feat: support parameterized replaceable evts

Author: cameri

migrations/20221030_134400_add_deduplication_to_events_table.js

@@ -0,0 +1,11 @@
+exports.up = function (knex) {
+  return knex.schema.alterTable('events', function (table) {
+    table.jsonb('event_deduplication').nullable()
+  })
+}
+
+exports.down = function (knex) {
+  return knex.schema.alterTable('events', function (table) {
+    table.dropColumn('event_deduplication')
+  })
+}

migrations/20221030_134500_add_dedulication_to_replaceable_events_unique_index.js

@@ -0,0 +1,25 @@
+exports.up = async function (knex) {
+  // NIP-33: Parameterized Replaceable Events
+
+  return knex.schema
+    .raw('DROP INDEX IF EXISTS replaceable_events_idx')
+    .raw(
+      `CREATE UNIQUE INDEX replaceable_events_idx
+      ON events ( event_pubkey, event_kind, event_deduplication )
+      WHERE
+        (
+          event_kind = 0
+          OR event_kind = 3
+          OR (event_kind >= 10000 AND event_kind < 20000)
+        )
+        OR (event_kind >= 30000 AND event_kind < 40000);`,
+    )
+}
+
+exports.down = function (knex) {
+  return knex.schema
+    .raw('DROP INDEX IF EXISTS replaceable_events_idx')
+    .raw(
+      'CREATE UNIQUE INDEX replaceable_events_idx ON events ( event_pubkey, event_kind ) WHERE event_kind = 0 OR event_kind = 3 OR (event_kind >= 10000 AND event_kind < 20000);',
+    )
+}

package.json

@@ -12,7 +12,8 @@
     15,
     16,
     22,
-    26
+    26,
+    33
   ],
   "main": "src/index.ts",
   "scripts": {

src/@types/event.ts

@@ -1,4 +1,4 @@
-import { EventDelegatorMetadataKey, EventKinds } from '../constants/base'
+import { EventDeduplicationMetadataKey, EventDelegatorMetadataKey, EventKinds } from '../constants/base'
 import { EventId, Pubkey, Tag } from './base'
 
 
@@ -16,6 +16,10 @@ export interface DelegatedEvent extends Event {
   [EventDelegatorMetadataKey]?: Pubkey
 }
 
+export interface ParameterizedReplaceableEvent extends Event {
+  [EventDeduplicationMetadataKey]: string[]
+}
+
 export interface DBEvent {
   id: string
   event_id: Buffer
@@ -26,6 +30,7 @@ export interface DBEvent {
   event_tags: Tag[]
   event_signature: Buffer
   event_delegator?: Buffer | null
+  event_deduplication?: string | null
   first_seen: Date
   deleted_at: Date
 }

src/constants/base.ts

@@ -13,7 +13,8 @@ export enum EventTags {
   Pubkey = 'p',
   //  Multicast = 'm',
   Delegation = 'delegation',
+  Deduplication = 'd',
 }
 
 export const EventDelegatorMetadataKey = Symbol('Delegator')
-
+export const EventDeduplicationMetadataKey = Symbol('Deduplication')

src/factories/event-strategy-factory.ts

@@ -1,4 +1,4 @@
-import { isDeleteEvent, isEphemeralEvent, isReplaceableEvent } from '../utils/event'
+import { isDeleteEvent, isEphemeralEvent, isParameterizedReplaceableEvent, isReplaceableEvent } from '../utils/event'
 import { DefaultEventStrategy } from '../handlers/event-strategies/default-event-strategy'
 import { DeleteEventStrategy } from '../handlers/event-strategies/delete-event-strategy'
 import { EphemeralEventStrategy } from '../handlers/event-strategies/ephemeral-event-strategy'
@@ -7,6 +7,7 @@ import { Factory } from '../@types/base'
 import { IEventRepository } from '../@types/repositories'
 import { IEventStrategy } from '../@types/message-handlers'
 import { IWebSocketAdapter } from '../@types/adapters'
+import { ParameterizedReplaceableEventStrategy } from '../handlers/event-strategies/parameterized-replaceable-event-strategy'
 import { ReplaceableEventStrategy } from '../handlers/event-strategies/replaceable-event-strategy'
 
 
@@ -20,6 +21,8 @@ export const eventStrategyFactory = (
       return new EphemeralEventStrategy(adapter)
     } else if (isDeleteEvent(event)) {
       return new DeleteEventStrategy(adapter, eventRepository)
+    } else if (isParameterizedReplaceableEvent(event)) {
+      return new ParameterizedReplaceableEventStrategy(adapter, eventRepository)
     }
 
     return new DefaultEventStrategy(adapter, eventRepository)

src/handlers/event-strategies/parameterized-replaceable-event-strategy.ts

@@ -0,0 +1,34 @@
+import { Event, ParameterizedReplaceableEvent } from '../../@types/event'
+import { EventDeduplicationMetadataKey, EventTags } from '../../constants/base'
+import { createLogger } from '../../factories/logger-factory'
+import { IEventRepository } from '../../@types/repositories'
+import { IEventStrategy } from '../../@types/message-handlers'
+import { IWebSocketAdapter } from '../../@types/adapters'
+import { WebSocketAdapterEvent } from '../../constants/adapter'
+
+const debug = createLogger('parameterized-replaceable-event-strategy')
+
+export class ParameterizedReplaceableEventStrategy implements IEventStrategy<Event, Promise<void>> {
+  public constructor(
+    private readonly webSocket: IWebSocketAdapter,
+    private readonly eventRepository: IEventRepository,
+  ) { }
+
+  public async execute(event: Event): Promise<void> {
+    debug('received event: %o', event)
+
+    const [, ...deduplication] = event.tags.find((tag) => tag.length >= 2 && tag[0] === EventTags.Deduplication) ?? [null, '']
+
+    const parameterizedReplaceableEvent: ParameterizedReplaceableEvent = {
+      ...event,
+      [EventDeduplicationMetadataKey]: deduplication,
+    }
+
+    const count = await this.eventRepository.upsert(parameterizedReplaceableEvent)
+    if (!count) {
+      return
+    }
+
+    this.webSocket.emit(WebSocketAdapterEvent.Broadcast, event)
+  }
+}

src/repositories/event-repository.ts

@@ -19,6 +19,7 @@ import {
   modulo,
   nth,
   omit,
+  paths,
   pipe,
   prop,
   propSatisfies,
@@ -28,10 +29,10 @@ import {
 
 import { DatabaseClient, EventId } from '../@types/base'
 import { DBEvent, Event } from '../@types/event'
+import { EventDeduplicationMetadataKey, EventDelegatorMetadataKey } from '../constants/base'
 import { IEventRepository, IQueryResult } from '../@types/repositories'
 import { toBuffer, toJSON } from '../utils/transform'
 import { createLogger } from '../factories/logger-factory'
-import { EventDelegatorMetadataKey } from '../constants/base'
 import { isGenericTagQuery } from '../utils/filter'
 import { SubscriptionFilter } from '../@types/subscription'
 
@@ -157,11 +158,11 @@ export class EventRepository implements IEventRepository {
   }
 
   public async create(event: Event): Promise<number> {
-    debug('creating event: %o', event)
     return this.insert(event).then(prop('rowCount') as () => number)
   }
 
   private insert(event: Event) {
+    debug('inserting event: %o', event)
     const row = applySpec({
       event_id: pipe(prop('id'), toBuffer),
       event_pubkey: pipe(prop('pubkey'), toBuffer),
@@ -186,6 +187,7 @@ export class EventRepository implements IEventRepository {
 
   public upsert(event: Event): Promise<number> {
     debug('upserting event: %o', event)
+
     const toJSON = (input: any) => JSON.stringify(input)
 
     const row = applySpec({
@@ -201,13 +203,23 @@ export class EventRepository implements IEventRepository {
         pipe(prop(EventDelegatorMetadataKey as any), toBuffer),
         always(null),
       ),
+      event_deduplication: ifElse(
+        propSatisfies(isNil, EventDeduplicationMetadataKey),
+        pipe(paths([['pubkey'], ['kind']]), toJSON),
+        pipe(prop(EventDeduplicationMetadataKey as any), toJSON),
+      ),
     })(event)
 
     const query = this.dbClient('events')
       .insert(row)
       // NIP-16: Replaceable Events
-      .onConflict(this.dbClient.raw('(event_pubkey, event_kind) WHERE event_kind = 0 OR event_kind = 3 OR event_kind >= 10000 AND event_kind < 2000'))
-      .merge(omit(['event_pubkey', 'event_kind'])(row))
+      // NIP-33: Parameterized Replaceable Events
+      .onConflict(
+        this.dbClient.raw(
+          '(event_pubkey, event_kind, event_deduplication) WHERE (event_kind = 0 OR event_kind = 3 OR (event_kind >= 10000 AND event_kind < 20000)) OR (event_kind >= 30000 AND event_kind < 40000)'
+        )
+      )
+      .merge(omit(['event_pubkey', 'event_kind', 'event_deduplication'])(row))
       .where('events.event_created_at', '<', row.event_created_at)
 
     const promise = query.then(prop('rowCount') as () => number)

src/utils/event.ts

@@ -174,6 +174,10 @@ export const isEphemeralEvent = (event: Event): boolean => {
   return event.kind >= 20000 && event.kind < 30000
 }
 
+export const isParameterizedReplaceableEvent = (event: Event): boolean => {
+  return event.kind >= 30000 && event.kind < 40000
+}
+
 export const isDeleteEvent = (event: Event): boolean => {
   return event.kind === EventKinds.DELETE
 }

test/unit/utils/event.spec.ts

@@ -9,6 +9,7 @@ import {
   isEventIdValid,
   isEventMatchingFilter,
   isEventSignatureValid,
+  isParameterizedReplaceableEvent,
   isReplaceableEvent,
   serializeEvent,
 } from '../../../src/utils/event'
@@ -475,3 +476,15 @@ describe('NIP-09', () => {
     })
   })
 })
+
+describe('NIP-33', () => {
+  describe('isParameterizedReplaceableEvent', () => {
+    it('returns true if event is a parameterized replaceable event', () => {
+      expect(isParameterizedReplaceableEvent({ kind: 30000 } as any)).to.be.true
+    })
+
+    it('returns false if event is a parameterized replaceable event', () => {
+      expect(isParameterizedReplaceableEvent({ kind: 40000 } as any)).to.be.false
+    })
+  })
+})