mirror of
https://github.com/fluencelabs/rust-libp2p
synced 2025-06-01 20:21:21 +00:00
68 lines
2.8 KiB
Rust
68 lines
2.8 KiB
Rust
// Copyright 2019 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.
|
|
|
|
//! Peer selection strategies for queries in the form of iterator-like state machines.
|
|
//!
|
|
//! Using a peer iterator in a query involves performing the following steps
|
|
//! repeatedly and in an alternating fashion:
|
|
//!
|
|
//! 1. Calling `next` to observe the next state of the iterator and determine
|
|
//! what to do, which is to either issue new requests to peers or continue
|
|
//! waiting for responses.
|
|
//!
|
|
//! 2. When responses are received or requests fail, providing input to the
|
|
//! iterator via the `on_success` and `on_failure` callbacks,
|
|
//! respectively, followed by repeating step (1).
|
|
//!
|
|
//! When a call to `next` returns [`Finished`], no more peers can be obtained
|
|
//! from the iterator and the results can be obtained from `into_result`.
|
|
//!
|
|
//! A peer iterator can be finished prematurely at any time through `finish`.
|
|
//!
|
|
//! [`Finished`]: PeersIterState::Finished
|
|
|
|
pub mod closest;
|
|
pub mod fixed;
|
|
|
|
use libp2p_core::PeerId;
|
|
use std::borrow::Cow;
|
|
|
|
/// The state of a peer iterator.
|
|
#[derive(Debug, Clone, PartialEq, Eq)]
|
|
pub enum PeersIterState<'a> {
|
|
/// The iterator is waiting for results.
|
|
///
|
|
/// `Some(peer)` indicates that the iterator is now waiting for a result
|
|
/// from `peer`, in addition to any other peers for which it is already
|
|
/// waiting for results.
|
|
///
|
|
/// `None` indicates that the iterator is waiting for results and there is no
|
|
/// new peer to contact, despite the iterator not being at capacity w.r.t.
|
|
/// the permitted parallelism.
|
|
Waiting(Option<Cow<'a, PeerId>>),
|
|
|
|
/// The iterator is waiting for results and is at capacity w.r.t. the
|
|
/// permitted parallelism.
|
|
WaitingAtCapacity,
|
|
|
|
/// The iterator finished.
|
|
Finished,
|
|
}
|