provides an implementation of an api for pubsub to be used as a datastore with TieredDatastore
npm install datastore-pubsub
const DatastorePubsub = require('datastore-pubsub')
const dsPubsub = new DatastorePubsub(pubsub, datastore, peerId, validator)
new DatastorePubsub(pubsub, datastore, peerId, validator, subscriptionKeyFn)
Creates a DatastorePubsub instance.
Arguments:
pubsub
(Object): implementation of a pubsub (must have publish and subscribe functions), such as libp2p/pubsub.datastore
(Object): datastore compliant with interface-datastore, such as datastore-fs.peerId
(PeerId
Instance): peer identifier object.validator
(Object): containing validate function and select function.subscriptionKeyFn
(function): function to manipulate the key topic received according to the needs, as well as to block the message received to be published.
Note: validator
object must be composed by two functions, validate (data, key, callback)
and select (receivedRecord, currentRecord, callback)
. validate
aims to verify if a new record received by pubsub is valid to be stored locally by the node. If it is valid and the node already has a local record stored, select
is the function provided to be responsible for deciding which record is the best (newer) between the already stored and the received through pubsub. A validator
example can be found at: TODO (js-ipns)
const dsPubsub = new DatastorePubsub(pubsub, datastore, peerId, validator)
const buf = await dsPubsub.get(key)
Try to subscribe a topic with Pubsub and receive the current local value if available.
Arguments:
key
(Buffer): a key representing a unique identifier of the object to subscribe.
Returns Promise<Buffer>
containing the most recent known record stored.
await dsPubsub.put(key, val)
Publishes a value through pubsub.
Arguments:
key
(Buffer): a key representing a unique identifier of the object to publish.val
(Buffer): value to be propagated.
Returns Promise<void>
await dsPubsub.unsubscribe(key)
Unsubscribe a previously subscribe value.
Arguments:
key
(Buffer): a key representing a unique identifier of the object to publish.
Returns Promise<void>
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This repository falls under the IPFS Code of Conduct.
Copyright (c) Protocol Labs, Inc. under the MIT License. See LICENSE file for details.