MAKLogger::DtLargeFileFunctions Class Reference

Provides an interface for large (64bit) File IO. More...

Static Public Member Functions
static DtFileDesc	openForReading (const DtFilename &filename, bool randomAccess)
	Open a file for reading.
static DtFileDesc	openForWriting (const DtFilename &filename, bool truncate=true)
	Open a file for writing.
static DtFileDesc	openForReadingAndWriting (DtFilename filename, bool truncate=false, bool randomAccess=true)
	Open a file for reading and writing.
static bool	close (DtFileDesc)
	Closes the file.
static DtInt64	size (DtFileDesc)
	Gets the size of the file in bytes.
static DtInt64	tell (DtFileDesc)
	Get the current position in the file.
static DtInt64	seekCurrent (DtFileDesc, DtInt64)
	Set the current position relative to it's current position.
static DtInt64	seekEnd (DtFileDesc, DtInt64)
	Set the current position relative to the end of the file.
static DtInt64	seekSet (DtFileDesc, DtInt64)
	Set the current position relative to the beginning of the file.
static size_t	read (DtFileDesc, void *buffer, size_t bytesToRead)
	Read data from the file into the supplied buffer.
template<typename T >
static bool	readStruct (DtFileDesc fd, T &structObject)
	Read a structure from the file.
static char *	readBytes (DtFileDesc, size_t bytesToRead, size_t &totalBytesRead)
	Read data into a newly created buffer.
static size_t	write (DtFileDesc, const void *buffer, size_t bytesToWrite)
	Write the data from the buffer into the file.
template<typename T >
static bool	writeStruct (DtFileDesc fd, const T &structObject)
	Write a structure to the file.

Detailed Description

Provides an interface for large (64bit) File IO.

Warning

For all functions that can fail, use errno an perror to get reason.

Member Function Documentation

static bool MAKLogger::DtLargeFileFunctions::close ( DtFileDesc  )

static

Closes the file.

Return values

true	The close succeeded.
false	The close failed.

static DtFileDesc MAKLogger::DtLargeFileFunctions::openForReading ( const DtFilename &  filename, bool  randomAccess  )

static

Open a file for reading.

Returns

Returns a file description.

Return values

0	Unable to open file for reading.

static DtFileDesc MAKLogger::DtLargeFileFunctions::openForReadingAndWriting ( DtFilename  filename, bool  truncate = false, bool  randomAccess = true  )

static

Open a file for reading and writing.

Returns

Returns a file description.

Return values

0	Unable to open file for reading and writing.

static DtFileDesc MAKLogger::DtLargeFileFunctions::openForWriting ( const DtFilename &  filename, bool  truncate = true  )

static

Open a file for writing.

Returns

Returns a valid file description.

Return values

0	Unable to open file for writing.

static size_t MAKLogger::DtLargeFileFunctions::read ( DtFileDesc  , void *  buffer, size_t  bytesToRead  )

static

Read data from the file into the supplied buffer.

Returns

Returns the number of bytes actually read.

Warning

This function is dangerous since buffer may not be large enough. Use readBytes for safer access. Also if the file was not opened to support reading this call will return zero.

Referenced by readStruct().

static char* MAKLogger::DtLargeFileFunctions::readBytes ( DtFileDesc  , size_t  bytesToRead, size_t &  totalBytesRead  )

static

Read data into a newly created buffer.

Returns

Returns a pointer to the data. This data will be allocated on the heap.

Return values

NULL	If the file does not support reading.

Warning

The buffer will contain undefined data after totalBytesRead bytes into the buffer if totalBytesRead != bytesToRead.

template<typename T >

static bool MAKLogger::DtLargeFileFunctions::readStruct ( DtFileDesc  fd, T &  structObject  )

inlinestatic

Read a structure from the file.

This function assumes the file data maps directly into the structure. This function will also work with built-in types.

Returns

Whether the read was successful.

Warning

If the read is not successful the object may not be in a complete state.

References read().

static DtInt64 MAKLogger::DtLargeFileFunctions::seekCurrent ( DtFileDesc  , DtInt64    )

static

Set the current position relative to it's current position.

Returns

Returns the position in the file relative to beginning.

static DtInt64 MAKLogger::DtLargeFileFunctions::seekEnd ( DtFileDesc  , DtInt64    )

static

Set the current position relative to the end of the file.

Returns

Returns the position in the file relative to beginning.

static DtInt64 MAKLogger::DtLargeFileFunctions::seekSet ( DtFileDesc  , DtInt64    )

static

Set the current position relative to the beginning of the file.

Returns

Returns the position in the file relative to beginning.

static DtInt64 MAKLogger::DtLargeFileFunctions::size ( DtFileDesc  )

static

Gets the size of the file in bytes.

static DtInt64 MAKLogger::DtLargeFileFunctions::tell ( DtFileDesc  )

static

Get the current position in the file.

static size_t MAKLogger::DtLargeFileFunctions::write ( DtFileDesc  , const void *  buffer, size_t  bytesToWrite  )

static

Write the data from the buffer into the file.

Returns

Returns the number of bytes written.

Warning

This function is dangerous since buffer may not be bytesToWrite.

Referenced by writeStruct().

template<typename T >

static bool MAKLogger::DtLargeFileFunctions::writeStruct ( DtFileDesc  fd, const T &  structObject  )

inlinestatic

Write a structure to the file.

This function assumes the file data maps directly into the structure. This function will also work with built-in types.

Warning

If the read is not successful the file may not be in a valid state. To solve this problem store the previous position and the position after the write to calculate the number of bytes written.

References write().

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

• largeFileFunctions.h