Roman Borschel cde93f5432
Kademlia: Somewhat complete the records implementation. (#1189)
* Somewhat complete the implementation of Kademlia records.

This commit relates to [libp2p-146] and [libp2p-1089].

  * All records expire (by default, configurable).
  * Provider records are also stored in the RecordStore, and the RecordStore
    API extended.
  * Background jobs for periodic (re-)replication and (re-)publication
    of records. Regular (value-)records are subject to re-replication and
    re-publication as per standard Kademlia. Provider records are only
    subject to re-publication.
  * For standard Kademlia value lookups (quorum = 1), the record is cached
    at the closest peer to the key that did not return the value, as per
    standard Kademlia.
  * Expiration times of regular (value-)records is computed exponentially
    inversely proportional to the number of nodes between the local node
    and the closest node known to the key (beyond the k closest), as per
    standard Kademlia.

The protobuf messages are extended with two fields: `ttl` and `publisher`
in order to implement the different semantics of re-replication (by any
of the k closest peers to the key, not affecting expiry) and re-publication
(by the original publisher, resetting the expiry). This is not done yet in
other libp2p Kademlia implementations, see e.g. [libp2p-go-323]. The new protobuf fields
have been given somewhat unique identifiers to prevent future collision.

Similarly, periodic re-publication of provider records does not seem to
be done yet in other implementations, see e.g. [libp2p-js-98].

[libp2p-146]: https://github.com/libp2p/rust-libp2p/issues/146
[libp2p-1089]: https://github.com/libp2p/rust-libp2p/issues/1089
[libp2p-go-323]: https://github.com/libp2p/go-libp2p-kad-dht/issues/323
[libp2p-js-98]: https://github.com/libp2p/js-libp2p-kad-dht/issues/98

* Tweak kad-ipfs example.

* Add missing files.

* Ensure new delays are polled immediately.

To ensure task notification, since `NotReady` is returned right after.

* Fix ipfs-kad example and use wasm_timer.

* Small cleanup.

* Incorporate some feedback.

* Adjustments after rebase.

* Distinguish events further.

In order for a user to easily distinguish the result of e.g.
a `put_record` operation from the result of a later republication,
different event constructors are used. Furthermore, for now,
re-replication and "caching" of records (at the closest peer to
the key that did not return a value during a successful lookup)
do not yield events for now as they are less interesting.

* Speed up tests for CI.

* Small refinements and more documentation.

  * Guard a node against overriding records for which it considers
    itself to be the publisher.

  * Document the jobs module more extensively.

* More inline docs around removal of "unreachable" addresses.

* Remove wildcard re-exports.

* Use NonZeroUsize for the constants.

* Re-add method lost on merge.

* Add missing 'pub'.

* Further increase the timeout in the ipfs-kad example.

* Readd log dependency to libp2p-kad.

* Simplify RecordStore API slightly.

* Some more commentary.

* Change Addresses::remove to return Result<(),()>.

Change the semantics of `Addresses::remove` so that the error case
is unambiguous, instead of the success case. Use the `Result` for
clearer semantics to that effect.

* Add some documentation to .
2019-07-17 14:40:48 +02:00

224 lines
7.4 KiB
Rust

// Copyright 2018 Parity Technologies (UK) Ltd.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
use libp2p_core_derive::*;
/// Small utility to check that a type implements `NetworkBehaviour`.
#[allow(dead_code)]
fn require_net_behaviour<T: libp2p::swarm::NetworkBehaviour>() {}
// TODO: doesn't compile
/*#[test]
fn empty() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Foo {}
}*/
#[test]
fn one_field() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Foo<TSubstream> {
ping: libp2p::ping::Ping<TSubstream>,
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::ping::PingEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::ping::PingEvent) {
}
}
#[allow(dead_code)]
fn foo<TSubstream: libp2p::tokio_io::AsyncRead + libp2p::tokio_io::AsyncWrite>() {
require_net_behaviour::<Foo<TSubstream>>();
}
}
#[test]
fn two_fields() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Foo<TSubstream> {
ping: libp2p::ping::Ping<TSubstream>,
identify: libp2p::identify::Identify<TSubstream>,
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::identify::IdentifyEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::identify::IdentifyEvent) {
}
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::ping::PingEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::ping::PingEvent) {
}
}
#[allow(dead_code)]
fn foo<TSubstream: libp2p::tokio_io::AsyncRead + libp2p::tokio_io::AsyncWrite>() {
require_net_behaviour::<Foo<TSubstream>>();
}
}
#[test]
fn three_fields() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Foo<TSubstream> {
ping: libp2p::ping::Ping<TSubstream>,
identify: libp2p::identify::Identify<TSubstream>,
kad: libp2p::kad::Kademlia<TSubstream, libp2p::kad::record::store::MemoryStore>,
#[behaviour(ignore)]
foo: String,
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::ping::PingEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::ping::PingEvent) {
}
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::identify::IdentifyEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::identify::IdentifyEvent) {
}
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::kad::KademliaEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::kad::KademliaEvent) {
}
}
#[allow(dead_code)]
fn foo<TSubstream: libp2p::tokio_io::AsyncRead + libp2p::tokio_io::AsyncWrite>() {
require_net_behaviour::<Foo<TSubstream>>();
}
}
#[test]
fn custom_polling() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
#[behaviour(poll_method = "foo")]
struct Foo<TSubstream> {
ping: libp2p::ping::Ping<TSubstream>,
identify: libp2p::identify::Identify<TSubstream>,
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::ping::PingEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::ping::PingEvent) {
}
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::identify::IdentifyEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::identify::IdentifyEvent) {
}
}
impl<TSubstream> Foo<TSubstream> {
fn foo<T>(&mut self) -> libp2p::futures::Async<libp2p::swarm::NetworkBehaviourAction<T, ()>> { libp2p::futures::Async::NotReady }
}
#[allow(dead_code)]
fn foo<TSubstream: libp2p::tokio_io::AsyncRead + libp2p::tokio_io::AsyncWrite>() {
require_net_behaviour::<Foo<TSubstream>>();
}
}
#[test]
fn custom_event_no_polling() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
#[behaviour(out_event = "Vec<String>")]
struct Foo<TSubstream> {
ping: libp2p::ping::Ping<TSubstream>,
identify: libp2p::identify::Identify<TSubstream>,
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::ping::PingEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::ping::PingEvent) {
}
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::identify::IdentifyEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::identify::IdentifyEvent) {
}
}
#[allow(dead_code)]
fn foo<TSubstream: libp2p::tokio_io::AsyncRead + libp2p::tokio_io::AsyncWrite>() {
require_net_behaviour::<Foo<TSubstream>>();
}
}
#[test]
fn custom_event_and_polling() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
#[behaviour(poll_method = "foo", out_event = "String")]
struct Foo<TSubstream> {
ping: libp2p::ping::Ping<TSubstream>,
identify: libp2p::identify::Identify<TSubstream>,
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::ping::PingEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::ping::PingEvent) {
}
}
impl<TSubstream> libp2p::swarm::NetworkBehaviourEventProcess<libp2p::identify::IdentifyEvent> for Foo<TSubstream> {
fn inject_event(&mut self, _: libp2p::identify::IdentifyEvent) {
}
}
impl<TSubstream> Foo<TSubstream> {
fn foo<T>(&mut self) -> libp2p::futures::Async<libp2p::swarm::NetworkBehaviourAction<T, String>> { libp2p::futures::Async::NotReady }
}
#[allow(dead_code)]
fn foo<TSubstream: libp2p::tokio_io::AsyncRead + libp2p::tokio_io::AsyncWrite>() {
require_net_behaviour::<Foo<TSubstream>>();
}
}
#[test]
fn where_clause() {
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Foo<TSubstream> where TSubstream: std::fmt::Debug {
ping: libp2p::ping::Ping<TSubstream>,
}
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Bar<TSubstream: std::fmt::Debug> {
ping: libp2p::ping::Ping<TSubstream>,
}
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Baz<TSubstream> where TSubstream: std::fmt::Debug + Clone, {
ping: libp2p::ping::Ping<TSubstream>,
}
#[allow(dead_code)]
#[derive(NetworkBehaviour)]
struct Qux<TSubstream: std::fmt::Debug> where TSubstream: Clone {
ping: libp2p::ping::Ping<TSubstream>,
}
}