feat!: support for cursors on store API

packages/core/package.json

@@ -93,6 +93,7 @@
     "@libp2p/interfaces": "^3.0.4",
     "@libp2p/peer-id": "^1.1.10",
     "@multiformats/multiaddr": "^11.0.6",
+    "@noble/hashes": "^1.1.3",
     "@waku/byte-utils": "*",
     "@waku/interfaces": "*",
     "debug": "^4.3.4",

packages/core/src/index.ts

@@ -21,4 +21,9 @@ export * as waku_relay from "./lib/waku_relay";
 export { wakuRelay } from "./lib/waku_relay";
 
 export * as waku_store from "./lib/waku_store";
-export { PageDirection, wakuStore, StoreCodec } from "./lib/waku_store";
+export {
+  PageDirection,
+  wakuStore,
+  StoreCodec,
+  createCursor,
+} from "./lib/waku_store";

packages/core/src/lib/waku_store/index.ts

@@ -2,7 +2,9 @@ import type { Connection } from "@libp2p/interface-connection";
 import type { ConnectionManager } from "@libp2p/interface-connection-manager";
 import type { PeerId } from "@libp2p/interface-peer-id";
 import type { Peer, PeerStore } from "@libp2p/interface-peer-store";
-import { DecodedMessage, Decoder, Store } from "@waku/interfaces";
+import { sha256 } from "@noble/hashes/sha256";
+import { concat, utf8ToBytes } from "@waku/byte-utils";
+import { DecodedMessage, Decoder, Index, Store } from "@waku/interfaces";
 import debug from "debug";
 import all from "it-all";
 import * as lp from "it-length-prefixed";
@@ -80,6 +82,10 @@ export interface QueryOptions {
    * Retrieve messages with a timestamp within the provided values.
    */
   timeFilter?: TimeFilter;
+  /**
+   * Cursor as an index to start a query from.
+   */
+  cursor?: Index;
 }
 
 /**
@@ -258,7 +264,8 @@ class WakuStore implements Store {
       connection,
       protocol,
       queryOpts,
-      decodersAsMap
+      decodersAsMap,
+      options?.cursor
     )) {
       yield messages;
     }
@@ -281,7 +288,8 @@ async function* paginate<T extends DecodedMessage>(
   connection: Connection,
   protocol: string,
   queryOpts: Params,
-  decoders: Map<string, Decoder<T>>
+  decoders: Map<string, Decoder<T>>,
+  cursor?: Index
 ): AsyncGenerator<Promise<T | undefined>[]> {
   if (
     queryOpts.contentTopics.toString() !==
@@ -292,7 +300,6 @@ async function* paginate<T extends DecodedMessage>(
     );
   }
 
-  let cursor = undefined;
   while (true) {
     queryOpts = Object.assign(queryOpts, { cursor });
 
@@ -382,6 +389,33 @@ export function isDefined<T>(msg: T | undefined): msg is T {
   return !!msg;
 }
 
+export async function createCursor(
+  message: DecodedMessage,
+  pubsubTopic: string = DefaultPubSubTopic
+): Promise<Index> {
+  if (
+    !message ||
+    !message.timestamp ||
+    !message.payload ||
+    !message.contentTopic
+  ) {
+    throw new Error("Message is missing required fields");
+  }
+
+  const contentTopicBytes = utf8ToBytes(message.contentTopic);
+
+  const digest = sha256(concat([contentTopicBytes, message.payload]));
+
+  const messageTime = BigInt(message.timestamp.getTime()) * BigInt(1000000);
+
+  return {
+    digest,
+    pubsubTopic,
+    senderTime: messageTime,
+    receivedTime: messageTime,
+  };
+}
+
 export function wakuStore(
   init: Partial<CreateOptions> = {}
 ): (components: StoreComponents) => Store {

packages/interfaces/src/index.ts

@@ -17,6 +17,12 @@ export interface PointToPointProtocol {
   peerStore: PeerStore;
   peers: () => Promise<Peer[]>;
 }
+export interface Index {
+  digest?: Uint8Array;
+  receivedTime?: bigint;
+  senderTime?: bigint;
+  pubsubTopic?: string;
+}
 
 export type ProtocolOptions = {
   pubSubTopic?: string;
@@ -74,6 +80,10 @@ export type StoreQueryOptions = {
    * Retrieve messages with a timestamp within the provided values.
    */
   timeFilter?: TimeFilter;
+  /**
+   * Cursor as an index to start a query from.
+   */
+  cursor?: Index;
 } & ProtocolOptions;
 
 export interface Store extends PointToPointProtocol {

packages/tests/tests/store.node.spec.ts

@@ -1,5 +1,5 @@
 import { bytesToUtf8, utf8ToBytes } from "@waku/byte-utils";
-import { PageDirection } from "@waku/core";
+import { createCursor, PageDirection } from "@waku/core";
 import { waitForRemotePeer } from "@waku/core/lib/wait_for_remote_peer";
 import { DecoderV0, EncoderV0 } from "@waku/core/lib/waku_message/version_0";
 import { createFullNode } from "@waku/create";
@@ -111,6 +111,62 @@ describe("Waku Store", () => {
     expect(messages?.length).eq(0);
   });
 
+  it("Passing a cursor", async function () {
+    this.timeout(4_000);
+    const totalMsgs = 20;
+
+    for (let i = 0; i < totalMsgs; i++) {
+      expect(
+        await nwaku.sendMessage(
+          Nwaku.toMessageRpcQuery({
+            payload: utf8ToBytes(`Message ${i}`),
+            contentTopic: TestContentTopic,
+          })
+        )
+      ).to.be.true;
+    }
+
+    waku = await createFullNode({
+      staticNoiseKey: NOISE_KEY_1,
+    });
+    await waku.start();
+    await waku.dial(await nwaku.getMultiaddrWithId());
+    await waitForRemotePeer(waku, [Protocols.Store]);
+
+    const query = waku.store.queryGenerator([TestDecoder]);
+
+    // messages in reversed order (first message at last index)
+    const messages: DecodedMessage[] = [];
+    for await (const page of query) {
+      for await (const msg of page.reverse()) {
+        messages.push(msg as DecodedMessage);
+      }
+    }
+
+    // index 2 would mean the third last message sent
+    const cursorIndex = 2;
+
+    // create cursor to extract messages after the 3rd index
+    const cursor = await createCursor(messages[cursorIndex]);
+
+    const messagesAfterCursor: DecodedMessage[] = [];
+    for await (const page of waku.store.queryGenerator([TestDecoder], {
+      cursor,
+    })) {
+      for await (const msg of page.reverse()) {
+        messagesAfterCursor.push(msg as DecodedMessage);
+      }
+    }
+
+    const testMessage = messagesAfterCursor[0];
+
+    expect(messages.length).be.eq(totalMsgs);
+
+    expect(bytesToUtf8(testMessage.payload!)).to.be.eq(
+      bytesToUtf8(messages[cursorIndex + 1].payload!)
+    );
+  });
+
   it("Callback on promise", async function () {
     this.timeout(15_000);