read.rs.html -- source

Files

aho_corasick

packed

teddy

compile.rs mod.rs runtime.rs

api.rs mod.rs pattern.rs rabinkarp.rs vector.rs

ahocorasick.rs automaton.rs buffer.rs byte_frequencies.rs classes.rs dfa.rs error.rs lib.rs nfa.rs prefilter.rs state_id.rs

ansi_term

ansi.rs debug.rs difference.rs display.rs lib.rs style.rs windows.rs write.rs

arrayvec

array.rs array_string.rs char.rs errors.rs lib.rs maybe_uninit_stable.rs range.rs

atty

backtrace

backtrace

libunwind.rs mod.rs

symbolize

dladdr.rs libbacktrace.rs mod.rs

capture.rs lib.rs print.rs types.rs

backtrace_sys

base64

write

encoder.rs mod.rs

chunked_encoder.rs decode.rs display.rs encode.rs lib.rs tables.rs

bincode

de

ser

config.rs error.rs internal.rs lib.rs

bitflags

byteorder

bytes

buf

buf.rs buf_mut.rs chain.rs from_buf.rs into_buf.rs iter.rs mod.rs reader.rs take.rs vec_deque.rs writer.rs

bytes.rs debug.rs lib.rs

c2_chacha

capnp

capnp_futures

lib.rs read_stream.rs serialize.rs write_queue.rs

capnp_rpc

attach.rs broken.rs forked_promise.rs lib.rs local.rs queued.rs rpc.rs sender_queue.rs split.rs task_set.rs twoparty.rs

cfg_if

chrono

format

mod.rs parse.rs parsed.rs scan.rs strftime.rs

naive

date.rs datetime.rs internals.rs isoweek.rs time.rs

offset

fixed.rs local.rs mod.rs utc.rs

date.rs datetime.rs div.rs lib.rs round.rs

clap

crossbeam_deque

crossbeam_epoch

sync

list.rs mod.rs queue.rs

atomic.rs collector.rs default.rs deferred.rs epoch.rs guard.rs internal.rs lib.rs

crossbeam_queue

array_queue.rs err.rs lib.rs seg_queue.rs

crossbeam_utils

atomic

atomic_cell.rs consume.rs mod.rs

sync

mod.rs parker.rs sharded_lock.rs wait_group.rs

backoff.rs cache_padded.rs lib.rs thread.rs

ctrlc

platform

unix

error.rs lib.rs signal.rs

daemon

daemon.rs lib.rs linux.rs singleton.rs

failure

backtrace

internal.rs mod.rs

error

error_impl.rs mod.rs

as_fail.rs box_std.rs compat.rs context.rs error_message.rs lib.rs macros.rs result_ext.rs sync_failure.rs

failure_derive

flexi_logger

writers

file_log_writer.rs log_writer.rs mod.rs

flexi_error.rs flexi_logger.rs formats.rs lib.rs log_specification.rs logger.rs primary_writer.rs reconfiguration_handle.rs

fnv

futures

future

sink

buffer.rs fanout.rs flush.rs from_err.rs map_err.rs mod.rs send.rs send_all.rs wait.rs with.rs with_flat_map.rs

stream

sync

mpsc

mod.rs queue.rs

bilock.rs mod.rs oneshot.rs

task_impl

std

data.rs mod.rs task_rc.rs unpark_mutex.rs

atomic_task.rs core.rs mod.rs

unsync

mod.rs mpsc.rs oneshot.rs

executor.rs lib.rs lock.rs poll.rs resultstream.rs task.rs

getrandom

error.rs error_impls.rs lib.rs linux_android.rs use_file.rs util.rs util_libc.rs

glob

hid_io

api

device

debug

hidusb

module

unicode

protocol

hidio

hidapi

error.rs ffi.rs lib.rs

install_service

install_service.rs

iovec

sys

lazy_static

inline_lazy.rs lib.rs

libc

unix

linux_like

linux

gnu

b64

x86_64

mod.rs not_x32.rs

align.rs mod.rs

align.rs mod.rs

align.rs mod.rs

fixed_width_ints.rs lib.rs macros.rs

lock_api

lib.rs mutex.rs remutex.rs rwlock.rs

log

lib.rs macros.rs

memchr

x86

avx.rs mod.rs sse2.rs

fallback.rs iter.rs lib.rs naive.rs

memoffset

lib.rs offset_of.rs span_of.rs

mio

mio_uds

datagram.rs lib.rs listener.rs socket.rs stream.rs

nanoid

alphabet.rs generator.rs lib.rs random.rs

net2

sys

unix

impls.rs mod.rs

ext.rs lib.rs socket.rs tcp.rs udp.rs unix.rs utils.rs

nix

nodrop

num_cpus

num_integer

lib.rs roots.rs

num_traits

ops

checked.rs inv.rs mod.rs mul_add.rs saturating.rs wrapping.rs

bounds.rs cast.rs float.rs identities.rs int.rs lib.rs macros.rs pow.rs sign.rs

open

parking_lot

condvar.rs deadlock.rs elision.rs lib.rs mutex.rs once.rs raw_mutex.rs raw_rwlock.rs remutex.rs rwlock.rs util.rs

parking_lot_core

thread_parker

linux.rs mod.rs

lib.rs parking_lot.rs spinwait.rs util.rs word_lock.rs

pem

errors.rs lib.rs

ppv_lite86

x86_64

lib.rs soft.rs types.rs

proc_macro2

fallback.rs lib.rs strnom.rs wrapper.rs

quote

ext.rs format.rs ident_fragment.rs lib.rs runtime.rs spanned.rs to_tokens.rs

rand

rand_chacha

chacha.rs lib.rs

rand_core

block.rs error.rs impls.rs le.rs lib.rs os.rs

rand_hc

hc128.rs lib.rs

rand_isaac

isaac.rs isaac64.rs isaac_array.rs lib.rs

rand_jitter

dummy_log.rs error.rs lib.rs platform.rs

rand_os

dummy_log.rs lib.rs linux_android.rs random_device.rs

rand_pcg

lib.rs pcg128.rs pcg64.rs

rand_xorshift

rcgen

regex

regex_syntax

remove_dir_all

ring

rustc_demangle

legacy.rs lib.rs v0.rs

rustls

scoped_tls

scopeguard

sct

serde

de

from_primitive.rs ignored_any.rs impls.rs mod.rs utf8.rs value.rs

private

de.rs macros.rs mod.rs ser.rs

ser

impls.rs impossible.rs mod.rs

export.rs integer128.rs lib.rs macros.rs

slab

smallvec

spin

lib.rs mutex.rs once.rs rw_lock.rs

stream_cancel

combinator.rs lib.rs wrapper.rs

strsim

syn

synstructure

lib.rs macros.rs

tempfile

file

imp

dir.rs error.rs lib.rs spooled.rs util.rs

textwrap

indentation.rs lib.rs splitting.rs

thread_local

lib.rs thread_id.rs unreachable.rs

time

display.rs duration.rs lib.rs parse.rs sys.rs

tokio

codec

length_delimited.rs mod.rs

executor

current_thread

reactor

mod.rs poll_evented.rs

runtime

current_thread

builder.rs mod.rs runtime.rs

threadpool

builder.rs mod.rs shutdown.rs task_executor.rs

util

enumerate.rs future.rs mod.rs stream.rs

clock.rs fs.rs io.rs lib.rs net.rs prelude.rs sync.rs timer.rs

tokio_codec

bytes_codec.rs lib.rs lines_codec.rs

tokio_core

tokio_current_thread

lib.rs scheduler.rs

tokio_executor

enter.rs error.rs executor.rs global.rs lib.rs park.rs typed.rs

tokio_fs

tokio_io

tokio_reactor

background.rs lib.rs poll_evented.rs registration.rs sharded_rwlock.rs

tokio_rustls

common

mod.rs vecbuf.rs

client.rs lib.rs server.rs

tokio_sync

mpsc

block.rs bounded.rs chan.rs list.rs mod.rs unbounded.rs

task

atomic_task.rs mod.rs

lib.rs lock.rs loom.rs oneshot.rs semaphore.rs watch.rs

tokio_tcp

incoming.rs lib.rs listener.rs stream.rs

tokio_threadpool

tokio_timer

tokio_udp

frame.rs lib.rs recv_dgram.rs send_dgram.rs socket.rs

tokio_uds

datagram.rs frame.rs incoming.rs lib.rs listener.rs recv_dgram.rs send_dgram.rs stream.rs ucred.rs

unicode_width

lib.rs tables.rs

unicode_xid

lib.rs tables.rs

untrusted

vec_map

void

webpki

calendar.rs cert.rs der.rs error.rs name.rs signed_data.rs time.rs trust_anchor_util.rs verify_cert.rs webpki.rs

windows_service

x11

dpms.rs glx.rs internal.rs keysym.rs lib.rs link.rs xcursor.rs xf86vmode.rs xfixes.rs xft.rs xinerama.rs xinput.rs xinput2.rs xlib.rs xlib_xcb.rs xmd.rs xmu.rs xrandr.rs xrecord.rs xrender.rs xss.rs xt.rs xtest.rs

xcb

ffi

base.rs big_requests.rs xc_misc.rs xkb.rs xproto.rs

base.rs big_requests.rs lib.rs xc_misc.rs xkb.rs xproto.rs

xkbcommon

xkb

x11

compose.rs ffi.rs keysyms.rs mod.rs

yasna

deserializer

models

der.rs mod.rs oid.rs time.rs

reader

error.rs mod.rs

serializer

tags

writer

use std::io;
use std::mem;

use futures::{Future, Poll};

use AsyncRead;

#[derive(Debug)]
enum State<R, T> {
    Pending { rd: R, buf: T },
    Empty,
}

/// Tries to read some bytes directly into the given `buf` in asynchronous
/// manner, returning a future type.
///
/// The returned future will resolve to both the I/O stream and the buffer
/// as well as the number of bytes read once the read operation is completed.
pub fn read<R, T>(rd: R, buf: T) -> Read<R, T>
where
    R: AsyncRead,
    T: AsMut<[u8]>,
{
    Read {
        state: State::Pending { rd: rd, buf: buf },
    }
}

/// A future which can be used to easily read available number of bytes to fill
/// a buffer.
///
/// Created by the [`read`] function.
#[derive(Debug)]
pub struct Read<R, T> {
    state: State<R, T>,
}

impl<R, T> Future for Read<R, T>
where
    R: AsyncRead,
    T: AsMut<[u8]>,
{
    type Item = (R, T, usize);
    type Error = io::Error;

    fn poll(&mut self) -> Poll<(R, T, usize), io::Error> {
        let nread = match self.state {
            State::Pending {
                ref mut rd,
                ref mut buf,
            } => try_ready!(rd.poll_read(&mut buf.as_mut()[..])),
            State::Empty => panic!("poll a Read after it's done"),
        };

        match mem::replace(&mut self.state, State::Empty) {
            State::Pending { rd, buf } => Ok((rd, buf, nread).into()),
            State::Empty => panic!("invalid internal state"),
        }
    }
}