[−][src]Trait libp2p_swarm::protocols_handler::ProtocolsHandler

pub trait ProtocolsHandler: Send + 'static {
    type InEvent: Send + 'static;
    type OutEvent: Send + 'static;
    type Error: Error + Send + 'static;
    type InboundProtocol: InboundUpgradeSend + Send + 'static;
    type OutboundProtocol: OutboundUpgradeSend;
    type InboundOpenInfo: Send + 'static;
    type OutboundOpenInfo: Send + 'static;
    fn listen_protocol(
        &self
    ) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo>;

    fn inject_fully_negotiated_inbound(
        &mut self, 
        protocol: <Self::InboundProtocol as InboundUpgradeSend>::Output, 
        info: Self::InboundOpenInfo
    );

    fn inject_fully_negotiated_outbound(
        &mut self, 
        protocol: <Self::OutboundProtocol as OutboundUpgradeSend>::Output, 
        info: Self::OutboundOpenInfo
    );

    fn inject_event(&mut self, event: Self::InEvent);

    fn inject_dial_upgrade_error(
        &mut self, 
        info: Self::OutboundOpenInfo, 
        error: ProtocolsHandlerUpgrErr<<Self::OutboundProtocol as OutboundUpgradeSend>::Error>
    );

    fn connection_keep_alive(&self) -> KeepAlive;

    fn poll(
        &mut self, 
        cx: &mut Context<'_>
    ) -> Poll<ProtocolsHandlerEvent<Self::OutboundProtocol, Self::OutboundOpenInfo, Self::OutEvent, Self::Error>>;

    fn inject_address_change(&mut self, _new_address: &Multiaddr) { ... }

    fn inject_listen_upgrade_error(
        &mut self, 
        _: Self::InboundOpenInfo, 
        _: ProtocolsHandlerUpgrErr<<Self::InboundProtocol as InboundUpgradeSend>::Error>
    ) { ... }

    fn map_in_event<TNewIn, TMap>(
        self, 
        map: TMap
    ) -> MapInEvent<Self, TNewIn, TMap>
    where
        Self: Sized,
        TMap: Fn(&TNewIn) -> Option<&Self::InEvent>,
    { ... }

    fn map_out_event<TMap, TNewOut>(self, map: TMap) -> MapOutEvent<Self, TMap>
    where
        Self: Sized,
        TMap: FnMut(Self::OutEvent) -> TNewOut,
    { ... }

    fn select<TProto2>(
        self, 
        other: TProto2
    ) -> ProtocolsHandlerSelect<Self, TProto2>
    where
        Self: Sized,
    { ... }

    fn into_node_handler_builder(self) -> NodeHandlerWrapperBuilder<Self>
    where
        Self: Sized,
    { ... }
}

A handler for a set of protocols used on a connection with a remote.

This trait should be implemented for a type that maintains the state for the execution of a specific protocol with a remote.

Handling a protocol

Communication with a remote over a set of protocols is initiated in one of two ways:

  1. Dialing by initiating a new outbound substream. In order to do so, ProtocolsHandler::poll() must return an ProtocolsHandlerEvent::OutboundSubstreamRequest, providing an instance of libp2p_core::upgrade::OutboundUpgrade that is used to negotiate the protocol(s). Upon success, ProtocolsHandler::inject_fully_negotiated_outbound is called with the final output of the upgrade.

  2. Listening by accepting a new inbound substream. When a new inbound substream is created on a connection, ProtocolsHandler::listen_protocol is called to obtain an instance of libp2p_core::upgrade::InboundUpgrade that is used to negotiate the protocol(s). Upon success, ProtocolsHandler::inject_fully_negotiated_inbound is called with the final output of the upgrade.

Connection Keep-Alive

A ProtocolsHandler can influence the lifetime of the underlying connection through ProtocolsHandler::connection_keep_alive. That is, the protocol implemented by the handler can include conditions for terminating the connection. The lifetime of successfully negotiated substreams is fully controlled by the handler.

Implementors of this trait should keep in mind that the connection can be closed at any time. When a connection is closed gracefully, the substreams used by the handler may still continue reading data until the remote closes its side of the connection.

Associated Types

type InEvent: Send + 'static

Custom event that can be received from the outside.

type OutEvent: Send + 'static

Custom event that can be produced by the handler and that will be returned to the outside.

type Error: Error + Send + 'static

The type of errors returned by ProtocolsHandler::poll.

type InboundProtocol: InboundUpgradeSend + Send + 'static

The inbound upgrade for the protocol(s) used by the handler.

type OutboundProtocol: OutboundUpgradeSend

The outbound upgrade for the protocol(s) used by the handler.

type InboundOpenInfo: Send + 'static

The type of additional information returned from listen_protocol.

type OutboundOpenInfo: Send + 'static

The type of additional information passed to an OutboundSubstreamRequest.

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Required methods

fn listen_protocol(
    &self
) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo>

The InboundUpgrade to apply on inbound substreams to negotiate the desired protocols.

Note: The returned InboundUpgrade should always accept all the generally supported protocols, even if in a specific context a particular one is not supported, (eg. when only allowing one substream at a time for a protocol). This allows a remote to put the list of supported protocols in a cache.

fn inject_fully_negotiated_inbound(
    &mut self,
    protocol: <Self::InboundProtocol as InboundUpgradeSend>::Output,
    info: Self::InboundOpenInfo
)

Injects the output of a successful upgrade on a new inbound substream.

fn inject_fully_negotiated_outbound(
    &mut self,
    protocol: <Self::OutboundProtocol as OutboundUpgradeSend>::Output,
    info: Self::OutboundOpenInfo
)

Injects the output of a successful upgrade on a new outbound substream.

The second argument is the information that was previously passed to ProtocolsHandlerEvent::OutboundSubstreamRequest.

fn inject_event(&mut self, event: Self::InEvent)

Injects an event coming from the outside in the handler.

fn inject_dial_upgrade_error(
    &mut self,
    info: Self::OutboundOpenInfo,
    error: ProtocolsHandlerUpgrErr<<Self::OutboundProtocol as OutboundUpgradeSend>::Error>
)

Indicates to the handler that upgrading an outbound substream to the given protocol has failed.

fn connection_keep_alive(&self) -> KeepAlive

Returns until when the connection should be kept alive.

This method is called by the Swarm after each invocation of ProtocolsHandler::poll to determine if the connection and the associated ProtocolsHandlers should be kept alive as far as this handler is concerned and if so, for how long.

Returning KeepAlive::No indicates that the connection should be closed and this handler destroyed immediately.

Returning KeepAlive::Until indicates that the connection may be closed and this handler destroyed after the specified Instant.

Returning KeepAlive::Yes indicates that the connection should be kept alive until the next call to this method.

Note: The connection is always closed and the handler destroyed when ProtocolsHandler::poll returns an error. Furthermore, the connection may be closed for reasons outside of the control of the handler.

fn poll(
    &mut self,
    cx: &mut Context<'_>
) -> Poll<ProtocolsHandlerEvent<Self::OutboundProtocol, Self::OutboundOpenInfo, Self::OutEvent, Self::Error>>

Should behave like Stream::poll().

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Provided methods

fn inject_address_change(&mut self, _new_address: &Multiaddr)

Notifies the handler of a change in the address of the remote.

fn inject_listen_upgrade_error(
    &mut self,
    _: Self::InboundOpenInfo,
    _: ProtocolsHandlerUpgrErr<<Self::InboundProtocol as InboundUpgradeSend>::Error>
)

Indicates to the handler that upgrading an inbound substream to the given protocol has failed.

fn map_in_event<TNewIn, TMap>(self, map: TMap) -> MapInEvent<Self, TNewIn, TMap> where
    Self: Sized,
    TMap: Fn(&TNewIn) -> Option<&Self::InEvent>, 

Adds a closure that turns the input event into something else.

fn map_out_event<TMap, TNewOut>(self, map: TMap) -> MapOutEvent<Self, TMap> where
    Self: Sized,
    TMap: FnMut(Self::OutEvent) -> TNewOut, 

Adds a closure that turns the output event into something else.

fn select<TProto2>(
    self,
    other: TProto2
) -> ProtocolsHandlerSelect<Self, TProto2> where
    Self: Sized, 

Creates a new ProtocolsHandler that selects either this handler or other by delegating methods calls appropriately.

Note: The largest KeepAlive returned by the two handlers takes precedence, i.e. is returned from ProtocolsHandler::connection_keep_alive by the returned handler.

fn into_node_handler_builder(self) -> NodeHandlerWrapperBuilder<Self> where
    Self: Sized, 

Creates a builder that allows creating a NodeHandler that handles this protocol exclusively.

Note: This method should not be redefined in a custom ProtocolsHandler.

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Implementors

impl ProtocolsHandler for DummyProtocolsHandler[src]

type InEvent = Void

type OutEvent = Void

type Error = Void

type InboundProtocol = DeniedUpgrade

type OutboundProtocol = DeniedUpgrade

type OutboundOpenInfo = Void

type InboundOpenInfo = ()

impl<K, H> ProtocolsHandler for MultiHandler<K, H> where
    K: Clone + Hash + Eq + Send + 'static,
    H: ProtocolsHandler,
    H::InboundProtocol: InboundUpgradeSend,
    H::OutboundProtocol: OutboundUpgradeSend, [src]

type InEvent = (K, <H as ProtocolsHandler>::InEvent)

type OutEvent = (K, <H as ProtocolsHandler>::OutEvent)

type Error = <H as ProtocolsHandler>::Error

type InboundProtocol = Upgrade<K, <H as ProtocolsHandler>::InboundProtocol>

type OutboundProtocol = <H as ProtocolsHandler>::OutboundProtocol

type InboundOpenInfo = Info<K, <H as ProtocolsHandler>::InboundOpenInfo>

type OutboundOpenInfo = (K, <H as ProtocolsHandler>::OutboundOpenInfo)

impl<TInbound, TOutbound, TEvent> ProtocolsHandler for OneShotHandler<TInbound, TOutbound, TEvent> where
    TInbound: InboundUpgradeSend + Send + 'static,
    TOutbound: OutboundUpgradeSend,
    TInbound::Output: Into<TEvent>,
    TOutbound::Output: Into<TEvent>,
    TOutbound::Error: Error + Send + 'static,
    SubstreamProtocol<TInbound, ()>: Clone,
    TEvent: Send + 'static, [src]

type InEvent = TOutbound

type OutEvent = TEvent

type Error = ProtocolsHandlerUpgrErr<<Self::OutboundProtocol as OutboundUpgradeSend>::Error>

type InboundProtocol = TInbound

type OutboundProtocol = TOutbound

type OutboundOpenInfo = ()

type InboundOpenInfo = ()

impl<TInner> ProtocolsHandler for ToggleProtoHandler<TInner> where
    TInner: ProtocolsHandler, [src]

type InEvent = TInner::InEvent

type OutEvent = TInner::OutEvent

type Error = TInner::Error

type InboundProtocol = EitherUpgrade<SendWrapper<TInner::InboundProtocol>, SendWrapper<DeniedUpgrade>>

type OutboundProtocol = TInner::OutboundProtocol

type OutboundOpenInfo = TInner::OutboundOpenInfo

type InboundOpenInfo = Either<TInner::InboundOpenInfo, ()>

impl<TProto1, TProto2> ProtocolsHandler for ProtocolsHandlerSelect<TProto1, TProto2> where
    TProto1: ProtocolsHandler,
    TProto2: ProtocolsHandler, [src]

type InEvent = EitherOutput<TProto1::InEvent, TProto2::InEvent>

type OutEvent = EitherOutput<TProto1::OutEvent, TProto2::OutEvent>

type Error = EitherError<TProto1::Error, TProto2::Error>

type InboundProtocol = SelectUpgrade<SendWrapper<<TProto1 as ProtocolsHandler>::InboundProtocol>, SendWrapper<<TProto2 as ProtocolsHandler>::InboundProtocol>>

type OutboundProtocol = EitherUpgrade<SendWrapper<TProto1::OutboundProtocol>, SendWrapper<TProto2::OutboundProtocol>>

type OutboundOpenInfo = EitherOutput<TProto1::OutboundOpenInfo, TProto2::OutboundOpenInfo>

type InboundOpenInfo = (TProto1::InboundOpenInfo, TProto2::InboundOpenInfo)

impl<TProtoHandler, TMap, TNewIn> ProtocolsHandler for MapInEvent<TProtoHandler, TNewIn, TMap> where
    TProtoHandler: ProtocolsHandler,
    TMap: Fn(TNewIn) -> Option<TProtoHandler::InEvent>,
    TNewIn: Send + 'static,
    TMap: Send + 'static, [src]

type InEvent = TNewIn

type OutEvent = TProtoHandler::OutEvent

type Error = TProtoHandler::Error

type InboundProtocol = TProtoHandler::InboundProtocol

type OutboundProtocol = TProtoHandler::OutboundProtocol

type InboundOpenInfo = TProtoHandler::InboundOpenInfo

type OutboundOpenInfo = TProtoHandler::OutboundOpenInfo

impl<TProtoHandler, TMap, TNewOut> ProtocolsHandler for MapOutEvent<TProtoHandler, TMap> where
    TProtoHandler: ProtocolsHandler,
    TMap: FnMut(TProtoHandler::OutEvent) -> TNewOut,
    TNewOut: Send + 'static,
    TMap: Send + 'static, [src]

type InEvent = TProtoHandler::InEvent

type OutEvent = TNewOut

type Error = TProtoHandler::Error

type InboundProtocol = TProtoHandler::InboundProtocol

type OutboundProtocol = TProtoHandler::OutboundProtocol

type InboundOpenInfo = TProtoHandler::InboundOpenInfo

type OutboundOpenInfo = TProtoHandler::OutboundOpenInfo

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