Retry connect, and connect in parallel

Cargo.toml

@@ -23,3 +23,4 @@ mailparse = "0.5.1"
toml = "0.3.1"
xdg = "2.0.0"
notify-rust = "3.2.1"
rayon = "0.6.0"

src/main.rs

@@ -1,17 +1,20 @@
extern crate xdg;
extern crate toml;
extern crate imap;
extern crate rayon;
extern crate openssl;
extern crate systray;
extern crate mailparse;
extern crate notify_rust;

use openssl::ssl::{SslContext, SslMethod};
use imap::client::Client;
use rayon::prelude::*;

use std::collections::HashSet;
use std::process::Command;
use std::io::prelude::*;
use std::time::Duration;
use std::sync::mpsc;
use std::fs::File;
use std::thread;
@@ -122,23 +125,49 @@ fn main() {
    // TODO: w.set_tooltip(&"Whatever".to_string());
    // TODO: app.wait_for_message();

    let accounts: Vec<_> = accounts.into_iter()
    let accounts: Vec<_> = accounts.par_iter()
        .filter_map(|a| {
            let name = a.name;
            Client::secure_connect(a.server, SslContext::new(SslMethod::Sslv23).unwrap())
                .map(move |mut c| {
                    c.login(a.username, &a.password).unwrap();
                    assert!(c.capability().unwrap().iter().any(|c| c == "IDLE"));
                    c.select("INBOX").unwrap();
                    (String::from(name), c)
                })
                .map_err(move |e| {
                    println!("Failed to connect account {}: {}", name, e);
                })
                .ok()
            let mut wait = 1;
            for _ in 0..5 {
                let c = Client::secure_connect(a.server,
                                               SslContext::new(SslMethod::Sslv23).unwrap())
                    .and_then(|mut c| {
                        try!(c.login(a.username, &a.password));
                        let cap = try!(c.capability());
                        if !cap.iter().any(|c| c == "IDLE") {
                            return Err(imap::error::Error::BadResponse(cap));
                        }
                        try!(c.select("INBOX"));
                        Ok((String::from(a.name), c))
                    });

                match c {
                    Ok(c) => return Some(c),
                    Err(imap::error::Error::Io(e)) => {
                        println!("Failed to connect account {}: {}; retrying in {}s",
                                 a.name,
                                 e,
                                 wait);
                        thread::sleep(Duration::from_secs(wait));
                    }
                    Err(e) => {
                        println!("{} host produced bad IMAP tunnel: {}", a.name, e);
                        break;
                    }
                }

                wait *= 2;
            }

            None
        })
        .collect();

    if accounts.is_empty() {
        println!("No accounts in config worked; exiting...");
        return;
    }

    // We have now connected
    app.set_icon_from_file(&"/usr/share/icons/Faenza/stock/24/stock_connect.png".to_string()).ok();