isReadWrite () const
bool	isClosed () const
bool	isInactive () const
bool	isOpen () const
virtual bool	isSynchronous () const
FXuval	readBlock (FXuchar *data, FXuval maxlen)
FXuval	writeBlock (const FXuchar *data, FXuval maxlen)
virtual FXuval	readLine (char *data, FXuval maxlen)
FXuval	readBlockFrom (FXuchar *data, FXuval maxlen, FXfval pos)
FXuval	writeBlockTo (FXfval pos, const FXuchar *data, FXuval maxlen)
virtual int	getch ()
virtual int	putch (int c)
FXfval	shredData (FXfval offset, FXfval len=(FXfval)-1)
Static Public Member Functions
static QIODevice &	stdio (bool applyCRLFTranslation=false)
static FXACL	permissions (const FXString &path)
static void	setPermissions (const FXString &path, const FXACL &perms)
static UnicodeType	determineUnicodeType (FXuchar *data, FXuval len) throw ()
static FXuval	applyCRLF (FXuchar *FXRESTRICT output, const FXuchar *FXRESTRICT input, FXuval outputlen, FXuval &inputlen, CRLFType crlftype=Default, UnicodeType utftype=NoTranslation)
static FXuval	removeCRLF (FXuchar *FXRESTRICT output, const FXuchar *FXRESTRICT input, FXuval outputlen, FXuval &inputlen, UnicodeType utftype=NoTranslation)
Protected Member Functions
void	setFlags (int f)
void	setMode (int m)
void	setState (int s)
Protected Attributes
FXfval	ioIndex
Friends
class	QMemMap
class	FXProcess
FXAPI FXStream &	operator<< (FXStream &s, QIODevice &i)
FXAPI FXStream &	operator>> (FXStream &s, QIODevice &i)

---

Member Enumeration Documentation

enum FX::QIODevice::CRLFType [inherited]

The type of CR/LF encoding you want.

Enumerator:

Default	Uses the host OS format.
Unix	Uses ASCII 10 to delimit lines.
MacOS	Uses ASCII 13 to delimit lines.
MSDOS	Uses ASCII 13,10 to delimit lines.

enum FX::QIODevice::UnicodeType [inherited]

The type of unicode translation you want.

Enumerator:

NoTranslation	Performs no translation.
UTF8	Outputs in native UTF-8.
UTF16	Converts between native (UTF-8) and UTF-16 big endian.
UTF16LE	Converts between native (UTF-8) and UTF-16 little endian.
UTF32	Converts between native (UTF-8) and UTF-32 big endian.
UTF32LE	Converts between native (UTF-8) and UTF-32 little endian.

---

Constructor & Destructor Documentation

FX::QFile::QFile

(

const FXString &

name

)

Constructs a new instance, setting the file name to be used to name.

---

Member Function Documentation

const FXString& FX::QFile::name

(

)

const

Returns the file name being addressed by this device.

void FX::QFile::setName

(

const FXString &

name

)

Sets the file name being addressed by this device. Closes the old file first.

bool FX::QFile::exists

(

)

const

Returns true if the file name points to an existing file.

bool FX::QFile::remove

(

)

Deletes the file name, closing the file first if open. Returns false if file doesn't exist.

FXfval FX::QFile::reloadSize

(

)

Reloads the size of the file. See description above.

static QIODevice& FX::QFile::stdio

(

bool

applyCRLFTranslation = false

)

[static]

Returns an QIODevice referring to stdin/stdout. This is somewhat of a special device in that it can't be closed, doesn't have a size and reads from it can block.

See also:

QPipe

virtual bool FX::QFile::open

(

FXuint

mode

)

[virtual]

Opens the device for the specified access.

Implements FX::QIODevice.

virtual void FX::QFile::close

(

)

[virtual]

Closes the device.

Implements FX::QIODevice.

virtual void FX::QFile::flush

(

)

[virtual]

Flushes the device's write buffer.

Implements FX::QIODevice.

virtual FXfval FX::QFile::size

(

)

const [virtual]

Returns the size of the data being accessed by the device.

Implements FX::QIODevice.

virtual void FX::QFile::truncate

(

FXfval

size

)

[virtual]

Truncates the data to the specified size. Extends the file if necessary & doesn't affect the current file pointer unless it is beyond the new file size, in which case it is moved to the end of the new file

Implements FX::QIODevice.

virtual FXfval FX::QFile::at

(

)

const [virtual]

Returns the current file pointer within the device

Note:

With IO_Translate enabled, this increments faster than the return values from either readBlock() or writeBlock()

Reimplemented from FX::QIODevice.

virtual bool FX::QFile::at

(

FXfval

newpos

)

[virtual]

Sets the current file pointer

Note:

With IO_Translate enabled, setting to anything other than a previously read at() can be hazardous.

Reimplemented from FX::QIODevice.

virtual bool FX::QFile::atEnd

(

)

const [virtual]

Returns true if there is no more data available to be read from the device.

Reimplemented from FX::QIODevice.

virtual const FXACL& FX::QFile::permissions

(

)

const [virtual]

Returns the ACL for this device.

Reimplemented from FX::QIODevice.

virtual void FX::QFile::setPermissions

(

const FXACL &

)

[virtual]

Sets the ACL for this device.

Reimplemented from FX::QIODevice.

static FXACL FX::QFile::permissions

(

const FXString &

path

)

[static]

Returns the permissions for the file at the specified path.

static void FX::QFile::setPermissions	(	const FXString &	path,
		const FXACL &	perms
	)			[static]

Sets the permissions for the file at the specified path.

virtual FXuval FX::QFile::readBlock	(	char *	data,
		FXuval	maxlen
	)			[virtual]

Reads up to the specified quantity of bytes into the buffer, returning how much was actually read

Note:

With IO_Translate enabled, this routine regularly returns less read than maxlen (as the CR's are stripped out).

Implements FX::QIODevice.

virtual FXuval FX::QFile::writeBlock	(	const char *	data,
		FXuval	maxlen
	)			[virtual]

Writes up to the specified quantity of bytes from the buffer, returning how much was actually written. Note that less being written due to error is returned as an exception, but some devices may write less in a non-error situation.

Implements FX::QIODevice.

virtual FXuval FX::QFile::readBlockFrom	(	char *	data,
		FXuval	maxlen,
		FXfval	pos
	)			[virtual]

Combines an at() and readBlock() together. Can be much more efficient than those two operations individually with some i/o devices, plus it's synchronous and thus threadsafe

Implements FX::QIODevice.

virtual FXuval FX::QFile::writeBlockTo	(	FXfval	pos,
		const char *	data,
		FXuval	maxlen
	)			[virtual]

Combines an at() and writeBlock() together. Can be much more efficient than those two operations individually with some i/o devices, plus it's synchronous and thus threadsafe

Implements FX::QIODevice.

virtual int FX::QFile::ungetch

(

int

c

)

[virtual]

Pushes back a byte to the read buffer.

Implements FX::QIODevice.

FXuint FX::QIODevice::flags

(

)

const [inline, inherited]

Returns the flags of this device.

FXuint FX::QIODevice::mode

(

)

const [inline, inherited]

Returns the mode of this device

See also:

QIODeviceOpenFlags

FXuint FX::QIODevice::state

(

)

const [inline, inherited]

Returns the state of this device

See also:

QIODeviceStateFlags

CRLFType FX::QIODevice::crlfFormat

(

)

const [inline, inherited]

Returns the CR/LF format of this device.

void FX::QIODevice::setCRLFFormat

(

CRLFType

type

)

[inline, inherited]

Sets the CR/LF format for output of this device.

UnicodeType FX::QIODevice::unicodeTranslation

(

)

const [inline, inherited]

Returns the unicode translation of this device.

void FX::QIODevice::setUnicodeTranslation

(

UnicodeType

type

)

[inline, inherited]

Sets the unicode translation of this device.

bool FX::QIODevice::isBuffered

(

)

const [inline, inherited]

Returns true if the device is buffered.

bool FX::QIODevice::isRaw

(

)

const [inline, inherited]

Returns true if the device is unbuffered.

bool FX::QIODevice::isTranslated

(

)

const [inline, inherited]

Returns true if the device is LR/CF translated.

bool FX::QIODevice::isUTF16Translated

(

)

const [inline, inherited]

Returns true if the device is UTF-16 translated.

bool FX::QIODevice::isUTF32Translated

(

)

const [inline, inherited]

Returns true if the device is UTF-32 translated.

bool FX::QIODevice::isReadable

(

)

const [inline, inherited]

Returns true if the device is readable.

bool FX::QIODevice::isWriteable

(

)

const [inline, inherited]

Returns true if the device is writeable.

bool FX::QIODevice::isReadWrite

(

)

const [inline, inherited]

Returns true if the device is readable & writeable.

bool FX::QIODevice::isClosed

(

)

const [inline, inherited]

Returns true if the device is closed.

bool FX::QIODevice::isOpen

(

)

const [inline, inherited]

Returns true if the device is opened.

virtual bool FX::QIODevice::isSynchronous

(

)

const [inline, virtual, inherited]

Returns true if this device is a synchronous device.

Reimplemented in FX::QIODeviceS, and FX::QSSLDevice.

virtual FXuval FX::QIODevice::readLine	(	char *	data,
		FXuval	maxlen
	)			[virtual, inherited]

Reads data until an end-of-line or maxlen is exceeded.

virtual int FX::QIODevice::getch

(

)

[virtual, inherited]

Reads a single byte. Returns -1 for no data found.

Reimplemented in FX::QBuffer, FX::QBZip2Device, FX::QGZipDevice, and FX::QMemMap.

virtual int FX::QIODevice::putch

(

int

c

)

[virtual, inherited]

Writes a single byte.

Reimplemented in FX::QBuffer, FX::QBZip2Device, FX::QGZipDevice, and FX::QMemMap.

static UnicodeType FX::QIODevice::determineUnicodeType	(	FXuchar *	data,
		FXuval	len
	)			throw () [static, inherited]

Looks at a sample of data and determines what kind of Unicode text it is, returning UnicodeType::NoTranslation if it isn't text. This routine isn't foolproof, but it's a good guess

static FXuval FX::QIODevice::applyCRLF	(	FXuchar *FXRESTRICT	output,
		const FXuchar *FXRESTRICT	input,
		FXuval	outputlen,
		FXuval &	inputlen,
		CRLFType	crlftype = Default,
		UnicodeType	utftype = NoTranslation
	)			[static, inherited]

Applies CR/LF and optional UTF-x translation returning bytes output. If outputlen would run out before inputlen can be exhausted it will return early (eg; if mid newline, or mid UTF-x sequence). You should rewind processing to the difference between entrant inputlen and returned inputlen.

static FXuval FX::QIODevice::removeCRLF	(	FXuchar *FXRESTRICT	output,
		const FXuchar *FXRESTRICT	input,
		FXuval	outputlen,
		FXuval &	inputlen,
		UnicodeType	utftype = NoTranslation
	)			[static, inherited]

Removes CR/LF translation intelligently (ie; self-adjusts to MS-DOS, Unix and MacOS formats or any mixture of these) and can perform optional UTF-x translation, returning bytes output. If outputlen would run out before inputlen can be exhausted it will return early (eg; if mid newline, or mid UTF-x sequence). You should rewind processing to the difference between entrant inputlen and returned inputlen.

FXfval FX::QIODevice::shredData	(	FXfval	offset,
		FXfval	len = (FXfval)-1
	)			[inherited]

Destroys the len bytes of data from offset offset into the file. Restores the file pointer afterwards and returns how much data was shredded before end of file if encountered. You must have the device open for both reading and writing for this call to succeed.

void FX::QIODevice::setFlags

(

int

f

)

[inline, protected, inherited]

Sets the flags.

void FX::QIODevice::setMode

(

int

m

)

[inline, protected, inherited]

Sets the mode.

void FX::QIODevice::setState

(

int

s

)

[inline, protected, inherited]

Sets the state.

---

Friends And Related Function Documentation

FXAPI FXStream& operator<<	(	FXStream &	s,
		QIODevice &	i
	)			[friend, inherited]

Appends the contents of an i/o device to stream s

Warning:

This operation is not thread-safe

FXAPI FXStream& operator>>	(	FXStream &	s,
		QIODevice &	i
	)			[friend, inherited]

Reads all available contents of the stream s to an i/o device, replacing its current contents and resetting the file pointer to the start

Warning:

This operation is not thread-safe

---

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

• QFile.h