libp2p::kad::store

Trait RecordStore

pub trait RecordStore {
    type RecordsIter<'a>: Iterator<Item = Cow<'a, Record>>
       where Self: 'a;
    type ProvidedIter<'a>: Iterator<Item = Cow<'a, ProviderRecord>>
       where Self: 'a;

    // Required methods
    fn get(&self, k: &Key) -> Option<Cow<'_, Record>>;
    fn put(&mut self, r: Record) -> Result<(), Error>;
    fn remove(&mut self, k: &Key);
    fn records(&self) -> Self::RecordsIter<'_>;
    fn add_provider(&mut self, record: ProviderRecord) -> Result<(), Error>;
    fn providers(&self, key: &Key) -> Vec<ProviderRecord>;
    fn provided(&self) -> Self::ProvidedIter<'_>;
    fn remove_provider(&mut self, k: &Key, p: &PeerId);
}

Available on crate feature kad only.

Expand description

Trait for types implementing a record store.

There are two types of records managed by a RecordStore:

Regular (value-)records. These records store an arbitrary value associated with a key which is distributed to the closest nodes to the key in the Kademlia DHT as per the standard Kademlia “push-model”. These records are subject to re-replication and re-publication as per the standard Kademlia protocol.
Provider records. These records associate the ID of a peer with a key who can supposedly provide the associated value. These records are mere “pointers” to the data which may be followed by contacting these providers to obtain the value. These records are specific to the libp2p Kademlia specification and realise a “pull-model” for distributed content. Just like a regular record, a provider record is distributed to the closest nodes to the key.

Required Associated Types§

type RecordsIter<'a>: Iterator<Item = Cow<'a, Record>> where Self: 'a

type ProvidedIter<'a>: Iterator<Item = Cow<'a, ProviderRecord>> where Self: 'a

Required Methods§

fn get(&self, k: &Key) -> Option<Cow<'_, Record>>

Gets a record from the store, given its key.

fn put(&mut self, r: Record) -> Result<(), Error>

Puts a record into the store.

fn remove(&mut self, k: &Key)

Removes the record with the given key from the store.

fn records(&self) -> Self::RecordsIter<'_>

Gets an iterator over all (value-) records currently stored.

fn add_provider(&mut self, record: ProviderRecord) -> Result<(), Error>

Adds a provider record to the store.

A record store only needs to store a number of provider records for a key corresponding to the replication factor and should store those records whose providers are closest to the key.