remove comment for bug that was fixed
[scpubgit/Object-Remote.git] / lib / Object / Remote /
5e2b2229 1package Object::Remote::Logging;
4e446335 3use Moo;
4use Scalar::Util qw(blessed);
5use Object::Remote::Logging::Logger;
f4a85080 6use Exporter::Declare;
663fb34f 7use Carp qw(carp croak);
5e2b2229 8
4e446335 9extends 'Log::Contextual';
5e2b2229 10
663fb34f 11exports(qw( ____ router arg_levels ));
f4a85080 12
4e446335 13sub router {
c0b2df05 14 our $Router_Instance ||= do {
15 require Object::Remote::Logging::Router;
16 Object::Remote::Logging::Router->new;
17 }
4e446335 18}
5e2b2229 19
9de32e1d 20#log level descriptions
21#info - standard log level - normal program output for the end user
22#warn - output for program that is executing quietly
23#error - output for program that is running more quietly
24#fatal - it is not possible to continue execution; this level is as quiet as is possible
25#verbose - output for program executing verbosely (-v)
26#debug - output for program running more verbosely (-v -v)
27#trace - output for program running extremely verbosely (-v -v -v)
4e446335 28sub arg_levels {
9de32e1d 29 #the order of the log levels is significant with the
30 #most verbose level being first in the list and the
31 #most quiet as the last item
32 return [qw( trace debug verbose info warn error fatal )];
4a9fa1a5 33}
5e2b2229 34
663fb34f 35sub before_import {
36 my ($class, $importer, $spec) = @_;
37 my $router = $class->router;
c2a69537 38 our $DID_INIT;
663fb34f 39
c2a69537 40 unless($DID_INIT) {
41 $DID_INIT = 1;
42 init_logging();
43 }
663fb34f 45 $class->SUPER::before_import($importer, $spec);
663fb34f 46}
ae198201 48sub _parse_selections {
49 my ($selections_string) = @_;
50 my %log_ok;
52 #example string:
53 #" * -Object::Remote::Logging Foo::Bar::Baz "
54 foreach(split(/\s+/, $selections_string)) {
55 next if $_ eq '';
56 if ($_ eq '*') {
57 $log_ok{$_} = 1;
58 } elsif (s/^-//) {
59 $log_ok{$_} = 0;
60 } else {
61 $log_ok{$_} = 1;
62 }
63 }
65 return %log_ok;
4e446335 68#this is invoked on all nodes
4a9fa1a5 69sub init_logging {
c0b2df05 70 my $level = $ENV{OBJECT_REMOTE_LOG_LEVEL};
0fe333eb 71 my $format = $ENV{OBJECT_REMOTE_LOG_FORMAT};
eb49c7df 72 my $selections = $ENV{OBJECT_REMOTE_LOG_SELECTIONS};
73 my %controller_should_log;
09f583a7 74
77 }
5cd5276e 78
09f583a7 79 return unless defined $level && $level ne '';
0fe333eb 80 $format = "[%l %r] %s" unless defined $format;
eb49c7df 81 $selections = __PACKAGE__ unless defined $selections;
ae198201 82 %controller_should_log = _parse_selections($selections);
f1d70835 83
84 {
85 no warnings 'once';
86 if (defined $Object::Remote::FatNode::REMOTE_NODE) {
87 #the connection id for the remote node comes in later
88 #as the controlling node inits remote logging
89 router()->_remote_metadata({ connection_id => undef });
90 }
91 }
c0b2df05 93 my $logger = Object::Remote::Logging::Logger->new(
0fe333eb 94 min_level => lc($level), format => $format,
c0b2df05 95 level_names => Object::Remote::Logging::arg_levels(),
96 );
c0b2df05 98 router()->connect(sub {
eb49c7df 99 my $controller = $_[1]->{controller};
ae198201 100 my $will_log = $controller_should_log{$controller};
102 $will_log = $controller_should_log{'*'} unless defined $will_log;
104 return unless $will_log;
c0b2df05 105 #skip things from remote hosts because they log to STDERR
106 #when OBJECT_REMOTE_LOG_LEVEL is in effect
107 return if $_[1]->{remote}->{connection_id};
108 $logger
109 });
4a9fa1a5 110}
4e446335 112#this is invoked by the controlling node
113#on the remote nodes
f1d70835 114sub init_remote_logging {
4e446335 115 my ($self, %controller_info) = @_;
f1d70835 117 router()->_remote_metadata(\%controller_info);
466ee2c4 118 router()->_forward_destination($controller_info{router}) if $ENV{OBJECT_REMOTE_LOG_FORWARDING};
4a9fa1a5 119}
5e2b2229 120
455d031c 122
d672a9bf 123__END__
125=head1 NAME
127Object::Remote::Logging - Logging subsystem for Object::Remote
129=head1 SYNOPSIS
b8176a97 131 use Object::Remote::Logging qw( :log :dlog arg_levels router );
d672a9bf 132
133 @levels = qw( trace debug verbose info warn error fatal );
134 @levels = arg_levels(); #same result
136 $ENV{OBJECT_REMOTE_LOG_LEVEL} = 'trace'; #or other level name
137 $ENV{OBJECT_REMOTE_LOG_FORMAT} = '%l %t: %p::%m %s'; #and more
d672a9bf 138 $ENV{OBJECT_REMOTE_LOG_SELECTIONS} = 'Object::Remote::Logging Some::Other::Subclass';
ae198201 139 $ENV{OBJECT_REMOTE_LOG_SELECTIONS} = '* -Object::Remote::Logging';
09f583a7 140 $ENV{OBJECT_REMOTE_LOG_FORWARDING} = 0; #default 1
d672a9bf 141
142 log_info { 'Trace log event' };
143 Dlog_verbose { "Debug event with Data::Dumper::Concise: $_" } { foo => 'bar' };
d672a9bf 144
147This is the logging framework for Object::Remote implemented as a subclass of
148L<Log::Contextual> with a slightly incompatible API. This system allows
149developers using Object::Remote and end users of that software to control
150Object::Remote logging so operation can be tracked if needed. This is also
151the API used to generate log messages inside the Object::Remote source code.
153The rest of the logging system comes from L<Object::Remote::Logging::Logger>
154which implements log rendering and output and L<Object::Remote::Logging::Router>
155which delivers log events to the loggers.
455d031c 157=head1 USAGE
159Object::Remote logging is not enabled by default. If you need to immediately start
160debugging set the OBJECT_REMOTE_LOG_LEVEL environment variable to either 'trace'
161or 'debug'. This will enable logging to STDERR on the local and all remote Perl
162interpreters. By default STDERR for all remote interpreters is passed through
163unmodified so this is sufficient to receive logs generated anywhere Object::Remote
164is running.
166Every time the local interpreter creates a new Object::Remote::Connection the connection
167is given an id that is unique to that connection on the local interpreter. The connection
168id and other metadata is available in the log output via a log format string that can
169be set via the OBJECT_REMOTE_LOG_FORMAT environment variable. The format string and
170available metadata is documented in L<Object::Remote::Logging::Logger>. Setting this
171environment variable on the local interpreter will cause it to be propagated to the
172remote interpreter so all logs will be formated the same way.
174This class is designed so any module can create their own logging sub-class using it.
f21127fd 175With out any additional configuration the consumers of this logging class will
176automatically be enabled via OBJECT_REMOTE_LOG_LEVEL and formated with
177OBJECT_REMOTE_LOG_FORMAT but those additional log messages are not sent to STDERR.
178By setting the OBJECT_REMOTE_LOG_SELECTIONS environment variable to a list of
179class names seperated by spaces then logs generated by packages that use those classes
ae198201 180will be sent to STDERR. If the asterisk character (*) is used in the place of a class
181name then all class names will be selected by default instead of ignored. An individual
182class name can be turned off by prefixing the name with a hypen character (-). This is
183also a configuration item that is forwarded to the remote interpreters so all logging
184is consistent.
455d031c 185
186Regardless of OBJECT_REMOTE_LOG_LEVEL the logging system is still active and loggers
187can access the stream of log messages to format and output them. Internally
188OBJECT_REMOTE_LOG_LEVEL causes an L<Object::Remote::Logging::Logger> to be built
189and connected to the L<Object::Remote::Logging::Router> instance. It is also possible
190to manually build a logger instance and connect it to the router. See the documentation
f21127fd 191for the logger and router classes.
455d031c 192
193The logging system also supports a method of forwarding log messages from remote
194interpreters to the local interpreter. Forwarded log messages are generated in the
195remote interpreter and the logger for the message is invoked in the local interpreter.
196Sub-classes of Object::Remote::Logging will have log messages forwarded automatically.
197Loggers receive forwarded log messages exactly the same way as non-forwarded messages
198except a forwarded message includes extra metadata about the remote interpreter. Log
09f583a7 199forwarding is enabled by default but comes with a performance hit; to disable it set the
200OBJECT_REMOTE_LOG_FORWARDING environment variable to 0. See L<Object::Remote::Logging::Router>.
455d031c 201
204=over 4
206=item arg_levels
208Returns an array reference that contains the ordered list of level names
209with the lowest log level first and the highest log level last.
211=item router
213Returns the instance of L<Object::Remote::Logging::Router> that is in use. The router
214instance is used in combination with L<Object::Remote::Logging::Logger> objects to
215select then render and output log messages.
217=item log_<level> and Dlog_<level>
219These methods come direct from L<Log::Contextual>; see that documentation for a
220complete reference. For each of the log level names there are subroutines with the log_
221and Dlog_ prefix that will generate the log message. The first argument is a code block
222that returns the log message contents and the optional further arguments are both passed
223to the block as the argument list and returned from the log method as a list.
225 log_trace { "A fine log message $_[0] " } 'if I do say so myself';
455d031c 226 %hash = Dlog_trace { "Very handy: $_" } ( foo => 'bar' );
d672a9bf 227
228=item logS_<level> and DlogS_<level>
230Works just like log_ and Dlog_ except returns only the first argument as a scalar value.
302ecfbf 232 my $beverage = logS_info { "Customer ordered $_[0]" } 'Coffee';
d672a9bf 233
d672a9bf 234=back
236=head1 LEVEL NAMES
293fb1ee 238Object::Remote uses an ordered list of log level names with the lowest level
239first and the highest level last. The list of level names can be accessed via
d672a9bf 240the arg_levels method which is exportable to the consumer of this class. The log
241level names are:
243=over 4
245=item trace
247As much information about operation as possible including multiple line dumps of
248large content. Tripple verbose operation (-v -v -v).
250=item debug
252Messages about operations that could hang as well as internal state changes,
253results from method invocations, and information useful when looking for faults.
254Double verbose operation (-v -v).
256=item verbose
258Additional optional messages to the user that can be enabled at their will. Single
259verbose operation (-v).
261=item info
263Messages from normal operation that are intended to be displayed to the end
264user if quiet operation is not indicated and more verbose operation is not
265in effect.
267=item warn
269Something wasn't supposed to happen but did. Operation was not impacted but
270otherwise the event is noteworthy. Single quiet operation (-q).
272=item error
274Something went wrong. Operation of the system may continue but some operation
275has most definitely failed. Double quiet operation (-q -q).
277=item fatal
279Something went wrong and recovery is not possible. The system should stop operating
280as soon as possible. Tripple quiet operation (-q -q -q).