Solana 计数器教程：账户数据的读写

在前文《Solana 与 Anchor 中的账户初始化》中，我们探讨了如何初始化账户以持久化存储数据。本文将展示如何向已初始化的账户写入数据，并读取其内容。

以下基于之前的代码，新增 set() 函数，用于更新 MyStorage 中的 x 值：

use anchor_lang::prelude::*;
use std::mem::size_of;

declare_id!("9XZGDi1imvGFV3bLuDJK1bkUht51GPCRsVxMe4DpqWEo");

#[program]
pub mod basic_storage {
    use super::*;

    pub fn initialize(ctx: Context<Initialize>) -> Result<()> {
        Ok(())
    }

    // 新增：写入 x 值
    pub fn set(ctx: Context<Set>, new_x: u64) -> Result<()> {
        ctx.accounts.my_storage.x = new_x;
        Ok(())
    }
}

// 新增：Set 账户结构
#[derive(Accounts)]
pub struct Set<'info> {
    #[account(mut, seeds = [], bump)]
    pub my_storage: Account<'info, MyStorage>,
}

#[derive(Accounts)]
pub struct Initialize<'info> {
    #[account(
        init,
        payer = signer,
        space = size_of::<MyStorage>() + 8,
        seeds = [],
        bump
    )]
    pub my_storage: Account<'info, MyStorage>,
    #[account(mut)]
    pub signer: Signer<'info>,
    pub system_program: Program<'info, System>,
}

#[account]
pub struct MyStorage {
    x: u64,
}

测试代码更新，新增调用 set(10)：

import * as anchor from "@coral-xyz/anchor";
import { Program } from "@coral-xyz/anchor";
import { BasicStorage } from "../target/types/basic_storage";
import { BN } from "@coral-xyz/anchor";

describe("basic_storage", () => {
  anchor.setProvider(anchor.AnchorProvider.env());

  const program = anchor.workspace.BasicStorage as Program<BasicStorage>;

  it("Is initialized!", async () => {
    const seeds = []
    const [myStorage, _bump] = anchor.web3.PublicKey.findProgramAddressSync(seeds, program.programId);

    console.log("the storage account address is", myStorage.toBase58());

    await program.methods.initialize().accounts({ myStorage: myStorage }).rpc();
  });

  it("set the value", async () => {
    const seeds = []
    const [myStorage, _bump] = anchor.web3.PublicKey.findProgramAddressSync(seeds, p...