JavaScript区块链挖矿模拟与性能分析

var difficulty = 5;        // 定义挖矿难度：哈希值开头所需'0'的个数
var maximumNonce = 50000000; // 设置最大nonce值，避免过长的挖矿时间

// 生成1到1000的输入数据
var inputs = [];
for (var i = 1; i <= 1000; i++) {
  inputs.push(i);
}

// 根据难度生成目标哈希模式
var pattern = '';
for (var x = 0; x < difficulty; x++) {
  pattern += '0';
}

// SHA256哈希函数
function sha256(block, chain) {
  return CryptoJS.SHA256(getText(block, chain));
}

// 更新区块状态
function updateState(block, chain) {
  if ($('#block' + block + 'chain' + chain + 'hash').val().substr(0, difficulty) === pattern) {
    $('#block' + block + 'chain' + chain + 'well').removeClass('well-error').addClass('well-success');
  } else {
    $('#block' + block + 'chain' + chain + 'well').removeClass('well-success').addClass('well-error');
  }
}

// 更新哈希值
function updateHash(block, chain) {
  $('#block' + block + 'chain' + chain + 'hash').val(sha256(block, chain));
  updateState(block, chain);
}

// 更新区块链
function updateChain(block, chain) {
  for (var x = block; x <= 5; x++) {
    if (x > 1) {
      $('#block' + x + 'chain' + chain + 'previous').val($('#block' + (x - 1).toString() + 'chain' + chain + 'hash').val());
    }
    updateHash(x, chain);
  }
}

// 挖矿函数
function mine(block, chain, isChain) {
  console.log('开始挖矿!');
  var t0 = performance.now();
  for (var x = 0; x <= maximumNonce; x++) {
    $('#block' + block + 'chain' + chain + 'nonce').val(x);
    $('#block' + block + 'chain' + chain + 'hash').val(sha256(block, chain));
    if ($('#block' + block + 'chain' + chain + 'hash').val().substr(0, difficulty) === pattern) {
      if (isChain) {
        updateChain(block, chain);
      } else {
        updateState(block, chain);
      }
      break;
    }
  }
  var t1 = performance.now();
  console.log('挖矿耗时：' + Math.floor(t1 - t0) + ' 毫秒');
  return Math.floor(t1 - t0);
}

// 执行300次挖矿，并统计平均时间
var totalTime = 0;
for (var i = 0; i < 300; i++) {
  for (var j = 0; j < 1000; j++) {
    $('#block1chain1data').val(inputs[j]);
    totalTime += mine(1, 1, false);
  }
}

var averageTime = totalTime / 300;
console.log('平均挖矿时间：' + averageTime + ' 毫秒');