給個rust blockchain example code看看

Rust是一种系统级编程语言，对于构建高性能的区块链应用特别适合，因为它强调内存安全和并发性。下面是一个简单的Rust区块链（以太坊风格）的例子，这个例子展示了如何创建一个基本的链数据结构和交易处理：

// 导入必要的库
use std::collections::HashMap;
use std::fmt;

// 定义区块结构
#[derive(Debug)]
struct Block {
    index: u64,
    timestamp: u64,
    transactions: Vec<Transaction>,
    previous_hash: String,
}

// 定义交易结构
#[derive(Debug)]
struct Transaction {
    sender: String,
    receiver: String,
    amount: u64,
}

// 区块链实现
impl Blockchain {
    fn new() -> Blockchain {
        Blockchain { chain: vec![Block::default()] }
    }

    // 添加新块到区块链
    fn add_block(&mut self, transaction: Transaction) {
        let last_block = &self.chain.last().unwrap();
        let next_index = last_block.index + 1;
        let current_timestamp = SystemTime::now()
            .duration_since(SystemTime::UNIX_EPOCH)
            .unwrap()
            .as_secs();

        let hash = calculate_hash(&last_block.hash, transaction.to_string(), current_timestamp);
        let new_block = Block {
            index: next_index,
            timestamp: current_timestamp,
            transactions: vec![transaction],
            previous_hash: hash,
        };

        self.chain.push(new_block);
    }

    // 计算哈希值
    fn calculate_hash(&self, prev_hash: &str, data: &str, timestamp: u64) -> String {
        // 这里仅作示例，实际中会用更复杂的加密算法如SHA-3
        format!("{}-{}-{}", prev_hash, data, timestamp)
    }
}

fn main() {
    let mut blockchain = Blockchain::new();
    
    // 创建并添加交易
    let tx1 = Transaction { sender: "Alice", receiver: "Bob", amount: 100 };
    blockchain.add_block(tx1);

    // 打印区块链
    for block in &blockchain.chain {
        println!("{:?}", block);
    }
}