text: /*
   * Copyright 2017 dmb.star-net.cn
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  'use strict';
  var cls= require('../cls');
  var PinpointTraceMetaData = require('../../utils/constants.js').PinpointTraceMetaData;
  var TRACE_CONTEXT = PinpointTraceMetaData.TRACE_CONTEXT;
  
  function getCurrentNamespace() {
      var namespace = cls.getNamespace(TRACE_CONTEXT);
      if (namespace === undefined) {
          namespace = cls.createNamespace(TRACE_CONTEXT);
      }
      return namespace;
  }
  
  function slice(args) {
      var array = [];
      for (var i=0; i<args.length; i++) {
          array[i] = args[i];
      }
      return array; 
  }
  
  module.exports = function methodInterceptor(original, wrapper) {
      var method = function originalWrapper() {
          var proxy = this;
          var args = slice(arguments);
          var namespace = getCurrentNamespace();
          if (namespace.active !== null) { 
              return wrapper(original, proxy, args);
          } else {
              //change namespace.active null to some value
              namespace.run(function cb() {
                  return wrapper(original, proxy, this.args);
             }.bind({args: args}));  
          }
      };
      return method;
  };
  