Method find_handler

sql/sp_pcontext.cc:578–640

sp_handler*
sp_pcontext::find_handler(const Sql_condition_identity &value) const
{
  sp_handler *found_handler= NULL;
  sp_condition_value *found_cv= NULL;

  for (size_t i= 0; i < m_handlers.elements(); ++i)
  {
    sp_handler *h= m_handlers.at(i);

    List_iterator_fast<sp_condition_value> li(h->condition_values);
    sp_condition_value *cv;

    while ((cv= li++))
    {
      if (cv->matches(value, found_cv))
      {
        found_cv= cv;
        found_handler= h;
      }
    }
  }

  if (found_handler)
    return found_handler;


  // There is no appropriate handler in this parsing context. We need to look up
  // in parent contexts. There might be two cases here:
  //
  // 1. The current context has REGULAR_SCOPE. That means, it's a simple
  // BEGIN..END block:
  //     ...
  //     BEGIN
  //       ... # We're here.
  //     END
  //     ...
  // In this case we simply call find_handler() on parent's context recursively.
  //
  // 2. The current context has HANDLER_SCOPE. That means, we're inside an
  // SQL-handler block:
  //   ...
  //   DECLARE ... HANDLER FOR ...
  //   BEGIN
  //     ... # We're here.
  //   END
  //   ...
  // In this case we can not just call parent's find_handler(), because
  // parent's handler don't catch conditions from this scope. Instead, we should
  // try to find first parent context (we might have nested handler
  // declarations), which has REGULAR_SCOPE (i.e. which is regular BEGIN..END
  // block).

  const sp_pcontext *p= this;

  while (p && p->m_scope == HANDLER_SCOPE)
    p= p->m_parent;