file.c File Reference

#include "config.h"
#include "error.h"
#include "file.h"
#include "file_open.h"
#include "internal.h"
#include "log.h"
#include "mem.h"
#include <fcntl.h>
#include <sys/stat.h>

Go to the source code of this file.

Data Structures
struct	FileLogContext

Functions
int	av_file_map (const char *filename, uint8_t **bufptr, size_t *size, int log_offset, void *log_ctx)
	Read the file with name filename, and put its content in a newly allocated buffer or map it with mmap() when available.
void	av_file_unmap (uint8_t *bufptr, size_t size)
	Unmap or free the buffer bufptr created by av_file_map().
int	av_file_map_shared (int fd, size_t size, void **bufptr)
	Map the beginning of an open file into memory for shared read and write access.
void	av_file_unmap_shared (void *bufptr, size_t size)
	Unmap the memory mapped by av_file_map_shared().

Variables
static const AVClass	file_log_ctx_class

Function Documentation

av_file_map()

int av_file_map	(	const char *	filename,
		uint8_t **	bufptr,
		size_t *	size,
		int	log_offset,
		void *	log_ctx )

Read the file with name filename, and put its content in a newly allocated buffer or map it with mmap() when available.

In case of success set *bufptr to the read or mmapped buffer, and *size to the size in bytes of the buffer in *bufptr. Unlike mmap this function succeeds with zero sized files, in this case *bufptr will be set to NULL and *size will be set to 0. The returned buffer must be released with av_file_unmap().

Parameters

	filename	path to the file
[out]	bufptr	pointee is set to the mapped or allocated buffer
[out]	size	pointee is set to the size in bytes of the buffer
	log_offset	loglevel offset used for logging
	log_ctx	context used for logging

Returns

a non negative number in case of success, a negative value corresponding to an AVERROR error code in case of failure

Examples

avio_read_callback.c.

Definition at line 114 of file file.c.

Referenced by ff_load_textfile(), init(), init(), init_pattern_from_file(), init_pattern_from_file(), init_vulkan(), main(), main(), parse_custom_lut(), parse_psfile(), parse_psfile(), and read_shape_from_file().

av_file_unmap()

void av_file_unmap	(	uint8_t *	bufptr,
		size_t	size )

Unmap or free the buffer bufptr created by av_file_map().

Parameters

bufptr	the buffer previously created with av_file_map()
size	size in bytes of bufptr, must be the same as returned by av_file_map()

Examples

avio_read_callback.c.

Definition at line 175 of file file.c.

Referenced by ff_load_textfile(), init(), init(), init_vulkan(), main(), main(), parse_custom_lut(), parse_psfile(), parse_psfile(), read_shape_from_file(), uninit(), and uninit().

av_file_map_shared()

int av_file_map_shared	(	int	fd,
		size_t	size,
		void **	bufptr )

Map the beginning of an open file into memory for shared read and write access.

Unlike av_file_map() the mapping is not a private copy of the file, every store to the returned memory is written to the file and is visible to every other mapping of it, in this process and in other processes. The file is extended to size bytes if it is shorter, it is never shortened. The mapping must be released with av_file_unmap_shared().

Parameters

	fd	file descriptor of a file opened for reading and writing
	size	number of bytes to map, must not be zero
[out]	bufptr	pointee is set to the mapped memory

Returns

0 in case of success, a negative value corresponding to an AVERROR error code in case of failure, AVERROR(ENOSYS) when the platform has no shared file mappings

Definition at line 186 of file file.c.

Referenced by cache_map(), and spacemap_remap().

av_file_unmap_shared()

void av_file_unmap_shared	(	void *	bufptr,
		size_t	size )

Unmap the memory mapped by av_file_map_shared().

Parameters

bufptr	the memory previously mapped by av_file_map_shared()
size	size in bytes of the mapping, must be the same as passed to av_file_map_shared()

Definition at line 198 of file file.c.

Referenced by cache_map(), shared_close(), and spacemap_remap().

Variable Documentation

file_log_ctx_class

const AVClass file_log_ctx_class

static

Initial value:

= {
    .class_name                = "FILE",
    .item_name                 = av_default_item_name,
    .option                    = NULL,
    .version                   = LIBAVUTIL_VERSION_INT,
    .log_level_offset_offset   =  0x42 ,
    .parent_log_context_offset =  0x42 ,
}

Definition at line 54 of file file.c.

Referenced by av_file_map(), and avpriv_tempfile().