Struct StreamDecoder 

pub struct StreamDecoder<F> { /* private fields */ }

Stateful wrapper that drives a Framer over a growing input buffer.

It owns the Framer::next_frame_from progress hint, so a delimiter search resumes where the previous call stopped. Use it whenever input arrives in pieces (a socket read loop, a serial port, a message queue).

The input contract is the one described on Framer::next_frame_from: between calls, only append to the buffer; after a frame is returned, drop its consumed() bytes from the front.

Example

use wire_codec::framing::{Delimited, StreamDecoder};

let mut decoder = StreamDecoder::new(Delimited::bounded(b"\n").unwrap());
let mut buffer: Vec<u8> = Vec::new();
let mut lines: Vec<Vec<u8>> = Vec::new();

for chunk in [&b"PI"[..], b"NG\nQU", b"IT\n"] {
    buffer.extend_from_slice(chunk);
    let mut start = 0;
    while let Some(frame) = decoder.decode(&buffer[start..]).unwrap() {
        lines.push(frame.payload().to_vec());
        start += frame.consumed();
    }
    buffer.drain(..start);
}
assert_eq!(lines, [b"PING".to_vec(), b"QUIT".to_vec()]);

Implementations

impl<F: Framer> StreamDecoder<F>

pub const fn new(framer: F) -> Self

Wrap framer with fresh streaming state.

pub fn decode<'a>(&mut self, input: &'a [u8]) -> Result<Option<Frame<'a>>>

Try to extract the next frame from the start of input.

Errors

Propagates the wrapped framer’s errors. The scan progress is cleared on error, because the usual response (discarding the buffered input and resynchronising) breaks the append-only contract the progress hint relies on. Call StreamDecoder::reset yourself whenever you discard or replace buffered input without an error.

pub fn reset(&mut self)

Forget any partial-scan progress, for example after discarding the buffered input or switching to a new connection.

pub const fn framer(&self) -> &F

Borrow the wrapped framer, for example to call Framer::write_frame on the outbound path.

pub fn into_inner(self) -> F

Consume the decoder and return the wrapped framer.

Trait Implementations

impl<F: Clone> Clone for StreamDecoder<F>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<F: Debug> Debug for StreamDecoder<F>

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

Formats the value using the given formatter.

impl<F: Default> Default for StreamDecoder<F>

fn default() -> Self

Returns the “default value” for a type.

impl<F: Eq> Eq for StreamDecoder<F>

impl<F: Hash> Hash for StreamDecoder<F>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<F: PartialEq> PartialEq for StreamDecoder<F>

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<F: PartialEq> StructuralPartialEq for StreamDecoder<F>