Struct protocol::wire::Reader

pub struct Reader { /* fields omitted */ }

A receive buffer that waits until enough data is ready and then returns the parsed parcels.

This mechanism can be used to send parcels without length prefixes.

Adding data to the receive buffer

Reader implements std::io::Write. Any bytes written to the reader are added to the receive queue for future processing.

Example

This example shows a reader only returning a u32 once enough data has been buffered.

use protocol;
use std::io::Write;

let mut reader = protocol::wire::Reader::new();
let settings = protocol::Settings::default();

// No bytes received yet.
assert_eq!(None, reader.poll::<u32>(&settings).unwrap());

// Two bytes received.
reader.write(&[0xff, 0x00]).unwrap();
assert_eq!(None, reader.poll::<u32>(&settings).unwrap());

// Three bytes received.
reader.write(&[0x00]).unwrap();
assert_eq!(None, reader.poll::<u32>(&settings).unwrap());

// All four bytes received.
reader.write(&[0x00]).unwrap();
assert_eq!(Some(0xff000000), reader.poll::<u32>(&settings).unwrap());

Methods

impl Reader

pub fn new() -> Self

Creates a new parcel reader.

pub fn poll<P>(&mut self, settings: &Settings) -> Result<Option<P>, Error> where
    P: Parcel, 

Polls the reader for a value.

Returns Ok(None) if further data must be received in order to interpret the value.

Returns Ok(Some(value)) if the value is ready to be read from the stream.

Returns Err(e) on error.

Trait Implementations

impl Default for Reader

fn default() -> Self

Returns the "default value" for a type.

impl Debug for Reader

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

Formats the value using the given formatter.

impl Write for Reader

fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

default fn write_vectored(&mut self, bufs: &[IoVec]) -> Result<usize, Error>

🔬 This is a nightly-only experimental API. (iovec)

Like write, except that it writes from a slice of buffers.

default fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

default fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

default fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Write.