Introduce extractor for TransformedERC20 events (#372)

Author: cbovis

config/default.js

@@ -24,6 +24,9 @@ module.exports = {
     logFill: {
       v1: 4145578,
     },
+    transformedErc20: {
+      v3: 10247094,
+    },
   },
   web3: {
     endpoint: process.env.WEB3_ENDPOINT,

packages/core/package.json

@@ -7,6 +7,7 @@
     "@0x-event-extractor/fill-extractor-v2": "^1.0.0",
     "@0x-event-extractor/fill-extractor-v3": "^1.0.0",
     "@0x-event-extractor/shared": "^1.0.0",
+    "@0x-event-extractor/transformed-erc20-extractor": "^1.0.0",
     "@bugsnag/js": "6.5.2",
     "bugsnag": "^2.4.3",
     "delay": "^4.3.0",

packages/core/src/jobs/extract-events.js

@@ -1,6 +1,7 @@
 const fillExtractorV1 = require('@0x-event-extractor/fill-extractor-v1');
 const fillExtractorV2 = require('@0x-event-extractor/fill-extractor-v2');
 const fillExtractorV3 = require('@0x-event-extractor/fill-extractor-v3');
+const transformedERC20Extractor = require('@0x-event-extractor/transformed-erc20-extractor');
 
 const { getLogger } = require('../util/logging');
 const BlockRange = require('../model/block-range');
@@ -109,6 +110,7 @@ const extractEvents = async () => {
   await performExtraction(currentBlock, fillExtractorV1);
   await performExtraction(currentBlock, fillExtractorV2);
   await performExtraction(currentBlock, fillExtractorV3);
+  await performExtraction(currentBlock, transformedERC20Extractor);
 
   logger.info('finished event extraction');
 };

packages/shared/src/web3.js

@@ -4,7 +4,6 @@ const { providerUtils } = require('@0x/utils');
 
 let wrapper;
 let providerEngine;
-
 /**
  * Initializes a web3 provider engine and create a reusable web3 wrapper. The
  * singletons can be accessed via getProviderEngine and getWrapper respectively.
@@ -16,11 +15,57 @@ const configure = ({ endpoint }) => {
   providerEngine = new Web3ProviderEngine();
   wrapper = new Web3Wrapper(providerEngine);
 
+  wrapper.abiDecoder.addABI([
+    {
+      anonymous: false,
+      inputs: [
+        {
+          indexed: true,
+          internalType: 'address',
+          name: 'taker',
+          type: 'address',
+        },
+        {
+          indexed: false,
+          internalType: 'address',
+          name: 'inputToken',
+          type: 'address',
+        },
+        {
+          indexed: false,
+          internalType: 'address',
+          name: 'outputToken',
+          type: 'address',
+        },
+        {
+          indexed: false,
+          internalType: 'uint256',
+          name: 'inputTokenAmount',
+          type: 'uint256',
+        },
+        {
+          indexed: false,
+          internalType: 'uint256',
+          name: 'outputTokenAmount',
+          type: 'uint256',
+        },
+      ],
+      name: 'TransformedERC20',
+      type: 'event',
+    },
+  ]);
+
   providerEngine.addProvider(new RPCSubprovider(endpoint));
   providerUtils.startProviderEngine(providerEngine);
 };
 
+/**
+ * Get the current global web3 wrapper instance.
+ *
+ * @returns {Web3Wrapper}
+ */
 const getWrapper = () => wrapper;
+
 const getProviderEngine = () => providerEngine;
 
 module.exports = { configure, getProviderEngine, getWrapper };

packages/transformed-erc20-extractor/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "@0x-event-extractor/transformed-erc20-extractor",
+  "description": "Extractor for exchange proxy ERC20 transform events",
+  "version": "1.0.0",
+  "main": "src/index.js",
+  "dependencies": {
+    "@0x-event-extractor/shared": "^1.0.0"
+  }
+}

packages/transformed-erc20-extractor/src/fetch-log-entries.js

@@ -0,0 +1,18 @@
+const { web3 } = require('@0x-event-extractor/shared');
+
+const EXCHANGE_PROXY_ADDRESS = '0xdef1c0ded9bec7f1a1670819833240f027b25eff';
+const TRANSFORMED_ERC20_EVENT_TOPIC =
+  '0x0f6672f78a59ba8e5e5b5d38df3ebc67f3c792e2c9259b8d97d7f00dd78ba1b3';
+
+const fetchEvents = async (fromBlock, toBlock) => {
+  const logs = await web3.getWrapper().getLogsAsync({
+    address: EXCHANGE_PROXY_ADDRESS,
+    fromBlock,
+    toBlock,
+    topics: [TRANSFORMED_ERC20_EVENT_TOPIC],
+  });
+
+  return logs;
+};
+
+module.exports = fetchEvents;

packages/transformed-erc20-extractor/src/get-event-data.js

@@ -0,0 +1,25 @@
+const { web3 } = require('@0x-event-extractor/shared');
+
+const getEventData = logEntry => {
+  const decoded = web3.getWrapper().abiDecoder.tryToDecodeLogOrNoop(logEntry);
+
+  const {
+    inputToken,
+    inputTokenAmount,
+    outputToken,
+    outputTokenAmount,
+    taker,
+  } = decoded.args;
+
+  const eventData = {
+    inputToken,
+    inputTokenAmount: inputTokenAmount.toString(),
+    outputToken,
+    outputTokenAmount: outputTokenAmount.toString(),
+    taker,
+  };
+
+  return eventData;
+};
+
+module.exports = getEventData;

packages/transformed-erc20-extractor/src/index.js

@@ -0,0 +1,10 @@
+const fetchLogEntries = require('./fetch-log-entries');
+const getEventData = require('./get-event-data');
+
+module.exports = {
+  configure: () => {},
+  eventType: 'TransformedERC20',
+  fetchLogEntries,
+  getEventData,
+  protocolVersion: 3,
+};