Rework replace_hosts and host_replacement

They do less cloning now.

components/net/http_loader.rs

@@ -30,7 +30,7 @@ use hyper_serde::Serde;
 use log;
 use msg::constellation_msg::PipelineId;
 use net_traits::{CookieSource, FetchMetadata, NetworkError, ReferrerPolicy};
-use net_traits::hosts::replace_hosts;
+use net_traits::hosts::replace_host_in_url;
 use net_traits::request::{CacheMode, CredentialsMode, Destination, Origin};
 use net_traits::request::{RedirectMode, Referrer, Request, RequestMode, ResponseTainting};
 use net_traits::response::{HttpsState, Response, ResponseBody, ResponseType};
@@ -408,7 +408,7 @@ fn obtain_response(request_factory: &NetworkHttpRequestFactory,
                    is_xhr: bool)
                    -> Result<(WrappedHttpResponse, Option<ChromeToDevtoolsControlMsg>), NetworkError> {
     let null_data = None;
-    let connection_url = replace_hosts(&url);
+    let connection_url = replace_host_in_url(url.clone());
 
     // loop trying connections in connection pool
     // they may have grown stale (disconnected), in which case we'll get

components/net/websocket_loader.rs

@@ -9,7 +9,7 @@ use http_loader;
 use hyper::header::{Host, SetCookie};
 use net_traits::{CookieSource, MessageData, WebSocketCommunicate};
 use net_traits::{WebSocketConnectData, WebSocketDomAction, WebSocketNetworkEvent};
-use net_traits::hosts::replace_hosts;
+use net_traits::hosts::replace_host_in_url;
 use servo_url::ServoUrl;
 use std::ascii::AsciiExt;
 use std::sync::{Arc, Mutex, RwLock};
@@ -44,7 +44,7 @@ fn establish_a_websocket_connection(resource_url: &ServoUrl,
     }
 
     // Steps 3-7.
-    let net_url = replace_hosts(resource_url);
+    let net_url = replace_host_in_url(resource_url.clone());
     let mut request = try!(Client::connect(net_url.as_url()));
 
     // Client::connect sets the Host header to the host of the URL that is

components/net_traits/hosts.rs

@@ -56,19 +56,18 @@ pub fn parse_hostsfile(hostsfile_content: &str) -> HashMap<String, IpAddr> {
     host_table
 }
 
-pub fn replace_hosts(url: &ServoUrl) -> ServoUrl {
-    HOST_TABLE.lock().unwrap().as_ref().map_or_else(|| url.clone(),
-                                                    |host_table| host_replacement(host_table, url))
+pub fn replace_host_in_url(url: ServoUrl) -> ServoUrl {
+    if let Some(table) = HOST_TABLE.lock().unwrap().as_ref() {
+        host_replacement(table, url)
+    } else {
+        url
+    }
 }
 
-pub fn host_replacement(host_table: &HashMap<String, IpAddr>, url: &ServoUrl) -> ServoUrl {
-    url.domain()
-        .and_then(|domain| {
-            host_table.get(domain).map(|ip| {
-                let mut new_url = url.clone();
-                new_url.set_ip_host(*ip).unwrap();
-                new_url
-            })
-        })
-        .unwrap_or_else(|| url.clone())
+pub fn host_replacement(host_table: &HashMap<String, IpAddr>, mut url: ServoUrl) -> ServoUrl {
+    let replacement = url.domain().and_then(|domain| host_table.get(domain));
+    if let Some(ip) = replacement {
+        url.set_ip_host(*ip).unwrap();
+    }
+    url
 }

tests/unit/net/resource_thread.rs

@@ -151,11 +151,11 @@ fn test_replace_hosts() {
     host_table.insert("servo.test.server".to_owned(), ip("127.0.0.2"));
 
     let url = ServoUrl::parse("http://foo.bar.com:8000/foo").unwrap();
-    assert_eq!(host_replacement(&host_table, &url).host_str().unwrap(), "127.0.0.1");
+    assert_eq!(host_replacement(&host_table, url).host_str().unwrap(), "127.0.0.1");
 
     let url = ServoUrl::parse("http://servo.test.server").unwrap();
-    assert_eq!(host_replacement(&host_table, &url).host_str().unwrap(), "127.0.0.2");
+    assert_eq!(host_replacement(&host_table, url).host_str().unwrap(), "127.0.0.2");
 
     let url = ServoUrl::parse("http://a.foo.bar.com").unwrap();
-    assert_eq!(host_replacement(&host_table, &url).host_str().unwrap(), "a.foo.bar.com");
+    assert_eq!(host_replacement(&host_table, url).host_str().unwrap(), "a.foo.bar.com");
 }