Job queue to process events (#137)

* Job queue to process events.

* Event queue processing changes.

packages/address-watcher/package.json

@@ -42,7 +42,6 @@
     "json-bigint": "^1.0.0",
     "lodash": "^4.17.21",
     "pg": "^8.6.0",
-    "pg-boss": "^6.1.0",
     "reflect-metadata": "^0.1.13",
     "toml": "^3.0.0",
     "typeorm": "^0.2.32",

packages/address-watcher/src/fill.ts

@@ -6,10 +6,9 @@ import debug from 'debug';
 
 import { getCache } from '@vulcanize/cache';
 import { EthClient } from '@vulcanize/ipld-eth-client';
+import { getConfig, JobQueue } from '@vulcanize/util';
 
 import { Database } from './database';
-import { getConfig } from './config';
-import { JobQueue } from './job-queue';
 import { QUEUE_TX_TRACING } from './tx-watcher';
 
 const log = debug('vulcanize:server');

packages/address-watcher/src/job-runner.ts

@@ -7,11 +7,10 @@ import debug from 'debug';
 import { getCache } from '@vulcanize/cache';
 import { EthClient } from '@vulcanize/ipld-eth-client';
 import { TracingClient } from '@vulcanize/tracing-client';
+import { getConfig, JobQueue } from '@vulcanize/util';
 
 import { Indexer } from './indexer';
 import { Database } from './database';
-import { getConfig } from './config';
-import { JobQueue } from './job-queue';
 import { QUEUE_TX_TRACING } from './tx-watcher';
 
 const log = debug('vulcanize:server');

packages/address-watcher/src/server.ts

@@ -10,7 +10,7 @@ import { createServer } from 'http';
 import { getCache } from '@vulcanize/cache';
 import { EthClient } from '@vulcanize/ipld-eth-client';
 import { TracingClient } from '@vulcanize/tracing-client';
-import { getConfig } from '@vulcanize/util';
+import { getConfig, JobQueue } from '@vulcanize/util';
 
 import typeDefs from './schema';
 
@@ -18,7 +18,6 @@ import { createResolvers } from './resolvers';
 import { Indexer } from './indexer';
 import { Database } from './database';
 import { TxWatcher } from './tx-watcher';
-import { JobQueue } from './job-queue';
 
 const log = debug('vulcanize:server');
 

packages/address-watcher/src/tx-watcher.ts

@@ -4,9 +4,9 @@ import _ from 'lodash';
 import { PubSub } from 'apollo-server-express';
 
 import { EthClient } from '@vulcanize/ipld-eth-client';
+import { JobQueue } from '@vulcanize/util';
 
 import { Indexer } from './indexer';
-import { JobQueue } from './job-queue';
 import { BlockProgress } from './entity/BlockProgress';
 
 const log = debug('vulcanize:tx-watcher');

packages/erc20-watcher/src/indexer.ts

@@ -291,7 +291,7 @@ export class Indexer {
   }
 
   async _fetchAndSaveEvents ({ blockHash, token }: { blockHash: string, token: string }): Promise<void> {
-    const logs = await this._ethClient.getLogs({ blockHash, contract: token });
+    const { logs } = await this._ethClient.getLogs({ blockHash, contract: token });
 
     const eventNameToTopic = getEventNameTopics(this._abi);
     const logTopicToEventName = invert(eventNameToTopic);

packages/ipld-eth-client/src/eth-client.ts

@@ -65,21 +65,15 @@ export class EthClient {
 
   async getLogs (vars: Vars): Promise<any> {
     const result = await this._getCachedOrFetch('getLogs', vars);
-    const { getLogs: logs, block: { number: blockNumHex, timestamp: timestampHex } } = result;
-    const blockNumber = parseInt(blockNumHex, 16);
-    const timestamp = parseInt(timestampHex, 16);
+    const { getLogs: resultLogs, block: { number: blockNumHex, timestamp: timestampHex } } = result;
+    const block = { hash: vars.blockHash, number: parseInt(blockNumHex, 16), timestamp: parseInt(timestampHex, 16) };
+    const logs = resultLogs.map((logEntry: any) => _.merge({}, logEntry, { transaction: { block }}));
 
-    return logs.map((logEntry: any) => {
-      return _.merge({}, logEntry, {
-        transaction: {
-          block: {
-            hash: vars.blockHash,
-            number: blockNumber,
-            timestamp
+    return { logs, block };
   }
-        }
-      });
-    });
+
+  async watchBlocks (onNext: (value: any) => void): Promise<ZenObservable.Subscription> {
+    return this._graphqlClient.subscribe(ethQueries.subscribeBlocks, onNext);
   }
 
   async watchLogs (onNext: (value: any) => void): Promise<ZenObservable.Subscription> {

packages/ipld-eth-client/src/eth-queries.ts

@@ -75,6 +75,19 @@ subscription SubscriptionReceipt {
 }
 `;
 
+export const subscribeBlocks = gql`
+subscription {
+  listen(topic: "header_cids") {
+    relatedNode {
+      ... on EthHeaderCid {
+        blockHash
+        blockNumber
+      }
+    }
+  }
+}
+`;
+
 export const subscribeTransactions = gql`
 subscription SubscriptionHeader {
   listen(topic: "transaction_cids") {
@@ -96,5 +109,6 @@ export default {
   getLogs,
   getBlockWithTransactions,
   subscribeLogs,
+  subscribeBlocks,
   subscribeTransactions
 };

packages/uni-info-watcher/src/indexer.ts

@@ -193,7 +193,7 @@ export class Indexer {
   }
 
   async _fetchAndSaveEvents ({ blockHash, token }: { blockHash: string, token: string }): Promise<void> {
-    const logs = await this._ethClient.getLogs({ blockHash, contract: token });
+    const { logs } = await this._ethClient.getLogs({ blockHash, contract: token });
 
     const eventNameToTopic = {}; // getEventNameTopics(this._abi);
     const logTopicToEventName = invert(eventNameToTopic);

packages/uni-watcher/README.md

@@ -1,5 +1,42 @@
 # Uniswap Watcher
 
+## Setup
+
+Create a postgres12 database for the job queue:
+
+```
+sudo su - postgres
+createdb uni-watcher-job-queue
+```
+
+Enable the `pgcrypto` extension on the job queue database (https://github.com/timgit/pg-boss/blob/master/docs/usage.md#intro).
+
+Example:
+
+```
+postgres@tesla:~$ psql -U postgres -h localhost uni-watcher-job-queue
+Password for user postgres:
+psql (12.7 (Ubuntu 12.7-1.pgdg18.04+1))
+SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
+Type "help" for help.
+
+uni-watcher-job-queue=# CREATE EXTENSION pgcrypto;
+CREATE EXTENSION
+uni-watcher-job-queue=# exit
+```
+
+Create a postgres12 database for the address watcher:
+
+```
+sudo su - postgres
+createdb uni-watcher
+```
+
+Update `environments/local.toml` with database connection settings for both the databases.
+
+
+## Run
+
 Run the server:
 
 ```bash

packages/uni-watcher/environments/local.toml

@@ -29,3 +29,7 @@
     name = "requests"
     enabled = false
     deleteOnStart = false
+
+[jobQueue]
+  dbConnectionString = "postgres://postgres:postgres@localhost/uni-watcher-job-queue"
+  maxCompletionLag = 300

packages/uni-watcher/package.json

@@ -7,6 +7,8 @@
   "scripts": {
     "server": "DEBUG=vulcanize:* nodemon src/server.ts -f environments/local.toml",
     "server:mock": "MOCK=1 nodemon src/server.ts -f environments/local.toml",
+    "job-runner": "DEBUG=vulcanize:* nodemon src/job-runner.ts -f environments/local.toml",
+    "fill": "DEBUG=vulcanize:* ts-node src/fill.ts -f environments/local.toml",
     "test": "mocha -r ts-node/register src/**/*.spec.ts",
     "lint": "eslint .",
     "build": "tsc",

packages/uni-watcher/src/database.ts

@@ -4,7 +4,7 @@ import { SnakeNamingStrategy } from 'typeorm-naming-strategies';
 
 import { Event } from './entity/Event';
 import { Contract } from './entity/Contract';
-import { EventSyncProgress } from './entity/EventProgress';
+import { BlockProgress } from './entity/BlockProgress';
 
 export class Database {
   _config: ConnectionOptions
@@ -28,17 +28,7 @@ export class Database {
     return this._conn.close();
   }
 
-  // Returns true if events have already been synced for the (block, token) combination.
-  async didSyncEvents ({ blockHash }: { blockHash: string }): Promise<boolean> {
-    const numRows = await this._conn.getRepository(EventSyncProgress)
-      .createQueryBuilder()
-      .where('block_hash = :blockHash', { blockHash })
-      .getCount();
-
-    return numRows > 0;
-  }
-
-  async getBlockEvents ({ blockHash }: { blockHash: string }): Promise<Event[]> {
+  async getBlockEvents (blockHash: string): Promise<Event[]> {
     return this._conn.getRepository(Event)
       .createQueryBuilder('event')
       .where('block_hash = :blockHash', { blockHash })
@@ -46,7 +36,7 @@ export class Database {
       .getMany();
   }
 
-  async getEvents ({ blockHash, contract }: { blockHash: string, contract: string }): Promise<Event[]> {
+  async getEvents (blockHash: string, contract: string): Promise<Event[]> {
     return this._conn.getRepository(Event)
       .createQueryBuilder('event')
       .where('block_hash = :blockHash AND contract = :contract', {
@@ -57,7 +47,7 @@ export class Database {
       .getMany();
   }
 
-  async getEventsByName ({ blockHash, contract, eventName }: { blockHash: string, contract: string, eventName: string }): Promise<Event[] | undefined> {
+  async getEventsByName (blockHash: string, contract: string, eventName: string): Promise<Event[] | undefined> {
     return this._conn.getRepository(Event)
       .createQueryBuilder('event')
       .where('block_hash = :blockHash AND contract = :contract AND event_name = :eventName', {
@@ -68,35 +58,33 @@ export class Database {
       .getMany();
   }
 
-  async saveEvents ({ blockHash, events }: { blockHash: string, events: DeepPartial<Event>[] }): Promise<void> {
+  async saveEvents (blockHash: string, blockNumber: number, events: DeepPartial<Event>[]): Promise<void> {
     // In a transaction:
     // (1) Save all the events in the database.
-    // (2) Add an entry to the event progress table.
-
+    // (2) Add an entry to the block progress table.
     await this._conn.transaction(async (tx) => {
-      const repo = tx.getRepository(EventSyncProgress);
-
-      // Check sync progress inside the transaction.
-      const numRows = await repo
-        .createQueryBuilder()
-        .where('block_hash = :blockHash', { blockHash })
-        .getCount();
-
-      if (numRows === 0) {
+      const numEvents = events.length;
+      const blockProgressRepo = tx.getRepository(BlockProgress);
+      const blockProgress = await blockProgressRepo.findOne({ where: { blockHash } });
+      if (!blockProgress) {
         // Bulk insert events.
-        await tx.createQueryBuilder()
-          .insert()
-          .into(Event)
-          .values(events)
-          .execute();
+        await tx.createQueryBuilder().insert().into(Event).values(events).execute();
 
-        // Update event sync progress.
-        const progress = repo.create({ blockHash });
-        await repo.save(progress);
+        const entity = blockProgressRepo.create({ blockHash, blockNumber, numEvents, numProcessedEvents: 0, isComplete: (numEvents === 0) });
+        await blockProgressRepo.save(entity);
       }
     });
   }
 
+  async getEvent (id: string): Promise<Event | undefined> {
+    return this._conn.getRepository(Event).findOne(id);
+  }
+
+  async saveEventEntity (entity: Event): Promise<Event> {
+    const repo = this._conn.getRepository(Event);
+    return await repo.save(entity);
+  }
+
   async getContract (address: string): Promise<Contract | undefined> {
     return this._conn.getRepository(Contract)
       .createQueryBuilder('contract')
@@ -119,4 +107,23 @@ export class Database {
       }
     });
   }
+
+  async getBlockProgress (blockHash: string): Promise<BlockProgress | undefined> {
+    const repo = this._conn.getRepository(BlockProgress);
+    return repo.findOne({ where: { blockHash } });
+  }
+
+  async updateBlockProgress (blockHash: string): Promise<void> {
+    await this._conn.transaction(async (tx) => {
+      const repo = tx.getRepository(BlockProgress);
+      const entity = await repo.findOne({ where: { blockHash } });
+      if (entity && !entity.isComplete) {
+        entity.numProcessedEvents++;
+        if (entity.numProcessedEvents >= entity.numEvents) {
+          entity.isComplete = true;
+        }
+        await repo.save(entity);
+      }
+    });
+  }
 }

packages/uni-watcher/src/entity/BlockProgress.ts

@@ -0,0 +1,23 @@
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash'], { unique: true })
+export class BlockProgress {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('numeric')
+  blockNumber!: number;
+
+  @Column('numeric')
+  numEvents!: number;
+
+  @Column('numeric')
+  numProcessedEvents!: number;
+
+  @Column('boolean')
+  isComplete!: boolean
+}

packages/uni-watcher/src/entity/Contract.ts

@@ -1,12 +1,15 @@
-import { Entity, PrimaryColumn, Column } from 'typeorm';
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
 
 export const KIND_FACTORY = 'factory';
-
 export const KIND_POOL = 'pool';
 
 @Entity()
+@Index(['address'], { unique: true })
 export class Contract {
-  @PrimaryColumn('varchar', { length: 42 })
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 42 })
   address!: string;
 
   @Column('varchar', { length: 8 })

packages/uni-watcher/src/entity/Event.ts

@@ -1,5 +1,7 @@
 import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
 
+export const UNKNOWN_EVENT_NAME = '__unknown__';
+
 @Entity()
 // Index to query all events for a contract efficiently.
 @Index(['blockHash', 'contract'])
@@ -36,9 +38,6 @@ export class Event {
   @Column('text')
   extraInfo!: string;
 
-  @Column('boolean', { default: false })
-  isProcessed!: boolean;
-
   @Column('text')
   proof!: string;
 }

packages/uni-watcher/src/entity/EventProgress.ts

@@ -1,17 +0,0 @@
-import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
-
-// Stores a row if events for a (block, token) combination have already been fetched.
-//
-// Required as a particular block may not have events from a particular contract,
-// and we need to differentiate between that case and the case where data hasn't
-// yet been synced from upstream.
-//
-@Entity()
-@Index(['blockHash'], { unique: true })
-export class EventSyncProgress {
-  @PrimaryGeneratedColumn()
-  id!: number;
-
-  @Column('varchar', { length: 66 })
-  blockHash!: string;
-}

packages/uni-watcher/src/events.ts

@@ -1,79 +1,115 @@
 import assert from 'assert';
 import debug from 'debug';
 import _ from 'lodash';
+import { PubSub } from 'apollo-server-express';
 
 import { EthClient } from '@vulcanize/ipld-eth-client';
+import { JobQueue } from '@vulcanize/util';
 
 import { Indexer } from './indexer';
+import { BlockProgress } from './entity/BlockProgress';
+import { UNKNOWN_EVENT_NAME } from './entity/Event';
 
 const log = debug('vulcanize:events');
 
+export const UniswapEvent = 'uniswap-event';
+export const BlockProgressEvent = 'block-progress-event';
+export const QUEUE_EVENT_PROCESSING = 'event-processing';
+export const QUEUE_BLOCK_PROCESSING = 'block-processing';
+
 export class EventWatcher {
   _ethClient: EthClient
   _indexer: Indexer
   _subscription: ZenObservable.Subscription | undefined
+  _pubsub: PubSub
+  _jobQueue: JobQueue
 
-  constructor (ethClient: EthClient, indexer: Indexer) {
-    assert(ethClient);
-    assert(indexer);
-
+  constructor (ethClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
     this._ethClient = ethClient;
     this._indexer = indexer;
+    this._pubsub = pubsub;
+    this._jobQueue = jobQueue;
+  }
+
+  getEventIterator (): AsyncIterator<any> {
+    return this._pubsub.asyncIterator([UniswapEvent]);
+  }
+
+  getBlockProgressEventIterator (): AsyncIterator<any> {
+    return this._pubsub.asyncIterator([BlockProgressEvent]);
   }
 
   async start (): Promise<void> {
     assert(!this._subscription, 'subscription already started');
 
-    log('Started watching upstream logs...');
+    log('Started watching upstream blocks...');
 
-    this._subscription = await this._ethClient.watchLogs(async (value) => {
-      const receipt = _.get(value, 'data.listen.relatedNode');
-      log('watchLogs', JSON.stringify(receipt, null, 2));
+    this._jobQueue.onComplete(QUEUE_BLOCK_PROCESSING, async (job) => {
+      const { data: { request: { data: { blockHash, blockNumber } } } } = job;
+      log(`Job onComplete block ${blockHash} ${blockNumber}`);
+    });
 
-      const blocks: string[] = [];
+    this._jobQueue.onComplete(QUEUE_EVENT_PROCESSING, async (job) => {
+      const { data: { request, failed, state, createdOn } } = job;
 
-      const { logContracts } = receipt;
-      if (logContracts && logContracts.length) {
-        for (let logIndex = 0; logIndex < logContracts.length; logIndex++) {
-          const { ethTransactionCidByTxId: { ethHeaderCidByHeaderId: { blockHash } } } = receipt;
-          await this._indexer.getBlockEvents(blockHash);
-          blocks.push(blockHash);
+      await this._indexer.updateBlockProgress(request.data.blockHash);
+      const blockProgress = await this._indexer.getBlockProgress(request.data.blockHash);
+      if (blockProgress && request.data.publishBlockProgress) {
+        await this.publishBlockProgressToSubscribers(blockProgress);
+      }
+
+      const timeElapsedInSeconds = (Date.now() - Date.parse(createdOn)) / 1000;
+      log(`Job onComplete event ${request.data.id} publish ${!!request.data.publish}`);
+      if (!failed && state === 'completed' && request.data.publish) {
+        // Check for max acceptable lag time between request and sending results to live subscribers.
+        if (timeElapsedInSeconds <= this._jobQueue.maxCompletionLag) {
+          return await this.publishUniswapEventToSubscribers(request.data.id, timeElapsedInSeconds);
+        } else {
+          log(`event ${request.data.id} is too old (${timeElapsedInSeconds}s), not broadcasting to live subscribers`);
+        }
+      }
+    });
+
+    this._subscription = await this._ethClient.watchBlocks(async (value) => {
+      const { blockHash, blockNumber } = _.get(value, 'data.listen.relatedNode');
+      log('watchBlock', blockHash, blockNumber);
+      await this._jobQueue.pushJob(QUEUE_BLOCK_PROCESSING, { blockHash, blockNumber });
+    });
+  }
+
+  async publishUniswapEventToSubscribers (id: string, timeElapsedInSeconds: number): Promise<void> {
+    const dbEvent = await this._indexer.getEvent(id);
+
+    if (dbEvent && dbEvent.eventName !== UNKNOWN_EVENT_NAME) {
+      const resultEvent = this._indexer.getResultEvent(dbEvent);
+
+      log(`pushing event to GQL subscribers (${timeElapsedInSeconds}s elapsed): ${resultEvent.event.__typename}`);
+
+      // Publishing the event here will result in pushing the payload to GQL subscribers for `onEvent`.
+      await this._pubsub.publish(UniswapEvent, {
+        onEvent: resultEvent
+      });
     }
   }
 
-      const processedBlocks: any = {};
-      if (!blocks.length) {
-        return;
-      }
+  async publishBlockProgressToSubscribers (blockProgress: BlockProgress): Promise<void> {
+    const { blockHash, blockNumber, numEvents, numProcessedEvents, isComplete } = blockProgress;
 
-      // Process events, if from known uniswap contracts.
-      for (let bi = 0; bi < blocks.length; bi++) {
-        const blockHash = blocks[bi];
-        if (processedBlocks[blockHash]) {
-          continue;
-        }
-
-        const events = await this._indexer.getBlockEvents(blockHash);
-        for (let ei = 0; ei < events.length; ei++) {
-          const eventObj = events[ei];
-          const uniContract = await this._indexer.isUniswapContract(eventObj.contract);
-          if (uniContract) {
-            log('event', JSON.stringify(eventObj, null, 2));
-
-            // TODO: Move processing to background queue (need sequential processing of events).
-            // Trigger other indexer methods based on event topic.
-            await this._indexer.processEvent(eventObj);
-          }
-        }
-
-        processedBlocks[blockHash] = true;
+    // Publishing the event here will result in pushing the payload to GQL subscribers for `onAddressEvent(address)`.
+    await this._pubsub.publish(BlockProgressEvent, {
+      onBlockProgressEvent: {
+        blockHash,
+        blockNumber,
+        numEvents,
+        numProcessedEvents,
+        isComplete
       }
     });
   }
 
   async stop (): Promise<void> {
     if (this._subscription) {
-      log('Stopped watching upstream logs');
+      log('Stopped watching upstream blocks');
       this._subscription.unsubscribe();
     }
   }

packages/uni-watcher/src/indexer.ts

@@ -1,17 +1,15 @@
-import assert from 'assert';
 import debug from 'debug';
-import _ from 'lodash';
 import { DeepPartial } from 'typeorm';
 import JSONbig from 'json-bigint';
 import { ethers } from 'ethers';
-import { PubSub } from 'apollo-server-express';
 
 import { EthClient } from '@vulcanize/ipld-eth-client';
 import { GetStorageAt } from '@vulcanize/solidity-mapper';
 import { Config } from '@vulcanize/util';
 
 import { Database } from './database';
-import { Event } from './entity/Event';
+import { Event, UNKNOWN_EVENT_NAME } from './entity/Event';
+import { BlockProgress } from './entity/BlockProgress';
 import { Contract, KIND_FACTORY, KIND_POOL } from './entity/Contract';
 
 import factoryABI from './artifacts/factory.json';
@@ -35,48 +33,21 @@ export class Indexer {
   _config: Config;
   _db: Database
   _ethClient: EthClient
-  _pubsub: PubSub
   _getStorageAt: GetStorageAt
 
   _factoryContract: ethers.utils.Interface
   _poolContract: ethers.utils.Interface
 
-  constructor (config: Config, db: Database, ethClient: EthClient, pubsub: PubSub) {
-    assert(config);
-    assert(db);
-    assert(ethClient);
-    assert(pubsub);
-
+  constructor (config: Config, db: Database, ethClient: EthClient) {
     this._config = config;
     this._db = db;
     this._ethClient = ethClient;
-    this._pubsub = pubsub;
     this._getStorageAt = this._ethClient.getStorageAt.bind(this._ethClient);
 
     this._factoryContract = new ethers.utils.Interface(factoryABI);
     this._poolContract = new ethers.utils.Interface(poolABI);
   }
 
-  getEventIterator (): AsyncIterator<any> {
-    return this._pubsub.asyncIterator(['event']);
-  }
-
-  async getBlockEvents (blockHash: string): Promise<Array<Event>> {
-    const didSyncEvents = await this._db.didSyncEvents({ blockHash });
-    if (!didSyncEvents) {
-      // Fetch and save events first and make a note in the event sync progress table.
-      await this.fetchAndSaveEvents({ blockHash });
-      log('getEvents: db miss, fetching from upstream server');
-    }
-
-    assert(await this._db.didSyncEvents({ blockHash }));
-
-    const events = await this._db.getBlockEvents({ blockHash });
-    log(`getEvents: db hit, num events: ${events.length}`);
-
-    return events;
-  }
-
   getResultEvent (event: Event): ResultEvent {
     const eventFields = JSON.parse(event.eventInfo);
 
@@ -100,29 +71,40 @@ export class Indexer {
       },
 
       // TODO: Return proof only if requested.
-      proof: JSON.parse(event.proof),
+      proof: JSON.parse(event.proof)
     };
   }
 
-  async getEvents (blockHash: string, contract: string, name: string | null): Promise<Array<Event>> {
+  // Note: Some event names might be unknown at this point, as earlier events might not yet be processed.
+  async getOrFetchBlockEvents (blockHash: string): Promise<Array<Event>> {
+    const blockProgress = await this._db.getBlockProgress(blockHash);
+    if (!blockProgress) {
+      // Fetch and save events first and make a note in the event sync progress table.
+      await this.fetchAndSaveEvents(blockHash);
+      log('getBlockEvents: db miss, fetching from upstream server');
+    }
+
+    const events = await this._db.getBlockEvents(blockHash);
+    log(`getBlockEvents: db hit, num events: ${events.length}`);
+
+    return events;
+  }
+
+  async getEventsByFilter (blockHash: string, contract: string, name: string | null): Promise<Array<Event>> {
     const uniContract = await this.isUniswapContract(contract);
     if (!uniContract) {
       throw new Error('Not a uniswap contract');
     }
 
-    const didSyncEvents = await this._db.didSyncEvents({ blockHash });
-    if (!didSyncEvents) {
-      // Fetch and save events first and make a note in the event sync progress table.
-      await this.fetchAndSaveEvents({ blockHash });
-      log('getEvents: db miss, fetching from upstream server');
-    }
+    // Fetch block events first.
+    await this.getOrFetchBlockEvents(blockHash);
 
-    assert(await this._db.didSyncEvents({ blockHash }));
-
-    const events = await this._db.getEvents({ blockHash, contract });
+    const events = await this._db.getEvents(blockHash, contract);
     log(`getEvents: db hit, num events: ${events.length}`);
 
+    // Filtering.
     const result = events
+      // TODO: Filter using db WHERE condition on contract.
       .filter(event => contract === event.contract)
       // TODO: Filter using db WHERE condition when name is not empty.
       .filter(event => !name || name === event.eventName);
@@ -141,17 +123,6 @@ export class Indexer {
     }
   }
 
-  async publishEventToSubscribers (dbEvent: Event): Promise<void> {
-    const resultEvent = this.getResultEvent(dbEvent);
-
-    log(`pushing event to GQL subscribers: ${resultEvent.event.__typename}`);
-
-    // Publishing the event here will result in pushing the payload to GQL subscribers for `onEvent`.
-    await this._pubsub.publish('event', {
-      onEvent: resultEvent
-    });
-  }
-
   async isUniswapContract (address: string): Promise<Contract | undefined> {
     return this._db.getContract(ethers.utils.getAddress(address));
   }
@@ -159,48 +130,15 @@ export class Indexer {
   async processEvent (event: Event): Promise<void> {
     // Trigger indexing of data based on the event.
     await this.triggerIndexingOnEvent(event);
-
-    // Also trigger downstream event watcher subscriptions.
-    await this.publishEventToSubscribers(event);
   }
 
-  async fetchAndSaveEvents ({ blockHash }: { blockHash: string }): Promise<void> {
-    const logs = await this._ethClient.getLogs({ blockHash });
-
-    const dbEvents: Array<DeepPartial<Event>> = [];
-
-    for (let li = 0; li < logs.length; li++) {
-      const logObj = logs[li];
-      const {
-        topics,
-        data,
-        index: logIndex,
-        cid,
-        ipldBlock,
-        account: {
-          address
-        },
-        transaction: {
-          hash: txHash,
-          block: {
-            number: blockNumber,
-            timestamp: blockTimestamp
-          }
-        }
-      } = logObj;
-
-      let eventName;
+  parseEventNameAndArgs (kind: string, logObj: any): any {
+    let eventName = UNKNOWN_EVENT_NAME;
     let eventInfo = {};
-      let extraInfo = {};
 
-      const contract = ethers.utils.getAddress(address);
-      const uniContract = await this.isUniswapContract(contract);
-      if (!uniContract) {
-        // TODO: Can only be known if events are processed serially.
-        continue;
-      }
+    const { topics, data } = logObj;
 
-      switch (uniContract.kind) {
+    switch (kind) {
       case KIND_FACTORY: {
         const logDescription = this._factoryContract.parseLog({ data, topics });
         switch (logDescription.name) {
@@ -275,7 +213,47 @@ export class Indexer {
       }
     }
 
-      if (eventName) {
+    return { eventName, eventInfo };
+  }
+
+  async fetchAndSaveEvents (blockHash: string): Promise<void> {
+    const { block, logs } = await this._ethClient.getLogs({ blockHash });
+
+    const dbEvents: Array<DeepPartial<Event>> = [];
+
+    for (let li = 0; li < logs.length; li++) {
+      const logObj = logs[li];
+      const {
+        topics,
+        data,
+        index: logIndex,
+        cid,
+        ipldBlock,
+        account: {
+          address
+        },
+        transaction: {
+          hash: txHash,
+          block: {
+            number: blockNumber,
+            timestamp: blockTimestamp
+          }
+        }
+      } = logObj;
+
+      let eventName = UNKNOWN_EVENT_NAME;
+      let eventInfo = {};
+      const extraInfo = { topics, data };
+
+      const contract = ethers.utils.getAddress(address);
+      const uniContract = await this.isUniswapContract(contract);
+
+      if (uniContract) {
+        const eventDetails = this.parseEventNameAndArgs(uniContract.kind, logObj);
+        eventName = eventDetails.eventName;
+        eventInfo = eventDetails.eventInfo;
+      }
+
       dbEvents.push({
         blockHash,
         blockNumber,
@@ -297,9 +275,23 @@ export class Indexer {
         })
       });
     }
+
+    await this._db.saveEvents(blockHash, block.number, dbEvents);
   }
 
-    const events: DeepPartial<Event>[] = _.compact(dbEvents);
-    await this._db.saveEvents({ blockHash, events });
+  async getEvent (id: string): Promise<Event | undefined> {
+    return this._db.getEvent(id);
+  }
+
+  async saveEventEntity (dbEvent: Event): Promise<Event> {
+    return this._db.saveEventEntity(dbEvent);
+  }
+
+  async getBlockProgress (blockHash: string): Promise<BlockProgress | undefined> {
+    return this._db.getBlockProgress(blockHash);
+  }
+
+  async updateBlockProgress (blockHash: string): Promise<void> {
+    return this._db.updateBlockProgress(blockHash);
   }
 }

packages/uni-watcher/src/job-runner.ts

@@ -0,0 +1,103 @@
+import assert from 'assert';
+import 'reflect-metadata';
+import yargs from 'yargs';
+import { hideBin } from 'yargs/helpers';
+import debug from 'debug';
+
+import { getCache } from '@vulcanize/cache';
+import { EthClient } from '@vulcanize/ipld-eth-client';
+import { getConfig, JobQueue } from '@vulcanize/util';
+
+import { Indexer } from './indexer';
+import { Database } from './database';
+import { UNKNOWN_EVENT_NAME } from './entity/Event';
+import { QUEUE_BLOCK_PROCESSING, QUEUE_EVENT_PROCESSING } from './events';
+
+const log = debug('vulcanize:job-runner');
+
+export const main = async (): Promise<any> => {
+  const argv = await yargs(hideBin(process.argv))
+    .option('f', {
+      alias: 'config-file',
+      demandOption: true,
+      describe: 'configuration file path (toml)',
+      type: 'string'
+    })
+    .argv;
+
+  const config = await getConfig(argv.f);
+
+  assert(config.server, 'Missing server config');
+
+  const { upstream, database: dbConfig, jobQueue: jobQueueConfig } = config;
+
+  assert(dbConfig, 'Missing database config');
+
+  const db = new Database(dbConfig);
+  await db.init();
+
+  assert(upstream, 'Missing upstream config');
+  const { gqlEndpoint, gqlSubscriptionEndpoint, cache: cacheConfig } = upstream;
+  assert(gqlEndpoint, 'Missing upstream gqlEndpoint');
+  assert(gqlSubscriptionEndpoint, 'Missing upstream gqlSubscriptionEndpoint');
+
+  const cache = await getCache(cacheConfig);
+
+  const ethClient = new EthClient({ gqlEndpoint, gqlSubscriptionEndpoint, cache });
+
+  const indexer = new Indexer(config, db, ethClient);
+
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLag } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag });
+  await jobQueue.start();
+
+  await jobQueue.subscribe(QUEUE_BLOCK_PROCESSING, async (job) => {
+    const { data: { blockHash, blockNumber } } = job;
+
+    log(`Processing block ${blockHash} ${blockNumber}`);
+
+    const events = await indexer.getOrFetchBlockEvents(blockHash);
+    for (let ei = 0; ei < events.length; ei++) {
+      const { blockHash, id } = events[ei];
+      await jobQueue.pushJob(QUEUE_EVENT_PROCESSING, { blockHash, id, publish: true });
+    }
+
+    await jobQueue.markComplete(job);
+  });
+
+  await jobQueue.subscribe(QUEUE_EVENT_PROCESSING, async (job) => {
+    const { data: { id } } = job;
+
+    log(`Processing event ${id}`);
+
+    let dbEvent = await indexer.getEvent(id);
+    assert(dbEvent);
+
+    const uniContract = await indexer.isUniswapContract(dbEvent.contract);
+    if (uniContract) {
+      // We might not have parsed this event yet. This can happen if the contract was added
+      // as a result of a previous event in the same block.
+      if (dbEvent.eventName === UNKNOWN_EVENT_NAME) {
+        const logObj = JSON.parse(dbEvent.extraInfo);
+        const { eventName, eventInfo } = indexer.parseEventNameAndArgs(uniContract.kind, logObj);
+        dbEvent.eventName = eventName;
+        dbEvent.eventInfo = JSON.stringify(eventInfo);
+        dbEvent = await indexer.saveEventEntity(dbEvent);
+      }
+
+      await indexer.processEvent(dbEvent);
+    }
+
+    await jobQueue.markComplete(job);
+  });
+};
+
+main().then(() => {
+  log('Starting job runner...');
+}).catch(err => {
+  log(err);
+});

packages/uni-watcher/src/resolvers.ts

@@ -3,12 +3,11 @@ import BigInt from 'apollo-type-bigint';
 import debug from 'debug';
 
 import { Indexer } from './indexer';
+import { EventWatcher } from './events';
 
 const log = debug('vulcanize:resolver');
 
-export const createResolvers = async (indexer: Indexer): Promise<any> => {
-  assert(indexer);
-
+export const createResolvers = async (indexer: Indexer, eventWatcher: EventWatcher): Promise<any> => {
   return {
     BigInt: new BigInt('bigInt'),
 
@@ -46,7 +45,11 @@ export const createResolvers = async (indexer: Indexer): Promise<any> => {
 
     Subscription: {
       onEvent: {
-        subscribe: () => indexer.getEventIterator()
+        subscribe: () => eventWatcher.getEventIterator()
+      },
+
+      onBlockProgressEvent: {
+        subscribe: () => eventWatcher.getBlockProgressEventIterator()
       }
     },
 
@@ -54,8 +57,14 @@ export const createResolvers = async (indexer: Indexer): Promise<any> => {
 
       events: async (_: any, { blockHash, contract, name }: { blockHash: string, contract: string, name: string }) => {
         log('events', blockHash, contract, name || '');
-        const events = await indexer.getEvents(blockHash, contract, name);
 
+        const blockProgress = await indexer.getBlockProgress(blockHash);
+        if (!blockProgress || !blockProgress.isComplete) {
+          // TODO: Trigger indexing for the block.
+          throw new Error('Not available');
+        }
+
+        const events = await indexer.getEventsByFilter(blockHash, contract, name);
         return events.map(event => indexer.getResultEvent(event));
       }
     }

packages/uni-watcher/src/schema.ts

@@ -187,6 +187,13 @@ type ResultEvent {
   proof: Proof
 }
 
+type BlockProgressEvent {
+  blockNumber: Int!
+  blockHash: String!
+  numEvents: Int!
+  numProcessedEvents: Int!
+  isComplete: Boolean!
+}
 
 #
 # Queries
@@ -245,7 +252,10 @@ type Query {
 #
 type Subscription {
 
-  # Watch for events (at head of chain).
+  # Watch for Wniswap events (at head of chain).
   onEvent: ResultEvent!
+
+  # Watch for block progress events from filler process.
+  onBlockProgressEvent: BlockProgressEvent!
 }
 `;

packages/uni-watcher/src/server.ts

@@ -10,7 +10,7 @@ import { createServer } from 'http';
 
 import { getCache } from '@vulcanize/cache';
 import { EthClient } from '@vulcanize/ipld-eth-client';
-import { getConfig } from '@vulcanize/util';
+import { getConfig, JobQueue } from '@vulcanize/util';
 
 import typeDefs from './schema';
 
@@ -38,7 +38,7 @@ export const main = async (): Promise<any> => {
 
   const { host, port } = config.server;
 
-  const { upstream, database: dbConfig } = config;
+  const { upstream, database: dbConfig, jobQueue: jobQueueConfig } = config;
 
   assert(dbConfig, 'Missing database config');
 
@@ -57,12 +57,20 @@ export const main = async (): Promise<any> => {
   // Note: In-memory pubsub works fine for now, as each watcher is a single process anyway.
   // Later: https://www.apollographql.com/docs/apollo-server/data/subscriptions/#production-pubsub-libraries
   const pubsub = new PubSub();
-  const indexer = new Indexer(config, db, ethClient, pubsub);
+  const indexer = new Indexer(config, db, ethClient);
 
-  const eventWatcher = new EventWatcher(ethClient, indexer);
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLag } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag });
+  await jobQueue.start();
+
+  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
   await eventWatcher.start();
 
-  const resolvers = process.env.MOCK ? await createMockResolvers() : await createResolvers(indexer);
+  const resolvers = process.env.MOCK ? await createMockResolvers() : await createResolvers(indexer, eventWatcher);
 
   const app: Application = express();
   const server = new ApolloServer({

packages/util/.eslintrc.json

@@ -14,5 +14,14 @@
     },
     "plugins": [
         "@typescript-eslint"
+    ],
+    "rules": {
+        "@typescript-eslint/no-explicit-any": "off",
+        "@typescript-eslint/explicit-module-boundary-types": [
+            "warn",
+            {
+                "allowArgumentsExplicitlyTypedAsAny": true
+            }
         ]
     }
+}

packages/util/index.ts

@@ -1,2 +1,3 @@
 export * from './src/config';
 export * from './src/database';
+export * from './src/job-queue';

packages/util/package.json

@@ -7,6 +7,8 @@
     "debug": "^4.3.1",
     "ethers": "^5.2.0",
     "fs-extra": "^10.0.0",
+    "pg": "^8.6.0",
+    "pg-boss": "^6.1.0",
     "toml": "^3.0.0"
   },
   "devDependencies": {