Move hosts module into net crate. Remove obsolete functions.

components/net/hosts.rs

@@ -0,0 +1,63 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use parse_hosts::HostsFile;
+use std::borrow::Cow;
+use std::collections::HashMap;
+use std::env;
+use std::fs::File;
+use std::io::{BufReader, Read};
+use std::net::IpAddr;
+use std::sync::Mutex;
+
+lazy_static! {
+    static ref HOST_TABLE: Mutex<Option<HashMap<String, IpAddr>>> = Mutex::new(create_host_table());
+}
+
+fn create_host_table() -> Option<HashMap<String, IpAddr>> {
+    // TODO: handle bad file path
+    let path = match env::var("HOST_FILE") {
+        Ok(host_file_path) => host_file_path,
+        Err(_) => return None,
+    };
+
+    let mut file = match File::open(&path) {
+        Ok(f) => BufReader::new(f),
+        Err(_) => return None,
+    };
+
+    let mut lines = String::new();
+    match file.read_to_string(&mut lines) {
+        Ok(_) => (),
+        Err(_) => return None,
+    };
+
+    Some(parse_hostsfile(&lines))
+}
+
+pub fn replace_host_table(table: HashMap<String, IpAddr>) {
+    *HOST_TABLE.lock().unwrap() = Some(table);
+}
+
+pub fn parse_hostsfile(hostsfile_content: &str) -> HashMap<String, IpAddr> {
+    let mut host_table = HashMap::new();
+
+    for line in HostsFile::read_buffered(hostsfile_content.as_bytes()).lines() {
+        if let Ok(ref line) = line {
+            for host in line.hosts() {
+                if let Some(ip) = line.ip() {
+                    host_table.insert(host.to_owned(), ip);
+                }
+            }
+        }
+    }
+
+    host_table
+}
+
+pub fn replace_host(host: &str) -> Cow<str> {
+    HOST_TABLE.lock().unwrap().as_ref()
+        .and_then(|table| table.get(host))
+        .map_or(host.into(), |replaced_host| replaced_host.to_string().into())
+}