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.
This allows the path for the default filter to be specified explicitly
when creating a stream and reduces the need to rely on the default path
function to magically supply the path.
The default path function is now only used if, when a filter is added to
a stream, it has neither a path nor a path function already.
Adapted the existing Log::create_stream calls to explicitly specify a
path value.
Addresses BIT-1324
* remotes/origin/topic/seth/modbus-merge:
Small modbus documentation update and tiny refactoring.
Final touches to modbus analyzer for now.
Major revisions to Modbus analyzer support (not quite done yet).
put some make-up on Modbus analyser
Modbus analyser, added support: FC=20,21
Modbus analyzer,added support: FC=1,2,15,24
Modbus analyzer, current support: FC=3,4,5,6,7,16,22,23
Closes#915.
- There are still some broken events in the modbus analyzer because
I don't have traffic to test with (coil and record related events primarily).
- There are a few example scripts in policy/protocols/modbus
