Functions to manage file blocks. More...

Functions
uint32_t	soGetFileBlock (int ih, uint32_t fbn)
	Get the data block number corresponding to the given file block. More...

uint32_t	soAllocFileBlock (int ih, uint32_t fbn)
	Associate a data block to the given file block position. More...

void	soFreeFileBlocks (int ih, uint32_t ffbn)
	Free all file blocks from the given position on. More...

void	soReadFileBlock (int ih, uint32_t fbn, void *buf)
	Read a file block. More...

void	soWriteFileBlock (int ih, uint32_t fbn, void *buf)
	Write a file block. More...

Detailed Description

Functions to manage file blocks.

Remarks: In case an error occurs, every function throws an SOException

Function Documentation

◆ soGetFileBlock()

uint32_t sofs19::soGetFileBlock	(	int	ih,
		uint32_t	fbn
	)

Get the data block number corresponding to the given file block.

Parameters

ih	inode handler
fbn	file block number

Remarks

Assumes ih is a valid handler of an inode in use opened;
Error EINVAL is thrown if fbn is not valid;
when calling a function of any layer, the version with prefix so is used.

Returns: the number of the corresponding block

◆ soAllocFileBlock()

uint32_t sofs19::soAllocFileBlock	(	int	ih,
		uint32_t	fbn
	)

Associate a data block to the given file block position.

Parameters

ih	inode handler
fbn	file block number

Remarks

Assumes ih is a valid handler of an inode in use opened;
Error EINVAL is thrown if fbn is not valid;
depending on the situation, 1, 2, or 3 data blocks are allocated;
when calling a function of any layer, the version with prefix so is used.

Returns: the number of the allocated block

◆ soFreeFileBlocks()

void sofs19::soFreeFileBlocks	(	int	ih,
		uint32_t	ffbn
	)

Free all file blocks from the given position on.

Parameters

ih	inode handler
ffbn	first file block number

Remarks

Assumes ih is a valid handler of an inode in use opened;
data blocks used to store references that become empty are also freed;
when calling a function of any layer, the version with prefix so is used.

◆ soReadFileBlock()

void sofs19::soReadFileBlock	(	int	ih,
		uint32_t	fbn,
		void *	buf
	)

Read a file block.

Data is read from a specific data block which is supposed to belong to an inode associated to a file (a regular file, a directory or a symbolic link).

Parameters

ih	inode handler
fbn	file block number
buf	pointer to the buffer where data must be read into

Remarks

Assumes ih is a valid handler of an inode in use opened;
If the referred file block has not been allocated yet, the returned data will consist of a byte stream filled with the null character (ascii code 0);
when calling a function of any layer, the version with prefix so is used.

◆ soWriteFileBlock()

void sofs19::soWriteFileBlock	(	int	ih,
		uint32_t	fbn,
		void *	buf
	)

Write a file block.

Data is written into a specific data block which is supposed to belong to an inode associated to a file (a regular file, a directory or a symbolic link).

Parameters

ih	inode handler
fbn	file block number
buf	pointer to the buffer containing data to be written

Remarks

Assumes ih is a valid handler of an inode in use opened;
If the referred block has not been allocated yet, it should be allocated now so that the data can be stored as its contents;
when calling a function of any layer, the version with prefix so is used.