chromiumoxide/handler/
commandfuture.rs

1use futures::channel::{
2    mpsc,
3    oneshot::{self, channel as oneshot_channel},
4};
5use pin_project_lite::pin_project;
6use std::future::Future;
7use std::marker::PhantomData;
8use std::pin::Pin;
9use std::task::{Context, Poll};
10
11use crate::cmd::{to_command_response, CommandMessage};
12use crate::error::Result;
13use crate::handler::target::TargetMessage;
14use chromiumoxide_cdp::cdp::browser_protocol::target::SessionId;
15use chromiumoxide_types::{Command, CommandResponse, MethodId, Response};
16
17pin_project! {
18    pub struct CommandFuture<T, M = Result<Response>> {
19        #[pin]
20        rx_command: oneshot::Receiver<M>,
21        #[pin]
22        target_sender: mpsc::Sender<TargetMessage>,
23        // We need delay to be pinned because it's a future
24        // and we need to be able to poll it
25        // it is used to timeout the command if page was closed while waiting for response
26        #[pin]
27        delay: futures_timer::Delay,
28
29        message: Option<TargetMessage>,
30
31        method: MethodId,
32
33        _marker: PhantomData<T>
34    }
35}
36
37impl<T: Command> CommandFuture<T> {
38    pub fn new(
39        cmd: T,
40        target_sender: mpsc::Sender<TargetMessage>,
41        session: Option<SessionId>,
42    ) -> Result<Self> {
43        let (tx, rx_command) = oneshot_channel::<Result<Response>>();
44        let method = cmd.identifier();
45
46        let message = Some(TargetMessage::Command(CommandMessage::with_session(
47            cmd, tx, session,
48        )?));
49
50        let delay = futures_timer::Delay::new(std::time::Duration::from_millis(
51            crate::handler::REQUEST_TIMEOUT,
52        ));
53
54        Ok(Self {
55            target_sender,
56            rx_command,
57            message,
58            delay,
59            method,
60            _marker: PhantomData,
61        })
62    }
63}
64
65impl<T> Future for CommandFuture<T>
66where
67    T: Command,
68{
69    type Output = Result<CommandResponse<T::Response>>;
70
71    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
72        let mut this = self.project();
73
74        if this.message.is_some() {
75            match this.target_sender.poll_ready(cx) {
76                Poll::Ready(Err(e)) => Poll::Ready(Err(e.into())),
77                Poll::Ready(Ok(_)) => {
78                    let message = this.message.take().expect("existence checked above");
79                    this.target_sender.start_send(message)?;
80
81                    cx.waker().wake_by_ref();
82                    Poll::Pending
83                }
84                Poll::Pending => Poll::Pending,
85            }
86        } else if this.delay.poll(cx).is_ready() {
87            Poll::Ready(Err(crate::error::CdpError::Timeout))
88        } else {
89            match this.rx_command.as_mut().poll(cx) {
90                Poll::Ready(Ok(Ok(response))) => {
91                    Poll::Ready(to_command_response::<T>(response, this.method.clone()))
92                }
93                Poll::Ready(Ok(Err(e))) => Poll::Ready(Err(e)),
94                Poll::Ready(Err(e)) => Poll::Ready(Err(e.into())),
95                Poll::Pending => Poll::Pending,
96            }
97        }
98    }
99}