/tmp/buildd/xz-utils-5.0.0/src/xz/file_io.h File Reference

I/O types and functions. More...

Data Structures
union	io_buf
struct	file_pair
Defines
#define	IO_BUFFER_SIZE   8192
Functions
void	io_init (void)
	Initialize the I/O module.
void	io_no_sparse (void)
	Disable creation of sparse files when decompressing.
file_pair *	io_open_src (const char *src_name)
	Open the source file.
bool	io_open_dest (file_pair *pair)
	Open the destination file.
void	io_close (file_pair *pair, bool success)
	Closes the file descriptors and frees possible allocated memory.
size_t	io_read (file_pair *pair, io_buf *buf, size_t size)
	Reads from the source file to a buffer.
bool	io_pread (file_pair *pair, io_buf *buf, size_t size, off_t pos)
	Read from source file from given offset to a buffer.
bool	io_write (file_pair *pair, const io_buf *buf, size_t size)
	Writes a buffer to the destination file.

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Detailed Description

I/O types and functions.

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Function Documentation

void io_init

(

void

)

Initialize the I/O module.

void io_no_sparse

(

void

)

Disable creation of sparse files when decompressing.

References try_sparse.

file_pair* io_open_src

(

const char *

src_name

)

Open the source file.

References io_open_src_real(), is_empty_filename(), signals_block(), signals_unblock(), and file_pair::src_name.

Referenced by coder_run(), and list_file().

bool io_open_dest

(

file_pair *

pair

)

Open the destination file.

References signals_block(), and signals_unblock().

Referenced by coder_run().

void io_close	(	file_pair *	pair,
		bool	success
	)

Closes the file descriptors and frees possible allocated memory.

The success argument determines if source or destination file gets unlinked:

• false: The destination file is unlinked.
• true: The source file is unlinked unless writing to stdout or --keep was used.

References file_pair::dest_fd, file_pair::dest_name, file_pair::dest_pending_sparse, file_pair::dest_try_sparse, io_close_dest(), io_close_src(), io_copy_attrs(), message_error(), signals_block(), and signals_unblock().

Referenced by coder_run(), and list_file().

size_t io_read	(	file_pair *	pair,
		io_buf *	buf,
		size_t	size
	)

Reads from the source file to a buffer.

Parameters:

	pair	File pair having the source file open for reading
	buf	Destination buffer to hold the read data
	size	Size of the buffer; assumed be smaller than SSIZE_MAX

Returns:

On success, number of bytes read is returned. On end of file zero is returned and pair->src_eof set to true. On error, SIZE_MAX is returned and error message printed.

References message_error(), file_pair::src_eof, file_pair::src_fd, file_pair::src_name, and user_abort.

Referenced by coder_normal(), coder_passthru(), coder_run(), and io_pread().

bool io_pread	(	file_pair *	pair,
		io_buf *	buf,
		size_t	size,
		off_t	pos
	)

Read from source file from given offset to a buffer.

This is remotely similar to standard pread(). This uses lseek() though, so the read offset is changed on each call.

Parameters:

	pair	Seekable source file
	buf	Destination buffer
	size	Amount of data to read
	pos	Offset relative to the beginning of the file, from which the data should be read.

Returns:

On success, false is returned. On error, error message is printed and true is returned.

References io_read(), message_error(), file_pair::src_fd, and file_pair::src_name.

Referenced by parse_block_header(), parse_check_value(), and parse_indexes().

bool io_write	(	file_pair *	pair,
		const io_buf *	buf,
		size_t	size
	)

Writes a buffer to the destination file.

Parameters:

	pair	File pair having the destination file open for writing
	buf	Buffer containing the data to be written
	size	Size of the buffer; assumed be smaller than SSIZE_MAX

Returns:

On success, zero is returned. On error, -1 is returned and error message printed.

References file_pair::dest_fd, file_pair::dest_name, file_pair::dest_pending_sparse, file_pair::dest_try_sparse, and message_error().

Referenced by coder_normal(), and coder_passthru().