Replace stringstream with string operations in url_encode_path

- Use std::string with reserve instead of stringstream for better performance
- Direct character lookup table for hex encoding instead of stream manipulators
- Remove unnecessary iomanip include
- More aligned with CasparCG's lean coding style

Author: dedicatedbroadcastsolutions

src/protocol/util/http_request.cpp

@@ -3,7 +3,6 @@
 #include <common/except.h>
 
 #include <boost/asio.hpp>
-#include <iomanip>
 #include <sstream>
 #include <string>
 
@@ -105,23 +104,25 @@ HTTPResponse request(const std::string& host, const std::string& port, const std
 // Only unreserved characters (A-Za-z0-9-_.~) are not encoded.
 std::string url_encode_path(const std::string& path)
 {
-    std::stringstream result;
-    result.fill('0');
-    result << std::hex;
+    std::string result;
+    result.reserve(path.size() * 2); // Reserve space to avoid reallocations
 
     for (auto c : path) {
         // Treat both forward slash and backslash as path separators
         // Always output forward slash for HTTP URLs
         if (c == '/' || c == '\\') {
-            result << '/';
+            result += '/';
         } else if (std::isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~') {
-            result << c;
+            result += c;
         } else {
-            result << std::uppercase << '%' << std::setw(2) << int((unsigned char)c) << std::nouppercase;
+            // Encode special character as %XX
+            result += '%';
+            result += "0123456789ABCDEF"[(unsigned char)c >> 4];
+            result += "0123456789ABCDEF"[(unsigned char)c & 0x0F];
         }
     }
 
-    return result.str();
+    return result;
 }
 
 }} // namespace caspar::http