feat(decentralization): work in progress => requesting seeds after co…

…nnection

package.json

@@ -35,6 +35,7 @@
     "mysql": "^2.18.1",
     "request": "^2.88.2",
     "socket.io": "^4.5.4",
+    "socket.io-client": "^4.8.1",
     "typeorm": "^0.3.11"
   },
   "devDependencies": {

src/config.ts

@@ -23,4 +23,7 @@ export const Config = {
     cleanEveryXHours: 24,
     cleanExpiredForXDays: 30,
   },
+  sync: {
+    seed: ["http://localhost:5005"],
+  },
 };

src/index.ts

@@ -7,6 +7,7 @@ import https from "https";
 import { Config } from "./config";
 import { AppDataSource } from "./database/data-source";
 import { DatabaseModule } from "./database/typeorm";
+import { ServerSyncLogic } from "./servers-sync/server-sync.logic";
 import { SignatureRequestApi } from "./signature-request/signature-request.api";
 import { SignatureRequestLogic } from "./signature-request/signature-request.logic";
 import { SocketIoLogic } from "./socket-io.logic";
@@ -38,6 +39,7 @@ const startServer = (app: Express) => {
   } else {
     const httpServer = createServer(app);
     SocketIoLogic.setup(httpServer);
+    ServerSyncLogic.initSync(httpServer);
 
     httpServer.listen(Config.port.server, () => {
       Logger.technical(

src/servers-sync/server-sync-messages.enum.ts

@@ -0,0 +1,6 @@
+export enum ServerSyncMessage {
+  NEW_ENTRY = "newEntry",
+  NEW_SEED = "newSeed",
+  FULL_SYNC = "fullSync",
+  REQUEST_SEEDS = "requestSeeds",
+}

src/servers-sync/server-sync.interface.ts

@@ -0,0 +1,35 @@
+import { SignatureRequest } from "../signature-request/signature-request.entity";
+import { Signer } from "../signature-request/signer/signer.entity";
+
+export interface NewSeedMessage {
+  ipAddress: string;
+}
+
+export enum NewEntryType {
+  TRANSACTION_BROADCASTED = "transactionBroadcasted",
+  NEW_SIGNATURE_REQUEST = "newSignatureRequest",
+  SIGNATURE_RECEIVED = "signatureReceived",
+}
+
+export interface NewEntryMessage {
+  type: NewEntryType;
+}
+
+export interface NewSignatureRequestEntry {
+  type: NewEntryType.NEW_SIGNATURE_REQUEST;
+  signatureRequest: SignatureRequest;
+}
+
+export interface SignatureReceivedEntry {
+  type: NewEntryType.SIGNATURE_RECEIVED;
+  signatureRequestId: SignatureRequest["id"];
+  signerId: Signer["id"];
+  signature: string;
+}
+
+export interface TransactionBroadcastedEntry {
+  type: NewEntryType.TRANSACTION_BROADCASTED;
+  signatureRequestId: SignatureRequest["id"];
+}
+
+export interface FullSyncMessage {}

src/servers-sync/server-sync.logic.ts

@@ -0,0 +1,69 @@
+import { DefaultEventsMap } from "@socket.io/component-emitter";
+import { Server } from "socket.io";
+import { connect, Socket } from "socket.io-client";
+import { Config } from "../config";
+import { ArrayUtils } from "../utils/array.utils";
+import { ServerSyncMessage } from "./server-sync-messages.enum";
+
+interface OutgoingConnection {
+  ipAddress: string;
+  socket: Socket;
+}
+
+let ioServer: Server;
+let ioClients: OutgoingConnection[] = [];
+
+let seeds = Config.sync.seed;
+
+const initSync = (httpServer: any) => {
+  ioServer = new Server(httpServer, {
+    cors: {
+      origin: "*",
+    },
+  });
+  for (const serverIpAddress of seeds) {
+    connectToServer(serverIpAddress);
+  }
+
+  ioServer.on("connection", (socket) => {
+    // Check if outgoing client connection exist. If not connect
+
+    console.log(socket.handshake.headers.host);
+
+    const outgoingConnection = ioClients.find(
+      (outgoingConnection) =>
+        outgoingConnection.ipAddress === socket.handshake.address
+    );
+    if (!outgoingConnection) {
+      connectToServer(socket.handshake.address);
+    }
+  });
+
+  ioServer.on(ServerSyncMessage.REQUEST_SEEDS, handleSeedsRequest);
+};
+
+const connectToServer = (ipAddress: string) => {
+  const newClient = { ipAddress: ipAddress, socket: connect(ipAddress) };
+  ioClients.push(newClient);
+  requestSeeds(newClient.socket);
+};
+
+const requestSeeds = (socket: Socket<DefaultEventsMap, DefaultEventsMap>) => {
+  socket.emit(ServerSyncMessage.REQUEST_SEEDS, null, (newSeeds: string[]) => {
+    seeds = ArrayUtils.mergeWithoutDuplicate(seeds, newSeeds);
+    for (const serverIpAddress of seeds) {
+      const outgoingConnection = ioClients.find(
+        (outgoingConnection) => outgoingConnection.ipAddress === serverIpAddress
+      );
+      if (!outgoingConnection) {
+        connectToServer(serverIpAddress);
+      }
+    }
+  });
+};
+
+const handleSeedsRequest = (callback: (seeds: string[]) => void) => {
+  callback(seeds);
+};
+
+export const ServerSyncLogic = { initSync };

src/utils/array.utils.ts

@@ -0,0 +1,18 @@
+const mergeWithoutDuplicate = (a: any[], b: any[], key?: string) => {
+  var list = [...a, ...b];
+  for (var i = 0; i < list.length; ++i) {
+    for (var j = i + 1; j < list.length; ++j) {
+      if (key) {
+        if (list[i][key] === list[j][key]) list.splice(j--, 1);
+      } else {
+        if (list[i] === list[j]) list.splice(j--, 1);
+      }
+    }
+  }
+
+  return list;
+};
+
+export const ArrayUtils = {
+  mergeWithoutDuplicate,
+};