>
>
>
V807. Decreased performance. Consider c…


V807. Decreased performance. Consider creating a pointer/reference to avoid using the same expression repeatedly.

The analyzer has detected code which can be optimized. The code contains homogeneous message chains intended to get access to some object.

The following constructs are understood by a message chain:

  • Get(1)->m_point.x
  • X.Foo().y
  • next->next->Foo()->Z

If a message chain is repeated more than twice, perhaps you should consider code refactoring.

Look at this example:

Some->getFoo()->doIt1();
Some->getFoo()->doIt2();
Some->getFoo()->doIt3();

If the 'getFoo()' function works slowly or if this code is placed inside a loop, you should rewrite this code. For example, you may create a temporary pointer:

Foo* a = Some->getFoo();
a->doIt1();
a->doIt2();
a->doIt3();

Of course, it is not always possible to write it in this way. And moreover, such refactoring does not always give you a performance gain. There exist too many various alternatives, so we cannot give you any general recommendations.

But presence of message chains usually indicates careless code. To improve such code you can use several methods of refactoring: