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

#include <QFile.h>

Inheritance diagram for FX::QFile:

Inheritance graph
[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 FXStringname () 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 FXACLpermissions () 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 QIODevicestdio (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 FXStreamoperator<< (FXStream &s, QIODevice &i)
FXAPI FXStreamoperator>> (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:

(C) 2002-2008 Niall Douglas. Some parts (C) to assorted authors.
Generated on Fri Jun 13 22:27:42 2008 for TnFOX by doxygen v1.5.6