Build the string directly instead of copying and then pruning tabs or newlines

include/ada/helpers.h

@@ -80,6 +80,13 @@ ada_really_inline void parse_prepared_path(std::string_view input,
  */
 ada_really_inline void remove_ascii_tab_or_newline(std::string& input) noexcept;
 
+/**
+ * @private
+ * Create a new string that all ASCII tab or newline characters are removed.
+ */
+[[nodiscard]] ada_really_inline std::string get_ascii_tab_or_newline_removed(
+    std::string_view input);
+
 /**
  * @private
  * Return the substring from input going from index pos to the end.

src/helpers.cpp

@@ -8,6 +8,7 @@
 #include <algorithm>
 #include <charconv>
 #include <cstring>
+#include <iterator>
 #include <sstream>
 
 namespace ada::helpers {
@@ -155,12 +156,21 @@ ada_really_inline void remove_ascii_tab_or_newline(
   // if this ever becomes a performance issue, we could use an approach similar
   // to has_tabs_or_newline
   input.erase(std::remove_if(input.begin(), input.end(),
-                             [](char c) {
-                               return ada::unicode::is_ascii_tab_or_newline(c);
-                             }),
+                             ada::unicode::is_ascii_tab_or_newline),
               input.end());
 }
 
+ada_really_inline std::string get_ascii_tab_or_newline_removed(
+    std::string_view input) {
+  std::string res;
+  res.reserve(input.size());
+
+  std::copy_if(input.begin(), input.end(), std::back_insert_iterator{res},
+               std::not_fn(ada::unicode::is_ascii_tab_or_newline));
+
+  return res;
+}
+
 ada_really_inline std::string_view substring(std::string_view input,
                                              size_t pos) noexcept {
   ADA_ASSERT_TRUE(pos <= input.size());

src/implementation.cpp

@@ -28,8 +28,7 @@ std::string href_from_file(std::string_view input) {
   std::string tmp_buffer;
   std::string_view internal_input;
   if (unicode::has_tabs_or_newline(input)) {
-    tmp_buffer = input;
-    helpers::remove_ascii_tab_or_newline(tmp_buffer);
+    tmp_buffer = helpers::get_ascii_tab_or_newline_removed(input);
     internal_input = tmp_buffer;
   } else {
     internal_input = input;

src/parser.cpp

@@ -1,6 +1,7 @@
 #include "ada.h"
 #include "ada/common_defs.h"
 #include "ada/character_sets-inl.h"
+#include "ada/helpers.h"
 #include "ada/unicode.h"
 #include "ada/url-inl.h"
 #include "ada/log.h"
@@ -72,10 +73,7 @@ result_type parse_url(std::string_view user_input,
   std::string tmp_buffer;
   std::string_view internal_input;
   if (unicode::has_tabs_or_newline(user_input)) {
-    tmp_buffer = user_input;
-    // Optimization opportunity: Instead of copying and then pruning, we could
-    // just directly build the string from user_input.
-    helpers::remove_ascii_tab_or_newline(tmp_buffer);
+    tmp_buffer = helpers::get_ascii_tab_or_newline_removed(user_input);
     internal_input = tmp_buffer;
   } else {
     internal_input = user_input;

src/url.cpp

@@ -496,10 +496,7 @@ ada_really_inline void url::parse_path(std::string_view input) {
   std::string tmp_buffer;
   std::string_view internal_input;
   if (unicode::has_tabs_or_newline(input)) {
-    tmp_buffer = input;
-    // Optimization opportunity: Instead of copying and then pruning, we could
-    // just directly build the string from user_input.
-    helpers::remove_ascii_tab_or_newline(tmp_buffer);
+    tmp_buffer = helpers::get_ascii_tab_or_newline_removed(input);
     internal_input = tmp_buffer;
   } else {
     internal_input = input;

src/url_aggregator.cpp

@@ -333,10 +333,7 @@ ada_really_inline void url_aggregator::parse_path(std::string_view input) {
   std::string tmp_buffer;
   std::string_view internal_input;
   if (unicode::has_tabs_or_newline(input)) {
-    tmp_buffer = input;
-    // Optimization opportunity: Instead of copying and then pruning, we could
-    // just directly build the string from user_input.
-    helpers::remove_ascii_tab_or_newline(tmp_buffer);
+    tmp_buffer = helpers::get_ascii_tab_or_newline_removed(input);
     internal_input = tmp_buffer;
   } else {
     internal_input = input;