From f628e70d4aa70b96f2126b376ec75014af0b62cb Mon Sep 17 00:00:00 2001
From: Arcterus <Arcterus@mail.com>
Date: Sun, 30 Nov 2014 15:28:00 -0800
Subject: [PATCH] tr: improve speed slightly

---
 src/tr/tr.rs | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/src/tr/tr.rs b/src/tr/tr.rs
index e03b5d7e6..157c0fa55 100644
--- a/src/tr/tr.rs
+++ b/src/tr/tr.rs
@@ -13,10 +13,9 @@
 extern crate collections;
 extern crate getopts;
 
-use collections::bitv_set::BitvSet;
-use collections::vec_map::VecMap;
 use getopts::OptGroup;
 use std::char::from_u32;
+use std::collections::{BitvSet, VecMap};
 use std::io::print;
 use std::io::stdio::{stdin,stdout};
 use std::iter::FromIterator;
@@ -28,6 +27,7 @@ mod util;
 static NAME : &'static str = "tr";
 static VERSION : &'static str = "1.0.0";
 
+#[inline]
 fn unescape_char(c: char) -> char {
     match c {
         'a' => 0x07u8 as char,
@@ -41,6 +41,7 @@ fn unescape_char(c: char) -> char {
     }
 }
 
+#[inline]
 fn unescape(v: Vec<char>) -> Vec<char> {
     let mut out = Vec::new();
     let mut input = v.as_slice();
@@ -60,6 +61,7 @@ fn unescape(v: Vec<char>) -> Vec<char> {
     out
 }
 
+#[inline]
 fn expand_range(from: char, to: char) -> Vec<char> {
     range(from as u32, to as u32 + 1).map(|c| from_u32(c).unwrap()).collect()
 }
@@ -109,12 +111,16 @@ fn delete(set: Vec<char>, complement: bool) {
 }
 
 fn tr(set1: &[char], set2: &[char]) {
-    let mut map = VecMap::<char>::new();
-    let mut out = stdout();
+    const BUFFER_LEN: uint = 1024;
 
+    let mut map = VecMap::new();
+    let mut stdout = stdout();
+    let mut outbuffer = String::with_capacity(BUFFER_LEN);
+
+    let set2_len = set2.len();
     for i in range(0, set1.len()) {
-        if i >= set2.len() {
-            map.insert(set1[i] as uint, set2[set2.len()-1]);
+        if i >= set2_len {
+            map.insert(set1[i] as uint, set2[set2_len - 1]);
         } else {
             map.insert(set1[i] as uint, set2[i]);
         }
@@ -127,22 +133,29 @@ fn tr(set1: &[char], set2: &[char]) {
                     Some(t) => *t,
                     None => inc,
                 };
-                out.write_char(trc).unwrap();
+                outbuffer.push(trc);
+                if outbuffer.len() >= BUFFER_LEN {
+                    stdout.write_str(outbuffer.as_slice()).unwrap();
+                    outbuffer.clear();
+                }
             }
             Err(err) => {
                 panic!("{}", err);
             }
         }
     }
+    if outbuffer.len() > 0 {
+        stdout.write_str(outbuffer.as_slice()).unwrap();
+    }
 }
 
 fn usage(opts: &[OptGroup]) {
-        println!("{} {}", NAME, VERSION);
-        println!("");
-        println!("Usage:");
-        println!("  {} [OPTIONS] SET1 [SET2]", NAME);
-        println!("");
-        print(getopts::usage("Translate or delete characters.", opts).as_slice());
+    println!("{} {}", NAME, VERSION);
+    println!("");
+    println!("Usage:");
+    println!("  {} [OPTIONS] SET1 [SET2]", NAME);
+    println!("");
+    print(getopts::usage("Translate or delete characters.", opts).as_slice());
 }
 
 pub fn uumain(args: Vec<String>) -> int {