code: def retrieveVals(self):
          
          opcinfo = OPCinfo(self._host, self._port, self._user, self._password, 
                            self._monpath, self._ssl)
          stats = opcinfo.getAllStats()
          
          if self.hasGraph('php_opc_memory') and stats:
              mem = stats['memory_usage']
              keys = ('used_memory', 'wasted_memory', 'free_memory')
              map(lambda k:self.setGraphVal('php_opc_memory',k,mem[k]), keys)
  
          if self.hasGraph('php_opc_opcache_statistics') and stats:
              st = stats['opcache_statistics']
              self.setGraphVal('php_opc_opcache_statistics', 'hits', 
                               st['hits'])
              self.setGraphVal('php_opc_opcache_statistics', 'misses', 
                               st['misses'])
  
          if self.hasGraph('php_opc_opcache_hitrate') and stats:
              st = stats['opcache_statistics']
              self.setGraphVal('php_opc_opcache_hitrate', 'opcache_hit_rate',
                               st['opcache_hit_rate'])
  
          if self.hasGraph('php_opc_key_status') and stats:
              st = stats['opcache_statistics']
              wasted = st['num_cached_keys'] - st['num_cached_scripts']
              free = st['max_cached_keys'] - st['num_cached_keys']
              self.setGraphVal('php_opc_key_status', 'num_cached_scripts', st['num_cached_scripts'])
              self.setGraphVal('php_opc_key_status', 'num_wasted_keys', wasted)
              self.setGraphVal('php_opc_key_status', 'num_free_keys', free)
docs: Retrieve values for graphs.