Change block processing to be pull based (#288)

* Implement pull based watcher for uni-watcher

* Fix same block processed multiple times

* Implement wait time for fetching block from config

* Use blockProgress event to fetch and process next block

* Rename utils index to misc

packages/address-watcher/src/indexer.ts

@@ -31,8 +31,8 @@ export class Indexer {
 
     this._db = db;
     this._ethClient = ethClient;
-    this._getStorageAt = this._ethClient.getStorageAt.bind(this._ethClient);
     this._tracingClient = tracingClient;
+    this._getStorageAt = this._ethClient.getStorageAt.bind(this._ethClient);
   }
 
   async isWatchedAddress (address : string): Promise<boolean> {

packages/codegen/src/templates/config-template.handlebars

@@ -18,6 +18,7 @@
     gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
     gqlPostgraphileEndpoint = "http://127.0.0.1:5000/graphql"
     rpcProviderEndpoint = "http://127.0.0.1:8081"
+    blockDelayInMilliSecs = 2000
 
   [upstream.cache]
     name = "requests"

packages/codegen/src/templates/events-template.handlebars

@@ -12,7 +12,8 @@ import {
   EventWatcher as BaseEventWatcher,
   QUEUE_BLOCK_PROCESSING,
   QUEUE_EVENT_PROCESSING,
-  UNKNOWN_EVENT_NAME
+  UNKNOWN_EVENT_NAME,
+  UpstreamConfig
 } from '@vulcanize/util';
 
 import { Indexer } from './indexer';
@@ -30,7 +31,7 @@ export class EventWatcher {
   _pubsub: PubSub
   _jobQueue: JobQueue
 
-  constructor (ethClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
+  constructor (upstreamConfig: UpstreamConfig, ethClient: EthClient, postgraphileClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
     assert(ethClient);
     assert(indexer);
 
@@ -38,7 +39,7 @@ export class EventWatcher {
     this._indexer = indexer;
     this._pubsub = pubsub;
     this._jobQueue = jobQueue;
-    this._baseEventWatcher = new BaseEventWatcher(this._ethClient, this._indexer, this._pubsub, this._jobQueue);
+    this._baseEventWatcher = new BaseEventWatcher(upstreamConfig, this._ethClient, postgraphileClient, this._indexer, this._pubsub, this._jobQueue);
   }
 
   getEventIterator (): AsyncIterator<any> {
@@ -52,22 +53,15 @@ export class EventWatcher {
   async start (): Promise<void> {
     assert(!this._subscription, 'subscription already started');
 
-    await this.watchBlocksAtChainHead();
     await this.initBlockProcessingOnCompleteHandler();
     await this.initEventProcessingOnCompleteHandler();
+    this._baseEventWatcher.startBlockProcessing();
   }
 
   async stop (): Promise<void> {
     this._baseEventWatcher.stop();
   }
 
-  async watchBlocksAtChainHead (): Promise<void> {
-    log('Started watching upstream blocks...');
-    this._subscription = await this._ethClient.watchBlocks(async (value) => {
-      await this._baseEventWatcher.blocksHandler(value);
-    });
-  }
-
   async initBlockProcessingOnCompleteHandler (): Promise<void> {
     this._jobQueue.onComplete(QUEUE_BLOCK_PROCESSING, async (job) => {
       const { id, data: { failed } } = job;

packages/codegen/src/templates/fill-template.handlebars

@@ -54,13 +54,13 @@ export const main = async (): Promise<any> => {
   await db.init();
 
   assert(upstream, 'Missing upstream config');
-  const { ethServer: { gqlPostgraphileEndpoint, rpcProviderEndpoint }, cache: cacheConfig } = upstream;
+  const { ethServer: { gqlApiEndpoint, gqlPostgraphileEndpoint, rpcProviderEndpoint, blockDelayInMilliSecs }, cache: cacheConfig } = upstream;
   assert(gqlPostgraphileEndpoint, 'Missing upstream ethServer.gqlPostgraphileEndpoint');
 
   const cache = await getCache(cacheConfig);
 
   const ethClient = new EthClient({
-    gqlEndpoint: gqlPostgraphileEndpoint,
+    gqlEndpoint: gqlApiEndpoint,
     gqlSubscriptionEndpoint: gqlPostgraphileEndpoint,
     cache
   });
@@ -83,11 +83,11 @@ export const main = async (): Promise<any> => {
   const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
   await jobQueue.start();
 
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubsub, jobQueue);
 
   assert(jobQueueConfig, 'Missing job queue config');
 
-  await fillBlocks(jobQueue, indexer, ethClient, eventWatcher, argv);
+  await fillBlocks(jobQueue, indexer, postgraphileClient, eventWatcher, blockDelayInMilliSecs, argv);
 };
 
 main().catch(err => {

packages/codegen/src/templates/indexer-template.handlebars

@@ -67,8 +67,8 @@ export class Indexer {
 
     this._db = db;
     this._ethClient = ethClient;
-    this._ethProvider = ethProvider;
     this._postgraphileClient = postgraphileClient;
+    this._ethProvider = ethProvider;
     this._baseIndexer = new BaseIndexer(this._db, this._ethClient, this._ethProvider);
 
     const { abi, storageLayout } = artifacts;

packages/codegen/src/templates/job-runner-template.handlebars

@@ -33,9 +33,9 @@ export class JobRunner {
   _jobQueueConfig: JobQueueConfig
 
   constructor (jobQueueConfig: JobQueueConfig, indexer: Indexer, jobQueue: JobQueue) {
+    this._jobQueueConfig = jobQueueConfig;
     this._indexer = indexer;
     this._jobQueue = jobQueue;
-    this._jobQueueConfig = jobQueueConfig;
     this._baseJobRunner = new BaseJobRunner(this._jobQueueConfig, this._indexer, this._jobQueue);
   }
 

packages/codegen/src/templates/server-template.handlebars

@@ -81,7 +81,7 @@ export const main = async (): Promise<any> => {
 
   const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
 
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubsub, jobQueue);
 
   if (watcherKind === KIND_ACTIVE) {
     await jobQueue.start();

packages/erc20-watcher/environments/local.toml

@@ -19,6 +19,7 @@
     gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
     gqlPostgraphileEndpoint = "http://127.0.0.1:5000/graphql"
     rpcProviderEndpoint = "http://127.0.0.1:8081"
+    blockDelayInMilliSecs = 2000
 
   [upstream.cache]
     name = "requests"

packages/erc20-watcher/src/events.ts

@@ -12,7 +12,8 @@ import {
   EventWatcher as BaseEventWatcher,
   QUEUE_BLOCK_PROCESSING,
   QUEUE_EVENT_PROCESSING,
-  UNKNOWN_EVENT_NAME
+  UNKNOWN_EVENT_NAME,
+  UpstreamConfig
 } from '@vulcanize/util';
 
 import { Indexer } from './indexer';
@@ -30,7 +31,7 @@ export class EventWatcher {
   _pubsub: PubSub
   _jobQueue: JobQueue
 
-  constructor (ethClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
+  constructor (upstreamConfig: UpstreamConfig, ethClient: EthClient, postgraphileClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
     assert(ethClient);
     assert(indexer);
 
@@ -38,7 +39,7 @@ export class EventWatcher {
     this._indexer = indexer;
     this._pubsub = pubsub;
     this._jobQueue = jobQueue;
-    this._baseEventWatcher = new BaseEventWatcher(this._ethClient, this._indexer, this._pubsub, this._jobQueue);
+    this._baseEventWatcher = new BaseEventWatcher(upstreamConfig, this._ethClient, postgraphileClient, this._indexer, this._pubsub, this._jobQueue);
   }
 
   getEventIterator (): AsyncIterator<any> {
@@ -52,22 +53,15 @@ export class EventWatcher {
   async start (): Promise<void> {
     assert(!this._subscription, 'subscription already started');
 
-    await this.watchBlocksAtChainHead();
     await this.initBlockProcessingOnCompleteHandler();
     await this.initEventProcessingOnCompleteHandler();
+    this._baseEventWatcher.startBlockProcessing();
   }
 
   async stop (): Promise<void> {
     this._baseEventWatcher.stop();
   }
 
-  async watchBlocksAtChainHead (): Promise<void> {
-    log('Started watching upstream blocks...');
-    this._subscription = await this._ethClient.watchBlocks(async (value) => {
-      await this._baseEventWatcher.blocksHandler(value);
-    });
-  }
-
   async initBlockProcessingOnCompleteHandler (): Promise<void> {
     this._jobQueue.onComplete(QUEUE_BLOCK_PROCESSING, async (job) => {
       const { id, data: { failed } } = job;

packages/erc20-watcher/src/fill.ts

@@ -57,16 +57,21 @@ export const main = async (): Promise<any> => {
   await db.init();
 
   assert(upstream, 'Missing upstream config');
-  const { ethServer: { gqlPostgraphileEndpoint, rpcProviderEndpoint }, cache: cacheConfig } = upstream;
+  const { ethServer: { gqlApiEndpoint, gqlPostgraphileEndpoint, rpcProviderEndpoint, blockDelayInMilliSecs }, cache: cacheConfig } = upstream;
   assert(gqlPostgraphileEndpoint, 'Missing upstream ethServer.gqlPostgraphileEndpoint');
 
   const cache = await getCache(cacheConfig);
   const ethClient = new EthClient({
-    gqlEndpoint: gqlPostgraphileEndpoint,
+    gqlEndpoint: gqlApiEndpoint,
     gqlSubscriptionEndpoint: gqlPostgraphileEndpoint,
     cache
   });
 
+  const postgraphileClient = new EthClient({
+    gqlEndpoint: gqlPostgraphileEndpoint,
+    cache
+  });
+
   const ethProvider = getCustomProvider(rpcProviderEndpoint);
 
   // Note: In-memory pubsub works fine for now, as each watcher is a single process anyway.
@@ -80,11 +85,11 @@ export const main = async (): Promise<any> => {
   const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
   await jobQueue.start();
 
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubsub, jobQueue);
 
   assert(jobQueueConfig, 'Missing job queue config');
 
-  await fillBlocks(jobQueue, indexer, ethClient, eventWatcher, argv);
+  await fillBlocks(jobQueue, indexer, postgraphileClient, eventWatcher, blockDelayInMilliSecs, argv);
 };
 
 main().catch(err => {

packages/erc20-watcher/src/job-runner.ts

@@ -33,9 +33,9 @@ export class JobRunner {
   _jobQueueConfig: JobQueueConfig
 
   constructor (jobQueueConfig: JobQueueConfig, indexer: Indexer, jobQueue: JobQueue) {
+    this._jobQueueConfig = jobQueueConfig;
     this._indexer = indexer;
     this._jobQueue = jobQueue;
-    this._jobQueueConfig = jobQueueConfig;
     this._baseJobRunner = new BaseJobRunner(this._jobQueueConfig, this._indexer, this._jobQueue);
   }
 

packages/erc20-watcher/src/server.ts

@@ -62,6 +62,11 @@ export const main = async (): Promise<any> => {
     cache
   });
 
+  const postgraphileClient = new EthClient({
+    gqlEndpoint: gqlPostgraphileEndpoint,
+    cache
+  });
+
   const ethProvider = getCustomProvider(rpcProviderEndpoint);
 
   // Note: In-memory pubsub works fine for now, as each watcher is a single process anyway.
@@ -75,7 +80,7 @@ export const main = async (): Promise<any> => {
   assert(dbConnectionString, 'Missing job queue db connection string');
 
   const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubsub, jobQueue);
 
   if (watcherKind === KIND_ACTIVE) {
     await jobQueue.start();

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

@@ -76,7 +76,7 @@ export class EthClient {
     return this._graphqlClient.query(ethQueries.getBlocksByNumber, { blockNumber });
   }
 
-  async getBlockByHash (blockHash: string): Promise<any> {
+  async getBlockByHash (blockHash?: string): Promise<any> {
     const { block } = await this._graphqlClient.query(ethQueries.getBlockByHash, { blockHash });
     block.number = parseInt(block.number, 16);
     block.timestamp = parseInt(block.timestamp, 16);

packages/uni-info-watcher/environments/local.toml

@@ -20,6 +20,7 @@
     gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
     gqlPostgraphileEndpoint = "http://127.0.0.1:5000/graphql"
     rpcProviderEndpoint = "http://127.0.0.1:8081"
+    blockDelayInMilliSecs = 2000
 
   [upstream.cache]
     name = "requests"

packages/uni-info-watcher/environments/test.toml

@@ -20,6 +20,7 @@
     gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
     gqlPostgraphileEndpoint = "http://127.0.0.1:5000/graphql"
     rpcProviderEndpoint = "http://127.0.0.1:8545"
+    blockDelayInMilliSecs = 2000
 
   [upstream.cache]
     name = "requests"

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

@@ -7,7 +7,7 @@ import debug from 'debug';
 import { PubSub } from 'apollo-server-express';
 
 import { EthClient } from '@vulcanize/ipld-eth-client';
-import { EventWatcher as BaseEventWatcher, EventWatcherInterface, JobQueue, QUEUE_BLOCK_PROCESSING, QUEUE_EVENT_PROCESSING } from '@vulcanize/util';
+import { EventWatcher as BaseEventWatcher, EventWatcherInterface, JobQueue, QUEUE_BLOCK_PROCESSING, QUEUE_EVENT_PROCESSING, UpstreamConfig } from '@vulcanize/util';
 
 import { Indexer } from './indexer';
 
@@ -124,12 +124,12 @@ export class EventWatcher implements EventWatcherInterface {
   _jobQueue: JobQueue
   _baseEventWatcher: BaseEventWatcher
 
-  constructor (ethClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
+  constructor (upstreamConfig: UpstreamConfig, ethClient: EthClient, postgraphileClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
     this._ethClient = ethClient;
     this._indexer = indexer;
     this._pubsub = pubsub;
     this._jobQueue = jobQueue;
-    this._baseEventWatcher = new BaseEventWatcher(this._ethClient, this._indexer, this._pubsub, this._jobQueue);
+    this._baseEventWatcher = new BaseEventWatcher(upstreamConfig, this._ethClient, postgraphileClient, this._indexer, this._pubsub, this._jobQueue);
   }
 
   getBlockProgressEventIterator (): AsyncIterator<any> {
@@ -140,21 +140,15 @@ export class EventWatcher implements EventWatcherInterface {
     assert(!this._subscription, 'subscription already started');
     log('Started watching upstream events...');
 
-    await this.watchBlocksAtChainHead();
     await this.initBlockProcessingOnCompleteHandler();
     await this.initEventProcessingOnCompleteHandler();
+    this._baseEventWatcher.startBlockProcessing();
   }
 
   async stop (): Promise<void> {
     this._baseEventWatcher.stop();
   }
 
-  async watchBlocksAtChainHead (): Promise<void> {
-    this._subscription = await this._ethClient.watchBlocks(async (value) => {
-      await this._baseEventWatcher.blocksHandler(value);
-    });
-  }
-
   async initBlockProcessingOnCompleteHandler (): Promise<void> {
     await this._jobQueue.onComplete(QUEUE_BLOCK_PROCESSING, async (job) => {
       const { id, data: { failed } } = job;

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

@@ -59,16 +59,21 @@ export const main = async (): Promise<any> => {
   await db.init();
 
   assert(upstream, 'Missing upstream config');
-  const { ethServer: { gqlPostgraphileEndpoint, rpcProviderEndpoint }, cache: cacheConfig, uniWatcher, tokenWatcher } = upstream;
+  const { ethServer: { gqlApiEndpoint, gqlPostgraphileEndpoint, rpcProviderEndpoint, blockDelayInMilliSecs }, cache: cacheConfig, uniWatcher, tokenWatcher } = upstream;
   assert(gqlPostgraphileEndpoint, 'Missing upstream ethServer.gqlPostgraphileEndpoint');
 
   const cache = await getCache(cacheConfig);
   const ethClient = new EthClient({
-    gqlEndpoint: gqlPostgraphileEndpoint,
+    gqlEndpoint: gqlApiEndpoint,
     gqlSubscriptionEndpoint: gqlPostgraphileEndpoint,
     cache
   });
 
+  const postgraphileClient = new EthClient({
+    gqlEndpoint: gqlPostgraphileEndpoint,
+    cache
+  });
+
   const uniClient = new UniClient(uniWatcher);
   const erc20Client = new ERC20Client(tokenWatcher);
   const ethProvider = getCustomProvider(rpcProviderEndpoint);
@@ -85,9 +90,9 @@ export const main = async (): Promise<any> => {
   const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
   await jobQueue.start();
 
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubsub, jobQueue);
 
-  await fillBlocks(jobQueue, indexer, ethClient, eventWatcher, argv);
+  await fillBlocks(jobQueue, indexer, postgraphileClient, eventWatcher, blockDelayInMilliSecs, argv);
 };
 
 main().catch(err => {

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

@@ -35,9 +35,9 @@ export class JobRunner {
   _jobQueueConfig: JobQueueConfig
 
   constructor (jobQueueConfig: JobQueueConfig, indexer: Indexer, jobQueue: JobQueue) {
+    this._jobQueueConfig = jobQueueConfig;
     this._indexer = indexer;
     this._jobQueue = jobQueue;
-    this._jobQueueConfig = jobQueueConfig;
     this._baseJobRunner = new BaseJobRunner(this._jobQueueConfig, this._indexer, this._jobQueue);
   }
 

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

@@ -74,6 +74,11 @@ export const main = async (): Promise<any> => {
     cache
   });
 
+  const postgraphileClient = new EthClient({
+    gqlEndpoint: gqlPostgraphileEndpoint,
+    cache
+  });
+
   const uniClient = new UniClient(uniWatcher);
   const erc20Client = new ERC20Client(tokenWatcher);
   const ethProvider = getCustomProvider(rpcProviderEndpoint);
@@ -88,7 +93,7 @@ export const main = async (): Promise<any> => {
   await jobQueue.start();
 
   const pubSub = new PubSub();
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubSub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubSub, jobQueue);
   await eventWatcher.start();
 
   const resolvers = process.env.MOCK ? await createMockResolvers() : await createResolvers(indexer, eventWatcher);

packages/uni-watcher/environments/local.toml

@@ -17,6 +17,7 @@
     gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
     gqlPostgraphileEndpoint = "http://127.0.0.1:5000/graphql"
     rpcProviderEndpoint = "http://127.0.0.1:8081"
+    blockDelayInMilliSecs = 2000
 
   [upstream.cache]
     name = "requests"

packages/uni-watcher/environments/test.toml

@@ -17,6 +17,7 @@
     gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
     gqlPostgraphileEndpoint = "http://127.0.0.1:5000/graphql"
     rpcProviderEndpoint = "http://127.0.0.1:8545"
+    blockDelayInMilliSecs = 2000
 
   [upstream.cache]
     name = "requests"

packages/uni-watcher/src/events.ts

@@ -12,7 +12,8 @@ import {
   EventWatcher as BaseEventWatcher,
   QUEUE_BLOCK_PROCESSING,
   QUEUE_EVENT_PROCESSING,
-  EventWatcherInterface
+  EventWatcherInterface,
+  UpstreamConfig
 } from '@vulcanize/util';
 
 import { Indexer } from './indexer';
@@ -30,12 +31,12 @@ export class EventWatcher implements EventWatcherInterface {
   _jobQueue: JobQueue
   _baseEventWatcher: BaseEventWatcher
 
-  constructor (ethClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
+  constructor (upstreamConfig: UpstreamConfig, ethClient: EthClient, postgraphileClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
     this._ethClient = ethClient;
     this._indexer = indexer;
     this._pubsub = pubsub;
     this._jobQueue = jobQueue;
-    this._baseEventWatcher = new BaseEventWatcher(this._ethClient, this._indexer, this._pubsub, this._jobQueue);
+    this._baseEventWatcher = new BaseEventWatcher(upstreamConfig, this._ethClient, postgraphileClient, this._indexer, this._pubsub, this._jobQueue);
   }
 
   getEventIterator (): AsyncIterator<any> {
@@ -49,22 +50,15 @@ export class EventWatcher implements EventWatcherInterface {
   async start (): Promise<void> {
     assert(!this._subscription, 'subscription already started');
 
-    await this.watchBlocksAtChainHead();
     await this.initBlockProcessingOnCompleteHandler();
     await this.initEventProcessingOnCompleteHandler();
+    this._baseEventWatcher.startBlockProcessing();
   }
 
   async stop (): Promise<void> {
     this._baseEventWatcher.stop();
   }
 
-  async watchBlocksAtChainHead (): Promise<void> {
-    log('Started watching upstream blocks...');
-    this._subscription = await this._ethClient.watchBlocks(async (value) => {
-      await this._baseEventWatcher.blocksHandler(value);
-    });
-  }
-
   async initBlockProcessingOnCompleteHandler (): Promise<void> {
     this._jobQueue.onComplete(QUEUE_BLOCK_PROCESSING, async (job) => {
       const { id, data: { failed } } = job;

packages/uni-watcher/src/fill.ts

@@ -57,12 +57,12 @@ export const main = async (): Promise<any> => {
   await db.init();
 
   assert(upstream, 'Missing upstream config');
-  const { ethServer: { gqlPostgraphileEndpoint, rpcProviderEndpoint }, cache: cacheConfig } = upstream;
+  const { ethServer: { gqlApiEndpoint, gqlPostgraphileEndpoint, rpcProviderEndpoint, blockDelayInMilliSecs }, cache: cacheConfig } = upstream;
   assert(gqlPostgraphileEndpoint, 'Missing upstream ethServer.gqlPostgraphileEndpoint');
 
   const cache = await getCache(cacheConfig);
   const ethClient = new EthClient({
-    gqlEndpoint: gqlPostgraphileEndpoint,
+    gqlEndpoint: gqlApiEndpoint,
     gqlSubscriptionEndpoint: gqlPostgraphileEndpoint,
     cache
   });
@@ -85,11 +85,11 @@ export const main = async (): Promise<any> => {
   const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
   await jobQueue.start();
 
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubsub, jobQueue);
 
   assert(jobQueueConfig, 'Missing job queue config');
 
-  await fillBlocks(jobQueue, indexer, ethClient, eventWatcher, argv);
+  await fillBlocks(jobQueue, indexer, postgraphileClient, eventWatcher, blockDelayInMilliSecs, argv);
 };
 
 main().catch(err => {

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

@@ -34,9 +34,9 @@ export class JobRunner {
   _jobQueueConfig: JobQueueConfig
 
   constructor (jobQueueConfig: JobQueueConfig, indexer: Indexer, jobQueue: JobQueue) {
+    this._jobQueueConfig = jobQueueConfig;
     this._indexer = indexer;
     this._jobQueue = jobQueue;
-    this._jobQueueConfig = jobQueueConfig;
     this._baseJobRunner = new BaseJobRunner(this._jobQueueConfig, this._indexer, this._jobQueue);
   }
 

packages/uni-watcher/src/server.ts

@@ -82,7 +82,7 @@ export const main = async (): Promise<any> => {
   const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
   await jobQueue.start();
 
-  const eventWatcher = new EventWatcher(ethClient, indexer, pubsub, jobQueue);
+  const eventWatcher = new EventWatcher(upstream, ethClient, postgraphileClient, indexer, pubsub, jobQueue);
   await eventWatcher.start();
 
   const resolvers = process.env.MOCK ? await createMockResolvers() : await createResolvers(indexer, eventWatcher);

packages/util/index.ts

@@ -6,7 +6,7 @@ export * from './src/config';
 export * from './src/database';
 export * from './src/job-queue';
 export * from './src/constants';
-export * from './src/index';
+export * from './src/misc';
 export * from './src/fill';
 export * from './src/events';
 export * from './src/types';

packages/util/src/common.ts

@@ -1,5 +1,13 @@
-import { JOB_KIND_PRUNE, QUEUE_BLOCK_PROCESSING } from './constants';
+import debug from 'debug';
+
+import { EthClient } from '@vulcanize/ipld-eth-client';
+
+import { JOB_KIND_PRUNE, QUEUE_BLOCK_PROCESSING, JOB_KIND_INDEX } from './constants';
 import { JobQueue } from './job-queue';
+import { IndexerInterface } from './types';
+import { wait } from './misc';
+
+const log = debug('vulcanize:common');
 
 /**
  * Create pruning job in QUEUE_BLOCK_PROCESSING.
@@ -24,3 +32,46 @@ export const createPruningJob = async (jobQueue: JobQueue, latestCanonicalBlockN
     }
   );
 };
+
+/**
+ * Method to fetch block by number and push to job queue.
+ * @param jobQueue
+ * @param indexer
+ * @param ethClient
+ * @param blockNumber
+ */
+export const processBlockByNumber = async (
+  jobQueue: JobQueue,
+  indexer: IndexerInterface,
+  ethClient: EthClient,
+  blockDelayInMilliSecs: number,
+  blockNumber: number
+): Promise<void> => {
+  log(`Process block ${blockNumber}`);
+
+  while (true) {
+    const result = await ethClient.getBlocksByNumber(blockNumber);
+    const { allEthHeaderCids: { nodes: blockNodes } } = result;
+
+    if (blockNodes.length) {
+      for (let bi = 0; bi < blockNodes.length; bi++) {
+        const { blockHash, blockNumber, parentHash, timestamp } = blockNodes[bi];
+        const blockProgress = await indexer.getBlockProgress(blockHash);
+
+        if (blockProgress) {
+          log(`Block number ${blockNumber}, block hash ${blockHash} already processed`);
+        } else {
+          await indexer.updateSyncStatusChainHead(blockHash, blockNumber);
+
+          await jobQueue.pushJob(QUEUE_BLOCK_PROCESSING, { kind: JOB_KIND_INDEX, blockHash, blockNumber, parentHash, timestamp });
+        }
+      }
+
+      return;
+    }
+
+    log(`No blocks fetched for block number ${blockNumber}, retrying after ${blockDelayInMilliSecs} ms delay.`);
+
+    await wait(blockDelayInMilliSecs);
+  }
+};

packages/util/src/config.ts

@@ -13,7 +13,7 @@ import { BaseProvider } from '@ethersproject/providers';
 import { Config as CacheConfig, getCache } from '@vulcanize/cache';
 import { EthClient } from '@vulcanize/ipld-eth-client';
 
-import { getCustomProvider } from './index';
+import { getCustomProvider } from './misc';
 
 const log = debug('vulcanize:config');
 
@@ -30,12 +30,13 @@ interface ServerConfig {
   kind: string;
 }
 
-interface UpstreamConfig {
+export interface UpstreamConfig {
   cache: CacheConfig,
   ethServer: {
     gqlApiEndpoint: string;
     gqlPostgraphileEndpoint: string;
-    rpcProviderEndpoint: string
+    rpcProviderEndpoint: string;
+    blockDelayInMilliSecs: number;
   }
   traceProviderEndpoint: string;
   uniWatcher: {

packages/util/src/events.ts

@@ -5,14 +5,14 @@
 import assert from 'assert';
 import debug from 'debug';
 import { PubSub } from 'apollo-server-express';
-import _ from 'lodash';
 
 import { EthClient } from '@vulcanize/ipld-eth-client';
 
 import { JobQueue } from './job-queue';
 import { BlockProgressInterface, EventInterface, IndexerInterface } from './types';
-import { QUEUE_BLOCK_PROCESSING, MAX_REORG_DEPTH, JOB_KIND_PRUNE, JOB_KIND_INDEX } from './constants';
-import { createPruningJob } from './common';
+import { MAX_REORG_DEPTH, JOB_KIND_PRUNE, JOB_KIND_INDEX } from './constants';
+import { createPruningJob, processBlockByNumber } from './common';
+import { UpstreamConfig } from './config';
 
 const log = debug('vulcanize:events');
 
@@ -20,13 +20,17 @@ export const BlockProgressEvent = 'block-progress-event';
 
 export class EventWatcher {
   _ethClient: EthClient
+  _postgraphileClient: EthClient
   _indexer: IndexerInterface
   _subscription?: ZenObservable.Subscription
   _pubsub: PubSub
   _jobQueue: JobQueue
+  _upstreamConfig: UpstreamConfig
 
-  constructor (ethClient: EthClient, indexer: IndexerInterface, pubsub: PubSub, jobQueue: JobQueue) {
+  constructor (upstreamConfig: UpstreamConfig, ethClient: EthClient, postgraphileClient: EthClient, indexer: IndexerInterface, pubsub: PubSub, jobQueue: JobQueue) {
+    this._upstreamConfig = upstreamConfig;
     this._ethClient = ethClient;
+    this._postgraphileClient = postgraphileClient;
     this._indexer = indexer;
     this._pubsub = pubsub;
     this._jobQueue = jobQueue;
@@ -36,14 +40,45 @@ export class EventWatcher {
     return this._pubsub.asyncIterator([BlockProgressEvent]);
   }
 
-  async blocksHandler (value: any): Promise<void> {
-    const { blockHash, blockNumber, parentHash, timestamp } = _.get(value, 'data.listen.relatedNode');
+  async stop (): Promise<void> {
+    if (this._subscription) {
+      log('Stopped watching upstream blocks');
+      this._subscription.unsubscribe();
+    }
+  }
 
-    await this._indexer.updateSyncStatusChainHead(blockHash, blockNumber);
+  async startBlockProcessing (): Promise<void> {
+    const syncStatus = await this._indexer.getSyncStatus();
+    let blockNumber;
 
-    log('watchBlock', blockHash, blockNumber);
+    if (!syncStatus) {
+      // Get latest block in chain.
+      const { block: currentBlock } = await this._ethClient.getBlockByHash();
+      blockNumber = currentBlock.number + 1;
+    } else {
+      blockNumber = syncStatus.latestIndexedBlockNumber + 1;
+    }
 
-    await this._jobQueue.pushJob(QUEUE_BLOCK_PROCESSING, { kind: JOB_KIND_INDEX, blockHash, blockNumber, parentHash, timestamp });
+    const { ethServer: { blockDelayInMilliSecs } } = this._upstreamConfig;
+
+    processBlockByNumber(this._jobQueue, this._indexer, this._postgraphileClient, blockDelayInMilliSecs, blockNumber + 1);
+
+    // Creating an AsyncIterable from AsyncIterator to iterate over the values.
+    // https://www.codementor.io/@tiagolopesferreira/asynchronous-iterators-in-javascript-jl1yg8la1#for-wait-of
+    const blockProgressEventIterable = {
+      // getBlockProgressEventIterator returns an AsyncIterator which can be used to listen to BlockProgress events.
+      [Symbol.asyncIterator]: this.getBlockProgressEventIterator.bind(this)
+    };
+
+    // Iterate over async iterable.
+    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for-await...of
+    for await (const data of blockProgressEventIterable) {
+      const { onBlockProgressEvent: { blockNumber, isComplete } } = data;
+
+      if (isComplete) {
+        processBlockByNumber(this._jobQueue, this._indexer, this._postgraphileClient, blockDelayInMilliSecs, blockNumber + 1);
+      }
+    }
   }
 
   async blockProcessingCompleteHandler (job: any): Promise<void> {
@@ -130,11 +165,4 @@ export class EventWatcher {
 
     await this._indexer.updateSyncStatusCanonicalBlock(block.blockHash, block.blockNumber);
   }
-
-  async stop (): Promise<void> {
-    if (this._subscription) {
-      log('Stopped watching upstream blocks');
-      this._subscription.unsubscribe();
-    }
-  }
 }

packages/util/src/fill.ts

@@ -2,22 +2,20 @@
 // Copyright 2021 Vulcanize, Inc.
 //
 
-import debug from 'debug';
 import assert from 'assert';
 
 import { EthClient } from '@vulcanize/ipld-eth-client';
 
 import { JobQueue } from './job-queue';
-import { JOB_KIND_INDEX, QUEUE_BLOCK_PROCESSING } from './constants';
 import { EventWatcherInterface, IndexerInterface } from './types';
-
-const log = debug('vulcanize:fill');
+import { processBlockByNumber } from './common';
 
 export const fillBlocks = async (
   jobQueue: JobQueue,
   indexer: IndexerInterface,
   ethClient: EthClient,
   eventWatcher: EventWatcherInterface,
+  blockDelayInMilliSecs: number,
   { startBlock, endBlock }: { startBlock: number, endBlock: number}
 ): Promise<any> => {
   assert(startBlock < endBlock, 'endBlock should be greater than startBlock');
@@ -36,7 +34,7 @@ export const fillBlocks = async (
     currentBlockNumber = syncStatus.latestIndexedBlockNumber + 1;
   }
 
-  processBlockByNumber(jobQueue, indexer, ethClient, currentBlockNumber);
+  processBlockByNumber(jobQueue, indexer, ethClient, blockDelayInMilliSecs, currentBlockNumber);
 
   // Creating an AsyncIterable from AsyncIterator to iterate over the values.
   // https://www.codementor.io/@tiagolopesferreira/asynchronous-iterators-in-javascript-jl1yg8la1#for-wait-of
@@ -57,39 +55,7 @@ export const fillBlocks = async (
       }
 
       currentBlockNumber++;
-      processBlockByNumber(jobQueue, indexer, ethClient, currentBlockNumber);
-    }
-  }
-};
-
-/**
- * Method to fetch block by number and push to job queue.
- * @param jobQueue
- * @param indexer
- * @param ethClient
- * @param blockNumber
- */
-const processBlockByNumber = async (
-  jobQueue: JobQueue,
-  indexer: IndexerInterface,
-  ethClient: EthClient,
-  blockNumber: number
-) => {
-  log(`Fill block ${blockNumber}`);
-
-  const result = await ethClient.getBlocksByNumber(blockNumber);
-  const { allEthHeaderCids: { nodes: blockNodes } } = result;
-
-  for (let bi = 0; bi < blockNodes.length; bi++) {
-    const { blockHash, blockNumber, parentHash, timestamp } = blockNodes[bi];
-    const blockProgress = await indexer.getBlockProgress(blockHash);
-
-    if (blockProgress) {
-      log(`Block number ${blockNumber}, block hash ${blockHash} already known, skip filling`);
-    } else {
-      await indexer.updateSyncStatusChainHead(blockHash, blockNumber);
-
-      await jobQueue.pushJob(QUEUE_BLOCK_PROCESSING, { kind: JOB_KIND_INDEX, blockHash, blockNumber, parentHash, timestamp });
+      processBlockByNumber(jobQueue, indexer, ethClient, blockDelayInMilliSecs, currentBlockNumber);
     }
   }
 };

packages/util/src/indexer.ts

@@ -34,8 +34,8 @@ export class Indexer {
   constructor (db: DatabaseInterface, ethClient: EthClient, ethProvider: ethers.providers.BaseProvider) {
     this._db = db;
     this._ethClient = ethClient;
-    this._getStorageAt = this._ethClient.getStorageAt.bind(this._ethClient);
     this._ethProvider = ethProvider;
+    this._getStorageAt = this._ethClient.getStorageAt.bind(this._ethClient);
   }
 
   async getSyncStatus (): Promise<SyncStatusInterface | undefined> {

packages/util/src/job-runner.ts

@@ -4,7 +4,7 @@
 
 import assert from 'assert';
 import debug from 'debug';
-import { wait } from '.';
+import { wait } from './misc';
 import { createPruningJob } from './common';
 
 import { JobQueueConfig } from './config';
@@ -20,9 +20,9 @@ export class JobRunner {
   _jobQueueConfig: JobQueueConfig
 
   constructor (jobQueueConfig: JobQueueConfig, indexer: IndexerInterface, jobQueue: JobQueue) {
+    this._jobQueueConfig = jobQueueConfig;
     this._indexer = indexer;
     this._jobQueue = jobQueue;
-    this._jobQueueConfig = jobQueueConfig;
   }
 
   async processBlock (job: any): Promise<void> {