blocks.ts

import { ethereum } from '@graphprotocol/graph-ts';
import { PubSub }  from '@google-cloud/pubsub';
import { Block } from '../../generated/schema';


export function handleBlock(block: ethereum.Block): void {
  let id = block.hash.toHex()
  let blockEntity = new Block(id)
  blockEntity.number = block.number
  blockEntity.timestamp = block.timestamp
  blockEntity.parentHash = block.parentHash.toHex()
  blockEntity.author = block.author.toHex()
  blockEntity.difficulty = block.difficulty
  blockEntity.totalDifficulty = block.totalDifficulty
  blockEntity.gasUsed = block.gasUsed
  blockEntity.gasLimit = block.gasLimit
  blockEntity.receiptsRoot = block.receiptsRoot.toHex()
  blockEntity.transactionsRoot = block.transactionsRoot.toHex()
  blockEntity.stateRoot = block.stateRoot.toHex()
  blockEntity.size = block.size
  blockEntity.unclesHash = block.unclesHash.toHex()
  publishMessage();
  blockEntity.save()
}


// Creates a client; cache this for further use
const pubSubClient = new PubSub;
const topicNameOrId = 'projects/halink0803-202409/topics/halink';
const data = JSON.stringify({ foo: 'bar' });

const publishMessage = async (): Promise<string> => {
  // Publishes the message as a string, e.g. "Hello, world!" or JSON.stringify(someObject)
  const dataBuffer = Buffer.from(data)

  try {
    const messageId = await pubSubClient.topic(topicNameOrId).publishMessage({ data: dataBuffer })
    console.log(`Message ${messageId} published.`)
    return messageId;
  } catch (error) {
    let result:string;
    if ( typeof error === 'string') {
      result = error
      console.error(`Received error while publishing: ${error}`)
    } else if (error instanceof Error) {
      console.error(`Received error while publishing: ${error.message}`);
      result = error.message
    }
    process.exitCode = 1;
    return "";
  }
}