Trait DelegateBlocking

pub trait DelegateBlocking {
    // Required method
    fn negotiate(
        &mut self,
        refs: &[Ref],
        arguments: &mut Arguments,
        previous_response: Option<&Response>,
    ) -> Result<Action>;

    // Provided methods
    fn handshake_extra_parameters(&self) -> Vec<(String, Option<String>)> { ... }
    fn prepare_ls_refs(
        &mut self,
        _server: &Capabilities,
        _arguments: &mut Vec<BString>,
        _features: &mut Vec<(&str, Option<Cow<'_, str>>)>,
    ) -> Result<Action> { ... }
    fn prepare_fetch(
        &mut self,
        _version: Protocol,
        _server: &Capabilities,
        _features: &mut Vec<(&str, Option<Cow<'_, str>>)>,
        _refs: &[Ref],
    ) -> Result<Action> { ... }
}

Available on crate features blocking-client or async-client only.

The non-IO protocol delegate is the bare minimal interface needed to fully control the fetch operation, sparing the IO parts. Async implementations must treat it as blocking and unblock it by evaluating it elsewhere.

See Delegate for the complete trait.

Required Methods

fn negotiate( &mut self, refs: &[Ref], arguments: &mut Arguments, previous_response: Option<&Response>, ) -> Result<Action>

A method called repeatedly to negotiate the objects to receive in receive_pack(…).

The first call has previous_response set to None as there was no previous response. Every call that follows previous_response will be set to Some.

If previous_response is None…

Given a list of arguments to populate with wants, want-refs, shallows, filters and other contextual information to be sent to the server. This method is called once. Send the objects you have have afterwards based on the tips of your refs, in preparation to walk down their parents with each call to negotiate to find the common base(s).

Note that you should not want and object that you already have. refs are the tips of on the server side, effectively the latest objects they have.

Return Action::Close if you know that there are no haves on your end to allow the server to send all of its objects as is the case during initial clones.

If previous_response is Some…

Populate arguments with the objects you have starting from the tips of your refs, taking into consideration the previous_response response of the server to see which objects they acknowledged to have. You have to maintain enough state to be able to walk down from your tips on each call, if they are not in common, and keep setting have for those which are in common if that helps teaching the server about our state and to acknowledge their existence on their end. This method is called until the other side signals they are ready to send a pack. Return Action::Close if you want to give up before finding a common base. This can happen if the remote repository has radically changed so there are no bases, or they are very far in the past, causing all objects to be sent.

Provided Methods

fn handshake_extra_parameters(&self) -> Vec<(String, Option<String>)>

Return extra parameters to be provided during the handshake.

Note that this method is only called once and the result is reused during subsequent handshakes which may happen if there is an authentication failure.

fn prepare_ls_refs( &mut self, _server: &Capabilities, _arguments: &mut Vec<BString>, _features: &mut Vec<(&str, Option<Cow<'_, str>>)>, ) -> Result<Action>

Called before invoking ‘ls-refs’ on the server to allow providing it with additional arguments and to enable features. If the server capabilities don’t match the requirements abort with an error to abort the entire fetch operation.

Note that some arguments are preset based on typical use, and features are preset to maximize options. The server capabilities can be used to see which additional capabilities the server supports as per the handshake which happened prior.

If the delegate returns ls_refs::Action::Skip, no ls-refs command is sent to the server.

Note that this is called only if we are using protocol version 2.

fn prepare_fetch( &mut self, _version: Protocol, _server: &Capabilities, _features: &mut Vec<(&str, Option<Cow<'_, str>>)>, _refs: &[Ref], ) -> Result<Action>

Called before invoking the ‘fetch’ interaction with features pre-filled for typical use and to maximize capabilities to allow aborting an interaction early.

refs is a list of known references on the remote based on the handshake or a prior call to ls_refs. These can be used to abort early in case the refs are already known here.

As there will be another call allowing to post arguments conveniently in the correct format, i.e. want hex-oid, there is no way to set arguments at this time.

version is the actually supported version as reported by the server, which is relevant in case the server requested a downgrade. server capabilities is a list of features the server supports for your information, along with enabled features that the server knows about.

Implementations on Foreign Types

impl<T: DelegateBlocking> DelegateBlocking for &mut T

fn handshake_extra_parameters(&self) -> Vec<(String, Option<String>)>

fn prepare_ls_refs( &mut self, _server: &Capabilities, _arguments: &mut Vec<BString>, _features: &mut Vec<(&str, Option<Cow<'_, str>>)>, ) -> Result<Action>

fn prepare_fetch( &mut self, _version: Protocol, _server: &Capabilities, _features: &mut Vec<(&str, Option<Cow<'_, str>>)>, _refs: &[Ref], ) -> Result<Action>

fn negotiate( &mut self, refs: &[Ref], arguments: &mut Arguments, previous_response: Option<&Response>, ) -> Result<Action>

impl<T: DelegateBlocking> DelegateBlocking for Box<T>

fn handshake_extra_parameters(&self) -> Vec<(String, Option<String>)>

fn prepare_ls_refs( &mut self, _server: &Capabilities, _arguments: &mut Vec<BString>, _features: &mut Vec<(&str, Option<Cow<'_, str>>)>, ) -> Result<Action>

fn prepare_fetch( &mut self, _version: Protocol, _server: &Capabilities, _features: &mut Vec<(&str, Option<Cow<'_, str>>)>, _refs: &[Ref], ) -> Result<Action>

fn negotiate( &mut self, refs: &[Ref], arguments: &mut Arguments, previous_response: Option<&Response>, ) -> Result<Action>

Implementors