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7 - 币的生命周期

Lifecycle of a Coin

您现在应该了解如何创建 Chialisp 谜语，用一组特定的规则锁定硬币。您可能想知道硬币是如何被锁定的，它存储在哪里，如何以及何时使用，以及谁可以使用它。让我们来看看硬币从创建到销毁所经历的步骤。

原文参考

You should now understand how to create Chialisp puzzles that lock up coins with a particular set of rules. You may be wondering how a coin gets locked up, where it is stored, how and when it gets spent, and who can spend it. Let's take a look at the steps a coin goes through from its creation to its destruction.

硬币集合模型​

Chia 关于硬币如何存储的模型称为硬币集合模型，它与比特币的 UTXO 模型密切相关。这个想法很简单，每个完整节点都持有一个硬币记录数据库：

class Coin:
  parent_coin_info: bytes32
  puzzle_hash: bytes32
  amount: uint64

class CoinRecord:
  coin: Coin
  confirmed_block_index: uint32
  spent_block_index: uint32
  spent: boolean
  coinbase: boolean
  timestamp: uint64

请注意，Coin 对象是区块链格式的一部分，无法更改，而 CoinRecord 对象是完整节点的一部分，可以通过替代实现进行修改

该数据库是通过从零高度查看区块链并处理所有交易直到它与当前峰值同步来生成的。当全节点处理花费时，它首先确保被花费的硬币存在于它的数据库中，运行并验证产生的 Chialisp 条件，将花费的硬币标记为花费，并添加任何新创建的硬币因此。

随着区块链的增长，这种方法使数据库变得非常轻巧，但仍然允许通过 Chialisp 实现复杂性和智能代币，Chialisp 致力于谜语哈希。这也是与其他一些区块链的一个重要区别，因为 Chialisp 中的所有状态都存储在硬币中。没有特殊的方式来存储数据以便人们可以访问它；该功能的大部分来自寻找方法来揭开谜语揭示中的正确信息，并通过承诺可预测的谜语哈希。

原文参考

  • The Coin Set Model​

Chia's model of how coins are stored is called the coin set model and is closely modelled after Bitcoin's UTXO model. The idea is simple, every full node holds onto a database of coin records:

class Coin:
  parent_coin_info: bytes32
  puzzle_hash: bytes32
  amount: uint64

class CoinRecord:
  coin: Coin
  confirmed_block_index: uint32
  spent_block_index: uint32
  spent: boolean
  coinbase: boolean
  timestamp: uint64

Note that the Coin object is part of the blockchain format and cannot be changed, while the CoinRecord object is part of the full node and can be modified by alternative implementations

This database is generated by looking at the blockchain from block height zero and processing all of the transactions until it is in sync with the current peak. When a full node processes a spend, it first makes sure that the coin being spent exists in its database, runs and validates the Chialisp conditions that are produced, marks the coin that was being spent as spent, and adds any new coins that were created as a result.

This approach makes the database very light as the blockchain grows, but still allows for complexity and smart coins through Chialisp which is committed to inside the puzzle hash. It is also an important distinction from some other blockchains in that all state in Chialisp is stored in the coins. There is no special way to store data so that people can access it; the majority of that functionality comes from finding ways to reveal the proper information in puzzle reveals and by committing to predictable puzzle hashes.

农业奖励​

您可能知道，农民在 Chia 创造了全新的价值。每隔 18.75 秒左右，就会出现一个新区块，允许农民凭空创造硬币，两种数量的非常特定的比率：1 比 7（农民与矿池）。以下是区块链第 10,000 个区块中产生的两个实际农业奖励：

[
  {
    "amount" : 1750000000000,
    "parent_coin_info" : "0xccd5bb71183532bff220ba46c268991a0000000000000000000000000000270b",
    "puzzle_hash" : "0x0b42a11b76d276f191026ae1a01c711cc0637e63d8ce0c2f62d6d079cc974920"
  },
  {
    "amount" : 250000000000,
    "parent_coin_info" : "0x3ff07eb358e8255a65c30a2dce0e5fbb0000000000000000000000000000270b",
    "puzzle_hash" : "0x0b42a11b76d276f191026ae1a01c711cc0637e63d8ce0c2f62d6d079cc974920"
  }
]

有趣的事实：创世挑战是在 Chia 网络启动时比特币区块的哈希值以及来自 Bram Cohen 的消息：““操作错误导致美联储支付系统崩溃”我们站在巨人的肩膀上，现在让我们 去种地！”

请注意，两者的 parent_coin_info 都有些奇怪。因为它们是凭空创造的，所以这些硬币被分配了一个特殊的价值作为它们的父币：“创世挑战”的一半，一些填充零，以及它们被耕种的区块的索引。

pool_parent_id = bytes32(genesis_challenge[:16] + block_height.to_bytes(16, "big"))
farmer_parent_id = bytes32(genesis_challenge[16:] + block_height.to_bytes(16, "big"))

这些信息通常不是很相关，但会被使用。例如，在汇集谜语中，奖励硬币需要在它被认领时发布公告，而另一个谜语需要声明该公告。还需要指出的是，由于创世挑战是父信息的一部分，并且由于主网和每个测试网的创世挑战不同，因此几乎不可能最终得到两个相同的硬币 ID。这在一定程度上是为了防止签名重放攻击：在测试网上签名的硬币将无法在主网上使用相同的签名。

原文参考

  • Farming Rewards​

As you probably know, farmers create the entirety of new value in Chia. Every 18.75 seconds or so, a new block pops into existence that allows for a farmer to create a coin out of thin air, in two amounts of a very specific ratio: 1 to 7 (farmer to pool). Here are two actual farming rewards that were generated in block 10,000 of the blockchain:

[
  {
    "amount" : 1750000000000,
    "parent_coin_info" : "0xccd5bb71183532bff220ba46c268991a0000000000000000000000000000270b",
    "puzzle_hash" : "0x0b42a11b76d276f191026ae1a01c711cc0637e63d8ce0c2f62d6d079cc974920"
  },
  {
    "amount" : 250000000000,
    "parent_coin_info" : "0x3ff07eb358e8255a65c30a2dce0e5fbb0000000000000000000000000000270b",
    "puzzle_hash" : "0x0b42a11b76d276f191026ae1a01c711cc0637e63d8ce0c2f62d6d079cc974920"
  }
]

Fun fact: The genesis challenge is the hash of a bitcoin block around the time when the Chia network was launched and the message from Bram Cohen: ""Operational error causes Fed payment system to crash" We stand on the shoulders of giants, now let's get farming!"

Notice that the parent_coin_info for both is a little strange. Because they are created out of thin air, the coins are assigned a special value as their parent coin: one half of the "genesis challenge", some filler zeroes, and the index of the block they are farmed in.

pool_parent_id = bytes32(genesis_challenge[:16] + block_height.to_bytes(16, "big"))
farmer_parent_id = bytes32(genesis_challenge[16:] + block_height.to_bytes(16, "big"))

This information is usually not very relevant, but it is used. For example, in the pooling puzzles, the reward coin needs to make an announcement as it's being claimed and another puzzle needs to assert that announcement. It's also important to point out that since the genesis challenge is part of the parent info, and since the genesis challenge is different between mainnet and each testnet, it's nearly impossible to end up with two identical coin ids. This is, in part, to prevent signature replay attacks: coins that are signed on testnet won't be able to use the same signature on mainnet.

花费组合​

好的，您已经收到了一些 XCH，并且想要部署您的第一个智能代币。为此，您首先必须创建一个花费组合。这有时被通俗地称为“交易”。花费组合是一个简单的结构。它是一个包含两件事的对象：一个硬币支出列表和一个聚合签名。

class SpendBundle:
  coin_solutions: List[CoinSpend]
  aggregated_signature: G2Element

硬币花费包含三件事：您尝试花费的硬币（parent_coin_info、amount、puzzle_hash）、揭开的谜语（需要树哈希到谜语哈希）和谜底。

class CoinSolution:
  coin: Coin
  puzzle_reveal: SerializedProgram
  solution: SerializedProgram

聚合签名是一个 BLS 签名，需要是由组合中谜语的条件输出的公钥/消息对的签名。您不能聚合额外的签名，也不能遗漏任何签名。如果没有输出 AGG_SIG_ME 或 AGG_SIG_UNSAFE 条件，则聚合签名必须是一个空签名，即“c”后跟 191 个零。

一旦你构建了一个花费组合，你就可以将它推送到 Chia 完整节点上的 /push_tx RPC 端点。但请记住以下几点：

  • 除非您种植该区块，否则您无法保证您的支出包是否或何时进入网络。如果两个支出以某种方式相互依赖，则它们必须在同一个花费组合中并绑定签名。
  • 使用短绝对时间锁时，请确保为花费组合到达网络留出合理的时间。有时，由于高费用压力，低费用交易可能需要一段时间才能进入。如果您的支出依赖于在时间锁定过去之前在区块链上提供硬币，这不是保证，因此请确保留出足够的时间以防万一。
  • 除了聚合签名和公告逻辑之外，从技术上讲，没有什么能将花费组合在一起。如果您进行的支出未声明来自支出中的另一个代币的公告并且不需要签名，则恶意节点或农民可能会将该支出从捆绑中排除。另请注意，未经您的许可，可以将一个花费组合与另一个组合在一起。事实上，区块创建代码在创建生成器时也做了类似的事情，我们很快就会谈到。

请记住，其他节点也在处理这部分数据，最好假设它们将尝试更改其所能更改的所有内容。确保如果以您不喜欢的方式进行任何更改，则整个组合都会失败。

原文参考

  • Spend Bundles​

Alright, so you've received some XCH and you want to deploy your first smart coin. To do that, you're first going to have to create a spend bundle. This is sometimes referred to colloquially as a "transaction". A spend bundle is a simple construct. It is an object that contains exactly two things: a list of coin spends and an aggregated signature.

class SpendBundle:
  coin_solutions: List[CoinSpend]
  aggregated_signature: G2Element

A coin spend contains exactly three things: The coin you are trying to spend (parent_coin_info, amount, puzzle_hash), the puzzle reveal (needs to tree hash to the puzzle hash), and the solution.

class CoinSolution:
  coin: Coin
  puzzle_reveal: SerializedProgram
  solution: SerializedProgram

The aggregated signature is a BLS signature and needs to be a signature of exactly the public key/message pairs that are output by the conditions from puzzles in the bundle. You cannot aggregate extra signatures, nor can you leave out any. If there are no AGG_SIG_ME or AGG_SIG_UNSAFE conditions that are output, the aggregated signature must be an empty signature which is a "c" followed 191 zeroes.

Once you have constructed a spend bundle, you can push it to the /push_tx RPC endpoint on a Chia full node. Keep in mind a few things though:

  • Unless you farm the block, you cannot guarantee if or when your spend bundle will make it to the network. If two spends rely on each other some way, they must be in the same spend bundle and bound with signatures.
  • When using short absolute timelocks, make sure to leave in a reasonable amount of time for the bundle to reach the network. Sometimes, due to high fee pressure, it may take a while for a low fee transaction to get in. If your spend relies on having the coin available on the blockchain before the timelock passes, it's not a guarantee, so make sure to leave in a good amount of time just in case.
  • Nothing technically keeps the spends in a spend bundle together except for the aggregated signature and announcement logic. If you make a spend that does not assert an announcement from another coin in the spend AND does not require a signature, that spend can be excluded from the bundle by a malicious node or farmer. Also note that a spend bundle can be aggregated with another without your permission. In fact, the block creation code does something similar when it creates the generator, which we will talk about soon.

Remember that other nodes are handling this piece of data as well, and it's best to assume that they will try to change everything that they can. Make sure that if anything changes in a way you don't like, the whole bundle will fail.

费用和内存池​

一旦您创建并推送花费组合，您的节点将对其进行验证，然后开始向其对等方八卦信息。当每个节点收到交易时，它会尝试自行验证它，如果它认为支出是无效。非常重要的是要注意，在验证它之前，节点可以运行尝试更改它的软件。这就是为什么以任何更改都会自动使签名无效的方式创建支出包非常重要或者谜语哈希。恶意节点可以将改变的交易推送给其他诚实节点，如果它不是无效的，诚实节点就会接受它。

一旦它验证了花费组合，它就会将相关信息包含到其内存池中。内存池是一个节点持有并等待放入块中的交易列表。内存池中的项目按以下顺序排序费用。当 CREATE_COIN 输出的总和小于正在花费的硬币金额时，就会产生费用。这意味着 Chia 生态系统中的任何价值都不会被破坏：如果你花费硬币并且不创造任何新硬币，农民可以将现有硬币的价值添加到他们的农业奖励中。

当内存池决定将哪些交易放入一个区块时，它看起来会放入费用/成本比率最高的交易。我们还没有过多谈论成本，但您可以在这里，我们将在后面的部分中更多地讨论优化。主要思想是：如果您使用大量数据进行复杂且难以运行的事务，您最终可能会支付在合理的时间范围内将其放入区块的费用更高。

原文参考

  • Fees and the Mempool​

Once you create and push a spend bundle, your node will validate it and then start gossiping the information out to its peers. When each node receives a transaction it tries to validate it on its own and will reject it if it considers the spend to be invalid. It is extremely important to note that before it validates it, the node can run software that tries to change it. This is why it's very important that you create your spend bundles in a way that any changes will automatically invalidate the signature or the puzzle hash. The malicious node can push the changed transaction to other honest nodes, and if it's not invalid, the honest nodes will accept it.

Once it has validated the spend bundle, it will include the relevant information into its mempool. The mempool is a list of transactions that a node is holding onto and waiting to put into a block. Items in the mempool are sorted by fees. A fee is created when the sum of the CREATE_COIN outputs is less than the amount of the coin that is being spent. This means that no value can ever be destroyed in the Chia ecosystem: if you spend a coin and don't create any new coins, the farmer can add the value of the existing coin to their farming rewards.

When the mempool is deciding which transactions to put into a block, it looks to put in the transactions with the highest fee / cost ratio. We haven't talked much about cost yet, but you can find out more about it here and we'll talk about optimization more in a later section. The main idea is: if you make a complex and hard to run transaction with a lot of data, you will probably end up paying a higher fee to get it into a block in a reasonable time frame.

交易生成器​

当农民决定在一个区块中包含交易时，他们会将所有交易聚合到一个称为交易生成器的东西中。生成器是一个 clvm 程序，它输出花费组合中的信息。它将产生一个列表包含以下内容的列表：

  • 花费硬币的父 ID
  • 谜语和谜底揭示
  • 硬币金额

然后该程序通过另一个 Chialisp 程序运行，这是共识的一部分在验证节点接收的每个块时使用。该程序解析生成器以获取谜题和解决方案，并返回块中每个交易的总条件列表。

这是一个重要的概念：一个区块中的所有交易都是并行运行的。所有这些交易都被评估为一个大程序的事实提供了一些有价值的好处：

农民不能在农场时间提前进行交易，因为交易没有顺序。他们可以踢交易，如果他们愿意，他们可以花费被踢交易计划花费的硬币，但他们不能再将交易添加回因为它曾经花费的硬币现在已经花费了。

此外，由于所有交易都作为单个条件列表返回，您的条件可能依赖来自其他交易的公告。如果您知道经常发生支出以创建公告，那么您的谜语可以在不是所有者的情况下断言该公告那笔交易！这是 Chia 网络上预言机的潜在实现。一个实体可以创建一个单例硬币，或者一个可验证只有一个的硬币，并且可以发布依赖于公告的谜语可以断言的每个块的公告。

此外，生成器还可以压缩块中的某些谜语以降低其成本。这完全取决于农民来实现这种压缩，作为 Chialisp 开发人员，您对其没有太多控制权。但是，它确实可以鼓励使用那些特定的可压缩谜语。例如，当农民创建一个包含标准交易格式的区块时，他们可以将这些交易压缩为一个公钥和一个参考块查找完整的未压缩谜语。如果您查看标准谜语并认为它太复杂而无法用作您正在编写的谜语的内部谜语，您可以尝试制作一个更简单的谜语以节省成本。但是，您实际上最终可能会支付更多成本，因为您的谜语可能不会被压缩，而标准交易会！

原文参考

  • Transaction Generators​

When a farmer decides to include transactions in a block, they will aggregate all of them into something called a transaction generator. A generator is a clvm program that outputs the information in the spend bundle. It will result in a list of lists that contain:

  • The parent ID of the coin being spent
  • The puzzle and solution reveals
  • The coin amount

That program is then run through another Chialisp program that is a part of consensus and is used when validating every block that a node receives. That program parses the generator for puzzle and solution reveals, and returns a total list of conditions for every transaction in the block.

This is an important concept: all transactions in a block are run in parallel. The fact that all of these transactions are evaluated as one big program provides some valuable benefits:

Farmers cannot front-run a transaction at farm time because there is no order to the transactions. They can kick transactions and spend the coins that the kicked transactions were planning to spend if they'd like, but they cannot then add the transaction back into the set because the coin it was spending is now already spent.

Also, since all transactions are returned as a single list of conditions, your conditions can potentially rely on announcements from other transactions. If you know that a spend frequently happens that creates an announcement, your puzzles can assert that announcement without being the owner of that transaction! This is a potential implementation for oracles on the Chia Network. An entity can create a singleton, or a coin that there is verifiably only one of, and can make announcements every block that puzzles reliant on the announcements can assert.

Furthermore, generators also enable the compression of certain puzzles in a block to reduce their cost. This is entirely dependent on the farmers to make this compression happen, and as a Chialisp developer you don't have much control over it. However, it does incentivize the use of those specific compress-able puzzles. For example, when farmers create a block with the standard transaction format in them, they can compress those transactions down to a single pubkey and a reference of a block to look in to find the full uncompressed puzzle. If you look at the standard puzzle and decide that it's too complex to use as an inner puzzle for a puzzle you are writing, you may try to make a simpler puzzle to save cost. However, you may actually end up paying more cost because your puzzle may not be compressed whereas the standard transaction will!

结论​

您现在应该对谜语运行的环境有一个相当不错的了解。编写安全的 Chialisp 谜语需要一种独特的方式来看待许多其他编程语言或区块链所没有的事物。对网络的理解与谜语的创造密不可分，虽然这会产生陡峭的学习曲线，但它也能以令人难以置信的紧凑格式实现令人难以置信的功能。

强烈建议您在决定部署任何智能代币之前充分理解本节，以确保它们的安全性和功能性。简单地在您的计算机上运行谜语并不能替代在数百万个具有不确定意图的节点上运行。

原文参考

You should now have a pretty decent grasp of the environment that your puzzles will be running in. Writing secure Chialisp puzzles requires a somewhat unique way of looking at things that is not shared by many other programming languages or blockchains. Understanding of the network is inextricably intertwined with the creation of puzzles and while that creates a steep learning curve, it also enables incredible functionality in an incredibly compact format.

It is highly recommended that you fully understand this section before you decide to deploy any smart coin so that you can ensure they are secure and functional. Simply running the puzzle on your computer is no substitute for having it run on millions of nodes with indeterminable intent.