performance: Implement getUntilAscii for Pig

Author: tbabej

src/Pig.cpp

@@ -124,6 +124,28 @@ bool Pig::skipPartial (const std::string& reference, std::string& result,
   return false;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// ASCII-only version of getUntil. Has better performance characteristics at
+// the cost of not considering utf-8 characters correctly. Use with caution.
+bool Pig::getUntilAscii (char end, std::string& result)
+{
+  auto save = _cursor;
+  auto found = _text->find (end, _cursor + 1);
+
+  if (found == std::string::npos)
+  {
+    found = _text->size ();
+    result = _text->substr (_cursor, found - _cursor);
+    _cursor = found;
+    return true;
+  }
+
+  result = _text->substr (_cursor, found - _cursor);
+  _cursor = _cursor + result.size();
+
+  return _cursor > save;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 bool Pig::getUntil (int end, std::string& result)
 {

src/Pig.h

@@ -43,6 +43,7 @@ class Pig
   bool skipPartial (const std::string&, std::string&, bool ignore_case = false);
 
   bool getUntil (int, std::string&);
+  bool getUntilAscii (char, std::string&);
   bool getUntilWS (std::string&);
   bool getCharacter (int&);
   bool getDigit (int&);