Module libp2p_core::upgrade
source · Expand description
Contains everything related to upgrading a connection or a substream to use a protocol.
After a connection with a remote has been successfully established or a substream successfully opened, the next step is to upgrade this connection or substream to use a protocol.
This is where the UpgradeInfo
, InboundUpgrade
and OutboundUpgrade
traits come into play.
The InboundUpgrade
and OutboundUpgrade
traits are implemented on types that represent a
collection of one or more possible protocols for respectively an ingoing or outgoing
connection or substream.
Note: Multiple versions of the same protocol are treated as different protocols. For example,
/foo/1.0.0
and/foo/1.1.0
are totally unrelated as far as upgrading is concerned.
Upgrade process
An upgrade is performed in two steps:
-
A protocol negotiation step. The
UpgradeInfo::protocol_info
method is called to determine which protocols are supported by the trait implementation. Themultistream-select
protocol is used in order to agree on which protocol to use amongst the ones supported. -
A handshake. After a successful negotiation, the
InboundUpgrade::upgrade_inbound
orOutboundUpgrade::upgrade_outbound
method is called. This method will return aFuture
that performs a handshake. This handshake is considered mandatory, however in practice it is possible for the trait implementation to return a dummyFuture
that doesn’t perform any action and immediately succeeds.
After an upgrade is successful, an object of type InboundUpgrade::Output
or
OutboundUpgrade::Output
is returned. The actual object depends on the implementation and
there is no constraint on the traits that it should implement, however it is expected that it
can be used by the user to control the behaviour of the protocol.
Note: You can use the
apply_inbound
orapply_outbound
methods to try upgrade a connection or substream. However if you use the recommendedSwarm
orConnectionHandler
APIs, the upgrade is automatically handled for you and you don’t need to use these methods.
Re-exports
pub use crate::Negotiated;
Structs
- Dummy implementation of
UpgradeInfo
/InboundUpgrade
/OutboundUpgrade
that doesn’t support any protocol. - Implements the
UpgradeInfo
,InboundUpgrade
andOutboundUpgrade
traits. - Future returned by
apply_inbound
. Drives the upgrade process. - Wraps around an upgrade and applies a closure to the output.
- Wraps around an upgrade and applies a closure to the error.
- Wraps around an upgrade and applies a closure to the output.
- Wraps around an upgrade and applies a closure to the error.
- A
Future
that waits on the completion of protocol negotiation. - Upgrade that can be disabled at runtime.
- Future returned by
apply_outbound
. Drives the upgrade process. - Implementation of
UpgradeInfo
,InboundUpgrade
andOutboundUpgrade
that always returns a pending upgrade. - Implementation of
UpgradeInfo
,InboundUpgrade
andOutboundUpgrade
that directly yields the substream. - Upgrade that combines two upgrades into one. Supports all the protocols supported by either sub-upgrade.
Enums
- A type to represent two possible upgrade types (inbound or outbound).
- Error that can happen when negotiating a protocol with the remote.
- A protocol error.
- Error that can happen when upgrading a connection or substream to use a protocol.
- Supported multistream-select versions.
Traits
- Possible upgrade on an inbound connection or substream.
- Extension trait for
InboundUpgrade
. Automatically implemented on all types that implementInboundUpgrade
. - Possible upgrade on an outbound connection or substream.
- Extention trait for
OutboundUpgrade
. Automatically implemented on all types that implementOutboundUpgrade
. - Types serving as protocol names.
- Common trait for upgrades that can be applied on inbound substreams, outbound substreams, or both.
Functions
- Applies an upgrade to the inbound and outbound direction of a connection or substream.
- Tries to perform an upgrade on an inbound connection or substream.
- Tries to perform an upgrade on an outbound connection or substream.
- Initializes a new
FromFnUpgrade
. - Reads a length-prefixed message from the given socket.
- Reads a variable-length integer from the
socket
. - Writes a message to the given socket with a length prefix appended to it. Also flushes the socket.
- Writes a variable-length integer to the
socket
.