#include <file.h>

Inheritance diagram for miosix::DirectoryBase:

Collaboration diagram for miosix::DirectoryBase:

Public Member Functions
	DirectoryBase (intrusive_ref_ptr< FilesystemBase > parent)

virtual ssize_t	write (const void *data, size_t len)

virtual ssize_t	read (void *data, size_t len)

virtual off_t	lseek (off_t pos, int whence)

virtual int	fstat (struct stat *pstat) const

Public Member Functions inherited from miosix::FileBase
	FileBase (intrusive_ref_ptr< FilesystemBase > parent)

virtual int	isatty () const

virtual int	fcntl (int cmd, int opt)

virtual int	ioctl (int cmd, void *arg)

virtual int	getdents (void *dp, int len)

const intrusive_ref_ptr < FilesystemBase >	getParent () const

virtual	~FileBase ()

Static Protected Member Functions
static int	addEntry (char *pos, char end, int ino, char type, const StringPart &n)

static int	addDefaultEntries (char **pos, int thisIno, int upIno)

static int	addTerminatingEntry (char *pos, char end)

Static Protected Attributes
static const int	direntHeaderSizeNoPadding =offsetof(struct dirent,d_name)

static const int	direntHeaderSize =(direntHeaderSizeNoPadding+3+3)/4*4

static const int	minimumBufferSize =3*direntHeaderSize
	Minimum buffer accepted by getdents, two for . and .., plus terminating.

Additional Inherited Members
Protected Member Functions inherited from miosix::IntrusiveRefCounted
	IntrusiveRefCounted ()

	IntrusiveRefCounted (const IntrusiveRefCounted &)

IntrusiveRefCounted &	operator= (const IntrusiveRefCounted &)

Detailed Description

Directories are a special kind of files that implement the getdents() call Classes of this type are reference counted, must be allocated on the heap and managed through intrusive_ref_ptr<DirectoryBase>

Constructor & Destructor Documentation

miosix::DirectoryBase::DirectoryBase ( intrusive_ref_ptr< FilesystemBase > parent )

inline

Constructor

Parameters

parent the filesystem to which this file belongs

Member Function Documentation

int miosix::DirectoryBase::addDefaultEntries	(	char **	pos,
		int	thisIno,
		int	upIno
	)

staticprotected

Helper function to add the default directory entries . and .. to a buffer

Parameters

pos	position where to add the entry (four word aligned). Pointer is incremented. The caller is responsible to guarantee that there is at least space for 2*direntHeaderSize
thisIno	inode number of .
upInode	inode number of ..

Returns: the number of bytes written

int miosix::DirectoryBase::addEntry	(	char **	pos,
		char *	end,
		int	ino,
		char	type,
		const StringPart &	n
	)

staticprotected

Helper function to add a directory entry to a buffer

Parameters

pos	position where to add the entry (four word aligned). Pointer is incremented.
end	end of buffer (one char past the last), for bound checking
ino	inode of file
type	file type
name	file name to append after the DirentHeader

Returns: the number of bytes written or -1 on failure (no space in buffer)

int miosix::DirectoryBase::addTerminatingEntry	(	char **	pos,
		char *	end
	)

staticprotected

Add an entry with d_reclen=0 which is used to terminate directory listing

Parameters

pos	position where to add the entry (four word aligned). Pointer is incremented. The caller is responsible to guarantee that there is at least space for direntHeaderSize, including padding
end	end of buffer (one char past the last), for bound checking

Returns: the number of bytes written or -1 on failure (no space in buffer)

int miosix::DirectoryBase::fstat ( struct stat * pstat ) const

virtual

Return file information.

Parameters

pstat pointer to stat struct

Returns: 0 on success, or a negative number on failure

Implements miosix::FileBase.

off_t miosix::DirectoryBase::lseek	(	off_t	pos,
		int	whence
	)

virtual

Move file pointer, if the file supports random-access.

Parameters

pos	offset to sum to the beginning of the file, current position or end of file, depending on whence
whence	SEEK_SET, SEEK_CUR or SEEK_END

Returns: the offset from the beginning of the file if the operation completed, or a negative number in case of errors

Implements miosix::FileBase.

ssize_t miosix::DirectoryBase::read	(	void *	data,
		size_t	len
	)

virtual

Read data from the file, if the file supports reading.

Parameters

data	buffer to store read data
len	the number of bytes to read

Returns: the number of read characters, or a negative number in case of errors

Implements miosix::FileBase.

ssize_t miosix::DirectoryBase::write	(	const void *	data,
		size_t	len
	)

virtual

Write data to the file, if the file supports writing.

Parameters

data	the data to write
len	the number of bytes to write

Returns: the number of written characters, or a negative number in case of errors

Implements miosix::FileBase.

Member Data Documentation

const int miosix::DirectoryBase::direntHeaderSize =(direntHeaderSizeNoPadding+3+3)/4*4

staticprotected

Size of struct dirent including room for the "." and ".." string in d_name, including terminating \0 and padding for 4-word alignment. First +3: make room for '..\0', 3 bytes Second +3 and /4*4: four word alignment

const int miosix::DirectoryBase::direntHeaderSizeNoPadding =offsetof(struct dirent,d_name)

staticprotected

Size of struct dirent excluding d_name. That is, the size of d_ino, d_off, d_reclen and d_type. Notice that there are 4 bytes of padding between d_ino and d_off as d_off is a 64 bit number. Should be 19.

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

file.h
file.cpp

Public Member Functions

Static Protected Member Functions

Static Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation