* Restore `RequestResponse::throttled`.
In contrast to the existing "throttled" approach this PR adds back-
pressure to the protocol without requiring pre-existing knowledge
of all nodes about their limits. It adds small, CBOR-encoded headers
to the actual payload data. Extra credit messages communicate back
to the sender how many more requests it is allowed to send.
* Remove some noise.
* Resend credit grant after connection closed.
Should an error in some lower layer cause a connection to be closed,
our previously sent credit grant may not have reached the remote peer.
Therefore, pessimistically, a credit grant is resent whenever a
connection is closed. The remote ignores duplicate grants.
* Remove inbound/outbound tracking per peer.
* Send ACK as response to duplicate credit grants.
* Simplify.
* Fix grammar.
* Incorporate review feedback.
- Remove `ResponseSent` which was a leftover from previous attemps
and issue a credit grant immediately in `send_response`.
- Only resend credit grants after a connection is closed if we are
still connected to this peer.
* Move codec/header.rs to throttled/codec.rs.
* More review suggestions.
* Generalise `ProtocolWrapper` and use shorter prefix.
* Update protocols/request-response/src/lib.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Update protocols/request-response/src/throttled.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Update protocols/request-response/src/throttled.rs
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Minor comment changes.
* Limit max. header size to 8KiB
* Always construct initial limit with 1.
Since honest senders always assume a send budget of 1 and wait for
credit afterwards, setting the default limit to a higher value
can only become effective after informing the peer about it which
means leaving `max_recv` at 1 and setting `next_max` to the desired
value.
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Add the libp2p-request-response protocol.
This crate provides a generic implementation for request/response
protocols, whereby each request is sent on a new substream.
* Fix OneShotHandler usage in floodsub.
* Custom ProtocolsHandler and multiple protocols.
1. Implement a custom ProtocolsHandler instead of using
the OneShotHandler for better control and error handling.
In particular, all request/response sending/receiving is
kept in the substreams upgrades and thus the background
task of a connection.
2. Support multiple protocols (usually protocol versions)
with a single `RequestResponse` instance, with
configurable inbound/outbound support.
* Small doc clarification.
* Remove unnecessary Sync bounds.
* Remove redundant Clone constraint.
* Update protocols/request-response/Cargo.toml
Co-authored-by: Toralf Wittner <tw@dtex.org>
* Update dev-dependencies.
* Update Cargo.tomls.
* Add changelog.
* Remove Sync bound from RequestResponseCodec::Protocol.
Apparently the compiler just needs some help with the scope
of borrows, which is unfortunate.
* Try async-trait.
* Allow checking whether a ResponseChannel is still open.
Also expand the commentary on `send_response` to indicate that
responses may be discard if they come in too late.
* Add `RequestResponse::is_pending`.
As an analogue of `ResponseChannel::is_open` for outbound requests.
* Revert now unnecessary changes to the OneShotHandler.
Since `libp2p-request-response` is no longer using it.
* Update CHANGELOG for libp2p-swarm.
Co-authored-by: Toralf Wittner <tw@dtex.org>
