From: John Napiorkowski Date: Fri, 27 Jun 2014 22:57:03 +0000 (-0400) Subject: first pass docs and code X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=catagits%2FCatalyst-Runtime.git;a=commitdiff_plain;h=7cd7116d8f47d62b1e6d6d13b2a06c05cb644ae6 first pass docs and code --- diff --git a/lib/Catalyst.pm b/lib/Catalyst.pm index f6b1d09..1eb3821 100755 --- a/lib/Catalyst.pm +++ b/lib/Catalyst.pm @@ -117,7 +117,7 @@ __PACKAGE__->mk_classdata($_) for qw/components arguments dispatcher engine log dispatcher_class engine_loader context_class request_class response_class stats_class setup_finished _psgi_app loading_psgi_file run_options _psgi_middleware - _data_handlers/; + _data_handlers trace_level trace_logger/; __PACKAGE__->dispatcher_class('Catalyst::Dispatcher'); __PACKAGE__->request_class('Catalyst::Request'); @@ -1137,6 +1137,7 @@ sub setup { $class->setup_log( delete $flags->{log} ); $class->setup_plugins( delete $flags->{plugins} ); + $class->setup_trace(); $class->setup_data_handlers(); $class->setup_dispatcher( delete $flags->{dispatcher} ); @@ -2900,6 +2901,78 @@ sub psgi_app { return $app->Catalyst::Utils::apply_registered_middleware($psgi); } + +=head2 trace_level + +Class attribute which is a positive number and defines the noiseness of the +application trace. See L. + +=head2 trace_logger + +Class attribute which is a handler for reporting your traces. See L. + +=head2 $c->setup_trace + +Examples your %ENV, configuation and application settings to setup how and if +application tracing is enabled. See L. + +=head2 $c->trace + +Accepts a string $message and level for a trace message. The configured +trace level must equal or exceed the level given. Level is required and should +be a positive integer. For more see L. + +=cut + +sub setup_trace { + my ($app, @args) = @_; + + # first we look for %ENV + if(my $trace = Catalyst::Utils::env_value( $app, 'TRACE' )) { + # extract a file path if it exists; + my ($level,$op, $path) = ($trace=~m/^(.+)(\=|\+\=)(.+)$/); + if($level && $op && $path) { + open(my $fh, '>', $path) + ||die "Cannot open trace file at $path: $!"; + $app->trace_logger($fh); + $app->trace_level($level); + } else { + $app->trace_level($trace); + } + } + + # Next, we look at config + $app->trace_level($app->config->{trace_level}) unless defined($app->trace_level); + $app->trace_logger($app->config->{trace_logger}) unless defined($app->trace_logger); + + # We do setup_trace AFTER setup_log, so this stuff should be all good to + # use by this point in application setup. For BackCompat, we will try to + # respect ->debug + + if($app->debug) { + $app->trace_level(1) unless defined($app->trace_level); + $app->trace_logger(sub { shift->log->debug }) unless defined($app->trace_logger); + } + + # Last, we set defaults if the settings are still emtpy + # Setup the defaults + + $app->trace_level(0) unless defined($app->trace_level); + $app->trace_logger(sub { shift->log->debug }) unless defined($app->trace_logger); + + return; +} + +sub trace { + my ($class, $message, $level) = @_; + die "Level is required" unless defined $level; + if($class->trace_level >= $level) { + ref($class->trace_logger) eq 'CODE' ? + $class->trace_logger->($class, $message, $level) : + $class->trace_logger->print($message); + } +} + =head2 $c->setup_home Sets up the home directory. @@ -3447,11 +3520,19 @@ backwardly compatible). =item * -C - See L. +C - See L. =item * -C - See L. +C - See L. + +=item * + +trace_level - This sets your application trace level - See L. + +=item * + +trace_logger - This sets your application trace logger - See L. =back @@ -3748,6 +3829,160 @@ to initialize the middleware object. Please see L for more on middleware. +=head1 TRACING + +B Tracing replaces the functionality of L. For now both +interfaces will be supported but it is suggested that you become familiar with +the new interface and begin using it. + +Application tracing is debugging information about the state of your L +application and a request / response cycle. This is often used when you want a +peek into the 'Catalyst Black Box' without needing to actually hack into the +core code and add debugging statements. Examples of application tracing include +startup information about loaded plugins, middleware, models, controllers and +views. It also includes details about how a request is dispatched (what actions +in what controllers are hit, and approximately how long each took) and how a +response is generated. Additional trace information includes details about errors +and some basic statistics on your running application. + +It is often the case when running an application in a development environment +for development purposes that you will enable tracing to assist you in your work. +However, application tracing is not strictly tied to environment so trace levels +are not automatically enabled based on any environment settings (although you are +allowed to set trace levels via configuration, which can be environment specific, +if you choose so). + +Application tracing is also not the same thing as logging. Logging is custom messages +that you've added to your custom application for the purposes of better understanding +your application and how effective your application is in achieving its goals. +Often logging is extended, unstructured meta data around your core business logic +such as details about when a user account is created or failed to be created, what +types of validation issues are occuring in your forms, page views, user engagement +and timestamps to help you understand your application performance. Basically this +is often information of business value that doesn't cleanly or meaningfully fit +into a database. Catalyst provides an interface for adding various kinds of +Loggers which can assist you in these tasks. Most Loggers allow one to log +messages at different levels of priority, such as debug, warning, critical, etc. +This is a useful feature since it permits one to turn the logging level down in +high traffic environments. In the past Catalyst tracing (previously called +'Debug') was conflated with log levels of debug, in that in order to enable +application tracing (or debugging) one was required to turn log level debug on +globally. Additionally, the Catalyst application tracing (or debugging) used +the defined logger to 'record' its messages. Neither is ideal since it leads +one to be forced to accept more logging than may be wished, and it also does +not allow one to separate development tracing from application debug logging. + +Application tracing fixes this issues by allowing you to turn on tracing +independently of setting your log level. It also lets you define a trace +log message handler separately from your logger. So for example you might +wish to send trace messages to STDOUT, but send your logging to Elasticsearch. +Here's an example: + + package MyApp; + + use Catalyst; + + __PACKAGE__->trace_level(1); + __PACKAGE__->trace_logger(sub { my $class = shift; ...}); + __PACKAGE__->setup; + +You may also configure tracing via configuration: + + package MyApp; + + use Catalyst; + + __PACKAGE__->config({ + trace_level => 1, + trace_logger => sub { my $class = shift; ...}, + }); + + __PACKAGE__->setup; + +Or, you may set tracing via environment varables, for example: + + CATALYST_TRACE=1 perl script/myapp_server.pl + MYAPP_TRACE=1 perl script/myapp_server.pl + MYAPP_TRACE=1=/var/log/traces perl script/myapp_server.pl + +The order of precidence is that custom application environment variables +('MYAPP_TRACE') come first, followed by global environment variables +('CATALYST_TRACE'), followed by configuration settings and lastly application +defaults. + +For backwards compatiblity, we respect classic Catalyst debugging (L) in +the following way. If debugging is true, we automatically set +C and set the C to your the debug method of your +defined log object (basically it works just as described in L). In this +case $c->debug will also be set to true. + +Please note that if you set C but not debugging then debugging +($c->debug) will NOT be set to true. + +Please note that if you set BOTH trace_level and 'class' debugging, your trace +level and trace configuation is respected at a high priority, however the state +of the debug method will be set as requested (although overridden). This is +done for backcompatibility with applications that overloaded the debug method +in custom applications. + +Please note that when setting trace levels via environment, you may use an +extended form of the value, which opens a filehandled to a specified path +and sends all trace information there: + + MYAPP_TRACE=1=/var/log/traces perl script/myapp_server.pl + +This would override any other settings for L<\trace_logger>. I + +=head2 trace_level + +This is a number that defaults to 0. It indicates the level of application +tracing that is desired. Larger numbers indicate greater level of tracing. +Currently trace levels are defined, although at this time respect is limited, +as this is a new feature. + +Levels 1,2 and 3 are reserved for Catalyst core code (code that is part of the +L distribution). + +Levels 4,5 and 6 are reserved for Catalyst extended ecosystem (Catalyst plugins, +models, views and distributions under the CatalystX namespace). + +Levels 7,8 and 9 are reserved but not currently defined. + +Levels 10 and higher are reserved for local (not on CPAN) application use. + +=head2 trace_logger + +This handles a trace message, if it is determined that one should be sent based +on the running L<\trace_level>. This can accept the following values + +=over 4 + +=item a CodeRef + +This is a code reference that gets the application class (your Catalyst.pm +subclass) as argument0, the message as argument1 and the level as argument3. +The message is expected to be a string. For example: + + __PACKAGE__->trace_logger( sub { + my ($app, $message, $level) = @_; + $app->log->debug($message); + }); + +Would send trace messages to the debug log handler (This is currently the +default behavior). + +=item A Filehandle or Object + +This must be an open filehandle setup to received output. We really +just look for a 'print' method, so strictly speaking this could be +any object that satisfies the duck type. + +=item A String + +A path that be be resolved as a file that we open a filehandle to. + +=back + =head1 ENCODING On request, decodes all params from encoding into a sequence of