Staking weight incorporation (#1264)

libs/ledger/include/ledger/chain/block.hpp

@@ -68,9 +68,11 @@ class Block
  Proof proof; ///< The consensus proof
  /// @}
 
+ // TODO(HUT): This should be part of body since it's no longer going to be metadata
+ uint64_t weight = 1;
+
  /// @name Metadata for block management
  /// @{
- uint64_t weight = 1;
  uint64_t total_weight = 1;
  bool is_loose = false;
  /// @}

libs/ledger/include/ledger/consensus/stake_manager.hpp

@@ -29,7 +29,7 @@ namespace ledger {
 class StakeSnapshot;
 class EntropyGeneratorInterface;
 
-class StakeManager : public StakeManagerInterface
+class StakeManager final : public StakeManagerInterface
 {
 public:
  using Committee = std::vector<Address>;
@@ -46,6 +46,7 @@ class StakeManager : public StakeManagerInterface
  void UpdateCurrentBlock(Block const &current) override;
  std::size_t GetBlockGenerationWeight(Block const &previous, Address const &address) override;
  bool ShouldGenerateBlock(Block const &previous, Address const &address) override;
+ bool ValidMinerForBlock(Block const &previous, Address const &address) override;
  /// @}
 
  // Accessors

libs/ledger/include/ledger/consensus/stake_manager_interface.hpp

@@ -39,6 +39,7 @@ class StakeManagerInterface
  virtual void UpdateCurrentBlock(Block const &current) = 0;
  virtual std::size_t GetBlockGenerationWeight(Block const &previous, Address const &address) = 0;
  virtual bool ShouldGenerateBlock(Block const &previous, Address const &address) = 0;
+ virtual bool ValidMinerForBlock(Block const &previous, Address const &address) = 0;
  /// @}
 
 private:

libs/ledger/src/chain/block_coordinator.cpp

@@ -417,6 +417,11 @@ BlockCoordinator::State BlockCoordinator::OnSynchronised(State current, State pr
  next_block_->body.block_number = current_block_->body.block_number + 1;
  next_block_->body.miner = mining_address_;
 
+ if (stake_)
+ {
+ next_block_->weight = stake_->GetBlockGenerationWeight(*current_block_, mining_address_);
+ }
+
  // Attach current DAG state
  if (dag_)
  {
@@ -469,6 +474,21 @@ BlockCoordinator::State BlockCoordinator::OnPreExecBlockValidation()
  return fail("No previous block in chain");
  }
 
+ // Check that the weight as given by the proof is correct
+ if (stake_)
+ {
+ if (!stake_->ValidMinerForBlock(*previous, current_block_->body.miner))
+ {
+ return fail("Block signed by miner deemed invalid by the staking mechanism");
+ }
+
+ if (current_block_->weight !=
+ stake_->GetBlockGenerationWeight(*previous, current_block_->body.miner))
+ {
+ return fail("Incorrect stake weight found for block");
+ }
+ }
+
  // Check: Ensure the block number is continuous
  uint64_t const expected_block_number = previous->body.block_number + 1u;
  if (expected_block_number != current_block_->body.block_number)

libs/ledger/src/chain/main_chain.cpp

@@ -106,13 +106,8 @@ BlockStatus MainChain::AddBlock(Block const &blk)
  // create a copy of the block
  auto block = std::make_shared<Block>(blk);
 
- // update the weight based on the proof and the number of transactions
- block->weight = 1;
+ // At this point we assume that the weight has been correctly set by the miner
  block->total_weight = 1;
- for (auto const &slice : block->body.slices)
- {
- block->weight += slice.size();
- }
 
  // pass the block to the
  auto const status = InsertBlock(block);

libs/ledger/src/consensus/stake_manager.cpp

@@ -176,5 +176,18 @@ void StakeManager::ResetInternal(StakeSnapshotPtr &&snapshot, std::size_t commit
  current_block_index_ = 0;
 }
 
+bool StakeManager::ValidMinerForBlock(Block const &previous, Address const &address)
+{
+ auto const committee = GetCommittee(previous);
+
+ if (!committee || committee->empty())
+ {
+ FETCH_LOG_WARN(LOGGING_NAME, "Unable to determine committee for block validation");
+ return false;
+ }
+
+ return std::find((*committee).begin(), (*committee).end(), address) != (*committee).end();
+}
+
 } // namespace ledger
 } // namespace fetch