Merge pull request #645 from ethereum/eventListener

Event Decoder

src/app.js

@@ -7,7 +7,8 @@ var base64 = require('js-base64').Base64
 var swarmgw = require('swarmgw')
 var csjs = require('csjs-inject')
 var yo = require('yo-yo')
-var EventManager = require('ethereum-remix').lib.EventManager
+var remix = require('ethereum-remix')
+var EventManager = remix.lib.EventManager
 
 var UniversalDApp = require('./universal-dapp.js')
 var Remixd = require('./lib/remixd')
@@ -30,7 +31,9 @@ var EditorPanel = require('./app/editor-panel')
 var RighthandPanel = require('./app/righthand-panel')
 var examples = require('./app/example-contracts')
 var modalDialogCustom = require('./app/modal-dialog-custom')
-// var Txlistener = require('./app/txListener')
+var Txlistener = require('./app/txListener')
+var EventsDecoder = require('./app/eventsDecoder')
+var Web3VMProvider = remix.web3.web3VMProvider
 
 var css = csjs`
   html { box-sizing: border-box; }
@@ -748,26 +751,62 @@ function run () {
   node.insertBefore(staticanalysis.render(), node.childNodes[0])
 
   // ----------------- Tx listener -----------------
-  // Commented for now. will be used later.
+  // not used right now
-  /*
+
-  var txlistener = new Txlistener({
+  // TODO the following should be put in execution context
-    api: {
+  var web3VM = new Web3VMProvider()
-      web3: function () { return executionContext.web3() },
+  web3VM.setVM(executionContext.vm())
-      isVM: function () { return executionContext.isVM() },
+
-      vm: function () { return executionContext.vm() },
+  var currentWeb3 = function () {
-      contracts: function () {
+    return executionContext.isVM() ? web3VM : executionContext.web3()
+  }
+
+  var transactionReceiptResolver = {
+    _transactionReceipts: {},
+    resolve: function (tx, cb) {
+      if (this._transactionReceipts[tx.hash]) {
+        return cb(null, this._transactionReceipts[tx.hash])
+      }
+      currentWeb3().eth.getTransactionReceipt(tx.hash, (error, receipt) => {
+        if (!error) {
+          this._transactionReceipts[tx.hash] = receipt
+          cb(null, receipt)
+        } else {
+          cb(error)
+        }
+      })
+    }
+  }
+
+  var compiledContracts = function () {
     if (compiler.lastCompilationResult && compiler.lastCompilationResult.data) {
       return compiler.lastCompilationResult.data.contracts
     }
     return null
-      },
+  }
+
+  var txlistener = new Txlistener({
+    api: {
+      web3: function () { return currentWeb3() },
+      isVM: function () { return executionContext.isVM() },
+      contracts: compiledContracts,
       context: function () {
         return executionContext.getProvider()
+      },
+      resolveReceipt: function (tx, cb) {
+        transactionReceiptResolver.resolve(tx, cb)
       }
     },
     event: {
       executionContext: executionContext.event,
       udapp: udapp.event
+    }})
+
+  var eventsDecoder = new EventsDecoder({
+    api: {
+      resolveReceipt: function (tx, cb) {
+        transactionReceiptResolver.resolve(tx, cb)
+      }
     }
   })
 
@@ -777,15 +816,31 @@ function run () {
     var resolvedTransaction = txlistener.resolvedTransaction(tx.hash)
     var address = null
     if (resolvedTransaction) {
+      var resolvedContract
       address = resolvedTransaction.contractAddress ? resolvedTransaction.contractAddress : tx.to
-    }
+      resolvedContract = txlistener.resolvedContract(address)
+      if (resolvedContract) {
+        eventsDecoder.parseLogs(tx, resolvedContract, compiledContracts(), (error, log) => {
+          console.log({
+            tx: tx,
+            resolvedTransaction: resolvedTransaction,
+            resolvedContract: resolvedContract,
+            resolvedEvents: (!error ? log : error)
+          })
+        })
+      } else {
         console.log({
           tx: tx,
-      resolvedContract: txlistener.resolvedContract(address),
           resolvedTransaction: resolvedTransaction
         })
+      }
+    } else {
+      // contract unknown - just displaying raw tx.
+      console.log({
+        tx: tx
+      })
+    }
   })
-  */
 
   // ----------------- autoCompile -----------------
   var autoCompile = document.querySelector('#autoCompile').checked

src/app/eventsDecoder.js

@@ -0,0 +1,77 @@
+'use strict'
+var ethJSABI = require('ethereumjs-abi')
+
+/**
+  * Register to txListener and extract events
+  *
+  */
+class EventsDecoder {
+  constructor (opt = {}) {
+    this._api = opt.api
+  }
+
+/**
+  * use Transaction Receipt to decode logs. assume that the transaction as already been resolved by txListener.
+  * logs are decoded only if the contract if known by remix.
+  *
+  * @param {Object} tx - transaction object
+  * @param {Function} cb - callback
+  */
+  parseLogs (tx, contractName, compiledContracts, cb) {
+    this._api.resolveReceipt(tx, (error, receipt) => {
+      if (error) cb(error)
+      this._decodeLogs(tx, receipt, contractName, compiledContracts, cb)
+    })
+  }
+
+  _decodeLogs (tx, receipt, contract, contracts, cb) {
+    if (!contract || !receipt) {
+      return cb('cannot decode logs - contract or receipt not resolved ')
+    }
+    if (!receipt.logs) {
+      return cb(null, [])
+    }
+    this._decodeEvents(tx, receipt.logs, contract, contracts, cb)
+  }
+
+  _eventABI (contractName, compiledContracts) {
+    var contractabi = JSON.parse(compiledContracts[contractName].interface)
+    var eventABI = {}
+    contractabi.forEach(function (funABI, i) {
+      if (funABI.type !== 'event') {
+        return
+      }
+      var hash = ethJSABI.eventID(funABI.name, funABI.inputs.map(function (item) { return item.type }))
+      eventABI[hash.toString('hex')] = { event: funABI.name, inputs: funABI.inputs }
+    })
+    return eventABI
+  }
+
+  _decodeEvents (tx, logs, contractName, compiledContracts, cb) {
+    var eventABI = this._eventABI(contractName, compiledContracts)
+    // FIXME: support indexed events
+    var events = []
+    for (var i in logs) {
+      // [address, topics, mem]
+      var log = logs[i]
+      var event
+      var decoded
+
+      try {
+        var abi = eventABI[log.topics[0].replace('0x', '')]
+        event = abi.event
+        var types = abi.inputs.map(function (item) {
+          return item.type
+        })
+        decoded = ethJSABI.rawDecode(types, new Buffer(log.data.replace('0x', ''), 'hex'))
+        decoded = ethJSABI.stringify(types, decoded)
+      } catch (e) {
+        decoded = log.data
+      }
+      events.push({ event: event, args: decoded })
+    }
+    cb(null, events)
+  }
+}
+
+module.exports = EventsDecoder

src/app/txListener.js

@@ -5,7 +5,6 @@ var ethJSUtil = require('ethereumjs-util')
 var EventManager = require('ethereum-remix').lib.EventManager
 var remix = require('ethereum-remix')
 var codeUtil = remix.util.code
-var Web3VMProvider = remix.web3.web3VMProvider
 
 /**
   * poll web3 each 2s if web3
@@ -18,8 +17,6 @@ class TxListener {
   constructor (opt) {
     this.event = new EventManager()
     this._api = opt.api
-    this._web3VMProvider = new Web3VMProvider() // TODO this should maybe be put in app.js
-    this._web3VMProvider.setVM(opt.api.vm())
     this._resolvedTransactions = {}
     this._resolvedContracts = {}
     this.init()
@@ -30,7 +27,7 @@ class TxListener {
     })
     opt.event.udapp.register('transactionExecuted', (to, data, lookupOnly, txResult) => {
       if (this.loopId && this._api.isVM()) {
-        this._web3VMProvider.getTransaction(txResult.transactionHash, (error, tx) => {
+        this._api.web3().eth.getTransaction(txResult.transactionHash, (error, tx) => {
           if (error) return console.log(error)
           this._newBlock({
             type: 'VM',
@@ -64,6 +61,7 @@ class TxListener {
     } else {
       this.loopId = setInterval(() => {
         this._api.web3().eth.getBlockNumber((error, blockNumber) => {
+          if (this.loopId === null || this.loopId === 'vm-listener') return
           if (error) return console.log(error)
           if (!this.lastBlock || blockNumber > this.lastBlock) {
             this.lastBlock = blockNumber
@@ -78,10 +76,6 @@ class TxListener {
     }
   }
 
-  currentWeb3 () { // TODO this should maybe be put in app.js
-    return this._api.isVM() ? this._web3VMProvider : this._api.web3()
-  }
-
   /**
     * stop listening for incoming transactions. do not reset the recorded pool.
     *
@@ -124,7 +118,9 @@ class TxListener {
 
   _resolve (block, callback) {
     async.each(block.transactions, (tx, cb) => {
-      this._resolveTx(tx, () => {
+      this._resolveTx(tx, (error, resolvedData) => {
+        if (error) cb(error)
+        if (resolvedData) this.event.trigger('txResolved', [tx, resolvedData])
         this.event.trigger('newTransaction', [tx])
         cb()
       })
@@ -144,14 +140,15 @@ class TxListener {
       var code = tx.input
       contractName = this._tryResolveContract(code, contracts, 'bytecode')
       if (contractName) {
-        this._resolveCreationAddress(tx, (error, address) => {
+        this._api.resolveReceipt(tx, (error, receipt) => {
           if (error) return cb(error)
+          var address = receipt.contractAddress
           this._resolvedContracts[address] = contractName
-          this._resolveFunction(contractName, contracts, tx, true)
+          var fun = this._resolveFunction(contractName, contracts, tx, true)
           if (this._resolvedTransactions[tx.hash]) {
             this._resolvedTransactions[tx.hash].contractAddress = address
           }
-          return cb()
+          return cb(null, {to: null, contractName: contractName, function: fun, creationAddress: address})
         })
         return
       }
@@ -160,13 +157,14 @@ class TxListener {
       // first check known contract, resolve against the `runtimeBytecode` if not known
       contractName = this._resolvedContracts[tx.to]
       if (!contractName) {
-        this.currentWeb3().eth.getCode(tx.to, (error, code) => {
+        this._api.web3().eth.getCode(tx.to, (error, code) => {
           if (error) return cb(error)
           if (code) {
             var contractName = this._tryResolveContract(code, contracts, 'runtimeBytecode')
             if (contractName) {
               this._resolvedContracts[tx.to] = contractName
-              this._resolveFunction(contractName, contracts, tx, false)
+              var fun = this._resolveFunction(contractName, contracts, tx, false)
+              return cb(null, {to: tx.to, contractName: contractName, function: fun})
             }
           }
           return cb()
@@ -174,22 +172,13 @@ class TxListener {
         return
       }
       if (contractName) {
-        this._resolveFunction(contractName, contracts, tx, false)
+        var fun = this._resolveFunction(contractName, contracts, tx, false)
+        return cb(null, {to: tx.to, contractName: contractName, function: fun})
       }
       return cb()
     }
   }
 
-  _resolveCreationAddress (tx, cb) {
-    this.currentWeb3().eth.getTransactionReceipt(tx.hash, (error, receipt) => {
-      if (!error) {
-        cb(null, receipt.contractAddress)
-      } else {
-        cb(error)
-      }
-    })
-  }
-
   _resolveFunction (contractName, compiledContracts, tx, isCtor) {
     var abi = JSON.parse(compiledContracts[contractName].interface)
     var inputData = tx.input.replace('0x', '')
@@ -222,6 +211,7 @@ class TxListener {
         params: params
       }
     }
+    return this._resolvedTransactions[tx.hash]
   }
 
   _tryResolveContract (codeToResolve, compiledContracts, type) {