http: let configure NoCache header directly in THttpCallArg

Reused in many places

Author: linev

net/http/inc/THttpCallArg.h

@@ -186,6 +186,8 @@ class THttpCallArg : public TObject {
 
    void AddHeader(const char *name, const char *value);
 
+   void AddNoCacheHeader();
+
    /** returns number of fields in header */
    Int_t NumHeader() const { return CountHeader(fHeader).Atoi(); }
 

net/http/src/TCivetweb.cxx

@@ -244,7 +244,7 @@ static int begin_request_handler(struct mg_connection *conn, void *)
             if (engine->GetMaxAge() > 0)
                arg->AddHeader("Cache-Control", TString::Format("max-age=%d", engine->GetMaxAge()));
             else
-               arg->AddHeader("Cache-Control", "private, no-cache, no-store, must-revalidate, max-age=0, proxy-revalidate, s-maxage=0");
+               arg->AddNoCacheHeader();
             arg->SetZipping();
          }
       } else {

net/http/src/THttpCallArg.cxx

@@ -346,6 +346,14 @@ void THttpCallArg::AddHeader(const char *name, const char *value)
       AccessHeader(fHeader, name, value, kTRUE);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Set CacheControl http header to disable browser caching
+
+void THttpCallArg::AddNoCacheHeader()
+{
+   AddHeader("Cache-Control", "private, no-cache, no-store, must-revalidate, max-age=0, proxy-revalidate, s-maxage=0");
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Fills HTTP header, which can be send at the beggining of reply on the http request
 /// \param name is HTTP protocol name (default "HTTP/1.1")

net/http/src/THttpServer.cxx

@@ -846,6 +846,7 @@ void THttpServer::ProcessRequest(THttpCallArg *arg)
             fname.ReplaceAll("$jsrootsys", fJSROOTSYS);
 
             arg->fContent = ReadFileContent(fname.Data());
+            arg->AddNoCacheHeader();
          }
       }
 
@@ -882,8 +883,8 @@ void THttpServer::ProcessRequest(THttpCallArg *arg)
 
             arg->ReplaceAllinContent(hjsontag, h_json.Data());
 
-            arg->AddHeader("Cache-Control",
-                           "private, no-cache, no-store, must-revalidate, max-age=0, proxy-revalidate, s-maxage=0");
+            arg->AddNoCacheHeader();
+
             if (arg->fQuery.Index("nozip") == kNPOS)
                arg->SetZipping();
          }
@@ -931,8 +932,7 @@ void THttpServer::ProcessRequest(THttpCallArg *arg)
             if (fSniffer->Produce(arg->fPathName.Data(), "root.json", "compact=23", str))
                arg->ReplaceAllinContent(rootjsontag, str);
          }
-         arg->AddHeader("Cache-Control",
-                        "private, no-cache, no-store, must-revalidate, max-age=0, proxy-revalidate, s-maxage=0");
+         arg->AddNoCacheHeader();
          if (arg->fQuery.Index("nozip") == kNPOS)
             arg->SetZipping();
          arg->SetContentType("text/html");
@@ -1017,8 +1017,7 @@ void THttpServer::ProcessRequest(THttpCallArg *arg)
    }
 
    // try to avoid caching on the browser
-   arg->AddHeader("Cache-Control",
-                  "private, no-cache, no-store, must-revalidate, max-age=0, proxy-revalidate, s-maxage=0");
+   arg->AddNoCacheHeader();
 
    // potentially add cors header
    if (IsCors())