casacore::BucketFile Class Reference

File object for BucketCache. More...

#include <BucketFile.h>

List of all members.

Public Member Functions
	BucketFile (const String &fileName, uInt bufSizeFile=0, Bool mappedFile=False, MultiFileBase *mfile=0)
	Create a BucketFile object for a new file.
	BucketFile (const String &fileName, Bool writable, uInt bufSizeFile=0, Bool mappedFile=False, MultiFileBase *mfile=0)
	Create a BucketFile object for an existing file.
virtual	~BucketFile ()
	The destructor closes the file (if open).
virtual CountedPtr< ByteIO >	makeFilebufIO (uInt bufferSize)
	Make a (temporary) buffered IO object for this file.
MMapfdIO *	mappedFile ()
	Get the mapped file object.
FilebufIO *	bufferedFile ()
	Get the buffered file object.
virtual void	open ()
	Open the file if not open yet.
virtual void	close ()
	Close the file (if open).
virtual void	remove ()
	Remove the file (and close it if needed).
virtual void	fsync ()
	Fsync the file (i.e.
virtual void	setRW ()
	Set the file to read/write access.
virtual const String &	name () const
	Get the file name.
Bool	isWritable () const
	Has the file logically been indicated as writable?
virtual uInt	read (void *buffer, uInt length)
	Read bytes from the file.
virtual uInt	write (const void *buffer, uInt length)
	Write bytes into the file.
virtual void	seek (Int64 offset)
	Seek in the file.
void	seek (Int offset)
virtual Int64	fileSize () const
	Get the (physical) size of the file.
Bool	isCached () const
	Is the file cached, mapped, or buffered?
Bool	isMapped () const
Bool	isBuffered () const
Private Member Functions
	BucketFile (const BucketFile &)
	Forbid copy constructor.
BucketFile &	operator= (const BucketFile &)
	Forbid assignment.
void	createMapBuf ()
	Create the mapped or buffered file object.
void	deleteMapBuf ()
	Delete the possible mapped or buffered file object.
Private Attributes
String	name_p
	The file name.
Bool	isWritable_p
	The (logical) writability of the file.
Bool	isMapped_p
uInt	bufSize_p
int	fd_p
CountedPtr< ByteIO >	file_p
	The unbuffered file.
MMapfdIO *	mappedFile_p
	The optional mapped file.
FilebufIO *	bufferedFile_p
	The optional buffered file.
MultiFileBase *	mfile_p
	The possibly used MultiFileBase.

---

Detailed Description

File object for BucketCache.

Intended use:

Internal

Review Status

Reviewed By:

UNKNOWN

Date Reviewed:

before2004/08/25

Etymology

BucketFile represents a data file for the BucketCache class.

Synopsis

A BucketFile object represents a data file. Currently it is used by the Table system, but it can easily be turned into a more general storage manager file class.
Creation of a BucketFile object does not open the file yet. An explicit open call has to be given before the file can be used.

The file can be opened as an ordinary file (with a file descriptor) or as a file in a MultiFileBase object. An ordinary file can be accessed in 3 ways:

• In an unbuffered way, where the parent BucketCache class accesses a bucket at a time (and possibly keeps it in a cache).
• In a memory-mapped way, where the parent BucketMapped class does the access using the MMapfdIO member.
• In a buffered way, where the parent BucketBuffered class does the access using the FilebufIO member.

A MultiFileBase file can only be accessed in the unbuffered way.

Motivation

Encapsulate the file creation and access into a single class to hide the file IO details.

Example

 // Create the file for the given storage manager.
 BucketFile file ("file.name");
 // Open the file and write into it.
 file.open();
 file.write (someBuffer, someLength);
 // Get the length of the file.
 uInt size = file.fileSize();

To Do

• Use the ByteIO classes when they are ready.

Definition at line 107 of file BucketFile.h.

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Constructor & Destructor Documentation

casacore::BucketFile::BucketFile	(	const String &	fileName,
		uInt	bufSizeFile = 0,
		Bool	mappedFile = False,
		MultiFileBase *	mfile = 0
	)			[explicit]

Create a BucketFile object for a new file.

The file with the given name will be created as a normal file or as part of a MultiFileBase (if mfile != 0). It can be indicated if a MMapfdIO and/or FilebufIO object must be created for the file. If a MultiFileBase is used, memory-mapped IO cannot be used and mappedFile is ignored.

casacore::BucketFile::BucketFile	(	const String &	fileName,
		Bool	writable,
		uInt	bufSizeFile = 0,
		Bool	mappedFile = False,
		MultiFileBase *	mfile = 0
	)

Create a BucketFile object for an existing file.

The file should be opened by the open. Tell if the file must be opened writable. It can be indicated if a MMapfdIO and/or FilebufIO object must be created for the file. If a MultiFileBase is used, memory-mapped IO cannot be used and mappedFile is ignored.

virtual casacore::BucketFile::~BucketFile

(

)

[virtual]

The destructor closes the file (if open).

casacore::BucketFile::BucketFile

(

const BucketFile &

)

[private]

Forbid copy constructor.

---

Member Function Documentation

FilebufIO* casacore::BucketFile::bufferedFile

(

)

[inline]

Get the buffered file object.

Definition at line 142 of file BucketFile.h.

References bufferedFile_p.

virtual void casacore::BucketFile::close

(

)

[virtual]

Close the file (if open).

void casacore::BucketFile::createMapBuf

(

)

[private]

Create the mapped or buffered file object.

void casacore::BucketFile::deleteMapBuf

(

)

[private]

Delete the possible mapped or buffered file object.

virtual Int64 casacore::BucketFile::fileSize

(

)

const [virtual]

Get the (physical) size of the file.

This is doing a seek and sets the file pointer to end-of-file.

virtual void casacore::BucketFile::fsync

(

)

[virtual]

Fsync the file (i.e.

force the data to be physically written).

Bool casacore::BucketFile::isBuffered

(

)

const [inline]

Definition at line 235 of file BucketFile.h.

References bufSize_p.

Bool casacore::BucketFile::isCached

(

)

const [inline]

Is the file cached, mapped, or buffered?

Definition at line 231 of file BucketFile.h.

References bufSize_p, and isMapped_p.

Bool casacore::BucketFile::isMapped

(

)

const [inline]

Definition at line 233 of file BucketFile.h.

References isMapped_p.

Bool casacore::BucketFile::isWritable

(

)

const [inline]

Has the file logically been indicated as writable?

Definition at line 225 of file BucketFile.h.

References isWritable_p.

virtual CountedPtr<ByteIO> casacore::BucketFile::makeFilebufIO

(

uInt

bufferSize

)

[virtual]

Make a (temporary) buffered IO object for this file.

That object should not close the file.

MMapfdIO* casacore::BucketFile::mappedFile

(

)

[inline]

Get the mapped file object.

Definition at line 138 of file BucketFile.h.

References mappedFile_p.

const String & casacore::BucketFile::name

(

)

const [inline, virtual]

Get the file name.

Definition at line 222 of file BucketFile.h.

References name_p.

virtual void casacore::BucketFile::open

(

)

[virtual]

Open the file if not open yet.

Referenced by casacore::TSMFile::open().

BucketFile& casacore::BucketFile::operator=

(

const BucketFile &

)

[private]

Forbid assignment.

virtual uInt casacore::BucketFile::read	(	void *	buffer,
		uInt	length
	)			[virtual]

Read bytes from the file.

virtual void casacore::BucketFile::remove

(

)

[virtual]

Remove the file (and close it if needed).

void casacore::BucketFile::seek

(

Int

offset

)

[inline]

Definition at line 228 of file BucketFile.h.

References seek().

virtual void casacore::BucketFile::seek

(

Int64

offset

)

[virtual]

Seek in the file.

Referenced by seek().

virtual void casacore::BucketFile::setRW

(

)

[virtual]

Set the file to read/write access.

It is reopened if not writable. It does nothing if the file is already writable.

virtual uInt casacore::BucketFile::write	(	const void *	buffer,
		uInt	length
	)			[virtual]

Write bytes into the file.

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Member Data Documentation

FilebufIO* casacore::BucketFile::bufferedFile_p [private]

The optional buffered file.

Definition at line 203 of file BucketFile.h.

Referenced by bufferedFile().

uInt casacore::BucketFile::bufSize_p [private]

Definition at line 196 of file BucketFile.h.

Referenced by isBuffered(), and isCached().

int casacore::BucketFile::fd_p [private]

Definition at line 197 of file BucketFile.h.

CountedPtr<ByteIO> casacore::BucketFile::file_p [private]

The unbuffered file.

Definition at line 199 of file BucketFile.h.

Bool casacore::BucketFile::isMapped_p [private]

Definition at line 195 of file BucketFile.h.

Referenced by isCached(), and isMapped().

Bool casacore::BucketFile::isWritable_p [private]

The (logical) writability of the file.

Definition at line 194 of file BucketFile.h.

Referenced by isWritable().

MMapfdIO* casacore::BucketFile::mappedFile_p [private]

The optional mapped file.

Definition at line 201 of file BucketFile.h.

Referenced by mappedFile().

MultiFileBase* casacore::BucketFile::mfile_p [private]

The possibly used MultiFileBase.

Definition at line 205 of file BucketFile.h.

String casacore::BucketFile::name_p [private]

The file name.

Definition at line 192 of file BucketFile.h.

Referenced by name().

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

• casacore/casa/IO/BucketFile.h