Rust跨链消息传递库xcm-runtime-apis的使用：实现Substrate区块链XCM（Cross-Consensus Messaging）运行时API集成

安装

在项目目录中运行以下Cargo命令：

cargo add xcm-runtime-apis

或者在Cargo.toml中添加以下行：

xcm-runtime-apis = "0.9.0"

使用示例

下面是一个完整的示例，展示如何使用xcm-runtime-apis库实现Substrate区块链的XCM运行时API集成：

// 引入必要的库和模块
use frame_support::{
    traits::{Get, OriginTrait},
    weights::Weight,
};
use xcm::latest::prelude::*;
use xcm_runtime_apis::{
    self as api,
    xcm::{ExecuteXcm, SendXcm},
};

// 实现XCM执行API
pub struct XcmExecuteApi;

impl ExecuteXcm for XcmExecuteApi {
    type Call = super::RuntimeCall;

    fn execute_xcm(
        origin: <Self::Origin as OriginTrait>::PalletsOrigin,
        message: Xcm<()>,
        max_weight: Weight,
    ) -> api::xcm::ExecuteXcmResult {
        // 在这里实现XCM消息的执行逻辑
        // 例如：验证origin、解析message、执行跨链操作等
        Ok(())
    }

    fn execute_xcm_in_credit(
        origin: <Self::Origin as OriginTrait>::PalletsOrigin,
        message: Xcm<()>,
        max_weight: Weight,
        weight_credit: Weight,
    ) -> api::xcm::ExecuteXcmResult {
        // 带权重信用的执行版本
        Ok(())
    }
}

// 实现XCM发送API
pub struct XcmSendApi;

impl SendXcm for XcmSendApi {
    fn send_xcm(
        destination: impl Into<MultiLocation>,
        message: Xcm<()>,
    ) -> api::xcm::SendXcmResult {
        // 在这里实现XCM消息的发送逻辑
        // 例如：验证destination、准备消息、发送到目标链等
        Ok(())
    }
}

// 在Runtime中集成XCM API
impl api::xcm::XcmApi for Runtime {
    type ExecuteXcm = XcmExecuteApi;
    type SendXcm = XcmSendApi;
}

// 示例Runtime配置
pub struct Runtime;

impl frame_system::Config for Runtime {
    type RuntimeCall = RuntimeCall;
    type RuntimeEvent = RuntimeEvent;
    type RuntimeOrigin = RuntimeOrigin;
    // 其他必要的关联类型
}

// 定义RuntimeCall和RuntimeEvent等类型
pub enum RuntimeCall {}
pub enum RuntimeEvent {}
pub struct RuntimeOrigin;

API说明

xcm-runtime-apis提供了以下关键API：

1. ExecuteXcm - 处理接收到的XCM消息的执行

   • execute_xcm() - 执行XCM消息
   • execute_xcm_in_credit() - 带权重信用的执行版本

2. SendXcm - 处理XCM消息的发送

   • send_xcm() - 发送XCM消息到目标链

3. XcmApi - 运行时API的主要接口，组合了执行和发送功能

实现注意事项

1. 需要为你的Runtime实现frame_system::Config和其他必要的trait
2. 在ExecuteXcm和SendXcm实现中处理错误情况和边界条件
3. 考虑权重计算和资源限制
4. 确保消息验证和安全性

完整示例代码

// 引入必要的库和模块
use frame_support::{
    traits::{Get, OriginTrait},
    weights::Weight,
};
use sp_std::marker::PhantomData;
use xcm::latest::prelude::*;
use xcm_runtime_apis::{
    self as api,
    xcm::{ExecuteXcm, SendXcm},
};

// 定义Runtime类型
pub struct Runtime;

// 实现frame_system::Config
impl frame_system::Config for Runtime {
    type RuntimeCall = RuntimeCall;
    type RuntimeEvent = RuntimeEvent;
    type RuntimeOrigin = RuntimeOrigin;
    type Block = Block;
    type AccountId = u64;
    type BlockHashCount = frame_support::traits::ConstU64<250>;
    type DbWeight = ();
    type BaseCallFilter = frame_support::traits::Everything;
    type Version = ();
    type PalletInfo = PalletInfo;
    type OnNewAccount = ();
    type OnKilledAccount = ();
    type SystemWeightInfo = ();
    type SS58Prefix = ();
    type OnSetCode = ();
    type MaxConsumers = frame_support::traits::ConstU32<16>;
}

// 定义RuntimeCall类型
pub enum RuntimeCall {
    System(SystemCall),
    Xcm(XcmCall),
}

// 定义SystemCall
pub enum SystemCall {
    remark { remark: Vec<u8> },
}

// 定义XcmCall
pub enum XcmCall {
    send { dest: MultiLocation, message: Xcm<()> },
}

// 定义RuntimeEvent类型
pub enum RuntimeEvent {
    System(SystemEvent),
    Xcm(XcmEvent),
}

// 定义SystemEvent
pub enum SystemEvent {
    Remarked { who: u64, hash: [u8; 32] },
}

// 定义XcmEvent
pub enum XcmEvent {
    Sent { message_id: [u8; 32] },
}

// 定义RuntimeOrigin类型
pub struct RuntimeOrigin;

// 实现OriginTrait for RuntimeOrigin
impl OriginTrait for RuntimeOrigin {
    type PalletsOrigin = PalletsOrigin;

    fn add_filter(&mut self, _filter: impl Fn(&Self::PalletsOrigin) -> bool + 'static) {
        unimplemented!()
    }

    fn reset_filter(&mut self) {
        unimplemented!()
    }
}

// 定义PalletsOrigin类型
pub enum PalletsOrigin {
    System,
    Xcm,
}

// 实现XCM执行API
pub struct XcmExecuteApi;

impl ExecuteXcm for XcmExecuteApi {
    type Call = RuntimeCall;

    fn execute_xcm(
        origin: <Self::Origin as OriginTrait>::PalletsOrigin,
        message: Xcm<()>,
        max_weight: Weight,
    ) -> api::xcm::ExecuteXcmResult {
        log::info!("Executing XCM message: {:?}", message);
        // 这里应该添加实际的执行逻辑
        Ok(())
    }

    fn execute_xcm_in_credit(
        origin: <Self::Origin as OriginTrait>::PalletsOrigin,
        message: Xcm<()>,
        max_weight: Weight,
        weight_credit: Weight,
    ) -> api::xcm::ExecuteXcmResult {
        log::info!("Executing XCM message with weight credit: {:?}", message);
        // 这里应该添加实际的执行逻辑
        Ok(())
    }
}

// 实现XCM发送API
pub struct XcmSendApi;

impl SendXcm for XcmSendApi {
    fn send_xcm(
        destination: impl Into<MultiLocation>,
        message: Xcm<()>,
    ) -> api::xcm::SendXcmResult {
        let dest = destination.into();
        log::info!("Sending XCM message to {:?}: {:?}", dest, message);
        // 这里应该添加实际的发送逻辑
        Ok(())
    }
}

// 在Runtime中集成XCM API
impl api::xcm::XcmApi for Runtime {
    type ExecuteXcm = XcmExecuteApi;
    type SendXcm = XcmSendApi;
}

// 其他必要的类型定义
pub struct Block;
pub struct PalletInfo;

这个完整示例扩展了原始示例，添加了更多类型定义和实现细节，包括：

• 完整的Runtime配置
• RuntimeCall和RuntimeEvent的具体实现
• 日志记录
• 更多必要的关联类型实现
• 更完整的类型系统定义