Files
hyper/src/http/message.rs
2016-05-02 12:33:49 -07:00

134 lines
4.2 KiB
Rust

//! Defines the `HttpMessage` trait that serves to encapsulate the operations of a single
//! request-response cycle on any HTTP connection.
use std::any::{Any, TypeId};
use std::fmt::Debug;
use std::io::{Read, Write};
use std::mem;
use std::io;
use std::time::Duration;
use typeable::Typeable;
use header::Headers;
use http::RawStatus;
use url::Url;
use method;
use version;
use traitobject;
/// The trait provides an API for creating new `HttpMessage`s depending on the underlying HTTP
/// protocol.
pub trait Protocol {
/// Creates a fresh `HttpMessage` bound to the given host, based on the given protocol scheme.
fn new_message(&self, host: &str, port: u16, scheme: &str) -> ::Result<Box<HttpMessage>>;
}
/// Describes a request.
#[derive(Clone, Debug)]
pub struct RequestHead {
/// The headers of the request
pub headers: Headers,
/// The method of the request
pub method: method::Method,
/// The URL of the request
pub url: Url,
}
/// Describes a response.
#[derive(Clone, Debug)]
pub struct ResponseHead {
/// The headers of the reponse
pub headers: Headers,
/// The raw status line of the response
pub raw_status: RawStatus,
/// The HTTP/2 version which generated the response
pub version: version::HttpVersion,
}
/// The trait provides an API for sending an receiving HTTP messages.
pub trait HttpMessage: Write + Read + Send + Any + Typeable + Debug {
/// Initiates a new outgoing request.
///
/// Only the request's head is provided (in terms of the `RequestHead` struct).
///
/// After this, the `HttpMessage` instance can be used as an `io::Write` in order to write the
/// body of the request.
fn set_outgoing(&mut self, head: RequestHead) -> ::Result<RequestHead>;
/// Obtains the incoming response and returns its head (i.e. the `ResponseHead` struct)
///
/// After this, the `HttpMessage` instance can be used as an `io::Read` in order to read out
/// the response body.
fn get_incoming(&mut self) -> ::Result<ResponseHead>;
/// Set the read timeout duration for this message.
fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()>;
/// Set the write timeout duration for this message.
fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()>;
/// Closes the underlying HTTP connection.
fn close_connection(&mut self) -> ::Result<()>;
/// Returns whether the incoming message has a body.
fn has_body(&self) -> bool;
/// Called when the Client wishes to use a Proxy.
fn set_proxied(&mut self, val: bool) {
// default implementation so as to not be a breaking change.
warn!("default set_proxied({:?})", val);
}
}
impl HttpMessage {
unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T {
mem::transmute(traitobject::data(self))
}
unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T {
mem::transmute(traitobject::data_mut(self))
}
unsafe fn downcast_unchecked<T: 'static>(self: Box<HttpMessage>) -> Box<T> {
let raw: *mut HttpMessage = mem::transmute(self);
mem::transmute(traitobject::data_mut(raw))
}
}
impl HttpMessage {
/// Is the underlying type in this trait object a T?
#[inline]
pub fn is<T: Any>(&self) -> bool {
(*self).get_type() == TypeId::of::<T>()
}
/// If the underlying type is T, get a reference to the contained data.
#[inline]
pub fn downcast_ref<T: Any>(&self) -> Option<&T> {
if self.is::<T>() {
Some(unsafe { self.downcast_ref_unchecked() })
} else {
None
}
}
/// If the underlying type is T, get a mutable reference to the contained
/// data.
#[inline]
pub fn downcast_mut<T: Any>(&mut self) -> Option<&mut T> {
if self.is::<T>() {
Some(unsafe { self.downcast_mut_unchecked() })
} else {
None
}
}
/// If the underlying type is T, extract it.
#[inline]
pub fn downcast<T: Any>(self: Box<HttpMessage>)
-> Result<Box<T>, Box<HttpMessage>> {
if self.is::<T>() {
Ok(unsafe { self.downcast_unchecked() })
} else {
Err(self)
}
}
}