Struct PlaceholderDataBox 

pub struct PlaceholderDataBox { /* private fields */ }

A PlaceholderDataBox allows you to reserve space in a JUMBF data structure for content that will be filled in after the overall JUMBF data structure is created.

You can specify a data size to reserve. When the initial JUMBF data structure is created, the box will be zero-filled to the specified size. Later, you can call replace_payload() to replace that reserved space with new content.

Implementations

impl PlaceholderDataBox

pub fn new(tbox: BoxType, size: usize) -> Self

Create a new placeholder data box that will reserve size bytes.

The box will be given the JUMBF box type specified by tbox.

pub fn offset(&self) -> Option<u64>

Return the offset in the stream where the payload can be written.

Will return None before the superbox’s write_jumbf() method is called.

pub fn replace_payload( &self, to_stream: &mut dyn WriteAndSeek, payload: &[u8], ) -> Result<()>

Replace the zero-filled placeholder content with actual content.

An error will be returned if payload is larger than the placeholder size specified when this PlaceholderDataBox was created.

Assuming the placeholder is not larger than the initial reservation, this method will seek the stream to offset() and write the new payload at that location.

Trait Implementations

impl ToBox for PlaceholderDataBox

fn box_type(&self) -> BoxType

Specifies the type of information which will be provided by the write_payload() method.

fn payload_size(&self) -> Result<usize>

Returns the size of the payload which will be provided by the write_payload() method.

fn write_payload(&self, to_stream: &mut dyn WriteAndSeek) -> Result<()>

Write the payload for this box to the JUMBF stream.