Struct FrameDecoder 

pub struct FrameDecoder { /* private fields */ }

Reassembles length-prefixed frames from a byte stream.

Implementations

impl FrameDecoder

pub fn new(max_frame: usize) -> Self

pub fn push(&mut self, bytes: &[u8])

Feed bytes straight off the socket.

pub fn buffered(&self) -> usize

Bytes held pending a complete frame.

pub fn needed(&self) -> usize

How many more bytes are needed before Self::next_frame can return.

This is what lets a reader size its read to the frame. A caller that reads into a small fixed buffer issues one syscall per chunk — for a 10 MiB fetch response and a 16 KiB buffer, more than six hundred of them — and copies every byte twice. Knowing the length prefix turns that into a handful of large reads.

Returns 4 while the prefix itself is incomplete, since that is what must be read before anything else can be known.

pub fn next_frame(&mut self) -> Result<Option<Bytes>>

Take the next complete frame, if one has arrived.

The length prefix is consumed and not returned: every caller wants the body, and handing back the prefix invites double-counting it.

Errors

Error::FrameTooLarge if the prefix exceeds the configured limit. The check happens before reserving, which is the entire point of it.

Trait Implementations

impl Debug for FrameDecoder

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

Formats the value using the given formatter.

impl Default for FrameDecoder

fn default() -> Self

Returns the “default value” for a type.