read.rs - source

Files

base64

read

decoder.rs mod.rs

write

encoder.rs encoder_string_writer.rs mod.rs

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

bitflags

bytes

buf

buf_impl.rs buf_mut.rs chain.rs iter.rs limit.rs mod.rs reader.rs take.rs uninit_slice.rs vec_deque.rs writer.rs

fmt

debug.rs hex.rs mod.rs

bytes.rs bytes_mut.rs lib.rs loom.rs

case

cfg_if

derive_error

error.rs lib.rs

encoding_rs

ascii.rs big5.rs data.rs euc_jp.rs euc_kr.rs gb18030.rs handles.rs iso_2022_jp.rs lib.rs macros.rs mem.rs replacement.rs shift_jis.rs single_byte.rs utf_16.rs utf_8.rs variant.rs x_user_defined.rs

fnv

foreign_types

foreign_types_shared

form_urlencoded

futures_channel

mpsc

mod.rs queue.rs

lib.rs lock.rs oneshot.rs

futures_core

task

__internal

atomic_waker.rs mod.rs

future.rs lib.rs stream.rs

futures_sink

futures_task

future_obj.rs lib.rs noop_waker.rs spawn.rs

futures_util

h2

hashbrown

external_trait_impls

raw

bitmask.rs mod.rs sse2.rs

lib.rs macros.rs map.rs scopeguard.rs set.rs

http

header

map.rs mod.rs name.rs value.rs

uri

authority.rs builder.rs mod.rs path.rs port.rs scheme.rs

byte_str.rs convert.rs error.rs extensions.rs lib.rs method.rs request.rs response.rs status.rs version.rs

http_body

combinators

box_body.rs map_data.rs map_err.rs mod.rs

empty.rs lib.rs next.rs size_hint.rs

httparse

simd

avx2.rs mod.rs sse42.rs

iter.rs lib.rs macros.rs

httpdate

httpdate.rs lib.rs

hyper

body

aggregate.rs body.rs length.rs mod.rs to_bytes.rs

client

connect

dns.rs http.rs mod.rs

client.rs conn.rs dispatch.rs mod.rs pool.rs service.rs

common

io

mod.rs rewind.rs

buf.rs exec.rs lazy.rs mod.rs never.rs task.rs watch.rs

proto

h1

conn.rs decode.rs dispatch.rs encode.rs io.rs mod.rs role.rs

h2

client.rs mod.rs ping.rs

service

http.rs make.rs mod.rs oneshot.rs util.rs

cfg.rs error.rs headers.rs lib.rs rt.rs upgrade.rs

hyper_tls

client.rs lib.rs stream.rs

idna

lib.rs punycode.rs uts46.rs

indexmap

map

core

equivalent.rs lib.rs macros.rs map.rs mutable_keys.rs set.rs util.rs

instant

lib.rs native.rs

ipnet

ipext.rs ipnet.rs lib.rs parser.rs

itoa

lazy_static

inline_lazy.rs lib.rs

libc

unix

linux_like

linux

arch

generic

gnu

b64

x86_64

align.rs 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

matches

memchr

x86

avx.rs mod.rs sse2.rs

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

mime

lib.rs parse.rs

mio

event

event.rs events.rs mod.rs source.rs

net

tcp

listener.rs mod.rs socket.rs stream.rs

uds

datagram.rs listener.rs mod.rs stream.rs

sys

unix

selector

epoll.rs mod.rs

uds

datagram.rs listener.rs mod.rs socketaddr.rs stream.rs

mod.rs net.rs pipe.rs sourcefd.rs tcp.rs udp.rs waker.rs

interest.rs io_source.rs lib.rs macros.rs poll.rs token.rs waker.rs

native_tls

imp

num_cpus

lib.rs linux.rs

once_cell

imp_std.rs lib.rs race.rs

openssl

openssl_probe

openssl_sys

parking_lot

condvar.rs deadlock.rs elision.rs fair_mutex.rs lib.rs mutex.rs once.rs raw_fair_mutex.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

percent_encoding

pin_project

pin_project_internal

pin_project

args.rs attribute.rs derive.rs mod.rs

lib.rs pinned_drop.rs utils.rs

pin_project_lite

pin_utils

lib.rs projection.rs stack_pin.rs

proc_macro2

detection.rs fallback.rs lib.rs marker.rs parse.rs wrapper.rs

rapr

reqwest

async_impl

body.rs client.rs decoder.rs mod.rs request.rs response.rs

connect.rs error.rs into_url.rs lib.rs proxy.rs redirect.rs tls.rs util.rs

ryu

buffer

pretty

exponent.rs mantissa.rs mod.rs

common.rs d2s.rs d2s_full_table.rs d2s_intrinsics.rs digit_table.rs f2s.rs f2s_intrinsics.rs lib.rs

scopeguard

serde

de

ignored_any.rs impls.rs mod.rs seed.rs utf8.rs value.rs

private

de.rs doc.rs mod.rs ser.rs size_hint.rs

ser

fmt.rs impls.rs impossible.rs mod.rs

integer128.rs lib.rs macros.rs

serde_json

features_check

io

value

de.rs from.rs index.rs mod.rs partial_eq.rs ser.rs

de.rs error.rs iter.rs lib.rs macros.rs map.rs number.rs read.rs ser.rs

serde_urlencoded

ser

key.rs mod.rs pair.rs part.rs value.rs

signal_hook_registry

half_lock.rs lib.rs

slab

smallvec

socket2

sys

lib.rs sockaddr.rs socket.rs sockref.rs

tinyvec

array

generated_impl.rs

array.rs arrayvec.rs arrayvec_drain.rs lib.rs slicevec.rs tinyvec.rs

tinyvec_macros

tokio

fs

future

block_on.rs maybe_done.rs mod.rs poll_fn.rs ready.rs try_join.rs

io

loom

std

atomic_ptr.rs atomic_u16.rs atomic_u32.rs atomic_u64.rs atomic_u8.rs atomic_usize.rs mod.rs mutex.rs parking_lot.rs unsafe_cell.rs

macros

cfg.rs join.rs loom.rs mod.rs pin.rs ready.rs scoped_tls.rs select.rs support.rs thread_local.rs try_join.rs

net

tcp

listener.rs mod.rs socket.rs split.rs split_owned.rs stream.rs

unix

datagram

mod.rs socket.rs

listener.rs mod.rs socketaddr.rs split.rs split_owned.rs stream.rs ucred.rs

addr.rs lookup_host.rs mod.rs udp.rs

park

either.rs mod.rs thread.rs

process

unix

driver.rs mod.rs orphan.rs reap.rs

runtime

signal

unix

ctrl_c.rs mod.rs registry.rs reusable_box.rs unix.rs

sync

task

blocking.rs local.rs mod.rs spawn.rs task_local.rs unconstrained.rs yield_now.rs

time

driver

wheel

level.rs mod.rs

entry.rs handle.rs mod.rs sleep.rs

clock.rs error.rs instant.rs interval.rs mod.rs timeout.rs

util

bit.rs error.rs linked_list.rs mod.rs rand.rs slab.rs trace.rs try_lock.rs wake.rs

blocking.rs coop.rs lib.rs

tokio_macros

entry.rs lib.rs select.rs

tokio_native_tls

tokio_util

tower_service

tracing

dispatcher.rs field.rs instrument.rs level_filters.rs lib.rs macros.rs span.rs stdlib.rs subscriber.rs

tracing_core

callsite.rs dispatcher.rs event.rs field.rs lib.rs metadata.rs parent.rs span.rs stdlib.rs subscriber.rs

try_lock

unicode_bidi

char_data

mod.rs tables.rs

deprecated.rs explicit.rs format_chars.rs implicit.rs level.rs lib.rs prepare.rs

unicode_normalization

__test_api.rs decompose.rs lib.rs lookups.rs no_std_prelude.rs normalize.rs perfect_hash.rs quick_check.rs recompose.rs replace.rs stream_safe.rs tables.rs

url

host.rs lib.rs origin.rs parser.rs path_segments.rs quirks.rs slicing.rs

want

use crate::io::{AsyncRead, ReadBuf};

use pin_project_lite::pin_project;
use std::future::Future;
use std::io;
use std::marker::PhantomPinned;
use std::marker::Unpin;
use std::pin::Pin;
use std::task::{Context, Poll};

/// 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(crate) fn read<'a, R>(reader: &'a mut R, buf: &'a mut [u8]) -> Read<'a, R>
where
    R: AsyncRead + Unpin + ?Sized,
{
    Read {
        reader,
        buf,
        _pin: PhantomPinned,
    }
}

pin_project! {
    /// A future which can be used to easily read available number of bytes to fill
    /// a buffer.
    ///
    /// Created by the [`read`] function.
    #[derive(Debug)]
    #[must_use = "futures do nothing unless you `.await` or poll them"]
    pub struct Read<'a, R: ?Sized> {
        reader: &'a mut R,
        buf: &'a mut [u8],
        // Make this future `!Unpin` for compatibility with async trait methods.
        #[pin]
        _pin: PhantomPinned,
    }
}

impl<R> Future for Read<'_, R>
where
    R: AsyncRead + Unpin + ?Sized,
{
    type Output = io::Result<usize>;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<usize>> {
        let me = self.project();
        let mut buf = ReadBuf::new(*me.buf);
        ready!(Pin::new(me.reader).poll_read(cx, &mut buf))?;
        Poll::Ready(Ok(buf.filled().len()))
    }
}