Refactor gossip code from one huge function (#10701)

gossip/src/main.rs

@@ -12,9 +12,7 @@ use std::error;
 use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::process::exit;
 
-fn main() -> Result<(), Box<dyn error::Error>> {
+fn parse_matches() -> ArgMatches<'static> {
-    solana_logger::setup_with_default("solana=info");
-
     let shred_version_arg = Arg::with_name("shred_version")
         .long("shred-version")
         .value_name("VERSION")
@@ -22,7 +20,7 @@ fn main() -> Result<(), Box<dyn error::Error>> {
         .default_value("0")
         .help("Filter gossip nodes by this shred version");
 
-    let matches = App::new(crate_name!())
+    App::new(crate_name!())
         .about(crate_description!())
         .version(solana_version::version!())
         .setting(AppSettings::SubcommandRequiredElseHelp)
@@ -150,37 +148,11 @@ fn main() -> Result<(), Box<dyn error::Error>> {
                         .help("Public key of a specific node to stop"),
                 ),
         )
-        .get_matches();
+        .get_matches()
-
-    fn parse_entrypoint(matches: &ArgMatches) -> Option<SocketAddr> {
-        matches.value_of("entrypoint").map(|entrypoint| {
-            solana_net_utils::parse_host_port(entrypoint).unwrap_or_else(|e| {
-                eprintln!("failed to parse entrypoint address: {}", e);
-                exit(1);
-            })
-        })
 }
 
-    match matches.subcommand() {
+fn parse_gossip_host(matches: &ArgMatches, entrypoint_addr: Option<SocketAddr>) -> IpAddr {
-        ("spy", Some(matches)) => {
+    matches
-            let num_nodes_exactly = matches
-                .value_of("num_nodes_exactly")
-                .map(|num| num.to_string().parse().unwrap());
-            let num_nodes = matches
-                .value_of("num_nodes")
-                .map(|num| num.to_string().parse().unwrap())
-                .or(num_nodes_exactly);
-            let timeout = matches
-                .value_of("timeout")
-                .map(|secs| secs.to_string().parse().unwrap());
-            let pubkey = matches
-                .value_of("node_pubkey")
-                .map(|pubkey_str| pubkey_str.parse::<Pubkey>().unwrap());
-            let shred_version = value_t_or_exit!(matches, "shred_version", u16);
-
-            let entrypoint_addr = parse_entrypoint(&matches);
-
-            let gossip_host = matches
         .value_of("gossip_host")
         .map(|gossip_host| {
             solana_net_utils::parse_host(gossip_host).unwrap_or_else(|e| {
@@ -190,41 +162,26 @@ fn main() -> Result<(), Box<dyn error::Error>> {
         })
         .unwrap_or_else(|| {
             if let Some(entrypoint_addr) = entrypoint_addr {
-                        solana_net_utils::get_public_ip_addr(&entrypoint_addr).unwrap_or_else(
+                solana_net_utils::get_public_ip_addr(&entrypoint_addr).unwrap_or_else(|err| {
-                            |err| {
                     eprintln!(
                         "Failed to contact cluster entrypoint {}: {}",
                         entrypoint_addr, err
                     );
                     exit(1);
-                            },
+                })
-                        )
             } else {
                 IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1))
             }
-                });
+        })
-
+}
-            let gossip_addr = SocketAddr::new(
-                gossip_host,
-                value_t!(matches, "gossip_port", u16).unwrap_or_else(|_| {
-                    solana_net_utils::find_available_port_in_range(
-                        IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)),
-                        (0, 1),
-                    )
-                    .expect("unable to find an available gossip port")
-                }),
-            );
-
-            let (_all_peers, validators) = discover(
-                entrypoint_addr.as_ref(),
-                num_nodes,
-                timeout,
-                pubkey,
-                None,
-                Some(&gossip_addr),
-                shred_version,
-            )?;
 
+fn process_spy_results(
+    timeout: Option<u64>,
+    validators: Vec<ContactInfo>,
+    num_nodes: Option<usize>,
+    num_nodes_exactly: Option<usize>,
+    pubkey: Option<Pubkey>,
+) {
     if timeout.is_some() {
         if let Some(num) = num_nodes {
             if validators.len() < num {
@@ -257,7 +214,63 @@ fn main() -> Result<(), Box<dyn error::Error>> {
         }
     }
 }
-        ("rpc-url", Some(matches)) => {
+
+fn process_spy(matches: &ArgMatches) -> std::io::Result<()> {
+    let num_nodes_exactly = matches
+        .value_of("num_nodes_exactly")
+        .map(|num| num.to_string().parse().unwrap());
+    let num_nodes = matches
+        .value_of("num_nodes")
+        .map(|num| num.to_string().parse().unwrap())
+        .or(num_nodes_exactly);
+    let timeout = matches
+        .value_of("timeout")
+        .map(|secs| secs.to_string().parse().unwrap());
+    let pubkey = matches
+        .value_of("node_pubkey")
+        .map(|pubkey_str| pubkey_str.parse::<Pubkey>().unwrap());
+    let shred_version = value_t_or_exit!(matches, "shred_version", u16);
+
+    let entrypoint_addr = parse_entrypoint(matches);
+
+    let gossip_host = parse_gossip_host(matches, entrypoint_addr);
+
+    let gossip_addr = SocketAddr::new(
+        gossip_host,
+        value_t!(matches, "gossip_port", u16).unwrap_or_else(|_| {
+            solana_net_utils::find_available_port_in_range(
+                IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)),
+                (0, 1),
+            )
+            .expect("unable to find an available gossip port")
+        }),
+    );
+
+    let (_all_peers, validators) = discover(
+        entrypoint_addr.as_ref(),
+        num_nodes,
+        timeout,
+        pubkey,
+        None,
+        Some(&gossip_addr),
+        shred_version,
+    )?;
+
+    process_spy_results(timeout, validators, num_nodes, num_nodes_exactly, pubkey);
+
+    Ok(())
+}
+
+fn parse_entrypoint(matches: &ArgMatches) -> Option<SocketAddr> {
+    matches.value_of("entrypoint").map(|entrypoint| {
+        solana_net_utils::parse_host_port(entrypoint).unwrap_or_else(|e| {
+            eprintln!("failed to parse entrypoint address: {}", e);
+            exit(1);
+        })
+    })
+}
+
+fn process_rpc_url(matches: &ArgMatches) -> std::io::Result<()> {
     let any = matches.is_present("any");
     let all = matches.is_present("all");
     let entrypoint_addr = parse_entrypoint(&matches);
@@ -296,8 +309,11 @@ fn main() -> Result<(), Box<dyn error::Error>> {
             break;
         }
     }
+
+    Ok(())
 }
-        ("stop", Some(matches)) => {
+
+fn process_stop(matches: &ArgMatches) -> Result<(), Box<dyn error::Error>> {
     let entrypoint_addr = parse_entrypoint(&matches);
     let pubkey = matches
         .value_of("node_pubkey")
@@ -330,6 +346,24 @@ fn main() -> Result<(), Box<dyn error::Error>> {
     } else {
         eprintln!("Error: Stop signal ignored");
     }
+
+    Ok(())
+}
+
+fn main() -> Result<(), Box<dyn error::Error>> {
+    solana_logger::setup_with_default("solana=info");
+
+    let matches = parse_matches();
+
+    match matches.subcommand() {
+        ("spy", Some(matches)) => {
+            process_spy(matches)?;
+        }
+        ("rpc-url", Some(matches)) => {
+            process_rpc_url(matches)?;
+        }
+        ("stop", Some(matches)) => {
+            process_stop(matches)?;
         }
         _ => unreachable!(),
     }