From d8373b227b2ca94c29ea6e29546bef20d2a35867 Mon Sep 17 00:00:00 2001
From: yann300 <yann.levreau@gmail.com>
Date: Wed, 16 Nov 2016 17:33:28 +0100
Subject: [PATCH] implement int, uint decoding

---
 src/solidity/types/Int.js  | 20 +++++++++++++++++++-
 src/solidity/types/Uint.js | 11 ++++++++++-
 src/solidity/types/util.js | 13 +++++++++++++
 3 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 src/solidity/types/util.js

diff --git a/src/solidity/types/Int.js b/src/solidity/types/Int.js
index 25df4c7f33..7604532466 100644
--- a/src/solidity/types/Int.js
+++ b/src/solidity/types/Int.js
@@ -1,4 +1,7 @@
 'use strict'
+var util = require('./util')
+var BN = require('ethereumjs-util').BN
+var ethutil = require('ethereumjs-util')
 
 function Int (storageBytes) {
   this.storageSlots = 1
@@ -7,7 +10,22 @@ function Int (storageBytes) {
 }
 
 Int.prototype.decodeFromStorage = function (location, storageContent) {
-  return '<not implemented yet>'
+  var slot = ethutil.bufferToHex(ethutil.setLengthLeft(location.slot, 32))
+  if (!storageContent[slot]) {
+    return '0'
+  }
+  var value = util.extractValue(storageContent[slot], this.storageBytes, location)
+  var bigNumber = new BN(value.replace('0x', ''), 16)
+  if (isNegative(bigNumber, this.storageBytes)) {
+    return ethutil.fromSigned(ethutil.toUnsigned(bigNumber)).toString(10)
+  } else {
+    return bigNumber.toString(10)
+  }
 }
 
 module.exports = Int
+
+function isNegative (value, storageBytes) {
+  var binary = value.toString(2)
+  return binary.length < storageBytes ? false : binary[0] === '1'
+}
diff --git a/src/solidity/types/Uint.js b/src/solidity/types/Uint.js
index b80d336791..1b59b693f3 100644
--- a/src/solidity/types/Uint.js
+++ b/src/solidity/types/Uint.js
@@ -1,4 +1,7 @@
 'use strict'
+var util = require('./util')
+var ethutil = require('ethereumjs-util')
+var BN = require('ethereumjs-util').BN
 
 function Uint (storageBytes) {
   this.storageSlots = 1
@@ -7,7 +10,13 @@ function Uint (storageBytes) {
 }
 
 Uint.prototype.decodeFromStorage = function (location, storageContent) {
-  return '<not implemented yet>'
+  var slot = ethutil.bufferToHex(ethutil.setLengthLeft(location.slot, 32))
+  if (!storageContent[slot]) {
+    return '0'
+  }
+  var value = util.extractValue(storageContent[slot], this.storageBytes, location)
+  var bigNumber = new BN(value.replace('0x', ''), 16)
+  return bigNumber.toString(10)
 }
 
 module.exports = Uint
diff --git a/src/solidity/types/util.js b/src/solidity/types/util.js
new file mode 100644
index 0000000000..e4070cc9d3
--- /dev/null
+++ b/src/solidity/types/util.js
@@ -0,0 +1,13 @@
+module.exports = {
+  extractValue: function (slotValue, storageBytes, location) {
+    slotValue = slotValue.replace('0x', '')
+    var offset = slotValue.length - 2 * location.offset - storageBytes / 4
+    if (offset >= 0) {
+      return '0x' + slotValue.substr(offset, storageBytes / 4)
+    } else if (offset + storageBytes > 0) {
+      return '0x' + slotValue.substr(0, storageBytes / 4 + offset)
+    } else {
+      return '0x0'
+    }
+  }
+}