From efdf60f5435d49b703ee2754d0e21a97bdf80d82 Mon Sep 17 00:00:00 2001
From: vng <viktor.govako@gmail.com>
Date: Thu, 7 Aug 2014 15:21:03 +0300
Subject: [PATCH] Faster url encoding/decoding.

---
 coding/hex.cpp        |  8 ++++----
 coding/hex.hpp        | 11 +++++++----
 coding/url_encode.hpp | 29 +++++++++++++++++++----------
 3 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/coding/hex.cpp b/coding/hex.cpp
index 0eab19f4b6..66ddffd678 100644
--- a/coding/hex.cpp
+++ b/coding/hex.cpp
@@ -1,8 +1,10 @@
-#include "../base/SRC_FIRST.hpp"
 #include "hex.hpp"
 
+#include "../base/assert.hpp"
 
-namespace impl {
+
+namespace impl
+{
   static const char kToHexTable[] = "0123456789ABCDEF";
 
   void ToHexRaw(void const * src, size_t size, void * dst)
@@ -19,8 +21,6 @@ namespace impl {
     }
   }
 
-//  static const char kFromHexTable[] = "0123456789ABCDEF";
-
   uint8_t HexDigitToRaw(uint8_t const digit)
   {
     if (digit >= '0' && digit <= '9')
diff --git a/coding/hex.hpp b/coding/hex.hpp
index 1fe22e29ca..251079cfa1 100644
--- a/coding/hex.hpp
+++ b/coding/hex.hpp
@@ -1,13 +1,14 @@
 #pragma once
 
 #include "../base/base.hpp"
-#include "../base/assert.hpp"
 
 #include "../std/string.hpp"
 
 #include <boost/type_traits/is_integral.hpp>
 
-namespace impl {
+
+namespace impl
+{
   void ToHexRaw(void const * src, size_t size, void * dst);
   void FromHexRaw(void const * src, size_t size, void * dst);
 }
@@ -71,14 +72,16 @@ inline string NumToHex<char>(char c)
 }
 /// @}
 
-inline string FromHex(void const * ptr, size_t size) {
+inline string FromHex(void const * ptr, size_t size)
+{
   string result;
   result.resize(size / 2);
   ::impl::FromHexRaw(ptr, size, &result[0]);
   return result;
 }
 
-inline string FromHex(string const & src) {
+inline string FromHex(string const & src)
+{
   return FromHex(src.c_str(), src.size());
 }
 
diff --git a/coding/url_encode.hpp b/coding/url_encode.hpp
index 4cadcae7fd..cba1ee497e 100644
--- a/coding/url_encode.hpp
+++ b/coding/url_encode.hpp
@@ -4,28 +4,36 @@
 
 #include "../std/string.hpp"
 
+
 inline string UrlEncode(string const & rawUrl)
 {
-  string result(rawUrl);
-  for (size_t i = 0; i < result.size(); ++i)
+  size_t const count = rawUrl.size();
+  string result;
+  result.reserve(count);
+
+  for (size_t i = 0; i < count; ++i)
   {
-    char const c = result[i];
-    if (c < '-' || c == '/' || (c > '9' && c < 'A') || (c > 'Z' && c < '_')
-        || c == '`' || (c > 'z' && c < '~') || c > '~')
+    char const c = rawUrl[i];
+    if (c < '-' || c == '/' || (c > '9' && c < 'A') || (c > 'Z' && c < '_') ||
+        c == '`' || (c > 'z' && c < '~') || c > '~')
     {
-      string hexStr("%");
-      hexStr += NumToHex(c);
-      result.replace(i, 1, hexStr);
-      i += 2;
+      result += '%';
+      result += NumToHex(c);
     }
+    else
+      result += rawUrl[i];
   }
+
   return result;
 }
 
 inline string UrlDecode(string const & encodedUrl)
 {
+  size_t const count = encodedUrl.size();
   string result;
-  for (size_t i = 0; i < encodedUrl.size(); ++i)
+  result.reserve(count);
+
+  for (size_t i = 0; i < count; ++i)
   {
     if (encodedUrl[i] == '%')
     {
@@ -35,5 +43,6 @@ inline string UrlDecode(string const & encodedUrl)
     else
       result += encodedUrl[i];
   }
+
   return result;
 }