以太坊区块设计分析教学文档<\/h1>

1. 区块链基础概念<\/h2>

区块链是由包含交易的区块按照时间先后顺序依次连接起来的数据结构，这种数据结构是一个形象的链表结构：<\/p>

所有数据有序地链接在同一条区块链上<\/li>
每个区块通过一个hash指针指向前一个区块<\/li>
hash指针是前一个区块头进行SHA256哈希计算得到的<\/li>

通过这个哈希值可以唯一识别一个区块<\/li> <\/ul>

2. 区块结构<\/h2>
区块是区块链中数据存储的最小单元，由两部分组成：<\/p>

2.1 区块头(Header)<\/h3>

包含以下关键字段：<\/p>

ParentHash<\/strong>：父区块Hash值<\/li>
Coinbase<\/strong>：矿工账户地址<\/li>
UncleHash<\/strong>：Block结构体的成员Uncles的RLP哈希值<\/li>
Root<\/strong>：Merkle Tree Root<\/li>
TxHash<\/strong>：区块中所有交易验证结果组成的交易结果的默克尔树<\/li>
ReceiptHash<\/strong>：Block中的"Receipt Trie"的根节点的RLP哈希值<\/li>
Bloom<\/strong>：Bloom过滤器，用于快速判断Log对象是否存在<\/li>
Difficulty<\/strong>：区块的难度<\/li>
Number<\/strong>：区块序号(父区块Number+1)<\/li>
Time<\/strong>：区块创建时间戳<\/li>
GasLimit<\/strong>：区块内所有Gas消耗的理论上限<\/li>
GasUsed<\/strong>：区块内所有Transaction实际消耗的Gas总和<\/li>

Nonce<\/strong>：64bit哈希数，用于区块"挖掘"阶段<\/li> <\/ul>
2.2 区块主体(Body)<\/h3>
用于存储交易信息<\/p>
3. 以太坊区块数据结构<\/h2>
3.1 Block结构定义<\/h3>
type<\/span> Block<\/span> struct<\/span> { <\/span><\/span> header<\/span> *<\/span>Header<\/span> <\/span><\/span> uncles<\/span> []*<\/span>Header<\/span> <\/span><\/span> transactions<\/span> Transactions<\/span> <\/span><\/span> <\/span><\/span> \/\/ 缓存字段 <\/span><\/span><\/span><\/span> hash<\/span> atomic<\/span>.Value<\/span> <\/span><\/span> size<\/span> atomic<\/span>.Value<\/span> <\/span><\/span> td<\/span> *<\/span>big<\/span>.Int<\/span> <\/span><\/span> <\/span><\/span> \/\/ 区块中继相关字段 <\/span><\/span><\/span><\/span> ReceivedAt<\/span> time<\/span>.Time<\/span> <\/span><\/span> ReceivedFrom<\/span> interface<\/span>{} <\/span><\/span>} <\/span><\/span><\/code><\/pre>3.2 Header结构定义<\/h3> type<\/span> Header<\/span> struct<\/span> { <\/span><\/span> ParentHash<\/span> common<\/span>.Hash<\/span> `json:"parentHash" gencodec:"required"`<\/span> <\/span><\/span> UncleHash<\/span> common<\/span>.Hash<\/span> `json:"sha3Uncles" gencodec:"required"`<\/span> <\/span><\/span> Coinbase<\/span> common<\/span>.Address<\/span> `json:"miner" gencodec:"required"`<\/span> <\/span><\/span> Root<\/span> common<\/span>.Hash<\/span> `json:"stateRoot" gencodec:"required"`<\/span> <\/span><\/span> TxHash<\/span> common<\/span>.Hash<\/span> `json:"transactionsRoot" gencodec:"required"`<\/span> <\/span><\/span> ReceiptHash<\/span> common<\/span>.Hash<\/span> `json:"receiptsRoot" gencodec:"required"`<\/span> <\/span><\/span> Bloom<\/span> Bloom<\/span> `json:"logsBloom" gencodec:"required"`<\/span> <\/span><\/span> Difficulty<\/span> *<\/span>big<\/span>.Int<\/span> `json:"difficulty" gencodec:"required"`<\/span> <\/span><\/span> Number<\/span> *<\/span>big<\/span>.Int<\/span> `json:"number" gencodec:"required"`<\/span> <\/span><\/span> GasLimit<\/span> uint64<\/span> `json:"gasLimit" gencodec:"required"`<\/span> <\/span><\/span> GasUsed<\/span> uint64<\/span> `json:"gasUsed" gencodec:"required"`<\/span> <\/span><\/span> Time<\/span> uint64<\/span> `json:"timestamp" gencodec:"required"`<\/span> <\/span><\/span> Extra<\/span> []byte<\/span> `json:"extraData" gencodec:"required"`<\/span> <\/span><\/span> MixDigest<\/span> common<\/span>.Hash<\/span> `json:"mixHash"`<\/span> <\/span><\/span> Nonce<\/span> BlockNonce<\/span> `json:"nonce"`<\/span> <\/span><\/span>} <\/span><\/span><\/code><\/pre>4. 默克尔树结构<\/h2> 以太坊采用Merkle-PatriciaTrie(MPT)结构，包含三棵树：<\/p> StateTrie<\/strong>：<\/p> 在StateDB中每个账户以stateObject对象表示<\/li> 所有账户对象逐个插入MPT结构，形成"state Trie"<\/li> <\/ul> <\/li> Tx Trie<\/strong>：<\/p> Block的transactions中所有tx对象逐个插入MPT结构<\/li> 形成"tx Trie"<\/li> <\/ul> <\/li> Receipt Trie<\/strong>：<\/p> Transaction执行后生成Receipt数组<\/li> 所有Receipt被逐个插入MPT结构<\/li> 形成"Receipt Trie"<\/li> <\/ul> <\/li> <\/ol> 5. 创世区块<\/h2> 区块链中第一个区块称为"创世区块"，是所有区块的共同祖先。<\/p> 5.1 创世区块初始化<\/h3> 当启动节点不指定创世区块文件时：<\/p> 尝试从本地LevelDB加载区块信息<\/li> 如果未获取到区块，则根据硬编码的创世区块信息初始化本地链<\/li> <\/ol> 5.2 主要网络创世哈希<\/h3> var<\/span> ( <\/span><\/span> MainnetGenesisHash<\/span> = common<\/span>.HexToHash<\/span>("0xd4e56740f876aef8c010b86a40d5f56745a118d0906a34e69aec8c0db1cb8fa3"<\/span>) <\/span><\/span> RopstenGenesisHash<\/span> = common<\/span>.HexToHash<\/span>("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"<\/span>) <\/span><\/span> RinkebyGenesisHash<\/span> = common<\/span>.HexToHash<\/span>("0x6341fd3daf94b748c72ced5a5b26028f2474f5f00d824504e4fa37a75767e177"<\/span>) <\/span><\/span> GoerliGenesisHash<\/span> = common<\/span>.HexToHash<\/span>("0xbf7e331f7f7c1dd2e05159666b3bf8bc7a8a3a9eb1d518969eab529dd9b88c1a"<\/span>) <\/span><\/span> YoloV3GenesisHash<\/span> = common<\/span>.HexToHash<\/span>("0x374f07cc7fa7c251fc5f36849f574b43db43600526410349efdca2bcea14101a"<\/span>) <\/span><\/span>) <\/span><\/span><\/code><\/pre>5.3 初始化创世区块流程<\/h3> 执行命令：.\/geth init <genesispath><\/code><\/li> 检查创世文件格式和权限<\/li> 调用makeConfigNode<\/code>加载全局配置<\/li> 调用SetupGenesisBlock<\/code>创建创世区块<\/li> <\/ol> 5.4 默认创世区块<\/h3> func<\/span> DefaultGenesisBlock<\/span>() *<\/span>Genesis<\/span> { <\/span><\/span> return<\/span> &<\/span>Genesis<\/span>{ <\/span><\/span> Config<\/span>: params<\/span>.MainnetChainConfig<\/span>, <\/span><\/span> Nonce<\/span>: 66<\/span>, <\/span><\/span> ExtraData<\/span>: hexutil<\/span>.MustDecode<\/span>("0x11bbe8db4e347b4e8c937c1c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa"<\/span>), <\/span><\/span> GasLimit<\/span>: 5000<\/span>, <\/span><\/span> Difficulty<\/span>: big<\/span>.NewInt<\/span>(17179869184<\/span>), <\/span><\/span> Alloc<\/span>: decodePrealloc<\/span>(mainnetAllocData<\/span>), <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>6. 新区块创建<\/h2> 新区块由矿工打包交易信息生成，主要流程：<\/p> mainLoop<\/code> goroutine打包新交易到区块<\/li> 调用updateSnapshot<\/code>更新快照<\/li> 调用NewBlock<\/code>更新区块信息<\/li> <\/ol> 6.1 NewBlock函数<\/h3> func<\/span> NewBlock<\/span>(header<\/span> *<\/span>Header<\/span>, txs<\/span> []*<\/span>Transaction<\/span>, uncles<\/span> []*<\/span>Header<\/span>, receipts<\/span> []*<\/span>Receipt<\/span>, hasher<\/span> TrieHasher<\/span>) *<\/span>Block<\/span> { <\/span><\/span> b<\/span> :=<\/span> &<\/span>Block<\/span>{header<\/span>: CopyHeader<\/span>(header<\/span>), td<\/span>: new(big<\/span>.Int<\/span>)} <\/span><\/span> <\/span><\/span> \/\/ 处理交易 <\/span><\/span><\/span><\/span> if<\/span> len(txs<\/span>) ==<\/span> 0<\/span> { <\/span><\/span> b<\/span>.header<\/span>.TxHash<\/span> = EmptyRootHash<\/span> <\/span><\/span> } else<\/span> { <\/span><\/span> b<\/span>.header<\/span>.TxHash<\/span> = DeriveSha<\/span>(Transactions<\/span>(txs<\/span>), hasher<\/span>) <\/span><\/span> b<\/span>.transactions<\/span> = make(Transactions<\/span>, len(txs<\/span>)) <\/span><\/span> copy(b<\/span>.transactions<\/span>, txs<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 处理收据 <\/span><\/span><\/span><\/span> if<\/span> len(receipts<\/span>) ==<\/span> 0<\/span> { <\/span><\/span> b<\/span>.header<\/span>.ReceiptHash<\/span> = EmptyRootHash<\/span> <\/span><\/span> } else<\/span> { <\/span><\/span> b<\/span>.header<\/span>.ReceiptHash<\/span> = DeriveSha<\/span>(Receipts<\/span>(receipts<\/span>), hasher<\/span>) <\/span><\/span> b<\/span>.header<\/span>.Bloom<\/span> = CreateBloom<\/span>(receipts<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 处理叔区块 <\/span><\/span><\/span><\/span> if<\/span> len(uncles<\/span>) ==<\/span> 0<\/span> { <\/span><\/span> b<\/span>.header<\/span>.UncleHash<\/span> = EmptyUncleHash<\/span> <\/span><\/span> } else<\/span> { <\/span><\/span> b<\/span>.header<\/span>.UncleHash<\/span> = CalcUncleHash<\/span>(uncles<\/span>) <\/span><\/span> b<\/span>.uncles<\/span> = make([]*<\/span>Header<\/span>, len(uncles<\/span>)) <\/span><\/span> for<\/span> i<\/span> :=<\/span> range<\/span> uncles<\/span> { <\/span><\/span> b<\/span>.uncles<\/span>[i<\/span>] = CopyHeader<\/span>(uncles<\/span>[i<\/span>]) <\/span><\/span> } <\/span><\/span> } <\/span><\/span> <\/span><\/span> return<\/span> b<\/span> <\/span><\/span>} <\/span><\/span><\/code><\/pre>7. 区块验证<\/h2> 区块验证是防止区块链分叉的重要手段，在以下情况会进行验证：<\/p> 挖矿节点成功挖掘区块并提交时<\/li> 用户通过API接口提交区块时<\/li> 同步区块时<\/li> 矿池节点向矿池提交工作时<\/li> <\/ol> 7.1 区块体验证<\/h3> func<\/span> (v<\/span> *<\/span>BlockValidator<\/span>) ValidateBody<\/span>(block<\/span> *<\/span>types<\/span>.Block<\/span>) error<\/span> { <\/span><\/span> \/\/ 检查区块是否已知 <\/span><\/span><\/span><\/span> if<\/span> v<\/span>.bc<\/span>.HasBlockAndState<\/span>(block<\/span>.Hash<\/span>(), block<\/span>.NumberU64<\/span>()) { <\/span><\/span> return<\/span> ErrKnownBlock<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证叔区块 <\/span><\/span><\/span><\/span> if<\/span> err<\/span> :=<\/span> v<\/span>.engine<\/span>.VerifyUncles<\/span>(v<\/span>.bc<\/span>, block<\/span>); err<\/span> !=<\/span> nil<\/span> { <\/span><\/span> return<\/span> err<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证叔区块哈希 <\/span><\/span><\/span><\/span> if<\/span> hash<\/span> :=<\/span> types<\/span>.CalcUncleHash<\/span>(block<\/span>.Uncles<\/span>()); hash<\/span> !=<\/span> header<\/span>.UncleHash<\/span> { <\/span><\/span> return<\/span> fmt<\/span>.Errorf<\/span>("uncle root hash mismatch: have %x, want %x"<\/span>, hash<\/span>, header<\/span>.UncleHash<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证交易哈希 <\/span><\/span><\/span><\/span> if<\/span> hash<\/span> :=<\/span> types<\/span>.DeriveSha<\/span>(block<\/span>.Transactions<\/span>(), trie<\/span>.NewStackTrie<\/span>(nil<\/span>)); hash<\/span> !=<\/span> header<\/span>.TxHash<\/span> { <\/span><\/span> return<\/span> fmt<\/span>.Errorf<\/span>("transaction root hash mismatch: have %x, want %x"<\/span>, hash<\/span>, header<\/span>.TxHash<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证父区块是否存在 <\/span><\/span><\/span><\/span> if<\/span> !v<\/span>.bc<\/span>.HasBlockAndState<\/span>(block<\/span>.ParentHash<\/span>(), block<\/span>.NumberU64<\/span>()-<\/span>1<\/span>) { <\/span><\/span> if<\/span> !v<\/span>.bc<\/span>.HasBlock<\/span>(block<\/span>.ParentHash<\/span>(), block<\/span>.NumberU64<\/span>()-<\/span>1<\/span>) { <\/span><\/span> return<\/span> consensus<\/span>.ErrUnknownAncestor<\/span> <\/span><\/span> } <\/span><\/span> return<\/span> consensus<\/span>.ErrPrunedAncestor<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> return<\/span> nil<\/span> <\/span><\/span>} <\/span><\/span><\/code><\/pre>7.2 叔区块验证<\/h3> func<\/span> (ethash<\/span> *<\/span>Ethash<\/span>) VerifyUncles<\/span>(chain<\/span> consensus<\/span>.ChainReader<\/span>, block<\/span> *<\/span>types<\/span>.Block<\/span>) error<\/span> { <\/span><\/span> \/\/ 验证叔区块数量(最多2个) <\/span><\/span><\/span><\/span> if<\/span> len(block<\/span>.Uncles<\/span>()) > maxUncles<\/span> { <\/span><\/span> return<\/span> errTooManyUncles<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 收集过去的叔区块和祖先 <\/span><\/span><\/span><\/span> uncles<\/span>, ancestors<\/span> :=<\/span> mapset<\/span>.NewSet<\/span>(), make(map<\/span>[common<\/span>.Hash<\/span>]*<\/span>types<\/span>.Header<\/span>) <\/span><\/span> <\/span><\/span> \/\/ 验证每个叔区块 <\/span><\/span><\/span><\/span> for<\/span> _<\/span>, uncle<\/span> :=<\/span> range<\/span> block<\/span>.Uncles<\/span>() { <\/span><\/span> \/\/ 确保每个叔区块只奖励一次 <\/span><\/span><\/span><\/span> hash<\/span> :=<\/span> uncle<\/span>.Hash<\/span>() <\/span><\/span> if<\/span> uncles<\/span>.Contains<\/span>(hash<\/span>) { <\/span><\/span> return<\/span> errDuplicateUncle<\/span> <\/span><\/span> } <\/span><\/span> uncles<\/span>.Add<\/span>(hash<\/span>) <\/span><\/span> <\/span><\/span> \/\/ 验证叔区块有有效的祖先 <\/span><\/span><\/span><\/span> if<\/span> ancestors<\/span>[hash<\/span>] !=<\/span> nil<\/span> { <\/span><\/span> return<\/span> errUncleIsAncestor<\/span> <\/span><\/span> } <\/span><\/span> if<\/span> ancestors<\/span>[uncle<\/span>.ParentHash<\/span>] ==<\/span> nil<\/span> ||<\/span> uncle<\/span>.ParentHash<\/span> ==<\/span> block<\/span>.ParentHash<\/span>() { <\/span><\/span> return<\/span> errDanglingUncle<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证叔区块头 <\/span><\/span><\/span><\/span> if<\/span> err<\/span> :=<\/span> ethash<\/span>.verifyHeader<\/span>(chain<\/span>, uncle<\/span>, ancestors<\/span>[uncle<\/span>.ParentHash<\/span>], true<\/span>, true<\/span>, time<\/span>.Now<\/span>().Unix<\/span>()); err<\/span> !=<\/span> nil<\/span> { <\/span><\/span> return<\/span> err<\/span> <\/span><\/span> } <\/span><\/span> } <\/span><\/span> return<\/span> nil<\/span> <\/span><\/span>} <\/span><\/span><\/code><\/pre>7.3 区块头验证<\/h3> func<\/span> (ethash<\/span> *<\/span>Ethash<\/span>) verifyHeader<\/span>(chain<\/span> consensus<\/span>.ChainHeaderReader<\/span>, header<\/span>, parent<\/span> *<\/span>types<\/span>.Header<\/span>, uncle<\/span> bool<\/span>, seal<\/span> bool<\/span>, unixNow<\/span> int64<\/span>) error<\/span> { <\/span><\/span> \/\/ 验证额外数据大小 <\/span><\/span><\/span><\/span> if<\/span> uint64(len(header<\/span>.Extra<\/span>)) > params<\/span>.MaximumExtraDataSize<\/span> { <\/span><\/span> return<\/span> fmt<\/span>.Errorf<\/span>("extra-data too long: %d > %d"<\/span>, len(header<\/span>.Extra<\/span>), params<\/span>.MaximumExtraDataSize<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证时间戳 <\/span><\/span><\/span><\/span> if<\/span> !uncle<\/span> { <\/span><\/span> if<\/span> header<\/span>.Time<\/span> > uint64(unixNow<\/span> +<\/span> allowedFutureBlockTimeSeconds<\/span>) { <\/span><\/span> return<\/span> consensus<\/span>.ErrFutureBlock<\/span> <\/span><\/span> } <\/span><\/span> } <\/span><\/span> if<\/span> header<\/span>.Time<\/span> <=<\/span> parent<\/span>.Time<\/span> { <\/span><\/span> return<\/span> errOlderBlockTime<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证难度 <\/span><\/span><\/span><\/span> expected<\/span> :=<\/span> ethash<\/span>.CalcDifficulty<\/span>(chain<\/span>, header<\/span>.Time<\/span>, parent<\/span>) <\/span><\/span> if<\/span> expected<\/span>.Cmp<\/span>(header<\/span>.Difficulty<\/span>) !=<\/span> { <\/span><\/span> return<\/span> fmt<\/span>.Errorf<\/span>("invalid difficulty: have %v, want %v"<\/span>, header<\/span>.Difficulty<\/span>, expected<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证Gas限制 <\/span><\/span><\/span><\/span> if<\/span> header<\/span>.GasLimit<\/span> > uint64(0x7fffffffffffffff<\/span>) { <\/span><\/span> return<\/span> fmt<\/span>.Errorf<\/span>("invalid gasLimit: have %v, max %v"<\/span>, header<\/span>.GasLimit<\/span>, cap<\/span>) <\/span><\/span> } <\/span><\/span> if<\/span> header<\/span>.GasUsed<\/span> > header<\/span>.GasLimit<\/span> { <\/span><\/span> return<\/span> fmt<\/span>.Errorf<\/span>("invalid gasUsed: have %d, gasLimit %d"<\/span>, header<\/span>.GasUsed<\/span>, header<\/span>.GasLimit<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证区块号 <\/span><\/span><\/span><\/span> if<\/span> diff<\/span> :=<\/span> new(big<\/span>.Int<\/span>).Sub<\/span>(header<\/span>.Number<\/span>, parent<\/span>.Number<\/span>); diff<\/span>.Cmp<\/span>(big<\/span>.NewInt<\/span>(1<\/span>)) !=<\/span> 0<\/span> { <\/span><\/span> return<\/span> consensus<\/span>.ErrInvalidNumber<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证Seal <\/span><\/span><\/span><\/span> if<\/span> seal<\/span> { <\/span><\/span> if<\/span> err<\/span> :=<\/span> ethash<\/span>.verifySeal<\/span>(chain<\/span>, header<\/span>, false<\/span>); err<\/span> !=<\/span> nil<\/span> { <\/span><\/span> return<\/span> err<\/span> <\/span><\/span> } <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 验证硬分叉特殊字段 <\/span><\/span><\/span><\/span> if<\/span> err<\/span> :=<\/span> misc<\/span>.VerifyDAOHeaderExtraData<\/span>(chain<\/span>.Config<\/span>(), header<\/span>); err<\/span> !=<\/span> nil<\/span> { <\/span><\/span> return<\/span> err<\/span> <\/span><\/span> } <\/span><\/span> if<\/span> err<\/span> :=<\/span> misc<\/span>.VerifyForkHashes<\/span>(chain<\/span>.Config<\/span>(), header<\/span>, uncle<\/span>); err<\/span> !=<\/span> nil<\/span> { <\/span><\/span> return<\/span> err<\/span> <\/span><\/span> } <\/span><\/span> <\/span><\/span> return<\/span> nil<\/span> <\/span><\/span>} <\/span><\/span><\/code><\/pre>8. 难度目标计算<\/h2> 难度调整算法根据不同的网络阶段使用不同版本：<\/p> func<\/span> CalcDifficulty<\/span>(config<\/span> *<\/span>params<\/span>.ChainConfig<\/span>, time<\/span> uint64<\/span>, parent<\/span> *<\/span>types<\/span>.Header<\/span>) *<\/span>big<\/span>.Int<\/span> { <\/span><\/span> next<\/span> :=<\/span> new(big<\/span>.Int<\/span>).Add<\/span>(parent<\/span>.Number<\/span>, big1<\/span>) <\/span><\/span> switch<\/span> { <\/span><\/span> case<\/span> config<\/span>.IsMuirGlacier<\/span>(next<\/span>): <\/span><\/span> return<\/span> calcDifficultyEip2384<\/span>(time<\/span>, parent<\/span>) <\/span><\/span> case<\/span> config<\/span>.IsConstantinople<\/span>(next<\/span>): <\/span><\/span> return<\/span> calcDifficultyConstantinople<\/span>(time<\/span>, parent<\/span>) <\/span><\/span> case<\/span> config<\/span>.IsByzantium<\/span>(next<\/span>): <\/span><\/span> return<\/span> calcDifficultyByzantium<\/span>(time<\/span>, parent<\/span>) <\/span><\/span> case<\/span> config<\/span>.IsHomestead<\/span>(next<\/span>): <\/span><\/span> return<\/span> calcDifficultyHomestead<\/span>(time<\/span>, parent<\/span>) <\/span><\/span> default<\/span>: <\/span><\/span> return<\/span> calcDifficultyFrontier<\/span>(time<\/span>, parent<\/span>) <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>8.1 Homestead难度计算<\/h3> func<\/span> calcDifficultyHomestead<\/span>(time<\/span> uint64<\/span>, parent<\/span> *<\/span>types<\/span>.Header<\/span>) *<\/span>big<\/span>.Int<\/span> { <\/span><\/span> \/\/ 算法公式： <\/span><\/span><\/span><\/span> \/\/ diff = (parent_diff + <\/span><\/span><\/span><\/span> \/\/ (parent_diff \/ 2048 * max(1 - (block_timestamp - parent_timestamp) \/ 10, -99)) <\/span><\/span><\/span><\/span> \/\/ ) + 2^(periodCount - 2) <\/span><\/span><\/span><\/span> <\/span><\/span> bigTime<\/span> :=<\/span> new(big<\/span>.Int<\/span>).SetUint64<\/span>(time<\/span>) <\/span><\/span> bigParentTime<\/span> :=<\/span> new(big<\/span>.Int<\/span>).SetUint64<\/span>(parent<\/span>.Time<\/span>) <\/span><\/span> <\/span><\/span> \/\/ 计算时间差因子 <\/span><\/span><\/span><\/span> x<\/span> :=<\/span> new(big<\/span>.Int<\/span>) <\/span><\/span> y<\/span> :=<\/span> new(big<\/span>.Int<\/span>) <\/span><\/span> x<\/span>.Sub<\/span>(bigTime<\/span>, bigParentTime<\/span>) <\/span><\/span> x<\/span>.Div<\/span>(x<\/span>, big10<\/span>) <\/span><\/span> x<\/span>.Sub<\/span>(big1<\/span>, x<\/span>) <\/span><\/span> <\/span><\/span> \/\/ 限制最小值为-99 <\/span><\/span><\/span><\/span> if<\/span> x<\/span>.Cmp<\/span>(bigMinus99<\/span>) < 0<\/span> { <\/span><\/span> x<\/span>.Set<\/span>(bigMinus99<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 计算难度调整 <\/span><\/span><\/span><\/span> y<\/span>.Div<\/span>(parent<\/span>.Difficulty<\/span>, params<\/span>.DifficultyBoundDivisor<\/span>) <\/span><\/span> x<\/span>.Mul<\/span>(y<\/span>, x<\/span>) <\/span><\/span> x<\/span>.Add<\/span>(parent<\/span>.Difficulty<\/span>, x<\/span>) <\/span><\/span> <\/span><\/span> \/\/ 确保不低于最小难度 <\/span><\/span><\/span><\/span> if<\/span> x<\/span>.Cmp<\/span>(params<\/span>.MinimumDifficulty<\/span>) < 0<\/span> { <\/span><\/span> x<\/span>.Set<\/span>(params<\/span>.MinimumDifficulty<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> \/\/ 计算指数因子(炸弹) <\/span><\/span><\/span><\/span> periodCount<\/span> :=<\/span> new(big<\/span>.Int<\/span>).Add<\/span>(parent<\/span>.Number<\/span>, big1<\/span>) <\/span><\/span> periodCount<\/span>.Div<\/span>(periodCount<\/span>, expDiffPeriod<\/span>) <\/span><\/span> if<\/span> periodCount<\/span>.Cmp<\/span>(big1<\/span>) > 0<\/span> { <\/span><\/span> y<\/span>.Sub<\/span>(periodCount<\/span>, big2<\/span>) <\/span><\/span> y<\/span>.Exp<\/span>(big2<\/span>, y<\/span>, nil<\/span>) <\/span><\/span> x<\/span>.Add<\/span>(x<\/span>, y<\/span>) <\/span><\/span> } <\/span><\/span> <\/span><\/span> return<\/span> x<\/span> <\/span><\/span>} <\/span><\/span><\/code><\/pre>9. 关键验证点总结<\/h2> 区块头验证<\/strong>：<\/p> 额外数据大小<\/li> 时间戳合理性<\/li> 难度计算正确性<\/li> Gas限制有效性<\/li> 区块号连续性<\/li> Seal验证<\/li> <\/ul> <\/li> 区块体验证<\/strong>：<\/p> 叔区块数量限制<\/li> 交易哈希正确性<\/li> 叔区块哈希正确性<\/li> 父区块存在性<\/li> <\/ul> <\/li> 特殊验证<\/strong>：<\/p> DAO硬分叉额外数据<\/li> 分叉哈希验证<\/li> 难度炸弹计算<\/li> <\/ul> <\/li> <\/ol> 通过以上全面的验证机制，以太坊确保了区块链的安全性和一致性，有效防止了分叉和无效区块的产生。<\/p>

以太坊区块设计分析教学文档<\/h1>

2. 区块结构<\/h2> 区块是区块链中数据存储的最小单元，由两部分组成：<\/p>

2.2 区块主体(Body)<\/h3> 用于存储交易信息<\/p>

3. 以太坊区块数据结构<\/h2>

5. 创世区块<\/h2> 区块链中第一个区块称为"创世区块"，是所有区块的共同祖先。<\/p>

2. 区块结构<\/h2>
区块是区块链中数据存储的最小单元，由两部分组成：<\/p>

2.2 区块主体(Body)<\/h3>
用于存储交易信息<\/p>

5. 创世区块<\/h2>
区块链中第一个区块称为"创世区块"，是所有区块的共同祖先。<\/p>