rust rusoto S3 obj fetcher with StaticProvider

s3_obj_fetcher.rs

extern crate rusoto_core;
extern crate rusoto_credential;
extern crate rusoto_s3;

use rusoto_core::Region;
use rusoto_credential::StaticProvider;

use rusoto_core::reactor::RequestDispatcher;
use rusoto_s3::{S3, S3Client, ListObjectsV2Request};

fn main() {
    // in lieu of toml cfg
    let aws_public_key: String = "xxx".to_string();
    let aws_private_key: String =  "yyy".to_string();
    let bucket_name: String = "abc-def-data".to_string();
    let meta_prefix:String = "zzz/metadata".to_string();
    let meta_postfix:String = "-onix.xml".to_string();

    let region = Region::UsEast1;
    let provider: StaticProvider = StaticProvider::new_minimal(aws_public_key, aws_private_key);
    let s3_client = S3Client::new(RequestDispatcher::default(), provider, region);


     let mut request = ListObjectsV2Request {bucket: bucket_name.clone(),
                                             prefix: Some(meta_prefix.clone()),
                                             ..Default::default()};

    let mut key_names:Vec<String> = Vec::new();
    let mut key_counter = 0u32;
    loop {
        let result = s3_client.list_objects_v2(&request).sync().unwrap();

        if !result.contents.is_some() {
            break;
        }

        let objs = &result.contents.unwrap();
        let last_obj = &objs[&objs.len() - 1];

        key_counter += result.key_count.unwrap() as u32;
        request.start_after = last_obj.key.clone();

        for obj in objs {
            if obj.key.is_some() {
                let key = obj.clone().key.unwrap();
                if key.ends_with(&meta_postfix) {
                    key_names.push(key);
                }
            }
            else {
                println!("got a borked S3 obj: {:?}", obj);
            }
        }
    }
    println!("loop counter: {}", key_counter);
    println!("key count     {}", key_names.len());
    assert_eq!(key_names.len(), 6511);

}
/* cargo.toml
[package]
name = "ru-s3"
version = "0.1.0"

[profile.release]
lto = true
panic = 'abort'

[dependencies]
rusoto_core = "0.32.0"
rusoto_credential = "0.11"
rusoto_s3 = "0.32.0"
*/