pub trait ProtocolsHandler: Send + 'static {
type InEvent: Send + 'static;
type OutEvent: Send + 'static;
type Error: Error + Send + 'static;
type InboundProtocol: InboundUpgradeSend;
type OutboundProtocol: OutboundUpgradeSend;
type InboundOpenInfo: Send + 'static;
type OutboundOpenInfo: Send + 'static;
Show 13 methods
// Required methods
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>>;
// Provided methods
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 { ... }
}Expand description
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:
-
Dialing by initiating a new outbound substream. In order to do so,
ProtocolsHandler::poll()must return anProtocolsHandlerEvent::OutboundSubstreamRequest, providing an instance oftet_libp2p_core::upgrade::OutboundUpgradethat is used to negotiate the protocol(s). Upon success,ProtocolsHandler::inject_fully_negotiated_outboundis called with the final output of the upgrade. -
Listening by accepting a new inbound substream. When a new inbound substream is created on a connection,
ProtocolsHandler::listen_protocolis called to obtain an instance oftet_libp2p_core::upgrade::InboundUpgradethat is used to negotiate the protocol(s). Upon success,ProtocolsHandler::inject_fully_negotiated_inboundis 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.
Required Associated Types§
Sourcetype OutEvent: Send + 'static
type OutEvent: Send + 'static
Custom event that can be produced by the handler and that will be returned to the outside.
Sourcetype Error: Error + Send + 'static
type Error: Error + Send + 'static
The type of errors returned by ProtocolsHandler::poll.
Sourcetype InboundProtocol: InboundUpgradeSend
type InboundProtocol: InboundUpgradeSend
The inbound upgrade for the protocol(s) used by the handler.
Sourcetype OutboundProtocol: OutboundUpgradeSend
type OutboundProtocol: OutboundUpgradeSend
The outbound upgrade for the protocol(s) used by the handler.
Sourcetype InboundOpenInfo: Send + 'static
type InboundOpenInfo: Send + 'static
The type of additional information returned from listen_protocol.
Sourcetype OutboundOpenInfo: Send + 'static
type OutboundOpenInfo: Send + 'static
The type of additional information passed to an OutboundSubstreamRequest.
Required Methods§
Sourcefn listen_protocol(
&self,
) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo>
fn listen_protocol( &self, ) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo>
The InboundUpgrade to apply on inbound
substreams to negotiate the desired protocols.
Note: The returned
InboundUpgradeshould 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.
Sourcefn inject_fully_negotiated_inbound(
&mut self,
protocol: <Self::InboundProtocol as InboundUpgradeSend>::Output,
info: Self::InboundOpenInfo,
)
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.
Sourcefn inject_fully_negotiated_outbound(
&mut self,
protocol: <Self::OutboundProtocol as OutboundUpgradeSend>::Output,
info: Self::OutboundOpenInfo,
)
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.
Sourcefn inject_event(&mut self, event: Self::InEvent)
fn inject_event(&mut self, event: Self::InEvent)
Injects an event coming from the outside in the handler.
Sourcefn inject_dial_upgrade_error(
&mut self,
info: Self::OutboundOpenInfo,
error: ProtocolsHandlerUpgrErr<<Self::OutboundProtocol as OutboundUpgradeSend>::Error>,
)
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.
Sourcefn connection_keep_alive(&self) -> KeepAlive
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::pollreturns an error. Furthermore, the connection may be closed for reasons outside of the control of the handler.
Sourcefn poll(
&mut self,
cx: &mut Context<'_>,
) -> Poll<ProtocolsHandlerEvent<Self::OutboundProtocol, Self::OutboundOpenInfo, Self::OutEvent, Self::Error>>
fn poll( &mut self, cx: &mut Context<'_>, ) -> Poll<ProtocolsHandlerEvent<Self::OutboundProtocol, Self::OutboundOpenInfo, Self::OutEvent, Self::Error>>
Should behave like Stream::poll().
Provided Methods§
Sourcefn inject_address_change(&mut self, _new_address: &Multiaddr)
fn inject_address_change(&mut self, _new_address: &Multiaddr)
Notifies the handler of a change in the address of the remote.
Sourcefn inject_listen_upgrade_error(
&mut self,
_: Self::InboundOpenInfo,
_: ProtocolsHandlerUpgrErr<<Self::InboundProtocol as InboundUpgradeSend>::Error>,
)
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.
Sourcefn map_in_event<TNewIn, TMap>(self, map: TMap) -> MapInEvent<Self, TNewIn, TMap>
fn map_in_event<TNewIn, TMap>(self, map: TMap) -> MapInEvent<Self, TNewIn, TMap>
Adds a closure that turns the input event into something else.
Sourcefn map_out_event<TMap, TNewOut>(self, map: TMap) -> MapOutEvent<Self, TMap>
fn map_out_event<TMap, TNewOut>(self, map: TMap) -> MapOutEvent<Self, TMap>
Adds a closure that turns the output event into something else.
Sourcefn select<TProto2>(
self,
other: TProto2,
) -> ProtocolsHandlerSelect<Self, TProto2>where
Self: Sized,
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
KeepAlivereturned by the two handlers takes precedence, i.e. is returned fromProtocolsHandler::connection_keep_aliveby the returned handler.
Sourcefn into_node_handler_builder(self) -> NodeHandlerWrapperBuilder<Self>where
Self: Sized,
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.