锈蚀AWS多部分上传使用rusoto，多线程(人造丝)惊慌失措‘没有反应堆运行...`

Question

我试图将一个文件上传到aws in rust，因为我使用的是rusoto_s3的s3锈蚀客户端，当这些部分是从单个线程发送时，我设法使多部分上传代码工作起来，然而，这不是我想要的，我想上传大文件，我希望能够在多个线程中发送这些部分，为此，我做了一点点谷歌搜索，并遇到了人丝。

关于多部分上传的工作方式如下：

1. 初始化多部分-> aws将返回一个ID
2. 使用此ID发送不同的部件，传递文件块，部件编号-> aws将返回一个Etag
3. 发送完所有部件后，发送包含所有已完成部件的完整上载请求，因为数组包含Etag和部件编号。

我是生锈新手，来自C++和Java背景，下面是我的代码：

#[tokio::test]
async fn if_multipart_then_upload_multiparts_dicom() {
    let now = Instant::now();
    dotenv().ok();
    let local_filename = "./files/test_big.DCM";
    let destination_filename = "24_time_test.dcm";

    let mut file = std::fs::File::open(local_filename).unwrap();
    const CHUNK_SIZE: usize = 7_000_000;
    let mut buffer = Vec::with_capacity(CHUNK_SIZE);

    let client = super::get_client().await;
    let create_multipart_request = CreateMultipartUploadRequest {
        bucket: client.bucket_name.to_owned(),
        key: destination_filename.to_owned(),
        ..Default::default()
    };

    // Start the multipart upload and note the upload_id generated
    let response = client
        .s3
        .create_multipart_upload(create_multipart_request)
        .await
        .expect("Couldn't create multipart upload");
    let upload_id = response.upload_id.unwrap();

    // Create upload parts
    let create_upload_part = |body: Vec<u8>, part_number: i64| -> UploadPartRequest {
        UploadPartRequest {
            body: Some(body.into()),
            bucket: client.bucket_name.to_owned(),
            key: destination_filename.to_owned(),
            upload_id: upload_id.to_owned(),
            part_number: part_number,
            ..Default::default()
        }
    };

    let completed_parts = Arc::new(Mutex::new(vec![]));

    rayon::scope(|scope| {
        let mut part_number = 1;
        loop {
            let maximum_bytes_to_read = CHUNK_SIZE - buffer.len();
            println!("maximum_bytes_to_read: {}", maximum_bytes_to_read);
            file.by_ref()
                .take(maximum_bytes_to_read as u64)
                .read_to_end(&mut buffer)
                .unwrap();

            println!("length: {}", buffer.len());
            println!("part_number: {}", part_number);
            if buffer.len() == 0 {
                // The file has ended.
                break;
            }

            let next_buffer = Vec::with_capacity(CHUNK_SIZE);
            let data_to_send = buffer;
            let completed_parts_cloned = completed_parts.clone();
            scope.spawn(move |_| {
                let part = create_upload_part(data_to_send.to_vec(), part_number);
                {
                    let part_number = part.part_number;
                    let client = executor::block_on(super::get_client());
                    let response = executor::block_on(client.s3.upload_part(part));

                    completed_parts_cloned.lock().unwrap().push(CompletedPart {
                        e_tag: response
                            .expect("Couldn't complete multipart upload")
                            .e_tag
                            .clone(),
                        part_number: Some(part_number),
                    });
                }
            });

            buffer = next_buffer;
            part_number = part_number + 1;
        }
    });

    let completed_upload = CompletedMultipartUpload {
        parts: Some(completed_parts.lock().unwrap().to_vec()),
    };

    let complete_req = CompleteMultipartUploadRequest {
        bucket: client.bucket_name.to_owned(),
        key: destination_filename.to_owned(),
        upload_id: upload_id.to_owned(),
        multipart_upload: Some(completed_upload),
        ..Default::default()
    };
    client
        .s3
        .complete_multipart_upload(complete_req)
        .await
        .expect("Couldn't complete multipart upload");
    println!(
        "time taken: {}, with chunk:: {}",
        now.elapsed().as_secs(),
        CHUNK_SIZE
    );
}

下面是我得到的输出和错误的示例：

maximum_bytes_to_read: 7000000
length: 7000000
part_number: 1
maximum_bytes_to_read: 7000000
length: 7000000
part_number: 2
maximum_bytes_to_read: 7000000
thread '<unnamed>' panicked at 'there is no reactor running, must be called from the context of a Tokio 1.x runtime', C:\Users\DNDT\.cargo\registry\src\github.com-1ecc6299db9ec823\tokio-1.2.0\src\runtime\blocking\pool.rs:85:33
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread '<unnamed>' panicked at 'there is no reactor running, must be called from the context of a Tokio 1.x runtime', C:\Users\DNDT\.cargo\registry\src\github.com-1ecc6299db9ec823\tokio-1.2.0\src\runtime\blocking\pool.rs:85:33
length: 7000000

我在googled上搜索了这个错误，但是我对它的实际内容并没有一个清晰的理解：

there is no reactor running, must be called from the context of Tokio runtime” 

下面是我发现的：有同样错误的另一个问题

还有另一个问题

这似乎是一些兼容性问题，因为s3可能正在使用与我所拥有的tokio版本不兼容的某些版本的tokio。

以下是一些相关的依赖关系：

tokio = { version = "1", features = ["full"] }
tokio-compat-02 = "0.1.2"
rusoto_s3 = "0.46.0"
rusoto_core = "0.46.0"
rusoto_credential = "0.46.0"
rayon = "1.5.0"

我认为主要的问题是想要在一个async线程中运行rayon代码。我尝试将我的async代码更改为使用executor::block_on阻止代码，我也花了一些时间试图让编译器高兴，我有多个线程他们都想写到let completed_parts = Arc::new(Mutex::new(vec![]));，所以我在这里做了一些克隆来让编译器高兴。

另外，如果我用过的蜡笔很重要，下面是它们：

extern crate dotenv;
extern crate tokio;
use bytes::Bytes;
use dotenv::dotenv;
use futures::executor;
use futures::*;
use rusoto_core::credential::{EnvironmentProvider, ProvideAwsCredentials};
use rusoto_s3::util::{PreSignedRequest, PreSignedRequestOption};
use rusoto_s3::PutObjectRequest;
use rusoto_s3::StreamingBody;
use rusoto_s3::{
    CompleteMultipartUploadRequest, CompletedMultipartUpload, CompletedPart,
    CreateMultipartUploadRequest, UploadPartRequest, S3,
};

use std::io::Read;
use std::sync::{Arc, Mutex};
use std::time::Duration;
use std::time::Instant;
use tokio::fs;

新生锈，所以有很多移动的碎片，以使这一项正确！

Answer 1

谢谢@Jmb的讨论，我摆脱了线程，并按照以下方式spawn了一个tokio任务：

创建一个持有或期货的向量，以便我们可以等待它们：

let mut multiple_parts_futures = Vec::new();

生成async任务：

loop { // loop file chuncks
    ...
    let send_part_task_future = tokio::task::spawn(async move {
    // Upload part
    ...
}

然后等待所有的未来：

let _results = futures::future::join_all(multiple_parts_futures).await;

值得一提的是，完成的部分需要排序：

let mut completed_parts_vector = completed_parts.lock().unwrap().to_vec();
completed_parts_vector.sort_by_key(|part| part.part_number);

整个守则是：

#[tokio::test]
async fn if_multipart_then_upload_multiparts_dicom() {
    let now = Instant::now();
    dotenv().ok();
    let local_filename = "./files/test_big.DCM";
    let destination_filename = generate_unique_name();
    let destination_filename_clone = destination_filename.clone();
    let mut file = std::fs::File::open(local_filename).unwrap();
    const CHUNK_SIZE: usize = 6_000_000;
    let mut buffer = Vec::with_capacity(CHUNK_SIZE);

    let client = super::get_client().await;
    let create_multipart_request = CreateMultipartUploadRequest {
        bucket: client.bucket_name.to_owned(),
        key: destination_filename.to_owned(),
        ..Default::default()
    };

    // Start the multipart upload and note the upload_id generated
    let response = client
        .s3
        .create_multipart_upload(create_multipart_request)
        .await
        .expect("Couldn't create multipart upload");
    let upload_id = response.upload_id.unwrap();

    let upload_id_clone = upload_id.clone();
    // Create upload parts
    let create_upload_part = move |body: Vec<u8>, part_number: i64| -> UploadPartRequest {
        UploadPartRequest {
            body: Some(body.into()),
            bucket: client.bucket_name.to_owned(),
            key: destination_filename_clone.to_owned(),
            upload_id: upload_id_clone.to_owned(),
            part_number: part_number,
            ..Default::default()
        }
    };

    let create_upload_part_arc = Arc::new(create_upload_part);
    let completed_parts = Arc::new(Mutex::new(vec![]));

    let mut part_number = 1;

    let mut multiple_parts_futures = Vec::new();
    loop {
        let maximum_bytes_to_read = CHUNK_SIZE - buffer.len();
        println!("maximum_bytes_to_read: {}", maximum_bytes_to_read);
        file.by_ref()
            .take(maximum_bytes_to_read as u64)
            .read_to_end(&mut buffer)
            .unwrap();
        println!("length: {}", buffer.len());
        println!("part_number: {}", part_number);
        if buffer.len() == 0 {
            // The file has ended.
            break;
        }
        let next_buffer = Vec::with_capacity(CHUNK_SIZE);
        let data_to_send = buffer;
        let completed_parts_cloned = completed_parts.clone();
        let create_upload_part_arc_cloned = create_upload_part_arc.clone();
        let send_part_task_future = tokio::task::spawn(async move {
            let part = create_upload_part_arc_cloned(data_to_send.to_vec(), part_number);
            {
                let part_number = part.part_number;
                let client = super::get_client().await;
                let response = client.s3.upload_part(part).await;
                completed_parts_cloned.lock().unwrap().push(CompletedPart {
                    e_tag: response
                        .expect("Couldn't complete multipart upload")
                        .e_tag
                        .clone(),
                    part_number: Some(part_number),
                });
            }
        });
        multiple_parts_futures.push(send_part_task_future);
        buffer = next_buffer;
        part_number = part_number + 1;
    }
    let client = super::get_client().await;
    println!("waiting for futures");
    let _results = futures::future::join_all(multiple_parts_futures).await;

    let mut completed_parts_vector = completed_parts.lock().unwrap().to_vec();
    completed_parts_vector.sort_by_key(|part| part.part_number);
    println!("futures done");
    let completed_upload = CompletedMultipartUpload {
        parts: Some(completed_parts_vector),
    };

    let complete_req = CompleteMultipartUploadRequest {
        bucket: client.bucket_name.to_owned(),
        key: destination_filename.to_owned(),
        upload_id: upload_id.to_owned(),
        multipart_upload: Some(completed_upload),
        ..Default::default()
    };

    client
        .s3
        .complete_multipart_upload(complete_req)
        .await
        .expect("Couldn't complete multipart upload");
    println!(
        "time taken: {}, with chunk:: {}",
        now.elapsed().as_secs(),
        CHUNK_SIZE
    );
}