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: uploader.rs
    path of file: ./repos/quickwit/quickwit/quickwit-indexing/src/actors
    
    the code of the file until where you have to start completion: // Copyright (C) 2024 Quickwit, Inc.
//
// Quickwit is offered under the AGPL v3.0 and as commercial software.
// For commercial licensing, contact us at hello@quickwit.io.
//
// AGPL:
// This program is free software: you can redistribute it an
    
    fn queue_capacity(&self) -> QueueCapacity {
        // We do not need a large capacity here...
        // The uploader just spawns tasks that are uploading,
        // so that in a sense, the CONCURRENT_UPLOAD_PERMITS semaphore also acts as
        // a queue capacity.
        //
        // Having a large queue is costly too, because each message is a handle over
        // a split directory. We DO need aggressive backpressure here.
        QueueCapacity::Bounded(0)
    }