X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=scpubgit%2FObject-Remote.git;a=blobdiff_plain;f=lib%2FObject%2FRemote%2FLogging.pm;h=7e030ff49a5c8108d278ee89431e0a2876ed6cc1;hp=cf85e10f6a7a71362abe80a5ebf12072063ae5ea;hb=f21127fd8c611eee83f769422168bb7bf3b25f0a;hpb=466ee2c442ee6958e077a02c3c250245f06ad819 diff --git a/lib/Object/Remote/Logging.pm b/lib/Object/Remote/Logging.pm index cf85e10..7e030ff 100644 --- a/lib/Object/Remote/Logging.pm +++ b/lib/Object/Remote/Logging.pm @@ -4,10 +4,15 @@ use Moo; use Scalar::Util qw(blessed); use Object::Remote::Logging::Logger; use Exporter::Declare; +use Carp qw(carp croak); extends 'Log::Contextual'; -exports(qw( router arg_levels )); +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 $Router_Instance ||= do { @@ -31,11 +36,52 @@ sub arg_levels { return [qw( trace debug verbose info warn error fatal )]; } +sub before_import { + my ($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}; - #TODO allow the selections value to be * so it selects everything my $selections = $ENV{OBJECT_REMOTE_LOG_SELECTIONS}; my %controller_should_log; @@ -51,7 +97,7 @@ sub init_logging { router()->connect(sub { my $controller = $_[1]->{controller}; - return unless $controller_should_log{'*'} || $controller_should_log{$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}; @@ -70,3 +116,174 @@ sub init_logging_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 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 +which implements log rendering and output and L +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. 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 to be built +and connected to the L 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. + +=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 that is in use. The router +instance is used in combination with L objects to +select then render and output log messages. + +=item log_ and Dlog_ + +These methods come direct from L; 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_ and DlogS_ + +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_ + +Log an event and then generate an exception by calling die() with the log message. + + Elog_error { "Could not open file: $!" }; + +=item Flog_ + +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