Merge pull request #139 from ethereum/typeDecoder

Refactor computeoffsets()

src/solidity/astHelper.js

@@ -37,28 +37,37 @@ function getLinearizedBaseContracts (id, contractsById) {
   *
   * @param {String} contractName - contract for which state var should be resolved
   * @param {Object} sourcesList - sources list (containing root AST node)
-  * @return {Array} - return an array of AST node of all state variables (including inherited) (this will include all enum/struct declarations)
+  * @return {Object} - return an object containing: stateItems - list of all the children node of the @arg contractName
+  *                                                 stateVariables - list of all the variable declaration of the @arg contractName
   */
-function extractStateVariables (contractName, sourcesList) {
+function extractState (contractName, sourcesList) {
   var contracts = extractContractDefinitions(sourcesList)
   var node = contracts.contractsByName[contractName]
   if (node) {
+    var stateItems = []
     var stateVar = []
     var baseContracts = getLinearizedBaseContracts(node.id, contracts.contractsById)
     baseContracts.reverse()
     for (var k in baseContracts) {
       var ctr = baseContracts[k]
       for (var i in ctr.children) {
-        stateVar.push(ctr.children[i])
+        var item = ctr.children[i]
+        stateItems.push(item)
+        if (item.name === 'VariableDeclaration') {
+          stateVar.push(item)
+        }
       }
     }
-    return stateVar
+    return {
+      stateItems: stateItems,
+      stateVariables: stateVar
+    }
   }
   return null
 }
 
 module.exports = {
-  extractStateVariables: extractStateVariables,
+  extractState: extractState,
   extractContractDefinitions: extractContractDefinitions,
   getLinearizedBaseContracts: getLinearizedBaseContracts
 }

src/solidity/decodeInfo.js

@@ -164,28 +164,17 @@ function getEnum (type, stateDefinitions) {
   * @return {Array} containing all members of the current struct type
   */
 function getStructMembers (typeName, stateDefinitions) {
-  var members = []
-  var storageBytes = 0
   for (var k in stateDefinitions) {
     var dec = stateDefinitions[k]
     if (dec.name === 'StructDefinition' && typeName === dec.attributes.name) {
-      for (var i in dec.children) {
+      var offsets = computeOffsets(dec.children, stateDefinitions)
-        var member = dec.children[i]
+      return {
-        var decoded = parseType(member.attributes.type, stateDefinitions)
+        members: offsets.typesOffsets,
-        if (!decoded) {
+        storageSlots: offsets.endLocation.slot
-          console.log('unable to retrieve decode info of ' + member.attributes.type)
-          return null
-        }
-        members.push(decoded)
-        storageBytes += decoded.storageBytes
       }
-      break
     }
   }
-  return {
+  return null
-    members: members,
-    storageBytes: storageBytes
-  }
 }
 
 /**
@@ -233,8 +222,57 @@ function parseType (type, stateDefinitions) {
   return decodeInfos[currentType](type, stateDefinitions)
 }
 
+/**
+  * compute offset (slot offset and byte offset of the @arg list of types)
+  *
+  * @param {Array} types - list of types
+  * @param {Object} stateItems - all state definitions given by the AST (including struct and enum type declaration)
+  * @return {Array} - return an array of types item: {name, type, location}. location defines the byte offset and slot offset
+  */
+function computeOffsets (types, stateItems, cb) {
+  var ret = []
+  var location = {
+    offset: 0,
+    slot: 0
+  }
+  for (var i in types) {
+    var variable = types[i]
+    var type = parseType(variable.attributes.type, stateItems)
+    if (!type) {
+      console.log('unable to retrieve decode info of ' + variable.attributes.type)
+      return null
+    }
+    if (location.offset + type.storageBytes > 32) {
+      location.slot++
+      location.offset = 0
+    }
+    ret.push({
+      name: variable.attributes.name,
+      type: type,
+      location: {
+        offset: location.offset,
+        slot: location.slot
+      }
+    })
+    if (type.storageSlots === 1 && location.offset + type.storageBytes <= 32) {
+      location.offset += type.storageBytes
+    } else {
+      location.slot += type.storageSlots
+      location.offset = 0
+    }
+  }
+  if (location.offset > 0) {
+    location.slot++
+  }
+  return {
+    typesOffsets: ret,
+    endLocation: location
+  }
+}
+
 module.exports = {
   parseType: parseType,
+  computeOffsets: computeOffsets,
   Uint: Uint,
   Address: Address,
   Bool: Bool,

src/solidity/stateDecoder.js

@@ -25,40 +25,13 @@ function decodeState (stateVars, storageContent) {
   * @return {Object} - return the location of all contract variables in the storage
   */
 function extractStateVariables (contractName, sourcesList) {
-  var stateDefinitions = astHelper.extractStateVariables(contractName, sourcesList)
+  var state = astHelper.extractState(contractName, sourcesList)
   var ret = []
-  if (!stateDefinitions) {
+  if (!state) {
     return ret
   }
-  var location = {
+  var offsets = decodeInfo.computeOffsets(state.stateVariables, state.stateItems)
-    offset: 0,
+  return offsets.typesOffsets
-    slot: 0
-  }
-  for (var k in stateDefinitions) {
-    var variable = stateDefinitions[k]
-    if (variable.name === 'VariableDeclaration') {
-      var type = decodeInfo.parseType(variable.attributes.type, stateDefinitions)
-      if (location.offset + type.storageBytes > 32) {
-        location.slot++
-        location.offset = 0
-      }
-      ret.push({
-        name: variable.attributes.name,
-        type: type,
-        location: {
-          offset: location.offset,
-          slot: location.slot
-        }
-      })
-      if (type.storageSlots === 1 && location.offset + type.storageBytes <= 32) {
-        location.offset += type.storageBytes
-      } else {
-        location.slot += type.storageSlots
-        location.offset = 0
-      }
-    }
-  }
-  return ret
 }
 
 /**
@@ -79,4 +52,3 @@ module.exports = {
   extractStateVariables: extractStateVariables,
   decodeState: decodeState
 }
-

src/solidity/types/Struct.js

@@ -1,7 +1,7 @@
 'use strict'
 
 function Struct (memberDetails) {
-  this.storageSlots = Math.ceil(memberDetails.storageBytes / 32)
+  this.storageSlots = memberDetails.storageSlots
   this.storageBytes = 32
   this.members = memberDetails.members
   this.typeName = 'struct'

test/solidity/decodeInfo.js

@@ -8,7 +8,7 @@ tape('solidity', function (t) {
   t.test('astHelper, decodeInfo', function (st) {
     var output = compiler.compile(contracts, 0)
 
-    var stateDec = index.solidity.astHelper.extractStateVariables('contractUint', output.sources)
+    var stateDec = index.solidity.astHelper.extractState('contractUint', output.sources).stateItems
     var decodeInfo = index.solidity.decodeInfo.parseType(stateDec[0].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 1, 1, 'uint')
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[2].attributes.type, stateDec)
@@ -18,7 +18,7 @@ tape('solidity', function (t) {
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[4].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 1, 16, 'bytesX')
 
-    stateDec = index.solidity.astHelper.extractStateVariables('contractStructAndArray', output.sources)
+    stateDec = index.solidity.astHelper.extractState('contractStructAndArray', output.sources).stateItems
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[1].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 2, 32, 'struct')
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[2].attributes.type, stateDec)
@@ -26,7 +26,7 @@ tape('solidity', function (t) {
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[3].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 2, 32, 'array')
 
-    stateDec = index.solidity.astHelper.extractStateVariables('contractArray', output.sources)
+    stateDec = index.solidity.astHelper.extractState('contractArray', output.sources).stateItems
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[0].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 1, 32, 'array')
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[1].attributes.type, stateDec)
@@ -34,11 +34,11 @@ tape('solidity', function (t) {
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[2].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 4, 32, 'array')
 
-    stateDec = index.solidity.astHelper.extractStateVariables('contractEnum', output.sources)
+    stateDec = index.solidity.astHelper.extractState('contractEnum', output.sources).stateItems
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[1].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 1, 2, 'enum')
 
-    stateDec = index.solidity.astHelper.extractStateVariables('contractSmallVariable', output.sources)
+    stateDec = index.solidity.astHelper.extractState('contractSmallVariable', output.sources).stateItems
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[0].attributes.type, stateDec)
     checkDecodeInfo(st, decodeInfo, 1, 1, 'int')
     decodeInfo = index.solidity.decodeInfo.parseType(stateDec[1].attributes.type, stateDec)