LibHTTP: Implement getting the correct reason phrase from HttpResponse

This adds a reason_phrase() getter and a static reason_phrase_for_code()
to the HttpResponse class.

It also changes the class to use east const style.

Userland/Libraries/LibHTTP/HttpResponse.cpp

@@ -18,4 +18,63 @@ HttpResponse::~HttpResponse()
 {
 }
 
+StringView HttpResponse::reason_phrase_for_code(int code)
+{
+ VERIFY(code >= 100 && code <= 599);
+
+ static HashMap<int, StringView> s_reason_phrases = {
+ { 100, "Continue"sv },
+ { 101, "Switching Protocols"sv },
+ { 200, "OK"sv },
+ { 201, "Created"sv },
+ { 202, "Accepted"sv },
+ { 203, "Non-Authoritative Information"sv },
+ { 204, "No Content"sv },
+ { 205, "Reset Content"sv },
+ { 206, "Partial Content"sv },
+ { 300, "Multiple Choices"sv },
+ { 301, "Moved Permanently"sv },
+ { 302, "Found"sv },
+ { 303, "See Other"sv },
+ { 304, "Not Modified"sv },
+ { 305, "Use Proxy"sv },
+ { 307, "Temporary Redirect"sv },
+ { 400, "Bad Request"sv },
+ { 401, "Unauthorized"sv },
+ { 402, "Payment Required"sv },
+ { 403, "Forbidden"sv },
+ { 404, "Not Found"sv },
+ { 405, "Method Not Allowed"sv },
+ { 406, "Not Acceptable"sv },
+ { 407, "Proxy Authentication Required"sv },
+ { 408, "Request Timeout"sv },
+ { 409, "Conflict"sv },
+ { 410, "Gone"sv },
+ { 411, "Length Required"sv },
+ { 412, "Precondition Failed"sv },
+ { 413, "Payload Too Large"sv },
+ { 414, "URI Too Long"sv },
+ { 415, "Unsupported Media Type"sv },
+ { 416, "Range Not Satisfiable"sv },
+ { 417, "Expectation Failed"sv },
+ { 426, "Upgrade Required"sv },
+ { 500, "Internal Server Error"sv },
+ { 501, "Not Implemented"sv },
+ { 502, "Bad Gateway"sv },
+ { 503, "Service Unavailable"sv },
+ { 504, "Gateway Timeout"sv },
+ { 505, "HTTP Version Not Supported"sv }
+ };
+
+ if (s_reason_phrases.contains(code))
+ return s_reason_phrases.ensure(code);
+
+ // NOTE: "A client MUST understand the class of any status code, as indicated by the first
+ // digit, and treat an unrecognized status code as being equivalent to the x00 status
+ // code of that class." (RFC 7231, section 6)
+ auto generic_code = (code / 100) * 100;
+ VERIFY(s_reason_phrases.contains(generic_code));
+ return s_reason_phrases.ensure(generic_code);
+}
+
 }

Userland/Libraries/LibHTTP/HttpResponse.h

@@ -21,7 +21,10 @@ class HttpResponse : public Core::NetworkResponse {
  }
 
  int code() const { return m_code; }
- const HashMap<String, String, CaseInsensitiveStringTraits>& headers() const { return m_headers; }
+ StringView reason_phrase() const { return reason_phrase_for_code(m_code); }
+ HashMap<String, String, CaseInsensitiveStringTraits> const& headers() const { return m_headers; }
+
+ static StringView reason_phrase_for_code(int code);
 
 private:
  HttpResponse(int code, HashMap<String, String, CaseInsensitiveStringTraits>&&);