refactor(body): separate body, payload, and chunk into their own internal mods

This commit is contained in:
Sean McArthur
2018-06-01 11:22:16 -07:00
parent 52e1700607
commit 789c2231f3
5 changed files with 149 additions and 139 deletions

View File

@@ -1,127 +1,19 @@
//! Streaming bodies for Requests and Responses
//!
//! For both [Clients](::client) and [Servers](::server), requests and
//! responses use streaming bodies, instead of complete buffering. This
//! allows applications to not use memory they don't need, and allows exerting
//! back-pressure on connections by only reading when asked.
//!
//! There are two pieces to this in hyper:
//!
//! - The [`Payload`](Payload) trait the describes all possible bodies. hyper
//! allows any body type that implements `Payload`, allowing applications to
//! have fine-grained control over their streaming.
//! - The [`Body`](Body) concrete type, which is an implementation of `Payload`,
//! and returned by hyper as a "receive stream" (so, for server requests and
//! client responses). It is also a decent default implementation if you don't
//! have very custom needs of your send streams.
use std::borrow::Cow;
use std::fmt;
use bytes::{Buf, Bytes};
use bytes::Bytes;
use futures::{Async, Future, Poll, Stream};
use futures::sync::{mpsc, oneshot};
use h2;
use http::HeaderMap;
use common::Never;
pub use chunk::Chunk;
use super::{Chunk, Payload};
use super::internal::{FullDataArg, FullDataRet};
use self::internal::{FullDataArg, FullDataRet};
type BodySender = mpsc::Sender<Result<Chunk, ::Error>>;
/// This trait represents a streaming body of a `Request` or `Response`.
///
/// The built-in implementation of this trait is [`Body`](Body), in case you
/// don't need to customize a send stream for your own application.
pub trait Payload: Send + 'static {
/// A buffer of bytes representing a single chunk of a body.
type Data: Buf + Send;
/// The error type of this stream.
type Error: Into<Box<::std::error::Error + Send + Sync>>;
/// Poll for a `Data` buffer.
///
/// Similar to `Stream::poll_next`, this yields `Some(Data)` until
/// the body ends, when it yields `None`.
fn poll_data(&mut self) -> Poll<Option<Self::Data>, Self::Error>;
/// Poll for an optional **single** `HeaderMap` of trailers.
///
/// This should **only** be called after `poll_data` has ended.
///
/// Note: Trailers aren't currently used for HTTP/1, only for HTTP/2.
fn poll_trailers(&mut self) -> Poll<Option<HeaderMap>, Self::Error> {
Ok(Async::Ready(None))
}
/// A hint that the `Body` is complete, and doesn't need to be polled more.
///
/// This can be useful to determine if the there is any body or trailers
/// without having to poll. An empty `Body` could return `true` and hyper
/// would be able to know that only the headers need to be sent. Or, it can
/// also be checked after each `poll_data` call, to allow hyper to try to
/// end the underlying stream with the last chunk, instead of needing to
/// send an extra `DATA` frame just to mark the stream as finished.
///
/// As a hint, it is used to try to optimize, and thus is OK for a default
/// implementation to return `false`.
fn is_end_stream(&self) -> bool {
false
}
/// Return a length of the total bytes that will be streamed, if known.
///
/// If an exact size of bytes is known, this would allow hyper to send a
/// `Content-Length` header automatically, not needing to fall back to
/// `Transfer-Encoding: chunked`.
///
/// This does not need to be kept updated after polls, it will only be
/// called once to create the headers.
fn content_length(&self) -> Option<u64> {
None
}
// This API is unstable, and is impossible to use outside of hyper. Some
// form of it may become stable in a later version.
//
// The only thing a user *could* do is reference the method, but DON'T
// DO THAT! :)
#[doc(hidden)]
fn __hyper_full_data(&mut self, FullDataArg) -> FullDataRet<Self::Data> {
FullDataRet(None)
}
}
impl<E: Payload> Payload for Box<E> {
type Data = E::Data;
type Error = E::Error;
fn poll_data(&mut self) -> Poll<Option<Self::Data>, Self::Error> {
(**self).poll_data()
}
fn poll_trailers(&mut self) -> Poll<Option<HeaderMap>, Self::Error> {
(**self).poll_trailers()
}
fn is_end_stream(&self) -> bool {
(**self).is_end_stream()
}
fn content_length(&self) -> Option<u64> {
(**self).content_length()
}
#[doc(hidden)]
fn __hyper_full_data(&mut self, arg: FullDataArg) -> FullDataRet<Self::Data> {
(**self).__hyper_full_data(arg)
}
}
/// A stream of `Chunk`s, used when receiving bodies.
///
/// A good default `Payload` to use in many applications.
@@ -496,35 +388,8 @@ impl From<Cow<'static, str>> for Body {
}
}
// The full_data API is not stable, so these types are to try to prevent
// users from being able to:
//
// - Implment `__hyper_full_data` on their own Payloads.
// - Call `__hyper_full_data` on any Payload.
//
// That's because to implement it, they need to name these types, and
// they can't because they aren't exported. And to call it, they would
// need to create one of these values, which they also can't.
pub(crate) mod internal {
#[allow(missing_debug_implementations)]
pub struct FullDataArg(pub(crate) ());
#[allow(missing_debug_implementations)]
pub struct FullDataRet<B>(pub(crate) Option<B>);
}
fn _assert_send_sync() {
fn _assert_send<T: Send>() {}
fn _assert_sync<T: Sync>() {}
_assert_send::<Body>();
_assert_send::<Chunk>();
_assert_sync::<Chunk>();
}
#[test]
fn test_body_stream_concat() {
use futures::{Stream, Future};
let body = Body::from("hello world");
let total = body

49
src/body/mod.rs Normal file
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@@ -0,0 +1,49 @@
//! Streaming bodies for Requests and Responses
//!
//! For both [Clients](::client) and [Servers](::server), requests and
//! responses use streaming bodies, instead of complete buffering. This
//! allows applications to not use memory they don't need, and allows exerting
//! back-pressure on connections by only reading when asked.
//!
//! There are two pieces to this in hyper:
//!
//! - The [`Payload`](Payload) trait the describes all possible bodies. hyper
//! allows any body type that implements `Payload`, allowing applications to
//! have fine-grained control over their streaming.
//! - The [`Body`](Body) concrete type, which is an implementation of `Payload`,
//! and returned by hyper as a "receive stream" (so, for server requests and
//! client responses). It is also a decent default implementation if you don't
//! have very custom needs of your send streams.
pub use self::body::{Body, Sender};
pub use self::chunk::Chunk;
pub use self::payload::Payload;
mod body;
mod chunk;
mod payload;
// The full_data API is not stable, so these types are to try to prevent
// users from being able to:
//
// - Implment `__hyper_full_data` on their own Payloads.
// - Call `__hyper_full_data` on any Payload.
//
// That's because to implement it, they need to name these types, and
// they can't because they aren't exported. And to call it, they would
// need to create one of these values, which they also can't.
pub(crate) mod internal {
#[allow(missing_debug_implementations)]
pub struct FullDataArg(pub(crate) ());
#[allow(missing_debug_implementations)]
pub struct FullDataRet<B>(pub(crate) Option<B>);
}
fn _assert_send_sync() {
fn _assert_send<T: Send>() {}
fn _assert_sync<T: Sync>() {}
_assert_send::<Body>();
_assert_send::<Chunk>();
_assert_sync::<Chunk>();
}

97
src/body/payload.rs Normal file
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@@ -0,0 +1,97 @@
use bytes::Buf;
use futures::{Async, Poll};
use http::HeaderMap;
use super::internal::{FullDataArg, FullDataRet};
/// This trait represents a streaming body of a `Request` or `Response`.
///
/// The built-in implementation of this trait is [`Body`](Body), in case you
/// don't need to customize a send stream for your own application.
pub trait Payload: Send + 'static {
/// A buffer of bytes representing a single chunk of a body.
type Data: Buf + Send;
/// The error type of this stream.
type Error: Into<Box<::std::error::Error + Send + Sync>>;
/// Poll for a `Data` buffer.
///
/// Similar to `Stream::poll_next`, this yields `Some(Data)` until
/// the body ends, when it yields `None`.
fn poll_data(&mut self) -> Poll<Option<Self::Data>, Self::Error>;
/// Poll for an optional **single** `HeaderMap` of trailers.
///
/// This should **only** be called after `poll_data` has ended.
///
/// Note: Trailers aren't currently used for HTTP/1, only for HTTP/2.
fn poll_trailers(&mut self) -> Poll<Option<HeaderMap>, Self::Error> {
Ok(Async::Ready(None))
}
/// A hint that the `Body` is complete, and doesn't need to be polled more.
///
/// This can be useful to determine if the there is any body or trailers
/// without having to poll. An empty `Body` could return `true` and hyper
/// would be able to know that only the headers need to be sent. Or, it can
/// also be checked after each `poll_data` call, to allow hyper to try to
/// end the underlying stream with the last chunk, instead of needing to
/// send an extra `DATA` frame just to mark the stream as finished.
///
/// As a hint, it is used to try to optimize, and thus is OK for a default
/// implementation to return `false`.
fn is_end_stream(&self) -> bool {
false
}
/// Return a length of the total bytes that will be streamed, if known.
///
/// If an exact size of bytes is known, this would allow hyper to send a
/// `Content-Length` header automatically, not needing to fall back to
/// `Transfer-Encoding: chunked`.
///
/// This does not need to be kept updated after polls, it will only be
/// called once to create the headers.
fn content_length(&self) -> Option<u64> {
None
}
// This API is unstable, and is impossible to use outside of hyper. Some
// form of it may become stable in a later version.
//
// The only thing a user *could* do is reference the method, but DON'T
// DO THAT! :)
#[doc(hidden)]
fn __hyper_full_data(&mut self, FullDataArg) -> FullDataRet<Self::Data> {
FullDataRet(None)
}
}
impl<E: Payload> Payload for Box<E> {
type Data = E::Data;
type Error = E::Error;
fn poll_data(&mut self) -> Poll<Option<Self::Data>, Self::Error> {
(**self).poll_data()
}
fn poll_trailers(&mut self) -> Poll<Option<HeaderMap>, Self::Error> {
(**self).poll_trailers()
}
fn is_end_stream(&self) -> bool {
(**self).is_end_stream()
}
fn content_length(&self) -> Option<u64> {
(**self).content_length()
}
#[doc(hidden)]
fn __hyper_full_data(&mut self, arg: FullDataArg) -> FullDataRet<Self::Data> {
(**self).__hyper_full_data(arg)
}
}

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@@ -57,7 +57,6 @@ mod common;
#[cfg(test)]
mod mock;
pub mod body;
mod chunk;
pub mod client;
pub mod error;
mod headers;