Enum libp2p_core::transport::upgrade::Version

pub enum Version {
    V1,
    V1Lazy,
}

Supported multistream-select versions.

Variants

V1

Version 1 of the multistream-select protocol. See 1 and 2.

V1Lazy

A “lazy” variant of version 1 that is identical on the wire but whereby the dialer delays flushing protocol negotiation data in order to combine it with initial application data, thus performing 0-RTT negotiation.

This strategy is only applicable for the node with the role of “dialer” in the negotiation and only if the dialer supports just a single application protocol. In that case the dialer immedidately “settles” on that protocol, buffering the negotiation messages to be sent with the first round of application protocol data (or an attempt is made to read from the Negotiated I/O stream).

A listener will behave identically to V1. This ensures interoperability with V1. Notably, it will immediately send the multistream header as well as the protocol confirmation, resulting in multiple frames being sent on the underlying transport. Nevertheless, if the listener supports the protocol that the dialer optimistically settled on, it can be a 0-RTT negotiation.

Note: V1Lazy is specific to rust-libp2p. The wire protocol is identical to V1 and generally interoperable with peers only supporting V1. Nevertheless, there is a pitfall that is rarely encountered: When nesting multiple protocol negotiations, the listener should either be known to support all of the dialer’s optimistically chosen protocols or there is must be no intermediate protocol without a payload and none of the protocol payloads must have the potential for being mistaken for a multistream-select protocol message. This avoids rare edge-cases whereby the listener may not recognize upgrade boundaries and erroneously process a request despite not supporting one of the intermediate protocols that the dialer committed to. See 1 and 2.

Trait Implementations

impl Clone for Version

fn clone(&self) -> Version

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Version

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for Version

fn default() -> Version

Returns the “default value” for a type.

impl PartialEq for Version

fn eq(&self, other: &Version) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Version

impl Eq for Version

impl StructuralPartialEq for Version