file Class Reference
[I/O primitives layer]

Defines interface of file. More...

#include <iobase.h>

Inheritance diagram for file:

[legend]

List of all members.

Public Types
enum	open_mode {   RDONLY = 1, WRONLY = 2, RDWR = 4, CREAT = 8,   DIRECT = 16, TRUNC = 32 }
	Definition of acceptable file open modes. More...
Public Member Functions
virtual request_ptr	aread (void *buffer, stxxl::int64 pos, size_t bytes, completion_handler on_cmpl)=0
	Schedules asynchronous read request to the file.
virtual request_ptr	awrite (void *buffer, stxxl::int64 pos, size_t bytes, completion_handler on_cmpl)=0
	Schedules asynchronous write request to the file.
virtual void	set_size (stxxl::int64 newsize)=0
	Changes the size of the file.
virtual stxxl::int64	size ()=0
	Returns size of the file.
int	get_disk_number ()
	deprecated, use stxxl::file::get_id() instead
int	get_id ()
	Returns file's identifier.
virtual void	lock ()
	Locks file for reading and writing.
Protected Member Functions
	file (int _id)
	Initializes file object.

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Detailed Description

Defines interface of file.

It is a base class for different implementations that might base on various file systems or even remote storage interfaces

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Member Enumeration Documentation

enum file::open_mode

Definition of acceptable file open modes.

Various open modes in a file system must be converted to this set of acceptable modes

Enumerator:

RDONLY	only reading of the file is allowed
WRONLY	only writing of the file is allowed
RDWR	read and write of the file are allowed
CREAT	in case file does not exist no error occurs and file is newly created
DIRECT	I/Os proceed bypassing file system buffers, i.e. unbuffered I/O.
TRUNC	once file is opened its length becomes zero

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Constructor & Destructor Documentation

file::file

(

int

_id

)

[inline, protected]

Initializes file object.

Parameters:

_id

file identifier

Remarks:

Called in implementations of file

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Member Function Documentation

virtual request_ptr file::aread	(	void *	buffer,
		stxxl::int64	pos,
		size_t	bytes,
		completion_handler	on_cmpl
	)			[pure virtual]

Schedules asynchronous read request to the file.

Parameters:

	buffer	pointer to memory buffer to read into
	pos	starting file position to read
	bytes	number of bytes to transfer
	on_cmpl	I/O completion handler

Returns:

request_ptr object, that can be used to track the status of the operation

Implemented in mmap_file, sim_disk_file, and syscall_file.

Referenced by typed_block< sizeof(block_type::value_type), block_type::value_type >::read().

virtual request_ptr file::awrite	(	void *	buffer,
		stxxl::int64	pos,
		size_t	bytes,
		completion_handler	on_cmpl
	)			[pure virtual]

Schedules asynchronous write request to the file.

Parameters:

	buffer	pointer to memory buffer to write from
	pos	starting file position to write
	bytes	number of bytes to transfer
	on_cmpl	I/O completion handler

Returns:

request_ptr object, that can be used to track the status of the operation

Implemented in mmap_file, sim_disk_file, and syscall_file.

Referenced by typed_block< sizeof(block_type::value_type), block_type::value_type >::write().

virtual void file::set_size

(

stxxl::int64

newsize

)

[pure virtual]

Changes the size of the file.

Parameters:

newsize

value of the new file size

Implemented in sim_disk_file, and ufs_file_base.

Referenced by vector< Tp_, PgSz_, PgTp_, BlkSize_, AllocStr_, SzTp_ >::vector().

virtual stxxl::int64 file::size

(

)

[pure virtual]

Returns size of the file.

Returns:

file size in bytes

Implemented in ufs_file_base.

int file::get_disk_number

(

)

[inline]

deprecated, use stxxl::file::get_id() instead

Referenced by block_manager::delete_block(), and vector< Tp_, PgSz_, PgTp_, BlkSize_, AllocStr_, SzTp_ >::vector().

int file::get_id

(

)

[inline]

Returns file's identifier.

Remarks:

might be used as disk's id in case disk to file mapping

Returns:

integer file identifier, passed as constructor parameter

Referenced by syscall_file::aread(), sim_disk_file::aread(), mmap_file::aread(), syscall_file::awrite(), sim_disk_file::awrite(), and mmap_file::awrite().

virtual void file::lock

(

)

[inline, virtual]

Locks file for reading and writing.

Reimplemented in ufs_file_base.

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

• iobase.h