Struct embly::Conn

pub struct Conn { /* fields omitted */ }

Connections that handle communication between functions or gateways

Receive Bytes

When a function begins execution it can optionally read in any bytes that it might have been sent. Maybe there are bytes ready on startup, maybe it'll receive them later.

use embly::{Conn};
use embly::prelude::*;
use std::io;
use failure::Error;

fn entrypoint(mut conn: Conn) -> Result<(), Error> {
    let mut buffer = Vec::new();
    // Conn implements std::io::Read
    conn.wait()?;
    conn.read_to_end(&mut buffer)?;
     
    // a little while later you might get another message
    conn.wait()?;
    conn.read_to_end(&mut buffer)?;
    return Ok(())
}

Write Bytes

Bytes can be written back. A spark is always executed by something. This could be a command line call, a load balancer or another spark. Writing to a connection will send those bytes back to the spark runner.

use embly::Conn;
use std::io;
use std::io::Write;

fn entrypoint(mut conn: Conn) -> io::Result<()> {
    // you can call write_all to send one message
    conn.write_all("Hello World".as_bytes())?;


    // Or you can make multiple calls with write if you want to construct a
    // message and then flush the response
    conn.write(b"Hello")?;
    conn.write(b"World")?;
    conn.flush()?;
    return Ok(())
}

Trait Implementations

impl Waitable for Conn

type Output = Result<(), Error>

asdfasdf

fn id(&self) -> i32

wait for it

fn fetch_result(&mut self) -> Result<(), Error>

asdfasdf

fn wait(&mut self) -> Self::Output where
    Self: Sized, 

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fn join<T: Waitable>(&mut self, other: T) -> (Self::Output, T::Output) where
    Self: Sized,
    T: Sized, 

join

impl Clone for Conn

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Conn

impl Debug for Conn

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

Formats the value using the given formatter.

impl Write for Conn

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.

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

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

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

Attempts to write an entire buffer into this writer.

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

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

Important traits for &'_ mut W

impl<'_, W> Write for &'_ mut W where
    W: Write + ?Sized, impl<'_, R> Read for &'_ mut R where
    R: Read + ?Sized, 

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

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

impl Read for Conn

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

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

unsafe fn initializer(&self) -> Initializer

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

Determines if this Reader can work with buffers of uninitialized memory.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf.

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

Read the exact number of bytes required to fill buf.

Important traits for &'_ mut W

impl<'_, W> Write for &'_ mut W where
    W: Write + ?Sized, impl<'_, R> Read for &'_ mut R where
    R: Read + ?Sized, 

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

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

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an [Iterator] over its bytes.

Important traits for Chain<T, U>

impl<T, U> Read for Chain<T, U> where
    T: Read,
    U: Read, 

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read, 

Creates an adaptor which will chain this stream with another.

Important traits for Take<T>

impl<T> Read for Take<T> where
    T: Read, 

fn take(self, limit: u64) -> Take<Self>

Creates an adaptor which will read at most limit bytes from it.