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use http::StatusCode;
use crate::body::BodyWriter;
use crate::parser::try_parse_response;
use crate::Error;
use super::state::Await100;
use super::{Await100Result, Call};
use crate::CloseReason;
impl Call<Await100> {
/// Attempt to read a 100-continue response.
///
/// Tries to interpret bytes sent by the server as a 100-continue response. The expect-100 mechanic
/// means we hope the server will give us an indication on whether to upload a potentially big
/// request body, before we start doing it.
///
/// * If the server supports expect-100, it will respond `HTTP/1.1 100 Continue\r\n\r\n`, or
/// some other response code (such as 403) if we are not allowed to post the body.
/// * If the server does not support expect-100, it will not respond at all, in which case
/// we will proceed to sending the request body after some timeout.
///
/// The results are:
///
/// * `Ok(0)` - not enough data yet, continue waiting (or `proceed()` if you think we waited enough)
/// * `Ok(n)` - `n` number of input bytes were consumed. Call `proceed()` next
/// * `Err(e)` - some error that is not recoverable
pub fn try_read_100(&mut self, input: &[u8]) -> Result<usize, Error> {
// Try parsing a status line without any headers. The line we are looking for is:
//
// HTTP/1.1 100 Continue\r\n\r\n
//
// There should be no headers.
match try_parse_response::<0>(input) {
Ok(v) => match v {
Some((input_used, response)) => {
self.inner.await_100_continue = false;
if response.status() == StatusCode::CONTINUE {
// should_send_body ought to be true since initialization.
assert!(self.inner.state.writer.has_body());
Ok(input_used)
} else {
// We encountered a status line, without headers, but it wasn't 100,
// so we should not continue to send the body. Furthermore we mustn't
// reuse the connection.
// https://curl.se/mail/lib-2004-08/0002.html
self.inner.close_reason.push(CloseReason::Not100Continue);
self.inner.state.writer = BodyWriter::new_none();
Ok(0)
}
}
// Not enough input yet.
None => Ok(0),
},
Err(e) => {
self.inner.await_100_continue = false;
if e == Error::HttpParseTooManyHeaders {
// We encountered headers after the status line. That means the server did
// not send 100-continue, and also continued to produce an answer before we
// sent the body. Regardless of what the answer is, we must not send the body.
// A 200-answer would be nonsensical given we haven't yet sent the body.
//
// We do however want to receive the response to be able to provide
// the Response<()> to the user. Hence this is not considered an error.
self.inner.close_reason.push(CloseReason::Not100Continue);
self.inner.state.writer = BodyWriter::new_none();
Ok(0)
} else {
Err(e)
}
}
}
}
/// Tell if there is any point in waiting for more data from the server.
///
/// Becomes `false` as soon as `try_read_100()` got enough data to determine what to do next.
/// This might become `false` even if `try_read_100` returns `Ok(0)`.
///
/// If this returns `false`, the user should continue with `proceed()`.
pub fn can_keep_await_100(&self) -> bool {
self.inner.await_100_continue
}
/// Proceed to the next state.
pub fn proceed(self) -> Result<Await100Result, Error> {
// We can always proceed out of Await100
if self.inner.state.writer.has_body() {
// TODO(martin): do i need this?
// call.inner.call.analyze_request()?;
let call = Call::wrap(self.inner);
Ok(Await100Result::SendBody(call))
} else {
Ok(Await100Result::RecvResponse(Call::wrap(self.inner)))
}
}
}