use crate::Protocol;use bstr::BString; /// The way to connect to a process speaking the `git` protocol.#[derive(PartialEq, Eq, Clone, Copy)]pub enum ConnectMode {    /// A git daemon.    Daemon,    /// A spawned `git` process to upload a pack to the client.    Process,} /// A TCP connection to either a `git` daemon or a spawned `git` process.////// When connecting to a daemon, additional context information is sent with the first line of the handshake. Otherwise that/// context is passed using command line arguments to a [spawned `git` process][crate::client::file::SpawnProcessOnDemand].pub struct Connection<R, W> {    pub(in crate::client) writer: W,    pub(in crate::client) line_provider: git_packetline::StreamingPeekableIter<R>,    pub(in crate::client) path: BString,    pub(in crate::client) virtual_host: Option<(String, Option<u16>)>,    pub(in crate::client) desired_version: Protocol,    supported_versions: [Protocol; 1],    custom_url: Option<String>,    pub(in crate::client) mode: ConnectMode,} impl<R, W> Connection<R, W> {    /// Return the inner reader and writer    pub fn into_inner(self) -> (R, W) {        (self.line_provider.into_inner(), self.writer)    }     /// Optionally set the URL to be returned when asked for it if `Some` or calculate a default for `None`.    ///    /// The URL is required as parameter for authentication helpers which are called in transports    /// that support authentication. Even though plain git transports don't support that, this    /// may well be the case in custom transports.    pub fn custom_url(mut self, url: Option<String>) -> Self {        self.custom_url = url;        self    }} mod message {    use crate::{Protocol, Service};    use bstr::{BString, ByteVec};     pub fn connect(        service: Service,        version: Protocol,        path: &[u8],        virtual_host: Option<&(String, Option<u16>)>,        extra_parameters: &[(&str, Option<&str>)],    ) -> BString {        let mut out = bstr::BString::from(service.as_str());        out.push(b' ');        let path = git_url::expand_path::for_shell(path.into());        out.extend_from_slice(&path);        out.push(0);        if let Some((host, port)) = virtual_host {            out.push_str("host=");            out.extend_from_slice(host.as_bytes());            if let Some(port) = port {                out.push_byte(b':');                out.push_str(&format!("{}", port));            }            out.push(0);        }        // We only send the version when needed, as otherwise a V2 server who is asked for V1 will respond with 'version 1'        // as extra lines in the reply, which we don't want to handle. Especially since an old server will not respond with that        // line (is what I assume, at least), so it's an optional part in the response to understand and handle. There is no value        // in that, so let's help V2 servers to respond in a way that assumes V1.        let extra_params_need_null_prefix = if version != Protocol::V1 {            out.push(0);            out.push_str(format!("version={}", version as usize));            out.push(0);            false        } else {            true        };         if !extra_parameters.is_empty() {            if extra_params_need_null_prefix {                out.push(0);            }            for (key, value) in extra_parameters {                match value {                    Some(value) => out.push_str(format!("{}={}", key, value)),                    None => out.push_str(key),                }                out.push(0);            }        }        out    }    #[cfg(test)]    mod tests {        use crate::{client::git, Protocol, Service};         #[test]        fn version_1_without_host_and_version() {            assert_eq!(                git::message::connect(Service::UploadPack, Protocol::V1, b"hello/world", None, &[]),                "git-upload-pack hello/world\0"            )        }        #[test]        fn version_2_without_host_and_version() {            assert_eq!(                git::message::connect(Service::UploadPack, Protocol::V2, b"hello\\world", None, &[]),                "git-upload-pack hello\\world\0\0version=2\0"            )        }        #[test]        fn version_2_without_host_and_version_and_exta_parameters() {            assert_eq!(                git::message::connect(                    Service::UploadPack,                    Protocol::V2,                    b"/path/project.git",                    None,                    &[("key", Some("value")), ("value-only", None)]                ),                "git-upload-pack /path/project.git\0\0version=2\0key=value\0value-only\0"            )        }        #[test]        fn with_host_without_port() {            assert_eq!(                git::message::connect(                    Service::UploadPack,                    Protocol::V1,                    b"hello\\world",                    Some(&("host".into(), None)),                    &[]                ),                "git-upload-pack hello\\world\0host=host\0"            )        }        #[test]        fn with_host_without_port_and_extra_parameters() {            assert_eq!(                git::message::connect(                    Service::UploadPack,                    Protocol::V1,                    b"hello\\world",                    Some(&("host".into(), None)),                    &[("key", Some("value")), ("value-only", None)]                ),                "git-upload-pack hello\\world\0host=host\0\0key=value\0value-only\0"            )        }        #[test]        fn with_host_with_port() {            assert_eq!(                git::message::connect(                    Service::UploadPack,                    Protocol::V1,                    b"hello\\world",                    Some(&("host".into(), Some(404))),                    &[]                ),                "git-upload-pack hello\\world\0host=host:404\0"            )        }    }} #[cfg(feature = "async-client")]mod async_io; #[cfg(feature = "blocking-client")]mod blocking_io;#[cfg(feature = "blocking-client")]pub use blocking_io::connect;