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.

Cargo.lock

@@ -18,11 +18,18 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9a60d744a80c30fcb657dfe2c1b22bcb3e814c1a1e3674f32bf5820b570fbff"
+
 [[package]]
 name = "aquatic"
 version = "0.1.0"
 dependencies = [
  "bittorrent_udp",
+ "cli_helpers",
  "dashmap",
  "histogram",
  "indexmap",
@@ -32,6 +39,7 @@ dependencies = [
  "quickcheck",
  "quickcheck_macros",
  "rand",
+ "serde",
 ]
 
 [[package]]
@@ -142,6 +150,16 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
+[[package]]
+name = "cli_helpers"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "gumdrop",
+ "serde",
+ "toml",
+]
+
 [[package]]
 name = "clicolors-control"
 version = "1.0.1"
@@ -237,6 +255,26 @@ dependencies = [
  "wasi",
 ]
 
+[[package]]
+name = "gumdrop"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee50908bc1beeac1f2902e0b4e0cd0d844e716f5ebdc6f0cfc1163fe5e10bcde"
+dependencies = [
+ "gumdrop_derive",
+]
+
+[[package]]
+name = "gumdrop_derive"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90454ce4de40b7ca6a8968b5ef367bdab48413962588d0d2b1638d60090c35d7"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.10"

Cargo.toml

@@ -1,9 +1,10 @@
 [workspace]
 
 members = [ 
-    "bittorrent_udp",
     "aquatic",
     "aquatic_bench",
+    "bittorrent_udp",
+    "cli_helpers",
 ]
 
 [profile.release]

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,

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 {

cli_helpers/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "cli_helpers"
+version = "0.1.0"
+authors = ["Joakim Frostegård <joakim.frostegard@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+anyhow = "1"
+gumdrop = "0.7"
+serde = { version = "1", features = ["derive"] }
+toml = "0.5"

cli_helpers/src/lib.rs

@@ -0,0 +1,80 @@
+use std::fs::File;
+use std::io::Read;
+
+use anyhow;
+use gumdrop::Options;
+use serde::{Serialize, de::DeserializeOwned};
+use toml;
+
+
+#[derive(Debug, Options)]
+struct AppOptions {
+    #[options(help = "run with config file", short = "c", meta = "PATH")]
+    config_file: Option<String>,
+    #[options(help = "print default config file")]
+    print_config: bool,
+    #[options(help = "print help message")]
+    help: bool,
+}
+
+
+fn config_from_toml_file<T>(path: String) -> anyhow::Result<T>
+    where T: DeserializeOwned
+{
+    let mut file = File::open(path)?;
+    let mut data = String::new();
+    file.read_to_string(&mut data)?;
+
+    toml::from_str(&data).map_err(|e| anyhow::anyhow!("Parse failed: {}", e))
+}
+
+fn default_config_as_toml<T>() -> String
+    where T: Default + Serialize
+{
+    toml::to_string_pretty(&T::default())
+        .expect("Could not serialize default config to toml")
+}
+
+
+pub fn run_with_cli_and_config<T, F>(
+    title: &str,
+    // Function that takes config file and runs application
+    f: F,
+) where T: Default + Serialize + DeserializeOwned, F: Fn(T) {
+    let args: Vec<String> = ::std::env::args().collect();
+
+    match AppOptions::parse_args_default(&args[1..]){
+        Ok(opts) => {
+            if opts.help_requested(){
+                print_help(title, None);
+            } else if opts.print_config {
+                print!("{}", default_config_as_toml::<T>());
+            } else if let Some(config_file) = opts.config_file {
+                match config_from_toml_file(config_file){
+                    Ok(config) => f(config),
+                    Err(err) => {
+                        eprintln!("Error while reading config file: {}", err);
+
+                        ::std::process::exit(1);
+                    }
+                }
+            } else {
+                f(T::default())
+            }
+        },
+        Err(err) => {
+            print_help(title, Some(&format!("{}", err)))
+        }
+    }
+}
+
+
+fn print_help(title: &str, opt_error: Option<&str>){
+    println!("{}", title);
+
+    if let Some(error) = opt_error {
+        println!("\nError: {}.", error);
+    }
+
+    println!("\n{}", AppOptions::usage());
+}

scripts/run-server.sh

@@ -2,4 +2,4 @@
 
 export RUSTFLAGS="-C target-cpu=native"
 
-cargo run --release --bin aquatic
+cargo run --release --bin aquatic -- $@