use Scalar::Util qw(blessed);
use Object::Remote::Logging::Logger;
use Exporter::Declare;
+use Carp qw(carp croak);
extends 'Log::Contextual';
-exports(qw( router ));
+exports(qw( ____ router arg_levels ));
+#exception log - log a message then die with that message
+export_tag elog => ('____');
+#fatal log - log a message then call exit(1)
+export_tag flog => ('____');
sub router {
our $Router_Instance ||= do {
return [qw( trace debug verbose info warn error fatal )];
}
+sub before_import {
+ my ($class, $importer, $spec) = @_;
+ my $router = $class->router;
+
+ $class->SUPER::before_import($importer, $spec);
+
+ my @levels = @{$class->arg_levels($spec->config->{levels})};
+ for my $level (@levels) {
+ if ($spec->config->{elog}) {
+ $spec->add_export("&Elog_$level", sub (&) {
+ my ($code, @args) = @_;
+ $router->handle_log_request({
+ controller => $class,
+ package => scalar(caller),
+ caller_level => 1,
+ level => $level,
+ }, $code);
+ #TODO this should get fed into a logger so it can be formatted
+ croak $code->();
+ });
+ }
+ if ($spec->config->{flog}) {
+ #TODO that prototype isn't right
+ $spec->add_export("&Flog_$level", sub (&@) {
+ my ($code, $exit_value) = @_;
+ $exit_value = 1 unless defined $exit_value;
+ #don't let it going wrong stop us from calling exit()
+ eval { $router->handle_log_request({
+ controller => $class,
+ package => scalar(caller),
+ caller_level => 1,
+ level => $level,
+ }, $code) };
+ warn "could not deliver log event during Flog_$level: $@" if defined $@;
+ eval { carp $code->() };
+ warn "could not emit warning during Flog_$level: $@" if defined $@;
+ exit($exit_value);
+ });
+ }
+ }
+}
+
#this is invoked on all nodes
sub init_logging {
my $level = $ENV{OBJECT_REMOTE_LOG_LEVEL};
my $format = $ENV{OBJECT_REMOTE_LOG_FORMAT};
+ my $selections = $ENV{OBJECT_REMOTE_LOG_SELECTIONS};
+ my %controller_should_log;
+
return unless defined $level;
$format = "[%l %r] %s" unless defined $format;
+ $selections = __PACKAGE__ unless defined $selections;
+ %controller_should_log = map { $_ => 1 } split(' ', $selections);
+
my $logger = Object::Remote::Logging::Logger->new(
min_level => lc($level), format => $format,
level_names => Object::Remote::Logging::arg_levels(),
);
- #TODO check on speed of string compare against a hash with a single key
router()->connect(sub {
- return unless $_[1]->{controller} eq __PACKAGE__;
+ my $controller = $_[1]->{controller};
+ return unless $controller_should_log{'*'} || $controller_should_log{$controller};
#skip things from remote hosts because they log to STDERR
#when OBJECT_REMOTE_LOG_LEVEL is in effect
return if $_[1]->{remote}->{connection_id};
my ($self, %controller_info) = @_;
router()->_remote_metadata({ connection_id => $controller_info{connection_id} });
- router()->_forward_destination($controller_info{router});
+ router()->_forward_destination($controller_info{router}) if $ENV{OBJECT_REMOTE_LOG_FORWARDING};
}
1;
+__END__
+
+=head1 NAME
+
+Object::Remote::Logging - Logging subsystem for Object::Remote
+
+=head1 SYNOPSIS
+
+ use Object::Remote::Logging qw( :log :dlog :elog :flog arg_levels router );
+
+ @levels = qw( trace debug verbose info warn error fatal );
+ @levels = arg_levels(); #same result
+
+ $ENV{OBJECT_REMOTE_LOG_LEVEL} = 'trace'; #or other level name
+ $ENV{OBJECT_REMOTE_LOG_FORMAT} = '%l %t: %p::%m %s'; #and more
+ $ENV{OBJECT_REMOTE_LOG_SELECTIONS} = 'Object::Remote::Logging Some::Other::Subclass';
+ $ENV{OBJECT_REMOTE_LOG_FORWARDING} = 0 || 1; #default 0
+
+ log_info { 'Trace log event' };
+ Dlog_verbose { "Debug event with Data::Dumper::Concise: $_" } { foo => 'bar' };
+ Elog_error { 'Error event that calls die() with this string' };
+ Flog_fatal { 'Fatal event calls warn() then exit()' } 1;
+
+=head1 DESCRIPTION
+
+This is the logging framework for Object::Remote implemented as a subclass of
+L<Log::Contextual> with a slightly incompatible API. This system allows
+developers using Object::Remote and end users of that software to control
+Object::Remote logging so operation can be tracked if needed. This is also
+the API used to generate log messages inside the Object::Remote source code.
+
+The rest of the logging system comes from L<Object::Remote::Logging::Logger>
+which implements log rendering and output and L<Object::Remote::Logging::Router>
+which delivers log events to the loggers.
+
+=head1 USAGE
+
+Object::Remote logging is not enabled by default. If you need to immediately start
+debugging set the OBJECT_REMOTE_LOG_LEVEL environment variable to either 'trace'
+or 'debug'. This will enable logging to STDERR on the local and all remote Perl
+interpreters. By default STDERR for all remote interpreters is passed through
+unmodified so this is sufficient to receive logs generated anywhere Object::Remote
+is running.
+
+Every time the local interpreter creates a new Object::Remote::Connection the connection
+is given an id that is unique to that connection on the local interpreter. The connection
+id and other metadata is available in the log output via a log format string that can
+be set via the OBJECT_REMOTE_LOG_FORMAT environment variable. The format string and
+available metadata is documented in L<Object::Remote::Logging::Logger>. Setting this
+environment variable on the local interpreter will cause it to be propagated to the
+remote interpreter so all logs will be formated the same way.
+
+This class is designed so any module can create their own logging sub-class using it.
+With out any additional configuration the consumers of this logging class will
+automatically be enabled via OBJECT_REMOTE_LOG_LEVEL and formated with
+OBJECT_REMOTE_LOG_FORMAT but those additional log messages are not sent to STDERR.
+By setting the OBJECT_REMOTE_LOG_SELECTIONS environment variable to a list of
+class names seperated by spaces then logs generated by packages that use those classes
+will be sent to STDERR. This is also a configuration item that is forwarded to the
+remote interpreters so all logging is consistent.
+
+Regardless of OBJECT_REMOTE_LOG_LEVEL the logging system is still active and loggers
+can access the stream of log messages to format and output them. Internally
+OBJECT_REMOTE_LOG_LEVEL causes an L<Object::Remote::Logging::Logger> to be built
+and connected to the L<Object::Remote::Logging::Router> instance. It is also possible
+to manually build a logger instance and connect it to the router. See the documentation
+for the logger and router classes.
+
+The logging system also supports a method of forwarding log messages from remote
+interpreters to the local interpreter. Forwarded log messages are generated in the
+remote interpreter and the logger for the message is invoked in the local interpreter.
+Sub-classes of Object::Remote::Logging will have log messages forwarded automatically.
+Loggers receive forwarded log messages exactly the same way as non-forwarded messages
+except a forwarded message includes extra metadata about the remote interpreter. Log
+forwarding is not currently enabled by default; to enable it set the
+OBJECT_REMOTE_LOG_FORWARDING environment variable to 1. See L<Object::Remote::Logging::Router>.
+
+=head1 EXPORTABLE SUBROUTINES
+
+=over 4
+
+=item arg_levels
+
+Returns an array reference that contains the ordered list of level names
+with the lowest log level first and the highest log level last.
+
+=item router
+
+Returns the instance of L<Object::Remote::Logging::Router> that is in use. The router
+instance is used in combination with L<Object::Remote::Logging::Logger> objects to
+select then render and output log messages.
+
+=item log_<level> and Dlog_<level>
+
+These methods come direct from L<Log::Contextual>; see that documentation for a
+complete reference. For each of the log level names there are subroutines with the log_
+and Dlog_ prefix that will generate the log message. The first argument is a code block
+that returns the log message contents and the optional further arguments are both passed
+to the block as the argument list and returned from the log method as a list.
+
+ log_trace { "A fine log message $_[0] " } 'if I do say so myself';
+ %hash = Dlog_trace { "Very handy: $_" } ( foo => 'bar' );
+
+=item logS_<level> and DlogS_<level>
+
+Works just like log_ and Dlog_ except returns only the first argument as a scalar value.
+
+ my $beverage = log_info { "Customer ordered $_[0]" } 'Coffee';
+
+=item Elog_<level>
+
+Log an event and then generate an exception by calling die() with the log message.
+
+ Elog_error { "Could not open file: $!" };
+
+=item Flog_<level>
+
+Log the event, generate a warning with the log message, then call exit(). The exit
+value will default to 1 or can be specified as an argument.
+
+ Flog_fatal { 'Could not lock resource' } 3;
+
+=back
+
+=head1 LEVEL NAMES
+
+Object::Remote uses an ordered list of log level names with the minimum level
+first and the maximum level last. The list of level names can be accessed via
+the arg_levels method which is exportable to the consumer of this class. The log
+level names are:
+
+=over 4
+
+=item trace
+
+As much information about operation as possible including multiple line dumps of
+large content. Tripple verbose operation (-v -v -v).
+
+=item debug
+
+Messages about operations that could hang as well as internal state changes,
+results from method invocations, and information useful when looking for faults.
+Double verbose operation (-v -v).
+
+=item verbose
+
+Additional optional messages to the user that can be enabled at their will. Single
+verbose operation (-v).
+
+=item info
+
+Messages from normal operation that are intended to be displayed to the end
+user if quiet operation is not indicated and more verbose operation is not
+in effect.
+
+=item warn
+
+Something wasn't supposed to happen but did. Operation was not impacted but
+otherwise the event is noteworthy. Single quiet operation (-q).
+
+=item error
+
+Something went wrong. Operation of the system may continue but some operation
+has most definitely failed. Double quiet operation (-q -q).
+
+=item fatal
+
+Something went wrong and recovery is not possible. The system should stop operating
+as soon as possible. Tripple quiet operation (-q -q -q).
+
+=back
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