evm: promisify async opFns (#491)

lib/evm/eei.js

@@ -1,3 +1,4 @@
+const promisify = require('util.promisify')
 const BN = require('bn.js')
 const { VmError, ERROR } = require('../exceptions')
 const PStateManager = require('../state/promisified')
@@ -34,21 +35,17 @@ module.exports = class EEI {
    * Returns balance of the given account.
    * @param {BN} address - Address of account
    */
-  getExternalBalance (address, cb) {
+  async getExternalBalance (address) {
     address = addressToBuffer(address)
 
     // shortcut if current account
     if (address.toString('hex') === this._env.address.toString('hex')) {
-      return cb(null, new BN(this._env.contract.balance))
+      return new BN(this._env.contract.balance)
     }
 
     // otherwise load account then return balance
-    this._env.stateManager.getAccount(address, (err, account) => {
-      if (err) {
-        return cb(err, null)
-      }
-      cb(null, new BN(account.balance))
-    })
+    const account = await this._state.getAccount(address)
+    return new BN(account.balance)
   }
 
   /**
@@ -111,26 +108,22 @@ module.exports = class EEI {
   /**
    * Get size of an account’s code.
    * @param {BN} address - Address of account
-   * @param {function} cb
    */
-  getExternalCodeSize (address, cb) {
+  async getExternalCodeSize (address) {
     address = addressToBuffer(address)
-    this._env.stateManager.getContractCode(address, (err, code) => {
-      if (err) return cb(err)
-      cb(null, new BN(code.length))
-    })
+    const code = await this._state.getContractCode(address)
+    return new BN(code.length)
   }
 
   /**
    * Returns  code of an account.
    * @param {BN} address - Address of account
-   * @param {function} cb
    */
-  getExternalCode (address, cb) {
+  async getExternalCode (address) {
     if (!Buffer.isBuffer(address)) {
       address = addressToBuffer(address)
     }
-    this._env.stateManager.getContractCode(address, cb)
+    return this._state.getContractCode(address)
   }
 
   /**
@@ -214,38 +207,30 @@ module.exports = class EEI {
   /**
    * Returns Gets the hash of one of the 256 most recent complete blocks.
    * @param {BN} - Number of block
-   * @param {function} cb
    */
-  getBlockHash (number, cb) {
-    this._env.blockchain.getBlock(number, (err, block) => {
-      if (err) return cb(err)
-      const blockHash = new BN(block.hash())
-      cb(null, blockHash)
-    })
+  async getBlockHash (number) {
+    const block = await promisify(this._env.blockchain.getBlock).bind(this._env.blockchain)(number)
+    return new BN(block.hash())
   }
 
   /**
    * Store 256-bit a value in memory to persistent storage.
    * @param {Buffer} key
    * @param {Buffer} value
    */
-  storageStore (key, value, cb) {
-    this._state.putContractStorage(this._env.address, key, value)
-      .then(() => this._state.getAccount(this._env.address))
-      .then((account) => {
-        this._env.contract = account
-        cb(null)
-      })
-      .catch(cb)
+  async storageStore (key, value) {
+    await this._state.putContractStorage(this._env.address, key, value)
+    const account = await this._state.getAccount(this._env.address)
+    this._env.contract = account
   }
 
   /**
    * Loads a 256-bit value to memory from persistent storage.
    * @param {Buffer} key - Storage key
    * @returns {Buffer}
    */
-  storageLoad (key, cb) {
-    this._env.stateManager.getContractStorage(this._env.address, key, cb)
+  async storageLoad (key) {
+    return this._state.getContractStorage(this._env.address, key)
   }
 
   /**
@@ -280,8 +265,8 @@ module.exports = class EEI {
    * execution will be aborted immediately.
    * @param {Buffer} toAddress - Beneficiary address
    */
-  selfDestruct (toAddress, cb) {
-    this._selfDestruct(toAddress).then(() => cb(null)).catch(cb)
+  async selfDestruct (toAddress) {
+    return this._selfDestruct(toAddress)
   }
 
   async _selfDestruct (toAddress) {
@@ -343,15 +328,8 @@ module.exports = class EEI {
    * @param {Buffer} address
    * @param {BN} value
    * @param {Buffer} data
-   * @param {Function} cb
    */
-  call (gasLimit, address, value, data, cb) {
-    this._call(gasLimit, address, value, data)
-      .then((ret) => cb(null, ret))
-      .catch((err) => cb(err, null))
-  }
-
-  async _call (gasLimit, address, value, data) {
+  async call (gasLimit, address, value, data) {
     const msg = new Message({
       caller: this._env.address,
       gasLimit: gasLimit,
@@ -371,15 +349,8 @@ module.exports = class EEI {
    * @param {Buffer} address
    * @param {BN} value
    * @param {Buffer} data
-   * @param {Function} cb
    */
-  callCode (gasLimit, address, value, data, cb) {
-    this._callCode(gasLimit, address, value, data)
-      .then((ret) => cb(null, ret))
-      .catch((err) => cb(err, null))
-  }
-
-  async _callCode (gasLimit, address, value, data) {
+  async callCode (gasLimit, address, value, data) {
     let { compiled, code } = await this._getCode(address)
 
     const msg = new Message({
@@ -405,15 +376,8 @@ module.exports = class EEI {
    * @param {Buffer} address
    * @param {BN} value
    * @param {Buffer} data
-   * @param {Function} cb
    */
-  callStatic (gasLimit, address, value, data, cb) {
-    this._callStatic(gasLimit, address, value, data)
-      .then((ret) => cb(null, ret))
-      .catch((err) => cb(err, null))
-  }
-
-  async _callStatic (gasLimit, address, value, data) {
+  async callStatic (gasLimit, address, value, data) {
     const msg = new Message({
       caller: this._env.address,
       gasLimit: gasLimit,
@@ -434,15 +398,8 @@ module.exports = class EEI {
    * @param {Buffer} address
    * @param {BN} value
    * @param {Buffer} data
-   * @param {Function} cb
    */
-  callDelegate (gasLimit, address, value, data, cb) {
-    this._callDelegate(gasLimit, address, value, data)
-      .then((ret) => cb(null, ret))
-      .catch((err) => cb(err, null))
-  }
-
-  async _callDelegate (gasLimit, address, value, data) {
+  async callDelegate (gasLimit, address, value, data) {
     let { compiled, code } = await this._getCode(address)
 
     const msg = new Message({
@@ -522,15 +479,8 @@ module.exports = class EEI {
    * @param {BN} gasLimit
    * @param {BN} value
    * @param {Buffer} data
-   * @param {Function} cb
    */
-  create (gasLimit, value, data, cb) {
-    this._create(gasLimit, value, data)
-      .then((ret) => cb(null, ret))
-      .catch((err) => cb(err, null))
-  }
-
-  async _create (gasLimit, value, data, salt = null) {
+  async create (gasLimit, value, data, salt = null) {
     const selfdestruct = Object.assign({}, this._env.selfdestruct)
     const msg = new Message({
       caller: this._env.address,
@@ -599,12 +549,9 @@ module.exports = class EEI {
    * @param {BN} value
    * @param {Buffer} data
    * @param {Buffer} salt
-   * @param {Function} cb
    */
-  create2 (gasLimit, value, data, salt, cb) {
-    this._create(gasLimit, value, data, salt)
-      .then((ret) => cb(null, ret))
-      .catch((err) => cb(err, null))
+  async create2 (gasLimit, value, data, salt) {
+    return this.create(gasLimit, value, data, salt)
   }
 }
 

lib/evm/loop.js

@@ -136,34 +136,16 @@ module.exports = class Loop {
     runState.static = prevStatic
   }
 
-  handleOp (runState, opInfo) {
-    return new Promise((resolve, reject) => {
-      const opFn = this.getOpHandler(opInfo)
-      let args = [runState]
-      // create a callback for async opFunc
-      if (opInfo.async) {
-        args.push((err) => {
-          if (err) return reject(err)
-          return resolve()
-        })
-      }
-
-      try {
-        // run the opcode
-        opFn.apply(null, args)
-      } catch (e) {
-        if (e.errorType && e.errorType === 'VmError') {
-          return reject(e)
-        } else {
-          throw e
-        }
-      }
+  async handleOp (runState, opInfo) {
+    const opFn = this.getOpHandler(opInfo)
+    let args = [runState]
 
-      // call the callback if opFn was sync
-      if (!opInfo.async) {
-        return resolve()
-      }
-    })
+    // run the opcode
+    if (opInfo.async) {
+      await opFn.apply(null, args)
+    } else {
+      opFn.apply(null, args)
+    }
   }
 
   getOpHandler (opInfo) {