Merge pull request #65 from hlongvu/master

Add version number to block
alexdovzhanyn · Nov 11, 2018 · 2b87c9d · 2b87c9d
2 parents 17ca0a7 + 1134cb0
commit 2b87c9d
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Showing 5 changed files with 368 additions and 314 deletions.
diff --git a/lib/block.ex b/lib/block.ex
@@ -11,6 +11,7 @@ defmodule Elixium.Blockchain.Block do
 
   defstruct index: nil,
             hash: nil,
+            version: 1,
             previous_hash: nil,
             difficulty: nil,
             nonce: 0,
@@ -31,9 +32,9 @@ defmodule Elixium.Blockchain.Block do
   """
   @spec initialize :: Block
   def initialize do
-    %Block{
+    block = %Block{
       index: 0,
-      hash: "79644A8F062F1BA9F7A32AF2242C04711A634D42F0628ADA6B985B3D21296EEA",
+      hash: "",
       difficulty: 5.0,
       timestamp: DateTime.utc_now() |> DateTime.to_string(),
       transactions: [
@@ -50,6 +51,9 @@ defmodule Elixium.Blockchain.Block do
         }
       ]
     }
+
+    %{block | hash: calculate_block_hash(block)}
+
   end
 
   @doc """
@@ -60,12 +64,35 @@ defmodule Elixium.Blockchain.Block do
   def initialize(%{index: index, hash: previous_hash}) do
     %Block{
       index: index + 1,
+      version: 1,
       previous_hash: previous_hash,
       difficulty: 4.0,
       timestamp: DateTime.utc_now() |> DateTime.to_string()
     }
   end
 
+
+  @spec calculate_block_hash(Block) :: String.t()
+  def calculate_block_hash(block) do
+    %{
+      index: index,
+      version: version,
+      previous_hash: previous_hash,
+      timestamp: timestamp,
+      nonce: nonce,
+      merkle_root: merkle_root
+    } = block
+
+    Utilities.sha3_base16([
+      Integer.to_string(index),
+      Integer.to_string(version),
+      previous_hash,
+      timestamp,
+      Integer.to_string(nonce),
+      merkle_root
+    ])
+  end
+
   @doc """
     The process of mining consists of hashing the index of the block, the hash
     of the previous block (thus linking the current and previous block), the
@@ -77,22 +104,9 @@ defmodule Elixium.Blockchain.Block do
   """
   @spec mine(Block) :: Block
   def mine(block) do
-    %{
-      index: index,
-      previous_hash: previous_hash,
-      timestamp: timestamp,
-      nonce: nonce,
-      merkle_root: merkle_root
-    } = block
+    %{nonce: nonce } = block
 
-    block =
-      Map.put(block, :hash, Utilities.sha3_base16([
-        Integer.to_string(index),
-        previous_hash,
-        timestamp,
-        Integer.to_string(nonce),
-        merkle_root
-      ]))
+    block = Map.put(block, :hash, calculate_block_hash(block))
 
     if hash_beat_target?(block) do
       block
@@ -109,6 +123,7 @@ defmodule Elixium.Blockchain.Block do
     %{
       hash: block.hash,
       index: block.index,
+      version: block.version,
       previous_hash: block.previous_hash,
       merkle_root: block.merkle_root,
       nonce: block.nonce,

diff --git a/lib/validator.ex b/lib/validator.ex
@@ -38,7 +38,7 @@ defmodule Elixium.Validator do
 
   @spec valid_hash?(Block, number) :: :ok | {:error, {:wrong_hash, {:too_high, String.t(), number}}}
   defp valid_hash?(b, difficulty) do
-    with :ok <- compare_hash({b.index, b.previous_hash, b.timestamp, b.nonce, b.merkle_root}, b.hash),
+    with :ok <- compare_hash({b.index, b.version, b.previous_hash, b.timestamp, b.nonce, b.merkle_root}, b.hash),
          :ok <- beat_target?(b.hash, b.difficulty)
          do
       :ok
@@ -55,11 +55,11 @@ defmodule Elixium.Validator do
     end
   end
 
-  @spec compare_hash({number, String.t(), String.t(), number, String.t()}, String.t()) ::
+  @spec compare_hash({number, number, String.t(), String.t(), number, String.t()}, String.t()) ::
           :ok | {:error, {:wrong_hash, {:doesnt_match_provided, String.t(), String.t()}}}
-  defp compare_hash({index, previous_hash, timestamp, nonce, merkle_root}, hash) do
+  defp compare_hash({index, version, previous_hash, timestamp, nonce, merkle_root}, hash) do
     computed =
-      [Integer.to_string(index), previous_hash, timestamp, Integer.to_string(nonce), merkle_root]
+      [Integer.to_string(index), Integer.to_string(version), previous_hash, timestamp, Integer.to_string(nonce), merkle_root]
       |> Utilities.sha3_base16()
 
     if computed == hash do

diff --git a/test/block_test.exs b/test/block_test.exs
@@ -8,7 +8,8 @@ defmodule BlockTest do
     genesis = Block.initialize()
 
     assert genesis.index == 0
-    assert genesis.hash == "79644A8F062F1BA9F7A32AF2242C04711A634D42F0628ADA6B985B3D21296EEA"
+    assert genesis.hash == Block.calculate_block_hash(genesis)
+    assert genesis.version == 1
   end
 
   test "can create a new empty block" do
@@ -20,8 +21,10 @@ defmodule BlockTest do
 
     assert block.index == genesis.index + 1
     assert block.previous_hash == genesis.hash
+    assert block.version == 1
   end
 
+
   test "can mine a block" do
     genesis = Block.initialize()
 

diff --git a/test/blockchain_test.exs b/test/blockchain_test.exs
@@ -41,4 +41,13 @@ defmodule BlockchainTest do
 
     assert Blockchain.recalculate_difficulty() == 0
   end
+
+  test "chain.exs contains valid block hash" do
+    {chain, _} = Code.eval_file("test/fixtures/chain.exs")
+    ok = chain
+    |> Enum.map(& &1.hash == Block.calculate_block_hash(&1))
+    |> Enum.all?()
+    assert ok
+  end
+
 end