Function git_protocol::fetch::handshake

source · 
pub fn handshake<AuthFn, T>(
    transport: T,
    authenticate: AuthFn,
    extra_parameters: Vec<(String, Option<String>)>,
    progress: &mut impl Progress
) -> Result<Outcome, Error>where
    AuthFn: FnMut(Action) -> Result,
    T: Transport,
Available on crate features blocking-client or async-client only.
Expand description

Perform a handshake with the server on the other side of transport, with authenticate being used if authentication turns out to be required. extra_parameters are the parameters (name, optional value) to add to the handshake, each time it is performed in case authentication is required. progress is used to inform about what’s currently happening.

Examples found in repository?
src/fetch_fn.rs (lines 71-76)
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pub async fn fetch<F, D, T, P>(
    mut transport: T,
    mut delegate: D,
    authenticate: F,
    mut progress: P,
    fetch_mode: FetchConnection,
    agent: impl Into<String>,
) -> Result<(), Error>
where
    F: FnMut(credentials::helper::Action) -> credentials::protocol::Result,
    D: Delegate,
    T: client::Transport,
    P: Progress,
    P::SubProgress: 'static,
{
    let crate::handshake::Outcome {
        server_protocol_version: protocol_version,
        refs,
        capabilities,
    } = crate::fetch::handshake(
        &mut transport,
        authenticate,
        delegate.handshake_extra_parameters(),
        &mut progress,
    )
    .await?;

    let agent = crate::agent(agent);
    let refs = match refs {
        Some(refs) => refs,
        None => {
            crate::ls_refs(
                &mut transport,
                &capabilities,
                |a, b, c| {
                    let res = delegate.prepare_ls_refs(a, b, c);
                    c.push(("agent", Some(Cow::Owned(agent.clone()))));
                    res
                },
                &mut progress,
            )
            .await?
        }
    };

    let fetch = Command::Fetch;
    let mut fetch_features = fetch.default_features(protocol_version, &capabilities);
    match delegate.prepare_fetch(protocol_version, &capabilities, &mut fetch_features, &refs) {
        Ok(Action::Cancel) => {
            return if matches!(protocol_version, git_transport::Protocol::V1)
                || matches!(fetch_mode, FetchConnection::TerminateOnSuccessfulCompletion)
            {
                indicate_end_of_interaction(transport).await.map_err(Into::into)
            } else {
                Ok(())
            };
        }
        Ok(Action::Continue) => {
            fetch.validate_argument_prefixes_or_panic(protocol_version, &capabilities, &[], &fetch_features);
        }
        Err(err) => {
            indicate_end_of_interaction(transport).await?;
            return Err(err.into());
        }
    }

    Response::check_required_features(protocol_version, &fetch_features)?;
    let sideband_all = fetch_features.iter().any(|(n, _)| *n == "sideband-all");
    fetch_features.push(("agent", Some(Cow::Owned(agent))));
    let mut arguments = Arguments::new(protocol_version, fetch_features);
    let mut previous_response = None::<Response>;
    let mut round = 1;
    'negotiation: loop {
        progress.step();
        progress.set_name(format!("negotiate (round {})", round));
        round += 1;
        let action = delegate.negotiate(&refs, &mut arguments, previous_response.as_ref())?;
        let mut reader = arguments.send(&mut transport, action == Action::Cancel).await?;
        if sideband_all {
            setup_remote_progress(&mut progress, &mut reader);
        }
        let response = Response::from_line_reader(protocol_version, &mut reader).await?;
        previous_response = if response.has_pack() {
            progress.step();
            progress.set_name("receiving pack");
            if !sideband_all {
                setup_remote_progress(&mut progress, &mut reader);
            }
            delegate.receive_pack(reader, progress, &refs, &response).await?;
            break 'negotiation;
        } else {
            match action {
                Action::Cancel => break 'negotiation,
                Action::Continue => Some(response),
            }
        }
    }
    if matches!(protocol_version, git_transport::Protocol::V2)
        && matches!(fetch_mode, FetchConnection::TerminateOnSuccessfulCompletion)
    {
        indicate_end_of_interaction(transport).await?;
    }
    Ok(())
}