* Rename RawSwarm* to Network*.
To complete the cut performed in [1].
The only remaining mention of a "swarm" in libp2p-core is in some tests
which actually depend on libp2p-swarm.
[1]: https://github.com/libp2p/rust-libp2p/pull/1188
* Post-merge corrections.
The example typically runs into a lot of connection timeouts,
which may cause the query to time out. A query timeout currently
results in the example to be considered failed, but the example
should only be considered failed if no closest peers are found,
whether the query timed out or not.
* Replace unbounded channels with bounded ones.
To remove the unbounded channels used for communicating with node tasks
an API similar to `futures::Sink` is used, i.e. sending is split into a
start and complete phase. The start phase returns `StartSend` and first
attempts to complete any pending send operations. Completing the send
means polling until `Poll::Ready(())` is returned.
In addition this PR has split the `handled_node_tasks` module into
several smaller ones (cf. `nodes::tasks`) and renamed some types:
- `nodes::handled_node_tasks::NodeTask` -> `nodes::tasks::task::Task`
- `nodes::handled_node_tasks::NodeTaskInner` -> `nodes::tasks::task::State`
- `nodes::handled_node_tasks::NodeTasks` -> `nodes::tasks::Manager`
- `nodes::handled_node_tasks::TaskClosedEvent` -> `nodes::tasks::Error`
- `nodes::handled_node_tasks::HandledNodesEvent` -> `nodes::tasks::Event`
- `nodes::handled_node_tasks::Task` -> `nodes::tasks::TaskEntry`
- `nodes::handled_node_tasks::ExtToInMessage` -> `nodes::tasks::task::ToTaskMessage`
- `nodes::handled_node_tasks::InToExtMessage` -> `nodes::tasks::task::FromTaskMessage`
* `take_over_to_complete` can be an `Option`.
Since it is always holding just a single pending message.
* `send_event_to_complete` can be an `Option`.
* Update core/src/nodes/tasks/manager.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Update core/src/nodes/tasks/manager.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Add comments to explain the need to flush sends ...
of take-over and event messages delivered over Sinks.
* Adds a retain method to kademlia.
* Add a store_mut getter to Kademlia
* Removes a blank line
* Changes store_mut comment appropriately
* Fixes build
* Return a type, not a trait
* Address some TODOs, refactor queries and public API.
The following left-over issues are addressed:
* The key for FIND_NODE requests is generalised to any Multihash,
instead of just peer IDs.
* All queries get a (configurable) timeout.
* Finishing queries as soon as enough results have been received is simplified
to avoid code duplication.
* No more panics in provider-API-related code paths. The provider API is
however still untested and (I think) still incomplete (e.g. expiration
of provider records).
* Numerous smaller TODOs encountered in the code.
The following public API changes / additions are made:
* Introduce a `KademliaConfig` with new configuration options for
the replication factor and query timeouts.
* Rename `find_node` to `get_closest_peers`.
* Rename `get_value` to `get_record` and `put_value` to `put_record`,
introducing a `Quorum` parameter for both functions, replacing the
existing `num_results` parameter with clearer semantics.
* Rename `add_providing` to `start_providing` and `remove_providing`
to `stop_providing`.
* Add a `bootstrap` function that implements a (almost) standard
Kademlia bootstrapping procedure.
* Rename `KademliaOut` to `KademliaEvent` with an updated list of
constructors (some renaming). All events that report query results
now report a `Result` to uniformly permit reporting of errors.
The following refactorings are made:
* Introduce some constants.
* Consolidate `query.rs` and `write.rs` behind a common query interface
to reduce duplication and facilitate better code reuse, introducing
the notion of a query peer iterator. `query/peers/closest.rs`
contains the code that was formerly in `query.rs`. `query/peers/fixed.rs` contains
a modified variant of `write.rs` (which is removed). The new `query.rs`
provides an interface for working with a collection of queries, taking
over some code from `behaviour.rs`.
* Reduce code duplication in tests and use the current_thread runtime for
polling swarms to avoid spurious errors in the test output due to aborted
connections when a test finishes prematurely (e.g. because a quorum of
results has been collected).
* Some additions / improvements to the existing tests.
* Fix test.
* Fix rebase.
* Tweak kad-ipfs example.
* Incorporate some feedback.
* Provide easy access and conversion to keys in error results.
multihash: Use `Bytes` instead of `Vec<u8>` internally.
To improve the efficiency of cloning multi-hashes (e.g. as the
representation of `PeerId`s), this PR replaces the `Vec<u8>`
representation with `Bytes`. The API is kept backwards
compatible and does not leak the representation type.
The transport should be able to continue processing other connections.
An error to determine a socket's address is not a fatal condition but
may happen when a connection is immediately reset after being
established. By the time the programme asks for the remote address, the
socket may already be gone.
Fixes#1182.
* Make `<SubstreamRef as AsyncWrite>::shutdown` imply flush
* Use try_ready
* Apply suggestions from code review
Co-Authored-By: Toralf Wittner <tw@dtex.org>
Refactoring of iterative queries (`query.rs`) to improve both
correctness and performance (for larger DHTs):
Correctness:
1. Queries no longer terminate prematurely due to counting results
from peers farther from the target while results from closer
peers are still pending. (#1105).
2. Queries no longer ignore reported closer peers that are not duplicates
just because they are currently not among the `num_results` closest.
The currently `max_results` closest may contain peers marked as failed
or pending / waiting. Hence all reported closer peers that are not
duplicates must be considered candidates that may still end up
among the `num_results` closest that successfully responded.
3. Bounded parallelism based on the `active_counter` was not working
correctly, as new (not yet contacted) peers closer to the target
may be discovered at any time and thus appear in `closer_peers`
before the already active / pending peers.
4. The `Frozen` query mechanism allowed all remaining not-yet contacted
peers to be contacted, but their results were discarded, because
`inject_rpc_result` would only incorporate results while the
query is `Iterating`. The `Frozen` state has been reworked into
a `Stalled` state that implements a slightly more permissive
variant of the following from the paper / specs: "If a round of
FIND_NODEs fails to return a node any closer than the closest
already seen, the initiator resends the FIND_NODE to all of the
k closest nodes it has not already queried.". Importantly, though
not explicitly mentioned, the query can move back to `Iterating`
if it makes further progress again as a result of these requests.
The `Stalled` state thus allows (temporarily) higher parallelism
in an effort to make progress and bring the query to an end.
Performance:
1. Repeated distance calculations between the same peers and the
target is avoided.
2. Enabled by #1108, use of a more appropriate data structure (`BTreeMap`) for
the incrementally updated list of closer peers. The data structure needs
efficient lookups (to avoid duplicates) and insertions at any position,
both of which large(r) vectors are not that good at. Unscientific benchmarks
showed a ~40-60% improvement in somewhat pathological scenarios with at least
20 healthy nodes, each possibly returning a distinct list of closer 20 peers
to the requestor. A previous assumption may have been that the vector always
stays very small, but that is not the case in larger clusters: Even if the
lists of closer peers reported by the 20 contacted peers are heavily overlapping,
typically a lot more than 20 peers have to be (at least temporarily) considered
as closest peers until the query completes. See also issue (2) above.
New tests are added for:
* Query termination conditions.
* Bounded parallelism.
* Absence of duplicates.
* Update soketto and enable deflate extension.
* libp2p-deflate and libp2p-websocket share flate2.
Due to the way feature resolution works in cargo today, the `deflate`
feature of `soketto` will include `flate2` with feature `zlib` which is
then also active for the `flate2` that `libp2p-deflate` depends on. This
leads to compilation failures for WASM targets. This PR therefore moves
libp2p-deflate to the crates which are not available on WASM.
* initial implementation of the records
* move to multihash keys
* correctly process query results
* comments and formatting
* correctly return closer_peers in query
* checking wrong peer id in test
* Apply suggestions from code review
Co-Authored-By: Roman Borschel <romanb@users.noreply.github.com>
* Fix changes from suggestions
* Send responses to PUT_VALUE requests
* Shortcut in get_value
* Update protocols/kad/src/behaviour.rs
Co-Authored-By: Roman Borschel <romanb@users.noreply.github.com>
* Revert "Update protocols/kad/src/behaviour.rs"
This reverts commit 579ce742a7f4c94587f1e1f0866d2a3a37418efb.
* Remove duplicate insertion
* Adds a record to a PUT_VALUE response
* Fix a racy put_value test
* Store value ourselves only if we are in K closest
* Abstract over storage
* Revert "Abstract over storage": bad take
This reverts commit eaebf5b6d915712eaf3b05929577fdf697f204d8.
* Abstract over records storage using hashmap as default
* Constructor for custom records
* New Record type and its traits
* Fix outdated storage name
* Fixes returning an event
* Change FindNodeReq key type to Multihash
* WriteState for a second stage of a PUT_VALUE request
* GET_VALUE should not have a record
* Refactor a match arm
* Add successes and failures counters to PutValueRes
* If value is found no need to return closer peers
* Remove a custo storage from tests
* Rename a test to get_value_not_found
* Adds a TODO to change FindNode request key to Multihash
Co-Authored-By: Roman Borschel <romanb@users.noreply.github.com>
* Move MemoryRecordStorage to record.rs
* Return a Cow-ed Record from get
* Fix incorrect GET_VALUE parsing
* Various fixes with review
* Fixes get_value_not_found
* Fix peerids names in test
* another fix
* PutValue correctly distributes values
* Simplify the test
* Check that results are actually the closest
* Reverts changes to tests
* Fix the test topology and checking the results
* Run put_value test ten times
* Adds a get_value test
* Apply suggestions from code review
Co-Authored-By: Roman Borschel <romanb@users.noreply.github.com>
* Make Record fields public
* Moves WriteState to write.rs
* A couple of minor fixes
* Another few fixes of review
* Simplify the put_value test
* Dont synchronously return an error from put_value
* Formatting fixes and comments
* Collect a bunch of results
* Take exactly as much elements as neede
* Check if the peer is still connected
* Adds a multiple GetValueResults results number test
* Unnecessary mut iterators in put_value
* Ask for num_results in get_value
* Dont allocate twice in get_value
* Dont count same errored peer multiple times
* Apply suggestions from code review
Co-Authored-By: Roman Borschel <romanb@users.noreply.github.com>
* Fix another review
* Apply suggestions from code review
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Bring back FromIterator and improve a panic message
* Update protocols/kad/src/behaviour.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Begin reimplementing the websocket transport.
* Add TLS support.
* Add support for redirects during handshake.
* Cosmetics.
* Remove unused error cases in tls module.
Left-overs from a previous implementation.
* No libp2p-websocket for wasm targets.
* Change tls::Config to make the server optional.
* Update transports/websocket/src/lib.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Duplicate config methods.
As per PR review feedback.
* Some improvements to the docs of NetworkBehaviour
* Apply suggestions from code review
Co-Authored-By: Roman Borschel <romanb@users.noreply.github.com>
* Map all 127.0.0.0/8 addresses to 127.0.0.1.
Since every local socket address in the 127.0.0.0/8 space is looped back
to 127.0.0.1/32 we should only have to report the later as the listen
address. For other addresses we still attempt to discover host addresses
when we encounter an unknown local address. We now also check that after
the host addresses have been reset that the address is now found,
otherwise we produce an error.
* Change listen address lookup.
Perform multiple steps:
1. Check for exact address match.
2. Else consider netmask and check for containment.
3. Else re-check host addresses and try 1 & 2 again.
4. Else report an error.
* Small fixes.
* Test and improve prefix_len.
* Simplify and inline the prefix_len logic.
* Fix status updates in KBuckets.
`KBucket::update` does currently not correctly update the `first_connected_pos`
before reinserting the node. This may result in connected nodes being considered
disconnected and thus eligible for replacement by a pending node if the bucket is
full and a new connected node is added.
Tests have been added for checking that `KBucket::update` preserves the status
and ordering of all other nodes in the bucket.
* Small test improvement.
Set an expectation for the new position, instead of taking the assigned position.
* Kademlia: Optimise iteration over closest entries.
The current implementation for finding the entries whose keys are closest
to some target key in the Kademlia routing table involves copying the
keys of all buckets into a new `Vec` which is then sorted based on the
distances to the target and turned into an iterator from which only a
small number of elements (by default 20) are drawn.
This commit introduces an iterator over buckets for finding the closest
keys to a target that visits the buckets in the optimal order, based on
the information contained in the distance bit-string representing the
distance between the local key and the target.
Correctness is tested against full-table scans.
Also included:
* Updated documentation.
* The `Entry` API was moved to the `kbucket::entry` sub-module for
ease of maintenance.
* The pending node handling has been slightly refactored in order to
bring code and documentation in agreement and clarify the semantics
a little.
* Rewrite pending node handling and add tests.
There are two issues with the current definition and use of Kademlia's
XOR metric:
1. The distance is currently equated with the bucket index, i.e.
`distance(a,b) - 1` is the index of the bucket into which either
peer is put by the other. The result is a metric that is not
unidirectional, as defined in the Kademlia paper and as implemented
in e.g. libp2p-go and libp2p-js, which is to interpret the result
of the XOR as an integer in its entirety.
2. The current `KBucketsPeerId` trait and its instances allow computing
distances between types with differing bit lengths as well as between
types that hash all inputs again (i.e. `KadHash`) and "plain" `PeerId`s
or `Multihash`es. This can result in computed distances that are either
incorrect as per the requirement of the libp2p specs that all distances
are to be computed from the XOR of the SHA256 of the input keys, or
even fall outside of the image of the metric used for the `KBucketsTable`.
In the latter case, such distances are not currently used as a bucket index
- they can only occur in the context of comparing distances for the purpose
of sorting peers - but that still seems undesirable.
These issues are addressed here as follows:
* Unidirectionality of the XOR metric is restored by keeping the "full"
integer representation of the bitwise XOR. The result is an XOR metric
as defined in the paper. This also opens the door to avoiding the
"full table scan" when searching for the keys closest to a given key -
the ideal order in which to visit the buckets can be computed with the
help of the distance bit string.
* As a simplification and to make it easy to "do the right thing", the
XOR metric is only defined on an opaque `kbucket::Key` type, partially
derived from the current `KadHash`. `KadHash` and `KBucketsPeerId`
are removed.
