Rust区块链存储迁移库pallet-state-trie-migration使用指南

完整示例代码

以下是基于提供内容的完整示例，展示如何使用pallet-state-trie-migration进行区块链存储迁移：

//! 完整的状态树迁移示例

use frame_support::{construct_runtime, parameter_types, traits::ConstU32};
use frame_system::EnsureRoot;
use pallet_balances;
use sp_core::H256;
use sp_runtime::{
    traits::{BlakeTwo256, IdentityLookup},
    BuildStorage,
};

// 1. 定义Runtime配置
type Block = frame_system::mocking::MockBlock<Runtime>;

frame_support::construct_runtime!(
    pub enum Runtime where
        Block = Block,
        NodeBlock = Block,
        UncheckedExtrinsic = (),
    {
        System: frame_system,
        Balances: pallet_balances,
        StateTrieMigration: pallet_state_trie_migration,
    }
);

parameter_types! {
    pub const BlockHashCount: u64 = 250;
    pub const SS58Prefix: u8 = 42;
}

impl frame_system::Config for Runtime {
    type BaseCallFilter = frame_support::traits::Everything;
    type BlockWeights = ();
    type BlockLength = ();
    type DbWeight = ();
    type RuntimeOrigin = RuntimeOrigin;
    type RuntimeCall = RuntimeCall;
    type Nonce = u64;
    type Hash = H256;
    type Hashing = BlakeTwo256;
    type AccountId = u64;
    type Lookup = IdentityLookup<Self::AccountId>;
    type Block = Block;
    type RuntimeEvent = RuntimeEvent;
    type BlockHashCount = BlockHashCount;
    type Version = ();
    type PalletInfo = PalletInfo;
    type AccountData = pallet_balances::AccountData<u64>;
    type OnNewAccount = ();
    type OnKilledAccount = ();
    type SystemWeightInfo = ();
    type SS58Prefix = SS58Prefix;
    type OnSetCode = ();
    type MaxConsumers = ConstU32<16>;
}

parameter_types! {
    pub const ExistentialDeposit: u64 = 1;
}

impl pallet_balances::Config for Runtime {
    type Balance = u64;
    type DustRemoval = ();
    type RuntimeEvent = RuntimeEvent;
    type ExistentialDeposit = ExistentialDeposit;
    type AccountStore = System;
    type WeightInfo = ();
    type MaxLocks = ();
    type MaxReserves = ();
    type ReserveIdentifier = [u8; 8];
    type HoldIdentifier = ();
    type FreezeIdentifier = ();
    type MaxHolds = ();
    type MaxFreezes = ();
}

// 2. 配置state-trie-migration pallet
impl pallet_state_trie_migration::Config for Runtime {
    type RuntimeEvent = RuntimeEvent;
    type Currency = Balances;
    type ControlOrigin = EnsureRoot<u64>;
    type MaxKeyLen = ConstU32<512>;
    type WeightInfo = ();
}

// 3. 测试函数 - 完整的迁移流程
fn test_migration_process() {
    // 初始化测试环境
    let mut ext = sp_io::TestExternalities::new(
        frame_system::GenesisConfig::<Runtime>::default().build_storage().unwrap()
    );
    
    ext.execute_with(|| {
        // 1. 开始迁移
        pallet_state_trie_migration::Pallet::<Runtime>::start(
            RuntimeOrigin::root()
        ).unwrap();
        
        // 2. 检查状态
        let status = pallet_state_trie_migration::Pallet::<Runtime>::status();
        assert!(matches!(status, pallet_state_trie_migration::MigrationStatus::NotStarted));
        
        // 3. 设置迁移参数
        pallet_state_trie_migration::Pallet::<Runtime>::set_config(
            RuntimeOrigin::root(),
            pallet_state_trie_migration::MigrationLimits {
                size: 1024 * 1024,  // 1MB
                item: 1000,         // 1000 items
            }
        ).unwrap();
        
        // 4. 执行迁移循环
        loop {
            let status = pallet_state_trie_migration::Pallet::<Runtime>::status();
            match status {
                pallet_state_trie_migration::MigrationStatus::Complete => break,
                _ => {
                    // 推进迁移
                    pallet_state_trie_migration::Pallet::<Runtime>::continue_migration(
                        RuntimeOrigin::root(),
                        1000,
                        1024 * 1024,
                    ).unwrap();
                    
                    // 模拟区块前进
                    frame_system::Pallet::<Runtime>::set_block_number(
                        frame_system::Pallet::<Runtime>::block_number() + 1
                    );
                }
            }
        }
        
        // 5. 完成迁移
        pallet_state_trie_migration::Pallet::<Runtime>::complete(
            RuntimeOrigin::root()
        ).unwrap();
    });
}

// 4. 监控迁移进度示例
fn monitor_migration_progress() {
    let status = pallet_state_trie_migration::Pallet::<Runtime>::status();
    
    match status {
        pallet_state_trie_migration::MigrationStatus::NotStarted => {
            println!("迁移尚未开始");
        },
        pallet_state_trie_migration::MigrationStatus::InProgress { top, child } => {
            println!("迁移进度: 顶层键 {} 个, 子键 {} 个", top, child);
            println!("迁移进度百分比: {:.2}%", 
                (top + child) as f32 / TOTAL_KEYS as f32 * 100.0
            );
        },
        pallet_state_trie_migration::MigrationStatus::Complete => {
            println!("迁移已完成");
        },
    }
}

// 假设的总键数
const TOTAL_KEYS: u32 = 10000;

fn main() {
    println!("状态树迁移示例");
    test_migration_process();
    monitor_migration_progress();
}

代码说明

1. Runtime配置:

   • 定义了完整的Runtime结构，包含系统模块、余额模块和状态迁移模块
   • 为每个模块实现了相应的配置trait

2. 迁移流程:

   • test_migration_process函数展示了完整的迁移生命周期
   • 从初始化、参数设置到分批执行和最终完成

3. 监控功能:

   • monitor_migration_progress函数演示如何获取和显示迁移进度
   • 可以计算并显示迁移完成的百分比

4. 关键参数:

   • MigrationLimits控制每次迁移的规模
   • status()调用获取当前迁移状态

执行流程

1. 初始化测试环境
2. 开始迁移过程
3. 配置迁移参数
4. 循环执行迁移直到完成
5. 监控和报告进度
6. 最终完成迁移

扩展建议

1. 可以添加日志记录功能，记录每次迁移的详细情况
2. 实现自动化监控和报警，当迁移停滞时发出警告
3. 添加性能指标收集，分析迁移对链性能的影响
4. 实现更复杂的错误恢复机制

这个完整示例涵盖了状态树迁移的主要操作场景，可以直接在测试环境中运行验证。