You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.rs
    path of file: ./repos/crates-io-cn/src
    
    the code of the file until where you have to start completion: #[macro_use]
extern crate log;
#[macro_use]
extern crate lazy_static;

use actix_web::middleware::Logger;
use actix_web::{get, web, App, HttpResponse, HttpServer};
use std::collections::Ha
    
async fn main() -> std::io::Result<()> {
    log4rs::init_file("config/log4rs.yml", Default::default()).unwrap();
    dotenv::dotenv().ok();
    let (tx, rx) = async_channel::unbounded();
    for i in 0..10 {
        let worker_rx = rx.clone();
        tokio::spawn(async move {
            while let Ok(krate) = worker_rx.recv().await {
                debug!("[worker#{}]start to sync {:?}", i, krate);
                match Crate::create(krate).await {
                    Ok(_) => (),
                    Err(e) => error!("{}", e),
                };
            }
        });
    }
    tokio::spawn(async move {
        let gi = GitIndex::new(
            GIT_INDEX_DIR.deref(),
            &Config {
                dl: DL_FORMAT.to_string(),
                ..Default::default()
            },
        )
        .unwrap();
        loop {
            let ddl = Instant::now().add(Duration::from_secs(300));
            info!("next update will on {:?}, exec git update now", ddl);
            #[cfg(all(feature = "systemd", target_os = "linux"))]
            systemd::notify_watchdog();
            let updated = gi.update();
            let crates = match updated {
                Ok(crates) => crates,
                Err(e) => {
                    error!("git update error: {}", e);
                    tokio::time::sleep(Duration::from_secs(10)).await;
                    continue;
                }
            };
            for krate in crates {
                if let Err(e) = tx.send(krate).await {
                    error!("{}", e);
                }
            }
            tokio::time::sleep_until(ddl).await;
        }
    });
    let server = HttpServer::new(|| App::new().wrap(Logger::default()).service(sync))
        .bind("127.0.0.1:8080")?
        .run();
    #[cfg(all(feature = "systemd", target_os = "linux"))]
    systemd::notify_ready();
    server.await
}