随着2024年初BTC的大热，各种BTC二层网络如雨后春笋般出现。在个人博客里《BTC Layer2的3种方案（转载+翻译）》 ，对当前火热的三个项目：B²、Merlin、BEVM 进行了初步介绍。 其中B²、BEVM实现原理是类似ethereum的ZK-Rollup的扩容方案，但局限于比特币脚本并不是图灵完备，实现上挑战还是比较高的。而Merlin是基于质押BTC的方式，质押节点是由Merlin指定的，不够去中心化。
接下来要介绍的Stacks与Merlin类似，也是基于质押的方式，但是任何人都能成为Stacker，创新性地引入新的共识算法PoX 实现去中心化。并且通过“链锚定”的方式，利用BTC主链的PoW 来保护Stacks子链的安全性，同时引入microblock、anchorblock机制来实现交易的快速确认，以此实现扩容。
下面将对如何启动Stacks、Stacker节点和代码进行具体介绍。还有对整体架构以及其中不同组件：区块生成、交易处理、共识机制、与比特币交互、Clarity智能合约进行分析。
1.启动Stacks节点
Stacks支持以不同网络模式启动节点，如果想完整的运行Stacks节点并加入已有网络进行挖矿的话，可以参考《Stacks Blockchain Miner 》。如果是基于Stacks进行开发或者调试，可以选择mocknet。这样并不需要启动比特币节点，能够快速把Stacks节点运行起来。下面是启动mocknet模式Stacks节点的流程：
1.0 安装rust依赖
Copy $ curl -sL https://deb.nodesource.com/setup_16.x | sudo -E bash -
$ sudo apt-get update -y && sudo apt-get install -y build-essential jq netcat nodejs git autoconf libboost-system-dev libboost-filesystem-dev libboost-thread-dev libboost-chrono-dev libevent-dev libzmq5 libtool m4 automake pkg-config libtool libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-program-options-dev libboost-test-dev libboost-thread-dev libboost-iostreams-dev
$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh && source $HOME/.cargo/env 1.1 下载代码
Copy git clone git@github.com:stacks-network/stacks-core.git 1.2 生成节点私钥
请将下面输出保存到安全地方
Copy $ cd $HOME && npm install @stacks/cli shx rimraf
$ npx @stacks/cli make_keychain 2>/dev/null | jq
{
"mnemonic": "frown lens very suit ocean trigger animal flip retire dose various mobile record emerge torch client sorry shy party session until planet member exclude",
"keyInfo": {
"privateKey": "ooxeemeitar4ahw0ca8anu4thae7aephahshae1pahtae5oocahthahho4ahn7eici",
"address": "STTXOG3AIHOHNAEH5AU6IEX9OOTOH8SEIWEI5IJ9",
"btcAddress": "Ook6goo1Jee5ZuPualeiqu9RiN8wooshoo",
"wif": "rohCie2ein2chaed9kaiyoo6zo1aeQu1yae4phooShov2oosh4ox",
"index": 0
}
} 上面mnemonic是助记词，privateKey是私钥，address是stx的地址，btcAddress是对应的比特币地址，wif(wallet import format)是可导入比特币钱包格式的私钥。
1.3 修改网络&节点配置
stacks在nakamoto升级后，才支持去中心化的signer，但是当前mocknet模式下的配置并不支持。需要修改testnet/stacks-node/src/burnchains/mocknet_controller.rs ：
Copy fn get_stacks_epochs(&self) -> Vec<StacksEpoch> {
match &self.config.burnchain.epochs {
Some(epochs) => epochs.clone(),
None => vec![
StacksEpoch {
epoch_id: StacksEpochId::Epoch20,
start_height: 0,
end_height: 1,
block_limit: ExecutionCost::max_value(),
network_epoch: PEER_VERSION_EPOCH_2_0,
},
StacksEpoch {
epoch_id: StacksEpochId::Epoch2_05,
start_height: 1,
end_height: 2,
block_limit: ExecutionCost::max_value(),
network_epoch: PEER_VERSION_EPOCH_2_05,
},
StacksEpoch {
epoch_id: StacksEpochId::Epoch21,
start_height: 2,
end_height: 3,
block_limit: ExecutionCost::max_value(),
network_epoch: PEER_VERSION_EPOCH_2_1,
},
StacksEpoch {
epoch_id: StacksEpochId::Epoch22,
start_height: 3,
end_height: 4,
block_limit: ExecutionCost::max_value(),
network_epoch: PEER_VERSION_EPOCH_2_2,
},
StacksEpoch {
epoch_id: StacksEpochId::Epoch23,
start_height: 4,
end_height: 5,
block_limit: ExecutionCost::max_value(),
network_epoch: PEER_VERSION_EPOCH_2_3,
},
StacksEpoch {
epoch_id: StacksEpochId::Epoch24,
start_height: 5,
end_height: 6,
block_limit: ExecutionCost::max_value(),
network_epoch: PEER_VERSION_EPOCH_2_4,
},
StacksEpoch {
epoch_id: StacksEpochId::Epoch25,
start_height: 6,
end_height: STACKS_EPOCH_MAX,
block_limit: ExecutionCost::max_value(),
network_epoch: PEER_VERSION_EPOCH_2_5,
},
],
}
} 为了便于debug，把pox相关参数stackslib/src/burnchains/mod.rs ，reward_cycle_length 、prepare_length、epoch生效时间改成与上面一致：
Copy pub fn regtest_default() -> PoxConstants {
PoxConstants::new(
20,
10,
11,
3333333333333333,
1,
BITCOIN_REGTEST_FIRST_BLOCK_HEIGHT + POX_SUNSET_START,
BITCOIN_REGTEST_FIRST_BLOCK_HEIGHT + POX_SUNSET_END,
3,
4,
7,
7,
)
} 以及testnet/stacks-node/src/node.rs :
Copy /// Constructs and returns a LeaderBlockCommitOp out of the provided params
fn generate_block_commit_op(
&mut self,
block_header_hash: BlockHeaderHash,
burn_fee: u64,
key: &RegisteredKey,
burnchain_tip: &BurnchainTip,
vrf_seed: VRFSeed,
) -> BlockstackOperationType {
//...
BlockstackOperationType::LeaderBlockCommit(LeaderBlockCommitOp {
sunset_burn: 0,
block_header_hash,
burn_fee,
input: (Txid([0; 32]), 0),
apparent_sender: self.keychain.get_burnchain_signer(),
key_block_ptr: key.block_height as u32,
key_vtxindex: key.op_vtxindex as u16,
memo: vec![STACKS_EPOCH_3_0_MARKER], // 原来是STACKS_EPOCH_2_1_MARKER，需要改为STACKS_EPOCH_3_0_MARKER
new_seed: vrf_seed,
parent_block_ptr,
parent_vtxindex,
vtxindex: 2,
txid,
commit_outs,
block_height: 0,
burn_header_hash: BurnchainHeaderHash::zero(),
burn_parent_modulus,
})
} 最后是修改节点配置testnet/stacks-node/conf/mocknet-miner-conf.toml ：
Copy [node]
# working_dir = "/dir/to/save/chainstate"
rpc_bind = "0.0.0.0:20443"
p2p_bind = "0.0.0.0:20444"
seed = "<npx privateKey>"
local_peer_seed = "<npx privateKey>"
miner = true
wait_time_for_microblocks = 10000
use_test_genesis_chainstate = true
[connection_options]
public_ip_address = "127.0.0.1:20444"
[burnchain]
chain = "bitcoin"
mode = "mocknet"
[[ustx_balance]]
address = "ST3EQ88S02BXXD0T5ZVT3KW947CRMQ1C6DMQY8H19"
amount = 100000000000000
[[ustx_balance]]
address = "ST3KCNDSWZSFZCC6BE4VA9AXWXC9KEB16FBTRK36T"
amount = 100000000000000
[[ustx_balance]]
address = "STB2BWB0K5XZGS3FXVTG3TKS46CQVV66NAK3YVN8"
amount = 100000000000000
[[ustx_balance]]
address = "STSTW15D618BSZQB85R058DS46THH86YQQY6XCB7"
amount = 100000000000000
将seed 、local_peer_seed 替换为上面npx命令输出的privateKey 。
1.4 启动节点
编译和运行节点：
Copy $cd stacks-core
$nohup cargo run --bin stacks-node -- start --config ./testnet/stacks-node/conf/mocknet-miner-conf.toml >> run.log 2>&1 & 2.启动Stacks Signer
创建signer配置：
Copy $touch testnet/stacks-node/conf/signer-config.toml
Copy # The IP address and port where your Stacks node can be accessed.
# The port 20443 is the default RPC endpoint for Stacks nodes.
# Note that you must use an IP address - DNS hosts are not supported at this time.
# This should be the IP address accessible via Docker, usually via a network.
node_host = "127.0.0.1:20443"
# This is the location where the signer will expose an RPC endpoint for
# receiving events from your Stacks node.
endpoint = "0.0.0.0:30000"
# Either “testnet” or “mainnet”
network = "testnet"
# this is a file path where your signer will persist data. If using Docker,
# this must be within a volume, so that data can be persisted across restarts
db_path = "/Users/bj89200ml/Documents/llm_signer_local/signer.db"
# an authentication token that is used for some HTTP requests made from the
# signer to your Stacks node. You’ll need to use this later on when configur$ng
# your Stacks node. You create this field yourself, rather than it being generated
# with your private key.
auth_password = "<mocknet-miner-conf.toml>"
# This is the privateKey field from the keys you generated in the
# previous step.
stacks_private_key = "<npx privateKey>" 3.质押STX，成为Stacker
参考https://github.com/hirosystems/stacks.js/tree/main/packages/cli 安装stx命令行工具：
但是由于这个不支持mocknet模式，并且不支持nakamoto的pox4合约的质押，需要修改cli.js相关代码:。
Copy async function stack(network, args) {
const amount = BigInt(args[0]);
const cycles = Number(args[1]);
const poxAddress = args[2];
const privateKey = args[3];
const maxAmountMicroStx = amount;
const signerPrivateKey = transactions_1.createStacksPrivateKey(privateKey);
const signerKey = transactions_1.getPublicKey(signerPrivateKey);
console.log("signerPrivateKey:", signerPrivateKey, "signerKey:", signerKey);
const txNetwork = network.isMainnet() ? new network_1.StacksMainnet() : new network_1.StacksTestnet({url: 'http://127.0.0.1:20443'}); // 指定为本地节点
const txVersion = txNetwork.isMainnet() ? transactions_1.TransactionVersion.Mainnet : transactions_1.TransactionVersion.Testnet;
const apiConfig = new blockchain_api_client_1.Configuration({
fetchApi: cross_fetch_1.default,
basePath: txNetwork.coreApiUrl,
});
const accounts = new blockchain_api_client_1.AccountsApi(apiConfig);
const stxAddress = (0, transactions_1.getAddressFromPrivateKey)(privateKey, txVersion);
/*const balancePromise = accounts.getAccountBalance({
principal: stxAddress,
});*/
const stacker = new stacking_1.StackingClient(stxAddress, txNetwork);
const poxInfoPromise = stacker.getPoxInfo();
const coreInfoPromise = stacker.getCoreInfo();
const stackingEligiblePromise = stacker.canStack({ poxAddress, cycles });
return Promise.all([poxInfoPromise, coreInfoPromise, stackingEligiblePromise])
.then(([poxInfo, coreInfo, stackingEligible]) => {
console.log("poxInfo:", poxInfo);
const minAmount = BigInt(poxInfo.min_amount_ustx);
const currentCycle = poxInfo.reward_cycle_id;
//const balanceBN = BigInt(balance.stx.balance);
console.log("coreInfo:", coreInfo);
const burnChainBlockHeight = coreInfo.burn_block_height;
const startBurnBlock = burnChainBlockHeight;
// const startBurnBlock = burnChainBlockHeight + 3;
if (minAmount > amount) {
throw new Error(`Stacking amount less than required minimum of ${minAmount.toString()} microstacks`);
}
/*if (amount > balanceBN) {
throw new Error(`Stacking amount greater than account balance of ${balanceBN.toString()} microstacks`);
}*/
if (!stackingEligible.eligible) {
throw new Error(`Account cannot participate in stacking. ${stackingEligible.reason}`);
}
console.log("amount:", amount, "poxAddress:", poxAddress, "cycles:", cycles, "privateKey:", privateKey, "startBurnBlock:", startBurnBlock);
// the auth id of the signer (a random id to not allow reusing the signature)
const authId = 702;
const signerSignature = stacker.signPoxSignature({
topic: 'stack-stx', // the topic of the transaction
poxAddress,
rewardCycle: currentCycle,
period: cycles,
maxAmount: amount,
authId,
signerPrivateKey,
});
return stacker.stack({
amountMicroStx: amount,
poxAddress,
cycles,
burnBlockHeight: burnChainBlockHeight,
signerKey: '<npx publicKey>',
signerSignature,
maxAmount: maxAmountMicroStx,
authId,
privateKey,
});
})
.then((response) => {
if (response.hasOwnProperty('error')) {
return response;
}
return {
txid: `0x${response.txid}`,
transaction: (0, utils_1.generateExplorerTxPageUrl)(response.txid, txNetwork),
};
})
.catch(error => {
return error;
});
} 质押stx：
Copy $stacks stack 8206330000000000 1 <npx btcAddress> <npx privateKey> -l 再通过下面url查询节点信息
Copy $curl -sL localhost:20443/v2/pox | jq 当前网络信息:
Copy {
"contract_id": "ST000000000000000000002AMW42H.pox-4",
"pox_activation_threshold_ustx": 1300057388429055,
"first_burnchain_block_height": 0,
"current_burnchain_block_height": 21,
"prepare_phase_block_length": 10,
"reward_phase_block_length": 10,
"reward_slots": 20,
"rejection_fraction": null,
"total_liquid_supply_ustx": 130005738842905579,
"current_cycle": {
"id": 1,
"min_threshold_ustx": 1625080000000000,
"stacked_ustx": 8206330000000000, // 刚才质押的数量
"is_pox_active": false
},
"next_cycle": {
"id": 2,
"min_threshold_ustx": 1625080000000000,
"min_increment_ustx": 16250717355363,
"stacked_ustx": 0,
"prepare_phase_start_block_height": 30,
"blocks_until_prepare_phase": 9,
"reward_phase_start_block_height": 40,
"blocks_until_reward_phase": 19,
"ustx_until_pox_rejection": null
},
"epochs": [
{
"epoch_id": "Epoch20",
"start_height": 0,
"end_height": 1,
"block_limit": {
"write_length": 18446744073709551615,
"write_count": 18446744073709551615,
"read_length": 18446744073709551615,
"read_count": 18446744073709551615,
"runtime": 18446744073709551615
},
"network_epoch": 0
},
{
"epoch_id": "Epoch2_05",
"start_height": 1,
"end_height": 2,
"block_limit": {
"write_length": 18446744073709551615,
"write_count": 18446744073709551615,
"read_length": 18446744073709551615,
"read_count": 18446744073709551615,
"runtime": 18446744073709551615
},
"network_epoch": 5
},
{
"epoch_id": "Epoch21",
"start_height": 2,
"end_height": 3,
"block_limit": {
"write_length": 18446744073709551615,
"write_count": 18446744073709551615,
"read_length": 18446744073709551615,
"read_count": 18446744073709551615,
"runtime": 18446744073709551615
},
"network_epoch": 6
},
{
"epoch_id": "Epoch22",
"start_height": 3,
"end_height": 4,
"block_limit": {
"write_length": 18446744073709551615,
"write_count": 18446744073709551615,
"read_length": 18446744073709551615,
"read_count": 18446744073709551615,
"runtime": 18446744073709551615
},
"network_epoch": 7
},
{
"epoch_id": "Epoch23",
"start_height": 4,
"end_height": 5,
"block_limit": {
"write_length": 18446744073709551615,
"write_count": 18446744073709551615,
"read_length": 18446744073709551615,
"read_count": 18446744073709551615,
"runtime": 18446744073709551615
},
"network_epoch": 8
},
{
"epoch_id": "Epoch24",
"start_height": 5,
"end_height": 6,
"block_limit": {
"write_length": 18446744073709551615,
"write_count": 18446744073709551615,
"read_length": 18446744073709551615,
"read_count": 18446744073709551615,
"runtime": 18446744073709551615
},
"network_epoch": 9
},
{
"epoch_id": "Epoch25",
"start_height": 6,
"end_height": 9223372036854775807,
"block_limit": {
"write_length": 18446744073709551615,
"write_count": 18446744073709551615,
"read_length": 18446744073709551615,
"read_count": 18446744073709551615,
"runtime": 18446744073709551615
},
"network_epoch": 10
}
],
"min_amount_ustx": 1625080000000000,
"prepare_cycle_length": 10,
"reward_cycle_id": 1,
"reward_cycle_length": 20,
"rejection_votes_left_required": null,
"next_reward_cycle_in": 19,
"contract_versions": [
{
"contract_id": "ST000000000000000000002AMW42H.pox",
"activation_burnchain_block_height": 0,
"first_reward_cycle_id": 0
},
{
"contract_id": "ST000000000000000000002AMW42H.pox-2",
"activation_burnchain_block_height": 3,
"first_reward_cycle_id": 1
},
{
"contract_id": "ST000000000000000000002AMW42H.pox-3",
"activation_burnchain_block_height": 7,
"first_reward_cycle_id": 1
},
{
"contract_id": "ST000000000000000000002AMW42H.pox-4",
"activation_burnchain_block_height": 7,
"first_reward_cycle_id": 1
}
]
} 这时候等网络达到reward cycle 1的时候再重启signer（因为mocknet模式下不支持推送burnchain block，无法主动刷新注册信息，故需要重启 ），就能看到以下输出：
4.整体架构及代码分析
4.1 整体机制
Stacks网络主要由2类节点组成，分别是miner和signer。其中miner负责参与竞选出块，而signer负责验证块的内容和签名，只有达到70%以上的signer同意，miner出的块才会被接受。如下图所示：signer通过质押stx成为stacker，获取btc奖励。而miner通过发送btc，获取coinbase和交易手续费奖励(stx形式)。以此将btc与stx代币经济模型形成闭环。
4.2 Miner流程：
1.发送RegisterKey交易到主链（btc），注册成为miner。
2.发送LeaderBlockCommit交易到主链（btc），里面会使用VRF从当前reward cycle里选中两个stacker进行发送btc，从而参与竞选。
3.由VRF选出任期内的miner，这里每一个btc块是一个单独的任期，miner也可以进行连任。miner由Verifiable Random Function（VRF）根据发送btc数量占当期总发送量为概率进行抽签选中。同样，接收btc奖励的stackers也是由VRF每次选择其中2个作为接收方。
4.被VRF选中的miner负责出microblocks，这个阶段执行交易出块会非常块，因为不需要进行锚定和共识，当满足出anchor block的条件时，会将多个microblocks串联成一个anchor block并锚定到主链（btc）上。间接利用主链的工作量证明来保护子链的安全，因为要篡改子链的区块，需要改写btc主链的区块，这个需要的计算量非常巨大。
4.3 Stacker流程
1.调用API获取有关即将到来的奖励周期的详细信息
2.对于特定的Stacks账户，确认其符合条件
3.确认比特币奖励地址和锁定期限
4.交易已广播，STX代币已被锁定。这需要在下一个奖励周期的准备阶段之前完成，即正在进行的奖励阶段的最后100个比特币块
5.stacking机制执行奖励周期，并向设置的BTC奖励地址发送奖励
6.在锁定期间，可以获取有关解锁时间、奖励等的详细信息
7.一旦锁定期结束，代币将被释放并再次可访问
8.显示奖励历史，包括以前奖励周期的收益等详细信
Note. 奖励周期的目标持续时间约为2周。这一持续时间基于比特币网络的目标块时间（10分钟），有时可能会因比特币网络的确认时间差异而增加。
4.4 Stacks节点代码分析
Stacks使用sqlite对主链、子链数据进行存储，节点启动的入口代码为testnet/stacks-node/src/main.rs 的main函数，会开启主线程main thread，由主线程再启动其他子线程，线程间使用channel进行通讯协作。
下面是Stacks节点的整体架构图：
4.4.1 主线程
1.创建burnchain_controller；
2.创建chains_coordinator；
3.创建StacksNode线程；
4.4.2 burnchain_controller
负责同步主链（burnchain）状态。主要做3件事：1.1 download 同步主链的区块；1.2 parse 解析主链区块里的stacks相关交易 1.3 db 将解析的stacks交易存储到本地数据库。
其中每接受到主链的块信息，a.1 announce_new_burn_block：会通知chains_coordinator进行处理。
4.4.3 chains_coordinator
负责协调microblocks的生成和确认，以及被anchor blocks安全引用。
a.2 handle_new_burnchain_block：接收到新的主链区块事件并处理。
b.6 handle_new_stacks_block: 接收到新的子链区块事件并处理。
4.4.4 StacksNode
1.创建relayer线程；
2.创建p2p线程；
4.4.4.1 relayer
1.创建miner线程：
miner负责子链的出块和执行具体的交易逻辑，处理流程：
b.1 mine_block: 按照块的大小及mempool里交易的手续费进行选择包含在当前microblock里的交易并执行；
b.2 propose_block: 将mined block发送到所监听的Signer；
b.3 coordinate_signature: 获取Signer的聚合签名，只有得到当前reward cycle内70%以上的Signer签名才会被认为有效；
b.5 announce_new_stacks_block: 通知chains_coordinator新的子链区块信息。
2.自身会处理4种指令：
HandleNetResult: 接收来自p2p线程的网络请求处理结果，比如接收到新的交易，会写入到mempool。
RegisterKey：会维护节点miner私钥的状态机，是否已注册、激活、停止。因为要成为miner，首先要先注册到当前的tenure里。
ProcessedBurnBlock：处理接收到的主链区块信息，如判断当前miner是否已经成功竞选为当前任期内的miner。
IssueBlockCommit: 向主链提交anchor block，会构造特殊的比特币交易，vout向选中的两个Stacker发送btc。构造实现如下：
Copy fn send_block_commit_operation (
&mut self,
epoch_id : StacksEpochId ,
payload : LeaderBlockCommitOp ,
signer : &mut BurnchainOpSigner ,
utxos_to_include : Option < UTXOSet >,
utxos_to_exclude : Option < UTXOSet >,
previous_fees : Option < LeaderBlockCommitFees >,
previous_txids : & Vec < Txid >,
) -> Option < Transaction > {
let mut estimated_fees = match previous_fees {
Some (fees) => fees . fees_from_previous_tx ( & payload, & self . config),
None => LeaderBlockCommitFees :: estimated_fees_from_payload ( & payload, & self . config),
};
let _ = self . sortdb_mut ();
let burn_chain_tip = self . burnchain_db . as_ref () ?. get_canonical_chain_tip () . ok () ? ;
let public_key = signer . get_public_key ();
let ( mut tx, mut utxos) = self . prepare_tx (
epoch_id,
& public_key,
estimated_fees . estimated_amount_required (),
utxos_to_include,
utxos_to_exclude,
burn_chain_tip . block_height,
) ? ;
// Serialize the payload
let op_bytes = {
let mut buffer = vec! [];
let mut magic_bytes = self . magic_bytes ();
buffer . append ( &mut magic_bytes);
payload
. consensus_serialize ( &mut buffer)
. expect ( "FATAL: invalid operation" );
buffer
};
let consensus_output = TxOut {
value : estimated_fees . sunset_fee,
script_pubkey : Builder :: new ()
. push_opcode (opcodes :: All :: OP_RETURN)
. push_slice ( & op_bytes)
. into_script (),
};
tx . output = vec! [consensus_output]; // 用于共识数据output
for commit_to in payload.commit_outs.iter() { // 这里为两个被选中stacker对应TxOut，value为转账数量，script_pubkey为基于stacker的地址类似所构造的脚本
tx . output
. push (commit_to . to_bitcoin_tx_out (estimated_fees . amount_per_output ()));
}
let fee_rate = estimated_fees . fee_rate;
self . finalize_tx (
epoch_id,
&mut tx,
estimated_fees . total_spent_in_outputs (),
estimated_fees . spent_in_attempts,
estimated_fees . min_tx_size (),
fee_rate,
&mut utxos,
signer,
) ? ;
let serialized_tx = SerializedTx :: new (tx . clone ());
let tx_size = serialized_tx . bytes . len () as u64 ;
estimated_fees . register_replacement (tx_size);
let mut txid = tx . txid () . as_bytes () . to_vec ();
txid . reverse ();
debug! ( "Transaction relying on UTXOs: {:?}" , utxos);
let txid = Txid :: from_bytes ( & txid[ .. ]) . unwrap ();
let mut txids = previous_txids . clone ();
txids . push (txid . clone ());
let ongoing_block_commit = OngoingBlockCommit {
payload,
utxos,
fees : estimated_fees,
txids,
};
info! (
"Miner node: submitting leader_block_commit (txid: {}, rbf: {}, total spent: {}, size: {}, fee_rate: {})" ,
txid . to_hex (),
ongoing_block_commit . fees . is_rbf_enabled,
ongoing_block_commit . fees . total_spent (),
ongoing_block_commit . fees . final_size,
fee_rate,
);
self . ongoing_block_commit = Some (ongoing_block_commit);
increment_btc_ops_sent_counter ();
Some (tx)
}
在 Stacks 区块链中，LeaderBlockCommit 交易是一种特殊的交易类型，用于将 Stacks 区块锚定到比特币区块链上。通过这种机制，Stacks 利用比特币的安全性，使得 Stacks 区块链的状态可以通过比特币交易进行验证。
LeaderBlockCommit 对应的比特币脚本
LeaderBlockCommit 交易通常包含以下组件：
OP_RETURN 输出 ：这个输出用于在比特币区块链上存储数据。这种方式不需要实际花费比特币，使用 OP_RETURN 输出可以存储最多 80 字节的任意数据。
承诺数据（Commitment Data） ：嵌入在 OP_RETURN 输出中的数据包括有关被提交的 Stacks 区块的信息。这些数据按照特定规则格式化，使 Stacks 网络能够解释。
脚本的详细分解
OP_RETURN 操作码 ：用于标记输出为携带数据的输出，而不是价值。这用于在比特币交易中嵌入任意数据。
承诺数据 ：紧随 OP_RETURN 操作码之后嵌入承诺数据。这些数据通常包括：
VRF 证明 ：用于领导者选举过程的可验证随机函数（VRF）的证明。
默克尔根 ：所提交的 Stacks 区块中交易的默克尔根。
LeaderBlockCommit 脚本示例
以下是一个 LeaderBlockCommit 交易脚本的示例：
Copy OP_RETURN <commitment_data> 其中，<commitment_data> 是各种组件（版本字节、区块高度、父区块哈希等）的连接。
LeaderBlockCommit 的意义
安全性 ：通过将 Stacks 区块锚定到比特币区块链，Stacks 继承了比特币的安全性。这使得攻击者难以在不更改比特币区块链的情况下篡改 Stacks 区块链。
可验证性 ：任何人都可以通过查看相应的比特币交易来验证 Stacks 区块链的状态。这使得 Stacks 区块链透明且可验证。
去中心化 ：通过利用比特币的去中心化网络，Stacks 增强了自身的去中心化和抗审查能力。
4.4.4.2 p2p
1.创建http loop线程：负责接收来自client的请求，比如转账、调用合约、质押stx等交易。
2.创建p2p loop线程：处理client发送的请求，及节点间的通讯，并将网络处理结果通知relayer：process_network_result。
4.4.4.2 Signer
Signer是一个关键组件，负责处理节点间的共识和数据验证。
用户通过client构造调用系统合约pox4的交易，将Signer的btc地址及子链私钥、公钥、地址注册到系统合约上。
使用注册的密钥信息启动Signer后，会不断保持节点的运行状态和同步 、更新分布式密钥（DKG） 信息，和持续接收所监听的Stacks节点事件并进行处理 。
Copy fn run_one_pass(
&mut self,
event: Option<SignerEvent>,
cmd: Option<RunLoopCommand>,
res: Sender<Vec<OperationResult>>,
) -> Option<Vec<OperationResult>> {
// ...
// 1.保持节点的运行状态和同步
if self.state == State::Uninitialized {
if let Err(e) = self.initialize_runloop() {
error!("Failed to initialize signer runloop: {e}.");
if let Some(event) = event {
warn!("Ignoring event: {event:?}");
}
return None;
}
} else if let Some(SignerEvent::NewBurnBlock(current_burn_block_height)) = event {
if let Err(e) = self.refresh_runloop(current_burn_block_height) {
error!("Failed to refresh signer runloop: {e}.");
warn!("Signer may have an outdated view of the network.");
}
}
// ...
for signer in self.stacks_signers.values_mut() {
// ...
// 更新DKG信息
if signer.approved_aggregate_public_key.is_none() {
if let Err(e) = retry_with_exponential_backoff(|| {
signer
.update_dkg(&self.stacks_client, current_reward_cycle)
.map_err(backoff::Error::transient)
}) {
error!("{signer}: failed to update DKG: {e}");
}
}
signer.refresh_coordinator();
// 持续接收所监听的Stacks节点事件并进行处理，如验证区块信息和签名
if let Err(e) = signer.process_event(
&self.stacks_client,
event.as_ref(),
res.clone(),
current_reward_cycle,
) {
error!("{signer}: errored processing event: {e}");
}
// ...
}
None
}
