Struct FileStream 

pub struct FileStream { /* private fields */ }

A stream that reads a file in chunks.

This stream reads files incrementally, yielding chunks of configurable size. It integrates with asupersync’s Cx for:

• Cancellation detection (client disconnect)
• Checkpoint calls between chunks for cooperative yielding

Memory Efficiency

Only one chunk is buffered at a time, making this suitable for streaming large files without excessive memory usage.

Example

use fastapi_http::streaming::{FileStream, StreamConfig};

let config = StreamConfig::default().with_chunk_size(32 * 1024);
let stream = FileStream::open("video.mp4", cx.clone(), config).await?;

Implementations

impl FileStream

pub fn open<P: AsRef<Path>>( path: P, cx: Cx, config: StreamConfig, ) -> Result<Self>

Open a file for streaming.

Arguments

• path - Path to the file to stream
• cx - Capability context for cancellation
• config - Streaming configuration

Errors

Returns an error if the file cannot be opened.

pub fn open_range<P: AsRef<Path>>( path: P, start: u64, length: u64, cx: Cx, config: StreamConfig, ) -> Result<Self>

Open a file for streaming with a byte range.

Useful for HTTP Range requests.

Arguments

• path - Path to the file
• start - Start byte offset
• length - Number of bytes to stream
• cx - Capability context
• config - Streaming configuration

Errors

Returns an error if the file cannot be opened or seeked.

pub fn remaining(&self) -> u64

Get the remaining bytes to be read.

pub fn is_complete(&self) -> bool

Check if the stream is complete.

Trait Implementations

impl Stream for FileStream

type Item = Vec<u8>

The type of values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, _ctx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.

impl Send for FileStream