将未来流对象的正文保存到磁盘

Question

我正在使用来自rusoto的PollyClient，我正在尝试处理我认为是来自方法synthesize_speech()的某种类型的Future响应。

以下是我所拥有的代码片段，它按原样编译和运行：

extern crate rusoto_core;
extern crate rusoto_polly;

use std::default::Default;
use tokio::{io};

use rusoto_core::credential::{ProfileProvider, ProvideAwsCredentials};
use rusoto_core::Region;
use rusoto_core::ByteStream;
use rusoto_polly::{PollyClient, SynthesizeSpeechInput, Polly};
use std::fs::File;
use futures::AsyncBufRead;
use std::pin::Pin;
use futures::Future;

fn main() {

    let region = Region::UsEast1;
    let polly_client = PollyClient::new(region); // using default credenetials

    let speech_input = SynthesizeSpeechInput{
        engine: Option::from(String::from("neural")),
        language_code: None,
        lexicon_names: None,
        output_format: "mp3".to_string(),
        sample_rate: None,
        speech_mark_types: None,
        text: String::from("hello world!"),
        text_type: None,
        voice_id: String::from("Amy")
    };
    let mut response = polly_client.synthesize_speech(speech_input);

    println!("Now how to we handle this respones object...");

}

我的目标是在响应中保存应该是MP3二进制数据的内容。我没有分享任何编译器错误，因为我经历了相当多不同的错误。我是Rust的新手，当我在使用非异步代码时，这是我第一次接触到它。

我是否需要将synthesize_speech()方法包装在闭包中，以便可以将其包装在某种await块中？

任何帮助或建议都将不胜感激。

Answer 1

我知道这只是一个玩具示例，但在从rusoto documentation中模仿了main()上的一些tokio async模式后，我能够让它工作：

extern crate rusoto_core;
extern crate rusoto_polly;

// use rusoto_core::credential::{ProfileProvider, ProvideAwsCredentials};
use rusoto_core::{Region};
use rusoto_polly::{PollyClient, SynthesizeSpeechInput, Polly};
use std::fs;

#[tokio::main] // https://docs.rs/tokio/0.2.2/tokio/attr.main.html
async fn main() {

    let region = Region::UsEast1;
    let polly_client = PollyClient::new(region); // using default credentials

    let speech_input = SynthesizeSpeechInput{
        engine: Option::from(String::from("neural")),
        language_code: None,
        lexicon_names: None,
        output_format: "mp3".to_string(),
        sample_rate: None,
        speech_mark_types: None,
        text: String::from("Hello world, from Rust!"),
        text_type: None,
        voice_id: String::from("Amy")
    };

    match polly_client.synthesize_speech(speech_input).await {
        Ok(output) => match output.audio_stream{
            Some(audio_stream) => {
                println!("{}", audio_stream.len());
                fs::write("mp3/rstts.mp3", audio_stream).expect("Unable to write file");
            },
            None => println!("audio stream not found"),
        },
        Err(error) => {
            println!("error: {:?}", error);
        }
    }
}