// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.8.0 <0.9.0;

/// @title ExecutionTracker - A contract that keeps track of executed and invalidated hashes
contract ExecutionTracker {
  error HashAlreadyConsumed(bytes32);

  event HashExecuted(bytes32);
  event HashInvalidated(bytes32);

  mapping(address => mapping(bytes32 => bool)) public consumed;

  function invalidate(bytes32 hash) external {
    consumed[msg.sender][hash] = true;
    emit HashInvalidated(hash);
  }
}