add crate cli_helpers with option and config parsing; use in aquatic

Putting cli functionality into its own crate will allow using it
from aquatic_bench and possibly other programs.

aquatic/Cargo.toml

@@ -13,6 +13,7 @@ name = "aquatic"
 
 [dependencies]
 bittorrent_udp = { path = "../bittorrent_udp" }
+cli_helpers = { path = "../cli_helpers" }
 dashmap = "3"
 histogram = "0.6"
 indexmap = "1"
@@ -20,6 +21,7 @@ mimalloc = { version = "0.1", default-features = false }
 mio = { version = "0.7", features = ["udp", "os-poll", "os-util"] }
 net2 = "0.2"
 rand = { version = "0.7", features = ["small_rng"] }
+serde = { version = "1", features = ["derive"] }
 
 [dev-dependencies]
 quickcheck = "0.9"

aquatic/src/bin/aquatic.rs

@@ -1,4 +1,5 @@
 use aquatic;
+use cli_helpers;
 
 
 #[global_allocator]
@@ -6,5 +7,8 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
 
 
 fn main(){
-    aquatic::run();
+    cli_helpers::run_with_cli_and_config(
+        "aquatic: udp bittorrent tracker",
+        aquatic::run,
+    )
 }

aquatic/src/lib/config.rs

@@ -1,7 +1,9 @@
 use std::net::SocketAddr;
 
+use serde::{Serialize, Deserialize};
 
-#[derive(Clone)]
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Config {
     /// Spawn this number of threads for workers
     pub num_threads: usize,
@@ -11,7 +13,7 @@ pub struct Config {
 }
 
 
-#[derive(Clone)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct NetworkConfig {
     /// Bind to this address
     pub address: SocketAddr,
@@ -27,14 +29,14 @@ pub struct NetworkConfig {
 }
 
 
-#[derive(Clone)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct StatisticsConfig {
     /// Print statistics this often (seconds). Don't print when set to zero.
     pub interval: u64,
 }
 
 
-#[derive(Clone)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct CleaningConfig {
     /// Clean torrents and connections this often (seconds)
     pub interval: u64,
@@ -88,4 +90,4 @@ impl Default for CleaningConfig {
             max_connection_age: 60 * 5,
         }
     }
-}
+}

aquatic/src/lib/lib.rs

@@ -10,8 +10,7 @@ use config::Config;
 use common::State;
 
 
-pub fn run(){
-    let config = Config::default();
+pub fn run(config: Config){
     let state = State::new();
 
     for i in 0..config.num_threads {