Stop indexing after SIGINT

Cargo.toml

@@ -9,6 +9,8 @@ arrayref = "0.3"
 base64 = "0.9"
 bincode = "1.0"
 bitcoin = "0.13"
+chan = "0.1"
+chan-signal = "0.3"
 error-chain = "0.11"
 hex = "0.3"
 log = "0.4"

TODO.txt

@@ -17,6 +17,5 @@ Flush only on the last write.
 
 = Rust
 Use Bytes instead of Vec[u8] when possible
-Handle SIGINT gracefully (https://www.reddit.com/r/rust/comments/6swidb/how_to_properly_catch_sigint_in_a_threaded_program/)
 Return errors instead of panics
 Use generators instead of vectors

src/app.rs

@@ -1,4 +1,6 @@
 use argparse::{ArgumentParser, Store, StoreTrue};
+use chan;
+use chan_signal;
 use error_chain::ChainedError;
 use simplelog::LevelFilter;
 use std::fs::OpenOptions;
@@ -100,7 +102,30 @@ impl App {
     }
 }
 
+struct Waiter {
+    signal: chan::Receiver<chan_signal::Signal>,
+    duration: Duration,
+}
+
+impl Waiter {
+    fn new(duration: Duration) -> Waiter {
+        let signal = chan_signal::notify(&[chan_signal::Signal::INT]);
+        Waiter { signal, duration }
+    }
+    fn wait(&self) -> Option<chan_signal::Signal> {
+        let signal = &self.signal;
+        let timeout = chan::after(self.duration);
+        let result;
+        chan_select! {
+            signal.recv() -> sig => { result = sig; },
+            timeout.recv() => { result = None; },
+        }
+        result
+    }
+}
+
 fn run_server(config: &Config) -> Result<()> {
+    let signal = Waiter::new(Duration::from_secs(5));
     let daemon = daemon::Daemon::new(config.network_type)?;
     debug!("{:?}", daemon.getblockchaininfo()?);
 
@@ -124,16 +149,16 @@ fn run_server(config: &Config) -> Result<()> {
     });
 
     let query = Arc::new(query::Query::new(app.clone()));
-    let poll_delay = Duration::from_secs(5);
     rpc::start(&config.rpc_addr, query.clone());
-    loop {
-        thread::sleep(poll_delay);
+    while let None = signal.wait() {
         query.update_mempool()?;
         if tip == app.daemon().getbestblockhash()? {
             continue;
         }
         tip = app.index().update(app.write_store(), app.daemon())?;
     }
+    info!("closing server");
+    Ok(())
 }
 
 fn setup_logging(config: &Config) {

src/lib.rs

@@ -4,6 +4,7 @@ extern crate argparse;
 extern crate base64;
 extern crate bincode;
 extern crate bitcoin;
+extern crate chan_signal;
 extern crate crypto;
 extern crate hex;
 extern crate pbr;
@@ -11,7 +12,8 @@ extern crate rocksdb;
 extern crate serde;
 extern crate simplelog;
 extern crate time;
-
+#[macro_use]
+extern crate chan;
 #[macro_use]
 extern crate arrayref;
 #[macro_use]