Struct libp2p_pubsub_core::SubscriptionBuilder

pub struct SubscriptionBuilder { /* private fields */ }

A builder for a subscription.

Implementations

impl SubscriptionBuilder

pub fn new<H: Hasher>(topic: Topic<H>) -> Self

Create a new subscription builder.

pub fn message_id_fn<F>(&mut self, id_fn: F) -> &mut Selfwhere F: Fn(&FrameMessage) -> MessageId + Send + Sync + 'static,

A user-defined function allowing the user to specify the message id of a pub-sub message. The default value is to concatenate the source peer id with a sequence number. Setting this parameter allows the user to address packets arbitrarily. One example is content based addressing, where this function may be set to hash(message). This would prevent messages of the same content from being duplicated.

The function takes a FrameMessage as input and outputs a String to be interpreted as the message id.

pub fn build(self) -> Subscription