rust-libp2p/protocols/kad/src/lib.rs

// Copyright 2018 Parity Technologies (UK) Ltd.
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//! Implementation of the libp2p-specific Kademlia protocol.

// TODO: we allow dead_code for now because this library contains a lot of unused code that will
//       be useful later for record store
#![allow(dead_code)]

pub mod handler;
pub mod kbucket;
pub mod protocol;
pub mod record;

mod addresses;
mod behaviour;
mod protobuf_structs;
mod query;

pub use behaviour::{Kademlia, KademliaConfig, KademliaEvent, Quorum};
pub use behaviour::{
    BootstrapResult,
    BootstrapOk,
    BootstrapError,

    GetRecordResult,
    GetRecordOk,
    GetRecordError,

    PutRecordResult,
    PutRecordOk,
    PutRecordError,

    GetClosestPeersResult,
    GetClosestPeersOk,
    GetClosestPeersError,

    AddProviderResult,
    AddProviderOk,
    AddProviderError,

    GetProvidersResult,
    GetProvidersOk,
    GetProvidersError,
};
pub use protocol::KadConnectionType;
pub use record::{RecordStore, RecordStorageError, MemoryRecordStorage};

use std::time::Duration;

/// The `k` parameter of the Kademlia specification.
///
/// This parameter determines:
///
///   1) The (fixed) maximum number of nodes in a bucket.
///   2) The (default) replication factor, which in turn determines:
///       a) The number of closer peers returned in response to a request.
///       b) The number of closest peers to a key to search for in an iterative query.
///
/// The choice of (1) is fixed to this constant. The replication factor is configurable
/// but should generally be no greater than `K_VALUE`. All nodes in a Kademlia
/// DHT should agree on the choices made for (1) and (2).
///
/// The current value is `20`.
pub const K_VALUE: usize = 20;

/// The `α` parameter of the Kademlia specification.
///
/// This parameter determines the default parallelism for iterative queries,
/// i.e. the allowed number of in-flight requests that an iterative query is
/// waiting for at a particular time while it continues to make progress towards
/// locating the closest peers to a key.
///
/// The current value is `3`.
pub const ALPHA_VALUE: usize = 3;

const KBUCKET_PENDING_TIMEOUT: Duration = Duration::from_secs(60);
const ADD_PROVIDER_INTERVAL: Duration = Duration::from_secs(60);