Deferred loading wrapper

DeferredAssetFetch allows to asynchronously load requested bytes in background thread(s). It is encouraged to use it for heavy latency fetch engines like file system or network fetch engines.

use keket::{
    database::AssetDatabase,
    fetch::{deferred::DeferredAssetFetch, file::FileAssetFetch},
    protocol::bytes::BytesAssetProtocol,
};
use std::error::Error;

fn main() -> Result<(), Box<dyn Error>> {
    let mut database = AssetDatabase::default()
        .with_protocol(BytesAssetProtocol)
        // Deferred asset fetch runs fetching jobs in threads for any fetch engine.
        .with_fetch(DeferredAssetFetch::new(
            FileAssetFetch::default().with_root("resources"),
        ));

    let package = database.ensure("bytes://package.zip")?;

    // Simulate waiting for asset bytes loading to complete.
    while package.awaits_deferred_job(&database) {
        println!("Package awaits deferred job done");
        database.maintain()?;
    }

    // Run another maintain pass to process loaded bytes.
    database.maintain()?;

    println!(
        "Package byte size: {}",
        package.access::<&Vec<u8>>(&database).len()
    );

    Ok(())
}