我有一个在 main(第 9 行)中初始化的变量，我想在我的一个路由处理程序中访问对这个变量的引用.
#[get("/")]fn index() ->细绳 {返回 fetch_data::fetch(format!("posts"), &redis_conn).unwrap();//我怎样才能得到redis_conn?}fn 主(){让 redis_conn = fetch_data::get_redis_connection();//在这里初始化Rocket::ignite().mount("/", routes![index]).launch();}在其他语言中，这个问题可以通过使用全局变量来解决.
请阅读 Rocket 文档
a>，特别是关于状态的部分.
使用 State 和Rocket::manage 共享状态:
#![feature(proc_macro_hygiene, decl_macro)]#[宏使用]外部板条箱火箭；//0.4.2使用火箭::状态；结构体RedisThing(i32);#[得到("/")]fn index(redis: State) ->细绳 {redis.0.to_string()}fn 主(){让 redis = RedisThing(42);火箭::点燃().管理(redis).mount("/", 路线！[索引]).发射();}如果您想改变 State 中的值，您需要将它包装在 Mutex 或其他类型的线程安全内部可变性中.
另见:
这个问题可以通过使用全局变量来解决.
另见:
I have a variable that gets initialized in main (line 9) and I want to access a reference to this variable inside of one of my route handlers.
#[get("/")]
fn index() -> String {
return fetch_data::fetch(format!("posts"), &redis_conn).unwrap(); // How can I get redis_conn?
}
fn main() {
let redis_conn = fetch_data::get_redis_connection(); // initialized here
rocket::ignite().mount("/", routes![index]).launch();
}
In other languages, this problem would be solvable by using global variables.
Please read the Rocket documentation, specifically the section on state.
Use State and Rocket::manage to have shared state:
#![feature(proc_macro_hygiene, decl_macro)]
#[macro_use]
extern crate rocket; // 0.4.2
use rocket::State;
struct RedisThing(i32);
#[get("/")]
fn index(redis: State<RedisThing>) -> String {
redis.0.to_string()
}
fn main() {
let redis = RedisThing(42);
rocket::ignite()
.manage(redis)
.mount("/", routes![index])
.launch();
}
If you want to mutate the value inside the State, you will need to wrap it in a Mutex or other type of thread-safe interior mutability.
See also:
See also:
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