private ConfigOverlay applyRequestHandler(CommandOperation op, ConfigOverlay overlay) {
      String name = op.getStr(NAME);
      op.getStr(CLASS_NAME);
      op.getMap(PluginInfo.DEFAULTS, null);
      op.getMap(PluginInfo.INVARIANTS, null);
      op.getMap(PluginInfo.APPENDS, null);
      if (op.hasError()) return overlay;

      if (CREATE_REQHANDLER.equals(op.name)) {
        if (overlay.getReqHandlers().containsKey(name)) {
          op.addError(
              MessageFormat.format(
                  " ''{0}'' already exists . Do an ''{1}'' , if you want to change it ",
                  name, UPDATE_REQHANDLER));
          return overlay;
        } else {
          return overlay.addReqHandler(op.getDataMap());
        }
      } else if (UPDATE_REQHANDLER.equals(op.name)) {
        if (!overlay.getReqHandlers().containsKey(name)) {
          op.addError(
              MessageFormat.format(
                  " ''{0}'' does not exist . Do an ''{1}'' , if you want to create it ",
                  name, CREATE_REQHANDLER));
          return overlay;
        } else {
          return overlay.addReqHandler(op.getDataMap());
        }
      }

      return overlay;
    }
 private ConfigOverlay applyDeleteHandler(CommandOperation op, ConfigOverlay overlay) {
   String name = op.getStr(CommandOperation.ROOT_OBJ);
   if (op.hasError()) return overlay;
   if (overlay.getReqHandlers().containsKey(name)) {
     return overlay.deleteHandler(name);
   } else {
     op.addError(MessageFormat.format("NO such requestHandler ''{0}'' ", name));
     return overlay;
   }
 }
 private ConfigOverlay applyUnsetUserProp(CommandOperation op, ConfigOverlay overlay) {
   List<String> name = op.getStrs(CommandOperation.ROOT_OBJ);
   if (op.hasError()) return overlay;
   for (String o : name) {
     if (!overlay.getUserProps().containsKey(o)) {
       op.addError(format("No such property ''{0}''", name));
     } else {
       overlay = overlay.unsetUserProperty(o);
     }
   }
   return overlay;
 }
    private ConfigOverlay applyUnset(CommandOperation op, ConfigOverlay overlay) {
      List<String> name = op.getStrs(CommandOperation.ROOT_OBJ);
      if (op.hasError()) return overlay;

      for (String o : name) {
        if (!ConfigOverlay.isEditableProp(o, false, null)) {
          op.addError(format(NOT_EDITABLE, name));
        } else {
          overlay = overlay.unsetProperty(o);
        }
      }
      return overlay;
    }
 private ConfigOverlay applySetProp(CommandOperation op, ConfigOverlay overlay) {
   Map<String, Object> m = op.getDataMap();
   if (op.hasError()) return overlay;
   for (Map.Entry<String, Object> e : m.entrySet()) {
     String name = e.getKey();
     Object val = e.getValue();
     if (!ConfigOverlay.isEditableProp(name, false, null)) {
       op.addError(format(NOT_EDITABLE, name));
       continue;
     }
     overlay = overlay.setProperty(name, val);
   }
   return overlay;
 }
    private void handleParams(ArrayList<CommandOperation> ops, RequestParams params) {
      for (CommandOperation op : ops) {
        switch (op.name) {
          case CREATE:
          case UPDATE:
            {
              Map<String, Object> map = op.getDataMap();
              if (op.hasError()) break;

              for (Map.Entry<String, Object> entry : map.entrySet()) {

                Map val = null;
                String key = entry.getKey();
                if (key == null || key.trim().isEmpty()) {
                  op.addError("null key ");
                  continue;
                }
                key = key.trim();
                if (!validName(key)) {
                  op.addError(
                      MessageFormat.format(
                          "''{0}'' name should only have chars [a-zA-Z_-.0-9] ", key));
                  continue;
                }

                try {
                  val = (Map) entry.getValue();
                } catch (Exception e1) {
                  op.addError("invalid params for key : " + key);
                  continue;
                }

                if (val.containsKey("")) {
                  op.addError("Empty keys are not allowed in params");
                  continue;
                }

                MapSolrParams old = params.getParams(key);
                if (op.name.equals(UPDATE)) {
                  LinkedHashMap m = new LinkedHashMap(old.getMap());
                  m.putAll(val);
                  val = m;
                }
                params = params.setParams(key, val);
              }
              break;
            }
          case "delete":
            {
              List<String> name = op.getStrs(CommandOperation.ROOT_OBJ);
              if (op.hasError()) break;
              for (String s : name) {
                if (params.getParams(s) == null) {
                  op.addError(
                      MessageFormat.format("can't delete . No such params ''{0}'' exist", s));
                }
                params = params.setParams(s, null);
              }
            }
        }
      }

      List errs = CommandOperation.captureErrors(ops);
      if (!errs.isEmpty()) {
        resp.add(CommandOperation.ERR_MSGS, errs);
        return;
      }

      SolrResourceLoader loader = req.getCore().getResourceLoader();
      if (loader instanceof ZkSolrResourceLoader) {
        ZkController.persistConfigResourceToZooKeeper(
            loader, params.getZnodeVersion(), RequestParams.RESOURCE, params.toByteArray(), true);

      } else {
        SolrResourceLoader.persistConfLocally(
            loader, ConfigOverlay.RESOURCE_NAME, params.toByteArray());
        req.getCore().getSolrConfig().refreshRequestParams();
      }
    }