Optimize the htmlTranslate method

examples/simple_example/api_v1_ApiTest.cc

@@ -44,9 +44,9 @@ void ApiTest::your_method_name(
     std::map<std::string, std::string> para;
     para["p1"] = std::to_string(p1);
     para["p2"] = std::to_string(p2);
-    para["p3"] = HttpViewData::htmlTranslate(
+    para["p3"] = HttpViewData::htmlTranslate(string_view(
         "<script>alert(\" This should not be displayed in a browser alert "
-        "box.\");</script>");
+        "box.\");</script>"));
     data.insert("parameters", para);
     auto res = HttpResponse::newHttpViewResponse("ListParaView", data);
     callback(res);

lib/inc/drogon/HttpViewData.h

@@ -136,6 +136,41 @@ class HttpViewData
      * > --> >
      */
     static std::string htmlTranslate(const std::string &str);
+    static std::string htmlTranslate(const string_view &str);
+    static bool needTranslation(const std::string &str)
+    {
+        for (auto const &c : str)
+        {
+            switch (c)
+            {
+                case '"':
+                case '&':
+                case '<':
+                case '>':
+                    return true;
+                default:
+                    continue;
+            }
+        }
+        return false;
+    }
+    static bool needTranslation(const string_view &str)
+    {
+        for (auto const &c : str)
+        {
+            switch (c)
+            {
+                case '"':
+                case '&':
+                case '<':
+                case '>':
+                    return true;
+                default:
+                    continue;
+            }
+        }
+        return false;
+    }
 
   protected:
     typedef std::unordered_map<std::string, any> ViewDataMap;

lib/src/HttpViewData.cc

@@ -17,24 +17,29 @@
 using namespace drogon;
 
 std::string HttpViewData::htmlTranslate(const std::string &str)
+{
+    return htmlTranslate(string_view(str));
+}
+
+std::string HttpViewData::htmlTranslate(const string_view &str)
 {
     std::string ret;
-    ret.reserve(str.length());
+    ret.reserve(str.length() + 64);
     for (auto &ch : str)
     {
         switch (ch)
         {
             case '"':
-                ret.append(""");
+                ret.append(""", 6);
-                break;
-            case '<':
-                ret.append("&lt;");
-                break;
-            case '>':
-                ret.append("&gt;");
                 break;
             case '&':
-                ret.append("&amp;");
+                ret.append("&amp;", 5);
+                break;
+            case '<':
+                ret.append("&lt;", 4);
+                break;
+            case '>':
+                ret.append("&gt;", 4);
                 break;
             default:
                 ret.push_back(ch);