package Object::Remote::Logging;
-use strictures 1;
+use Moo;
+use Scalar::Util qw(blessed);
+use Object::Remote::Logging::Logger;
+use Exporter::Declare;
+use Carp qw(carp croak);
-use Log::Contextual qw( :log );
-use Object::Remote::LogRouter;
-use Object::Remote::LogDestination;
-use Log::Contextual::SimpleLogger;
-use Carp qw(cluck);
+extends 'Log::Contextual';
-use base qw(Log::Contextual);
+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 arg_router {
- return $_[1] if defined $_[1];
- our $Router_Instance;
-
- return $Router_Instance if defined $Router_Instance;
-
- $Router_Instance = Object::Remote::LogRouter->new(
- description => $_[0],
- );
+sub router {
+ our $Router_Instance ||= do {
+ require Object::Remote::Logging::Router;
+ Object::Remote::Logging::Router->new;
+ }
}
-sub init_logging {
- my ($class) = @_;
- our $Did_Init;
-
- return if $Did_Init;
- $Did_Init = 1;
-
- if ($ENV{OBJECT_REMOTE_LOG_LEVEL}) {
- $class->init_logging_stderr($ENV{OBJECT_REMOTE_LOG_LEVEL});
- }
+#log level descriptions
+#info - standard log level - normal program output for the end user
+#warn - output for program that is executing quietly
+#error - output for program that is running more quietly
+#fatal - it is not possible to continue execution; this level is as quiet as is possible
+#verbose - output for program executing verbosely (-v)
+#debug - output for program running more verbosely (-v -v)
+#trace - output for program running extremely verbosely (-v -v -v)
+sub arg_levels {
+ #the order of the log levels is significant with the
+ #most verbose level being first in the list and the
+ #most quiet as the last item
+ return [qw( trace debug verbose info warn error fatal )];
}
-sub init_logging_stderr {
- my ($class, $level) = @_;
- our $Log_Level = $level;
- chomp(my $hostname = `hostname`);
- our $Log_Output = Object::Remote::LogDestination->new(
- logger => Log::Contextual::SimpleLogger->new({
- levels_upto => $Log_Level,
- coderef => sub { warn "[$hostname $$] ", @_ },
- })
- );
- $Log_Output->connect($class->arg_router);
-}
+sub before_import {
+ my ($class, $importer, $spec) = @_;
+ my $router = $class->router;
-sub init_logging_forwarding {
- my ($class, $remote_parent) = @_;
- chomp(my $host = `hostname`);
- $class->arg_router->description("$$ $host");
- $class->arg_router->parent_router($remote_parent);
- $remote_parent->add_child_router($class->arg_router);
-}
+ $class->SUPER::before_import($importer, $spec);
-1;
+ my @levels = @{$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;
+ $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
+ carp $code->();
+ exit($exit_value);
+ });
+ }
+ }
+}
-#__END__
-#
-#Hierarchical routed logging concept
-#
-# Why?
-#
-# Object::Remote and systems built on it would benefit from a standard model
-# for logging that enables simple and transparent log generation and consumption
-# that can cross the Perl interpreter instance boundaries transparently. More
-# generally CPAN would benefit from a common logging framework that allows all
-# log message generators to play nicely with all log message consumers with out
-# making the generators or consumers jump through hoops to do what they want to do.
-# If these two solutions are the same then all modules built using the
-# logging framework will transparently operate properly when run under Object::Remote.
-#
-# Such a solution needs to be flexible and have a low performance impact when it is not
-# actively logging. The hiearchy of log message routers is the way to achieve all of these
-# goals. The abstracted message router interface introduced to Log::Contextual allows
-# the hierarchical routing system to be built and tested inside Object::Remote with possible
-# larger scale deployment in the future.
-#
-# Hierarchy of log routers
-#
-# * Each Perl module ideally would use at least a router dedicated
-# to that module and may have child routers if the module is complex.
-# * Log messages inserted at low levels in the hierarchy
-# are available at routers at higher levels in the hierarchy.
-# * Each running Perl instance has a root router which receives
-# all log messages generated in the Perl instance.
-# * The routing hierarchy is available for introspection and connections
-# from child routers to parent routers have human readable strings
-# * The entire routing system is dynamic
-# * Add and remove routers while the system is in operation
-# * Add and remove taps into routers while the system is in operation
-# * Auto-solves Object::Remote logging by setting the parent router of the
-# root router in the remote instance to a router in the local instance the
-# log messages will flow into the local router via a proxy object
-# * Should probably be two modes of operation for Object::Remote logging
-# * forwarding across instances for ease of use during normal operation
-# * stderr output by default for debugging cases to limit the usage of
-# object::remote
-#
-#
-# Example hiearchy
-#
-# Root [1]
-# * System::Introspector
-# * Object::Remote [2]
-# * local [3]
-# * remote [4]
-# * hostname-1.example.com [5]
-# * Root
-# * System::Introspector
-# * Object::Remote
-# * local
-# * hostname-2.example.com
-# * Root
-# * System::Introspector
-# * Object::Remote
-# * local
-#
-# [1] This router has all logs generated anywhere
-# even on remote hosts
-# [2] Everything related to Object::Remote including
-# log messages from remote nodes for things other
-# than Object::Remote
-# [3] Log messages generated by Object::Remote on the local
-# node only
-# [4] All log messages from all remote nodes
-# [5] This is the connection from a remote instance to the
-# local instance using a proxy object
-#
-# As a demonstration of the flexibility of the this system consider a CPAN testers GUI
-# tool. This hypothetical tool would allow a tester to select a module by name and perform
-# the automated tests for that package and all dependent packages. Inside the tool is a pane for
-# the output of the process (STDOUT and STDERR), a pane for log messages, and a pane displaying
-# the modules that are participating in routed logging. The tester could then click on individual
-# packages and enable logging for that package dynamically. If neccassary more than one package
-# could be monitored if neccassary. If the GUI is wrapping a program that runs for long periods of
-# time or if the application is a daemon then being able to dynamically add and remove logging
-# becomes very useful.
-#
-# Log message selection and output
-#
-# * Assumptions
-# * Modules and packages know how they want to format log messages
-# * Consumers of log messages want to know
-# * Which Perl module/package generated that message
-# * When running with Object::Remote if the log message is from
-# a remote node and if so which node
-# * Consuming a log message is something the consumer knows how it wants
-# to be done; the module/package should not be dictating how to receive
-# the log messages
-# * Most log messages most of the time will be completely ignored and unused
-# * Router taps
-# * A consumer of log messages will tap into a router at any arbitrary point
-# in the router hierarchy even across machines if Object::Remote is involved
-# * The tap is used to access a stream of log data and is not used to select
-# which packages/modules should be logged
-# * For instance Object::Remote has log messages flowing through it that
-# include logs generated on remote nodes even if those logs were generated
-# by a module other than Object::Remote
-# * Selection
-# * The module has defined what the log message format is
-# * The tap has defined the scope of messages that will be
-# available for selection, ie: all log messages everywhere,
-# all logs generated on Object::Remote nodes, etc
-# * Selection defines what log messages are going to be delivered
-# to a logger object instance
-# * Selectors act as a gate between a tap and the logger object
-# * Selectors are closures that perform introspection on the log
-# message; if the selector returns true the logger will be invoked
-# to log this message
-# * The logger still has a log level assigned to it and still will have
-# the is_$level method invoked to only log at that specific level
-# * Destinations
-# * A log destination is an instance of a logger object and the associated
-# selectors.
-# * Consuming logging data from this system is a matter of
-# * Constructing an instance of a logging destination object which has
-# the following attributes:
-# * logger - the logger object, like warnlogger or log4perl instance
-# * selectors - a list of closures; the first one that returns true
-# causes the logger to be checked for this log_level and
-# invoked if neccassary
-# * Register selectors with the destination by invoking a method and specifying
-# sub refs as an argument
-#
-# Technical considerations
-# * Log contextual likes to have the logger invoked directly inside the exported log
-# specific methods because it removes a need to muck with logger caller depths to
-# report back the proper caller information for the logger.
-# * Because of this the best strategy identified is to return a list of loggers
-# to those exported methods which then invoke the loggers inside the method
-# * This means that log message forwarding is a process of querying each parent
-# router for a list of logger objects that should be invoked. Each router along
-# the hierarchy adds to this list and the log_* method will invoke all loggers
-# directly.
-# * The routing hierarchy has cycles where parent routers hold a reference to the child
-# and the child holds a reference to the parent. The cycles are not a problem if weak
-# references are used however proxy objects don't seem to currently work with weak
-# references.
-# * Once a logger hits a proxy object the caller information is totally blown; this
-# crossing isn't transparent yet
-#
-#
-#
+#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;
+
+ 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(),
+ );
+ router()->connect(sub {
+ 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};
+ $logger
+ });
+}
+#this is invoked by the controlling node
+#on the remote nodes
+sub init_logging_forwarding {
+ my ($self, %controller_info) = @_;
+
+ router()->_remote_metadata({ connection_id => $controller_info{connection_id} });
+ router()->_forward_destination($controller_info{router}) if $ENV{OBJECT_REMOTE_LOG_FORWARDING};
+}
+1;
projects / scpubgit/Object-Remote.git / blobdiff