Struct libheif_sys::heif_reader

#[repr(C)]
pub struct heif_reader {
    pub reader_api_version: c_int,
    pub get_position: Option<unsafe extern "C" fn(userdata: *mut c_void) -> i64>,
    pub read: Option<unsafe extern "C" fn(data: *mut c_void, size: usize, userdata: *mut c_void) -> c_int>,
    pub seek: Option<unsafe extern "C" fn(position: i64, userdata: *mut c_void) -> c_int>,
    pub wait_for_file_size: Option<unsafe extern "C" fn(target_size: i64, userdata: *mut c_void) -> heif_reader_grow_status>,
}

Fields

reader_api_version: c_int

API version supported by this reader

get_position: Option<unsafe extern "C" fn(userdata: *mut c_void) -> i64>

— version 1 functions —

read: Option<unsafe extern "C" fn(data: *mut c_void, size: usize, userdata: *mut c_void) -> c_int>

The functions read(), and seek() return heif_error_ok on success. Generally, libheif will make sure that we do not read past the file size.

seek: Option<unsafe extern "C" fn(position: i64, userdata: *mut c_void) -> c_int>

wait_for_file_size: Option<unsafe extern "C" fn(target_size: i64, userdata: *mut c_void) -> heif_reader_grow_status>

When calling this function, libheif wants to make sure that it can read the file up to ‘target_size’. This is useful when the file is currently downloaded and may grow with time. You may, for example, extract the image sizes even before the actual compressed image data has been completely downloaded.

Even if your input files will not grow, you will have to implement at least detection whether the target_size is above the (fixed) file length (in this case, return ‘size_beyond_eof’).

Trait Implementations

impl Clone for heif_reader

fn clone(&self) -> heif_reader

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for heif_reader

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for heif_reader