如何解决“借用的价值寿命不够长”的问题from serde_json::from_slice 不会导致内存泄漏？

发布于 2025-01-11 02:13:44 字数 706 浏览 0 评论 0原文

考虑以下代码片段：

pub async fn parse_bytes<'a, R: Deserialize<'a>>(_query: serde_json::Value) -> R {
    let result: Vec<u8> = vec![]; // fetch_result(&query).await

    serde_json::from_slice::<R>(result.as_slice())
        .expect("Can't parse bytes response")
}

错误

它无法编译：

`result` does not live long enough
borrowed value does not live long enough

暂定解决方案

提供 result.leak() 可以，但我不确定这是正确的解决方案：该方法的文档叙述：

此函数主要对于在程序剩余生命周期中存在的数据有用。删除返回的引用将导致内存泄漏

，并且一旦函数结束，返回的引用就会被删除。

问题

如何解决上述问题而不引起内存泄漏？

原文

Consider the following piece of code:

pub async fn parse_bytes<'a, R: Deserialize<'a>>(_query: serde_json::Value) -> R {
    let result: Vec<u8> = vec![]; // fetch_result(&query).await

    serde_json::from_slice::<R>(result.as_slice())
        .expect("Can't parse bytes response")
}

Error

It doesn't compile:

`result` does not live long enough
borrowed value does not live long enough

Tentative solution

Providing result.leak() instead works, but I'm not sure it's the right solution: the method's documentation recites:

This function is mainly useful for data that lives for the remainder of the program's life. Dropping the returned reference will cause a memory leak

And the returned reference is dropped as soon as the function ends.

Question

How do I fix the above without incurring a memory leak?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

怎会甘心 2025-01-18 02:13:44

请改用 DeserializeOwned。

use serde::de::DeserializeOwned;

pub async fn parse_bytes<R: DeserializeOwned>(_query: serde_json::Value) -> R {
    let result: Vec<u8> = vec![]; // fetch_result(&query).await

    serde_json::from_slice::<R>(result.as_slice())
        .expect("Can't parse bytes response")
}

Use DeserializeOwned instead.

use serde::de::DeserializeOwned;

pub async fn parse_bytes<R: DeserializeOwned>(_query: serde_json::Value) -> R {
    let result: Vec<u8> = vec![]; // fetch_result(&query).await

    serde_json::from_slice::<R>(result.as_slice())
        .expect("Can't parse bytes response")
}

回复收藏 0 原文

~没有更多了~