How to set Windows to return the memory occupied to the system immediately?

[cjon123]

Read the blob field from the database and output the image through the Axum web library. After the content is output, the memory occupied is not returned to the system.

use axum::{
extract::Path,
body::Body,
http::{header, StatusCode,Response},
response::IntoResponse,
routing::get,
Router,
};
use futures::StreamExt;
use sqlx::mysql::MySqlPoolOptions;
use sqlx::Row;

use mimalloc::MiMalloc;

#[global_allocator]
static GLOBAL: MiMalloc = MiMalloc;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
let pool = MySqlPoolOptions::new()
.max_connections(5)
.connect("mysql://chating:123456@192.168.2.230:3306/jp8")
.await?;

let app = Router::new()
    .route("/image/{waiter}", get(get_image))
    .with_state(pool);

println!("Server running on http://127.0.0.1:3000");
axum::serve(
    tokio::net::TcpListener::bind("127.0.0.1:3000").await?,
    app,
)
.await?;

Ok(())

}

async fn get_image(
Path(id): Path,
state: axum::extract::Statesqlx::MySqlPool,
) -> impl IntoResponse {
// search MEDIUMBLOB field
let mut rows = sqlx::query("SELECT MIMG FROM chat_message WHERE id = ?")
.bind(id)
.fetch(&state.0);

if let Some(Ok(row)) = rows.next().await {
    let data: Vec<u8> = row.get("MIMG");
    let _body = Body::from(data);

    Response::builder()
        .header(header::CONTENT_TYPE, "image/jpeg")
        .body(_body)
        .unwrap()
} else {
    (StatusCode::NOT_FOUND, "Image not found").into_response()
}

}