While we support initializing records via coercion from an expression
list, e.g.,
local x: X = [$x1=1, $x2=2];
this can sometimes obscure the code to readers, e.g., when assigning to
value declared and typed elsewhere. The language runtime has a similar
overhead since instead of just constructing a known type it needs to
check at runtime that the coercion from the expression list is valid;
this can be slower than just writing the readible code in the first
place, see #4559.
With this patch we use explicit construction, e.g.,
local x = X($x1=1, $x2=2);
rule_added_policy allows the modification of rules just after they have
been added. This allows the implementation of some more complex features
- like changing rule states depending on insertion in other plugins.
Catch-and-release logs now include the plugin that is responsible for an
action. Furthermore, the catch-and-release log also includes instances
where a rule already existed, and where an error occurred during an
operation.
This adds a "policy" hook into the logging framework's streams and
filters to replace the existing log filter predicates. The hook
signature is as follows:
hook(rec: any, id: Log::ID, filter: Log::Filter);
The logging manager invokes hooks on each log record. Hooks can veto
log records via a break, and modify them if necessary. Log filters
inherit the stream-level hook, but can override or remove the hook as
needed.
The distribution's existing log streams now come with pre-defined
hooks that users can add handlers to. Their name is standardized as
"log_policy" by convention, with additional suffixes when a module
provides multiple streams. The following adds a handler to the Conn
module's default log policy hook:
hook Conn::log_policy(rec: Conn::Info, id: Log::ID, filter: Log::Filter)
{
if ( some_veto_reason(rec) )
break;
}
By default, this handler will get invoked for any log filter
associated with the Conn::LOG stream.
The existing predicates are deprecated for removal in 4.1 but continue
to work.
``NetControl::DROP`` had 3 conflicting definitions that could potentially
be used incorrectly without any warnings or type-checking errors.
Such enum redefinition conflicts are now caught and treated as errors,
so the ``NetControl::DROP`` enums had to be renamed:
* The use as enum of type ``Log::ID`` is renamed to ``NetControl::DROP_LOG``
* The use as enum of type ``NetControl::CatchReleaseInfo`` is renamed to
``NetControl::DROP_REQUESTED``
* The use as enum of type ``NetControl::RuleType`` is unchanged and still
named ``NetControl::DROP``
For event/hook handlers that had a previous declaration, any &default
arguments are ineffective. Only &default uses in the initial
prototype's arguments have an effect (that includes if the handler
is actually the site at which the declaration occurs).
These are no longer loaded by default due to the performance impact they
cause simply by being loaded (they have event handlers for commonly
generated events) and they aren't generally useful enough to justify it.
