Updated the build system and related source files to use libpcre2 as the
default regex library instead of the deprecated libpcre. This change
ensures future compatibility and aligns with the library's maintenance status.
To build with the old libpcre, the `--with-pcre` configuration parameter
can be specified.
- Avoids copying std::shared_ptr when lifetime of the RuleMessage
is controlled by the caller.
- The RuleMessage instance is created in RuleWithActions::evaluate and
then used to call the overloaded version of this method that is
specialized by subclasses.
- Once the call to the overloaded method returns, the std::shared_ptr
is destroyed as it's not stored by any of the callers, so it can
be replaced with a stack variable and avoid paying the cost of
copying the std::shared_ptr (and its control block that is
guaranteed to be thread-safe and thus is not a straightforward
pointer copy)
- Introduced RuleMessage::reset because this is required by
RuleWithActions::performLogging when it's not the 'last log', the rule
has multimatch and it's to be logged.
- The current version is creating allocating another instance of
RuleMessage on the heap to copy the Rule & Transaction related state
while all the other members in the RuleMessage are set to their
default values.
- The new version leverages the existent, unused and incomplete
function 'clean' (renamed as 'reset') to do this on the current
instance.
- Notice that the current code preserves the value of m_saveMessage,
so 'reset' provides an argument for the caller to control whether
this member should be reinitialized.
