Struct DataDownload

pub struct DataDownload<'s> { /* private fields */ }

Data download helper

To success stream data over usb it needs to be sent in blocks that are multiple of the max endpoint size, otherwise the receiver may complain. It also should only send as much data as was indicate in the DATA command.

This helper ensures both invariants are met. To do this data needs to be sent by using DataDownload::extend_from_slice or DataDownload::get_mut_data, after sending the data DataDownload::finish should be called to validate and finalize.

Implementations

impl DataDownload<'_>

pub fn size(&self) -> u32

Total size of the data transfer

pub fn left(&self) -> u32

Data left to be sent/queued

pub async fn extend_from_slice( &mut self, data: &[u8], ) -> Result<(), DownloadError>

Extend the streaming from a slice

This will copy all provided data and send it out if enough is collected. The total amount of data being sent should not exceed the download size

pub async fn get_mut_data( &mut self, max: usize, ) -> Result<&mut [u8], DownloadError>

This will provide a mutable reference to a u8 of at most max size. The returned slice should be completely filled with data to be downloaded to the device

The total amount of data should not exceed the download size

pub async fn finish(self) -> Result<(), DownloadError>

Finish all pending transfer

This should only be called if all data has been queued up (matching the total size)