Trait Reader

pub trait Reader:
    AsyncRead
    + Unpin
    + Send
    + Sync {
    // Required method
    fn seekable(
        &mut self,
    ) -> Result<&mut dyn SeekableReader, ReaderNotSeekableError>;

    // Provided method
    fn read_to_end<'a>(
        &'a mut self,
        buf: &'a mut Vec<u8>,
    ) -> StackFuture<'a, Result<usize, Error>, bevy_asset::::io::Reader::read_to_end::{constant#0}>  { ... }
}

A type returned from AssetReader::read, which is used to read the contents of a file (or virtual file) corresponding to an asset.

This is essentially a trait alias for types implementing AsyncRead and AsyncSeek. The only reason a blanket implementation is not provided for applicable types is to allow implementors to override the provided implementation of Reader::read_to_end.

Required Methods

fn seekable( &mut self, ) -> Result<&mut dyn SeekableReader, ReaderNotSeekableError>

Casts this Reader as a SeekableReader, which layers on AsyncSeek functionality. Returns Ok if this Reader supports seeking. Otherwise returns Err.

Implementers of Reader are highly encouraged to provide this functionality, as it makes the reader compatible with “seeking” AssetLoader implementations.

AssetLoader implementations that call this are encouraged to provide fallback behavior when it fails, such as reading into a seek-able Vec (or AsyncSeek-able VecReader):

let mut fallback_reader;
let reader = match reader.seekable() {
    Ok(seek) => seek,
    Err(_) => {
        fallback_reader = VecReader::new(Vec::new());
        reader.read_to_end(&mut fallback_reader.bytes).await.unwrap();
        &mut fallback_reader
    }
};
reader.seek(SeekFrom::Start(10)).await.unwrap();

Provided Methods

fn read_to_end<'a>( &'a mut self, buf: &'a mut Vec<u8>, ) -> StackFuture<'a, Result<usize, Error>, bevy_asset::::io::Reader::read_to_end::{constant#0}>

Reads the entire contents of this reader and appends them to a vec.

Note for implementors

You should override the provided implementation if you can fill up the buffer more efficiently than the default implementation, which calls poll_read repeatedly to fill up the buffer 32 bytes at a time.

Trait Implementations

impl Reader for Box<dyn Reader + '_>

fn read_to_end<'a>( &'a mut self, buf: &'a mut Vec<u8>, ) -> StackFuture<'a, Result<usize, Error>, bevy_asset::::io::{impl#4}::read_to_end::{constant#0}>

Reads the entire contents of this reader and appends them to a vec.

fn seekable( &mut self, ) -> Result<&mut dyn SeekableReader, ReaderNotSeekableError>

Casts this Reader as a SeekableReader, which layers on AsyncSeek functionality. Returns Ok if this Reader supports seeking. Otherwise returns Err.

Implementations on Foreign Types

impl Reader for File

fn seekable( &mut self, ) -> Result<&mut dyn SeekableReader, ReaderNotSeekableError>

Implementors

impl Reader for Box<dyn Reader + '_>

impl Reader for TransactionLockedReader<'_>

impl Reader for SliceReader<'_>

impl Reader for VecReader