MDC(3) User Contributed Perl Documentation MDC(3)NAMELog::Log4perl::MDC - Mapped Diagnostic Context
DESCRIPTION
Log::Log4perl allows loggers to maintain global thread-specific data,
called the Nested Diagnostic Context (NDC) and Mapped Diagnostic
Context (MDC).
The MDC is a simple thread-specific hash table, in which the
application can stuff values under certain keys and retrieve them later
via the "%X{key}" placeholder in
"Log::Log4perl::Layout::PatternLayout"s.
Log::Log4perl::MDC->put($key, $value);
Store a value $value under key $key in the map.
my $value = Log::Log4perl::MDC->get($key);
Retrieve the content of the map under the specified key. Typically
done by %X{key} in "Log::Log4perl::Layout::PatternLayout". If no
value exists to the given key, "undef" is returned.
my $text = Log::Log4perl::MDC->remove();
Delete all entries from the map.
Log::Log4perl::MDC->get_context();
Returns a reference to the hash table.
Please note that all of the methods above are class methods, there's no
instances of this class. Since the thread model in perl 5.8.0 is "no
shared data unless explicetly requested" the data structures used are
just global (and therefore thread-specific).
COPYRIGHT AND LICENSE
Copyright 2002-2009 by Mike Schilli <m@perlmeister.com> and Kevin Goess
<cpan@goess.org>.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.1 2011-05-02 MDC(3)
