Fix more Clippy warnings

examples/index.rs

@@ -12,7 +12,7 @@ use electrs::{
 use error_chain::ChainedError;
 
 fn run() -> Result<()> {
-    let signal = Waiter::new();
+    let signal = Waiter::start();
     let config = Config::from_args();
     let metrics = Metrics::new(config.monitoring_addr);
     metrics.start();

src/bin/electrs.rs

@@ -23,7 +23,7 @@ use electrs::{
 };
 
 fn run_server(config: &Config) -> Result<()> {
-    let signal = Waiter::new();
+    let signal = Waiter::start();
     let metrics = Metrics::new(config.monitoring_addr);
     metrics.start();
 

src/daemon.rs

@@ -8,7 +8,7 @@ use bitcoin_hashes::hex::{FromHex, ToHex};
 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
 use glob;
 use hex;
-use serde_json::{from_str, from_value, Value};
+use serde_json::{from_str, from_value, Map, Value};
 use std::collections::{HashMap, HashSet};
 use std::io::{BufRead, BufReader, Lines, Write};
 use std::net::{SocketAddr, TcpStream};
@@ -55,23 +55,28 @@ fn tx_from_value(value: Value) -> Result<Transaction> {
 
 /// Parse JSONRPC error code, if exists.
 fn parse_error_code(err: &Value) -> Option<i64> {
+    if err.is_null() {
+        return None;
+    }
     err.as_object()?.get("code")?.as_i64()
 }
 
-fn parse_jsonrpc_reply(mut reply: Value, method: &str, expected_id: u64) -> Result<Value> {
-    if let Some(reply_obj) = reply.as_object_mut() {
+fn check_error_code(reply_obj: &Map<String, Value>, method: &str) -> Result<()> {
     if let Some(err) = reply_obj.get("error") {
-            if !err.is_null() {
         if let Some(code) = parse_error_code(&err) {
             match code {
                 // RPC_IN_WARMUP -> retry by later reconnection
                 -28 => bail!(ErrorKind::Connection(err.to_string())),
-                        _ => (),
+                _ => bail!("{} RPC error: {}", method, err),
             }
         }
-                bail!("{} RPC error: {}", method, err);
-            }
     }
+    Ok(())
+}
+
+fn parse_jsonrpc_reply(mut reply: Value, method: &str, expected_id: u64) -> Result<Value> {
+    if let Some(reply_obj) = reply.as_object_mut() {
+        check_error_code(reply_obj, method)?;
         let id = reply_obj
             .get("id")
             .chain_err(|| format!("no id in reply: {:?}", reply_obj))?
@@ -612,7 +617,7 @@ impl Daemon {
         bestblockhash: &Sha256dHash,
     ) -> Result<Vec<BlockHeader>> {
         // Iterate back over headers until known blockash is found:
-        if indexed_headers.len() == 0 {
+        if indexed_headers.is_empty() {
             return self.get_all_headers(bestblockhash);
         }
         debug!(

src/index.rs

@@ -133,7 +133,7 @@ impl TxRow {
         }
     }
 
-    pub fn filter_prefix(txid_prefix: &HashPrefix) -> Bytes {
+    pub fn filter_prefix(txid_prefix: HashPrefix) -> Bytes {
         [b"T", &txid_prefix[..]].concat()
     }
 

src/query.rs

@@ -149,9 +149,9 @@ fn txrow_by_txid(store: &ReadStore, txid: &Sha256dHash) -> Option<TxRow> {
     Some(TxRow::from_row(&Row { key, value }))
 }
 
-fn txrows_by_prefix(store: &ReadStore, txid_prefix: &HashPrefix) -> Vec<TxRow> {
+fn txrows_by_prefix(store: &ReadStore, txid_prefix: HashPrefix) -> Vec<TxRow> {
     store
-        .scan(&TxRow::filter_prefix(&txid_prefix))
+        .scan(&TxRow::filter_prefix(txid_prefix))
         .iter()
         .map(|row| TxRow::from_row(row))
         .collect()
@@ -230,7 +230,7 @@ impl Query {
     ) -> Result<Vec<TxnHeight>> {
         let mut txns = vec![];
         for txid_prefix in prefixes {
-            for tx_row in txrows_by_prefix(store, &txid_prefix) {
+            for tx_row in txrows_by_prefix(store, txid_prefix) {
                 let txid: Sha256dHash = deserialize(&tx_row.key.txid).unwrap();
                 let txn = self
                     .tx_cache

src/rpc.rs

@@ -503,7 +503,7 @@ impl RPC {
     }
 
     fn start_acceptor(addr: SocketAddr) -> Channel<Option<(TcpStream, SocketAddr)>> {
-        let chan = Channel::new();
+        let chan = Channel::unbounded();
         let acceptor = chan.sender();
         spawn_thread("acceptor", move || {
             let listener =
@@ -531,7 +531,7 @@ impl RPC {
                 "# of Electrum subscriptions",
             )),
         });
-        let notification = Channel::new();
+        let notification = Channel::unbounded();
         RPC {
             notification: notification.sender(),
             server: Some(spawn_thread("rpc", move || {

src/signal.rs

@@ -10,7 +10,7 @@ pub struct Waiter {
 }
 
 impl Waiter {
-    pub fn new() -> Waiter {
+    pub fn start() -> Waiter {
         Waiter {
             signal: chan_signal::notify(&[chan_signal::Signal::INT, chan_signal::Signal::TERM]),
         }

src/util.rs

@@ -187,6 +187,10 @@ impl HeaderList {
         self.headers.len()
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.headers.is_empty()
+    }
+
     pub fn iter(&self) -> slice::Iter<HeaderEntry> {
         self.headers.iter()
     }
@@ -222,7 +226,7 @@ pub struct Channel<T> {
 }
 
 impl<T> Channel<T> {
-    pub fn new() -> Channel<T> {
+    pub fn unbounded() -> Self {
         let (tx, rx) = channel();
         Channel { tx, rx }
     }