[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent/Log.pm

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.16 by root, Sat Aug 20 02:19:18 2011 UTC vs.
Revision 1.20 by root, Sat Aug 20 22:27:07 2011 UTC

…		…
20	$tracer->("i am here") if $trace;	20	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		22
23	# configuration	23	# configuration
24		24
25	# set logging for this package to errors and higher only	25	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("error");	26	AnyEvent::Log::ctx->level ("error");
27		27
28	# set logging globally to anything below debug	28	# set logging globally to anything below debug
29	$AnyEvent::Log::Root->level ("notice");	29	$AnyEvent::Log::FILTER->level ("notice");
30		30
31	# see also EXAMPLES, below	31	# see also EXAMPLES, below
32		32
33	=head1 DESCRIPTION	33	=head1 DESCRIPTION
34		34
…		…
36	attempt to be "the" logging solution or even "a" logging solution for	36	attempt to be "the" logging solution or even "a" logging solution for
37	AnyEvent - AnyEvent simply creates logging messages internally, and this	37	AnyEvent - AnyEvent simply creates logging messages internally, and this
38	module more or less exposes the mechanism, with some extra spiff to allow	38	module more or less exposes the mechanism, with some extra spiff to allow
39	using it from other modules as well.	39	using it from other modules as well.
40		40
41	Remember that the default verbosity level is C<0>, so nothing will be	41	Remember that the default verbosity level is C<0> (C<off>), so nothing
42	logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number before	42	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
43	starting your program, or change the logging level at runtime with	43	before starting your program, or change the logging level at runtime with
44	something like:	44	something like:
45		45
46	use AnyEvent;	46	use AnyEvent::Log;
47	(AnyEvent::Log::ctx "")->level ("info");	47	AnyEvent::Log::FILTER->level ("info");
48		48
49	The design goal behind this module was to keep it simple (and small),	49	The design goal behind this module was to keep it simple (and small),
50	but make it powerful enough to be potentially useful for any module, and	50	but make it powerful enough to be potentially useful for any module, and
51	extensive enough for the most common tasks, such as logging to multiple	51	extensive enough for the most common tasks, such as logging to multiple
52	targets, or being able to log into a database.	52	targets, or being able to log into a database.
53		53
54	The amount of documentation might indicate otherwise, but the module is	54	The amount of documentation might indicate otherwise, but the module is
55	still just 240 lines or so.	55	still just below 300 lines of code.
		56
		57	=head1 LOGGING LEVELS
		58
		59	Logging levels in this module range from C<1> (highest priority) to C<9>
		60	(lowest priority). Note that the lowest numerical value is the highest
		61	priority, so when this document says "higher priority" it means "lower
		62	numerical value".
		63
		64	Instead of specifying levels by name you can also specify them by aliases:
		65
		66	LVL NAME SYSLOG PERL NOTE
		67	1 fatal emerg exit aborts program!
		68	2 alert
		69	3 critical crit
		70	4 error err die
		71	5 warn warning
		72	6 note notice
		73	7 info
		74	8 debug
		75	9 trace
		76
		77	As you can see, some logging levels have multiple aliases - the first one
		78	is the "official" name, the second one the "syslog" name (if it differs)
		79	and the third one the "perl" name, suggesting that you log C<die> messages
		80	at C<error> priority.
		81
		82	You can normally only log a single message at highest priority level
		83	(C<1>, C<fatal>), because logging a fatal message will also quit the
		84	program - so use it sparingly :)
		85
		86	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		87	or C<all> - these are only valid in the methods they are documented for.
56		88
57	=head1 LOGGING FUNCTIONS	89	=head1 LOGGING FUNCTIONS
58		90
59	These functions allow you to log messages. They always use the caller's	91	These functions allow you to log messages. They always use the caller's
60	package as a "logging module/source". Also, the main logging function is	92	package as a "logging context". Also, the main logging function C<log> is
61	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	93	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
62	loaded.	94	loaded.
63		95
64	=over 4	96	=over 4
65		97
…		…
72		104
73	use AnyEvent (); BEGIN { AnyEvent::common_sense }	105	use AnyEvent (); BEGIN { AnyEvent::common_sense }
74	use AnyEvent::Util ();	106	use AnyEvent::Util ();
75		107
76	our $VERSION = $AnyEvent::VERSION;	108	our $VERSION = $AnyEvent::VERSION;
		109
		110	our ($COLLECT, $FILTER, $LOG);
77		111
78	our ($now_int, $now_str1, $now_str2);	112	our ($now_int, $now_str1, $now_str2);
79		113
80	# Format Time, not public - yet?	114	# Format Time, not public - yet?
81	sub ft($) {	115	sub ft($) {
…		…
86	if $now_int != $i;	120	if $now_int != $i;
87		121
88	"$now_str1$f$now_str2"	122	"$now_str1$f$now_str2"
89	}	123	}
90		124
91	our %CTX; # all logging contexts	125	our %CTX; # all package contexts
92		126
93	# creates a default package context object for the given package	127	# creates a default package context object for the given package
94	sub _pkg_ctx($) {	128	sub _pkg_ctx($) {
95	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	129	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
96		130
97	# link "parent" package	131	# link "parent" package
98	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	132	my $parent = $_[0] =~ /^(.+)::/
		133	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		134	: $COLLECT;
99		135
100	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
101	$ctx->[2]{$pkg+0} = $pkg;	136	$ctx->[2]{$parent+0} = $parent;
102		137
103	$ctx	138	$ctx
104	}	139	}
105		140
106	=item AnyEvent::Log::log $level, $msg[, @args]	141	=item AnyEvent::Log::log $level, $msg[, @args]
107		142
108	Requests logging of the given C<$msg> with the given log level (1..9).	143	Requests logging of the given C<$msg> with the given log level.
109	You can also use the following strings as log level: C<fatal> (1),
110	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
111	C<info> (7), C<debug> (8), C<trace> (9).
112		144
113	For C<fatal> log levels, the program will abort.	145	For C<fatal> log levels, the program will abort.
114		146
115	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	147	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
116	C<$msg> is interpreted as an sprintf format string.	148	C<$msg> is interpreted as an sprintf format string.
…		…
149		181
150	=cut	182	=cut
151		183
152	# also allow syslog equivalent names	184	# also allow syslog equivalent names
153	our %STR2LEVEL = (	185	our %STR2LEVEL = (
154	fatal => 1, emerg => 1,	186	fatal => 1, emerg => 1, exit => 1,
155	alert => 2,	187	alert => 2,
156	critical => 3, crit => 3,	188	critical => 3, crit => 3,
157	error => 4, err => 4,	189	error => 4, err => 4, die => 4,
158	warn => 5, warning => 5,	190	warn => 5, warning => 5,
159	note => 6, notice => 6,	191	note => 6, notice => 6,
160	info => 7,	192	info => 7,
161	debug => 8,	193	debug => 8,
162	trace => 9,	194	trace => 9,
…		…
212	};	244	};
213		245
214	# format msg	246	# format msg
215	my $str = $ctx->[4]	247	my $str = $ctx->[4]
216	? $ctx->[4]($now, $_[0], $level, $format)	248	? $ctx->[4]($now, $_[0], $level, $format)
217	: $fmt \|\|= _format $now, $_[0], $level, $format;	249	: ($fmt \|\|= _format $now, $_[0], $level, $format);
218		250
219	$ctx->[3]($str);	251	$ctx->[3]($str, $_[0], $level)
		252	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		253	} else {
		254	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
220	}	255	}
221
222	# not masked, not consumed - propagate to parent contexts
223	push @ctx, values %{ $ctx->[2] };
224	}	256	}
225	}	257	}
226	while $ctx = pop @ctx;	258	while $ctx = pop @ctx;
227		259
228	exit 1 if $level <= 1;	260	exit 1 if $level <= 1;
…		…
278		310
279	our %LOGGER;	311	our %LOGGER;
280		312
281	# re-assess logging status for all loggers	313	# re-assess logging status for all loggers
282	sub _reassess {	314	sub _reassess {
		315	local $SIG{__DIE__};
		316	my $die = sub { die };
		317
283	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	318	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
284	my ($ctx, $level, $renabled) = @$_;	319	my ($ctx, $level, $renabled) = @$_;
285		320
286	# to detect whether a message would be logged, we # actually	321	# to detect whether a message would be logged, we actually
287	# try to log one and die. this isn't fast, but we can be	322	# try to log one and die. this isn't fast, but we can be
288	# sure that the logging decision is correct :)	323	# sure that the logging decision is correct :)
289		324
290	$$renabled = !eval {	325	$$renabled = !eval {
291	local $SIG{__DIE__};
292
293	_log $ctx, $level, sub { die };	326	_log $ctx, $level, $die;
294		327
295	1	328	1
296	};	329	};
297
298	$$renabled = 1; # TODO
299	}	330	}
300	}	331	}
301		332
302	sub _logger {	333	sub _logger {
303	my ($ctx, $level, $renabled) = @_;	334	my ($ctx, $level, $renabled) = @_;
…		…
348	timestamp, context, level and string message and formats it in the way	379	timestamp, context, level and string message and formats it in the way
349	it should be logged) and a logging callback (which is responsible for	380	it should be logged) and a logging callback (which is responsible for
350	actually logging the formatted message and telling C<AnyEvent::Log>	381	actually logging the formatted message and telling C<AnyEvent::Log>
351	whether it has consumed the message, or whether it should be propagated).	382	whether it has consumed the message, or whether it should be propagated).
352		383
353	For propagation, a context can have any number of attached I<parent	384	For propagation, a context can have any number of attached I<slave
354	contexts>. Any message that is neither masked by the logging mask nor	385	contexts>. Any message that is neither masked by the logging mask nor
355	masked by the logging callback returning true will be passed to all parent	386	masked by the logging callback returning true will be passed to all slave
356	contexts.	387	contexts.
357		388
358	Each call to a logging function will log the message at most once per	389	Each call to a logging function will log the message at most once per
359	context, so it does not matter (much) if there are cycles or if the	390	context, so it does not matter (much) if there are cycles or if the
360	message can arrive at the same context via multiple paths.	391	message can arrive at the same context via multiple paths.
…		…
364	By default, all logging contexts have an full set of log levels ("all"), a	395	By default, all logging contexts have an full set of log levels ("all"), a
365	disabled logging callback and the default formatting callback.	396	disabled logging callback and the default formatting callback.
366		397
367	Package contexts have the package name as logging title by default.	398	Package contexts have the package name as logging title by default.
368		399
369	They have exactly one parent - the context of the "parent" package. The	400	They have exactly one slave - the context of the "parent" package. The
370	parent package is simply defined to be the package name without the last	401	parent package is simply defined to be the package name without the last
371	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	402	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
372	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	403	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
373	exception of the rule - just like the parent of any package name in	404	exception of the rule - just like the "parent" of any single-component
374	Perl is C<main>, the default parent of any top-level package context is	405	package name in Perl is C<main>, the default slave of any top-level
375	C<AnyEvent::Log::Top>.	406	package context is C<$AnyEvent::Log::COLLECT>.
376		407
377	Since perl packages form only an approximate hierarchy, this parent	408	Since perl packages form only an approximate hierarchy, this slave
378	context can of course be removed.	409	context can of course be removed.
379		410
380	All other (anonymous) contexts have no parents and an empty title by	411	All other (anonymous) contexts have no slaves and an empty title by
381	default.	412	default.
382		413
383	When the module is loaded it creates the default context called	414	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
384	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	415	context that simply logs everything via C<warn>, without propagating
385	which simply logs everything via C<warn> and doesn't propagate anything
386	anywhere by default. The purpose of the default context is to provide	416	anything anywhere by default. The purpose of this context is to provide
387	a convenient place to override the global logging target or to attach	417	a convenient place to override the global logging target or to attach
388	additional log targets. It's not meant for filtering.	418	additional log targets. It's not meant for filtering.
389		419
390	It then creates the root context called C<AnyEvent::Log::Root> (also	420	It then creates the C<$AnyEvent::Log::FILTER> context whose
391	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	421	purpose is to suppress all messages with priority higher
392	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	422	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
393	then attached the default logging context to it. The purpose of the root	423	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
394	context is to simply provide filtering according to some global log level.	424	is to simply provide filtering according to some global log level.
395		425
396	Finally it creates the top-level package context called	426	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
397	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	427	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
398	C<$AnyEvent::Log::Top>) and attached the root context but otherwise leaves
399	it at default config. It's purpose is simply to collect all log messages	428	leaves it at default config. Its purpose is simply to collect all log
400	system-wide.	429	messages system-wide.
401		430
402	These three special contexts can also be referred to by the	431	The hierarchy is then:
403	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
404	C<AE::Log::Top>.
405		432
		433	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		434
406	The effect of all this is that log messages, by default, wander up	435	The effect of all this is that log messages, by default, wander up to the
407	to the root context where log messages with lower priority then	436	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		437	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
408	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	438	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
409	AnyEvent::Log::Default context to be passed to C<warn>.	439	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
410		440
411	Splitting the top level context into three contexts makes it easy to set	441	This makes it easy to set a global logging level (by modifying $FILTER),
412	a global logging level (by modifying the root context), but still allow	442	but still allow other contexts to send, for example, their debug and trace
413	other contexts to log, for example, their debug and trace messages to the
414	default target despite the global logging level, or to attach additional	443	messages to the $LOG target despite the global logging level, or to attach
415	log targets that log messages, regardless of the global logging level.	444	additional log targets that log messages, regardless of the global logging
		445	level.
416		446
417	It also makes it easy to replace the default warn-logger by something that	447	It also makes it easy to modify the default warn-logger ($LOG) to
418	logs to a file, or to attach additional logging targets.	448	something that logs to a file, or to attach additional logging targets
		449	(such as loggign to a file) by attaching it to $FILTER.
419		450
420	=head2 CREATING/FINDING/DESTROYING CONTEXTS	451	=head2 CREATING/FINDING/DESTROYING CONTEXTS
421		452
422	=over 4	453	=over 4
423		454
…		…
457		488
458	=cut	489	=cut
459		490
460	sub reset {	491	sub reset {
461	# hard to kill complex data structures	492	# hard to kill complex data structures
462	# we recreate all package loggers and reset the hierarchy	493	# we "recreate" all package loggers and reset the hierarchy
463	while (my ($k, $v) = each %CTX) {	494	while (my ($k, $v) = each %CTX) {
464	@$v = ($k, (1 << 10) - 1 - 1, { });	495	@$v = ($k, (1 << 10) - 1 - 1, { });
465		496
466	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	497	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
467	$v->attach ($CTX{$pkg});
468	}	498	}
469		499
470	$AnyEvent::Log::Default->parents;	500	@$_ = ($_->[0], (1 << 10) - 1 - 1)
471	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	501	for $LOG, $FILTER, $COLLECT;
472	$AnyEvent::Log::Default->log_cb (sub {	502
		503	$LOG->slaves;
		504	$LOG->title ('$AnyEvent::Log::LOG');
		505	$LOG->log_cb (sub {
473	warn shift;	506	warn shift;
474	0	507	0
475	});	508	});
476	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
477		509
478	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	510	$FILTER->slaves ($LOG);
479	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	511	$FILTER->title ('$AnyEvent::Log::FILTER');
480	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	512	$FILTER->level ($AnyEvent::VERBOSE);
481	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
482		513
483	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	514	$COLLECT->slaves ($FILTER);
484	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	515	$COLLECT->title ('$AnyEvent::Log::COLLECT');
485	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;
486		516
487	_reassess;	517	_reassess;
488	}	518	}
489		519
490	# create the default logger contexts	520	# create the default logger contexts
491	$AnyEvent::Log::Default = ctx undef;	521	$LOG = ctx undef;
492	$AnyEvent::Log::Root = ctx undef;	522	$FILTER = ctx undef;
493	$AnyEvent::Log::Top = ctx undef;	523	$COLLECT = ctx undef;
494		524
495	AnyEvent::Log::reset;	525	AnyEvent::Log::reset;
496		526
497	# hello, CPAN, please catch me	527	# hello, CPAN, please catch me
498	package AnyEvent::Log::Default;
499	package AE::Log::Default;
500	package AnyEvent::Log::Root;
501	package AE::Log::Root;
502	package AnyEvent::Log::Top;	528	package AnyEvent::Log::LOG;
503	package AE::Log::Top;	529	package AE::Log::LOG;
		530	package AnyEvent::Log::FILTER;
		531	package AE::Log::FILTER;
		532	package AnyEvent::Log::COLLECT;
		533	package AE::Log::COLLECT;
504		534
505	package AnyEvent::Log::Ctx;	535	package AnyEvent::Log::Ctx;
506		536
507	# 0 1 2 3 4	537	# 0 1 2 3 4
508	# [$title, $level, %$parents, &$logcb, &$fmtcb]	538	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
509		539
510	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	540	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
511		541
512	This is a convenience constructor that makes it simpler to construct	542	This is a convenience constructor that makes it simpler to construct
513	anonymous logging contexts.	543	anonymous logging contexts.
…		…
516	name as the key with the value as parameter, unless the value is an	546	name as the key with the value as parameter, unless the value is an
517	arrayref, in which case it calls the method with the contents of the	547	arrayref, in which case it calls the method with the contents of the
518	array. The methods are called in the same order as specified.	548	array. The methods are called in the same order as specified.
519		549
520	Example: create a new logging context and set both the default logging	550	Example: create a new logging context and set both the default logging
521	level, some parent contexts and a logging callback.	551	level, some slave contexts and a logging callback.
522		552
523	$ctx = new AnyEvent::Log::Ctx	553	$ctx = new AnyEvent::Log::Ctx
524	title => "dubious messages",	554	title => "dubious messages",
525	level => "error",	555	level => "error",
526	log_cb => sub { print STDOUT shift; 0 },	556	log_cb => sub { print STDOUT shift; 0 },
527	parents => [$ctx1, $ctx, $ctx2],	557	slaves => [$ctx1, $ctx, $ctx2],
528	;	558	;
529		559
530	=back	560	=back
531		561
532	=cut	562	=cut
…		…
645	AnyEvent::Log::_reassess;	675	AnyEvent::Log::_reassess;
646	}	676	}
647		677
648	=back	678	=back
649		679
650	=head3 PARENT CONTEXTS	680	=head3 SLAVE CONTEXTS
651		681
652	The following methods attach and detach another logging context to a	682	The following methods attach and detach another logging context to a
653	logging context.	683	logging context.
654		684
655	Log messages are propagated to all parent contexts, unless the logging	685	Log messages are propagated to all slave contexts, unless the logging
656	callback consumes the message.	686	callback consumes the message.
657		687
658	=over 4	688	=over 4
659		689
660	=item $ctx->attach ($ctx2[, $ctx3...])	690	=item $ctx->attach ($ctx2[, $ctx3...])
661		691
662	Attaches the given contexts as parents to this context. It is not an error	692	Attaches the given contexts as slaves to this context. It is not an error
663	to add a context twice (the second add will be ignored).	693	to add a context twice (the second add will be ignored).
664		694
665	A context can be specified either as package name or as a context object.	695	A context can be specified either as package name or as a context object.
666		696
667	=item $ctx->detach ($ctx2[, $ctx3...])	697	=item $ctx->detach ($ctx2[, $ctx3...])
668		698
669	Removes the given parents from this context - it's not an error to attempt	699	Removes the given slaves from this context - it's not an error to attempt
670	to remove a context that hasn't been added.	700	to remove a context that hasn't been added.
671		701
672	A context can be specified either as package name or as a context object.	702	A context can be specified either as package name or as a context object.
673		703
674	=item $ctx->parents ($ctx2[, $ctx3...])	704	=item $ctx->slaves ($ctx2[, $ctx3...])
675		705
676	Replaces all parents attached to this context by the ones given.	706	Replaces all slaves attached to this context by the ones given.
677		707
678	=cut	708	=cut
679		709
680	sub attach {	710	sub attach {
681	my $ctx = shift;	711	my $ctx = shift;
…		…
689		719
690	delete $ctx->[2]{$_+0}	720	delete $ctx->[2]{$_+0}
691	for map { AnyEvent::Log::ctx $_ } @_;	721	for map { AnyEvent::Log::ctx $_ } @_;
692	}	722	}
693		723
694	sub parents {	724	sub slaves {
695	undef $_[0][2];	725	undef $_[0][2];
696	&attach;	726	&attach;
697	}	727	}
698		728
699	=back	729	=back
700		730
701	=head3 MESSAGE LOGGING	731	=head3 LOG TARGETS
702		732
703	The following methods configure how the logging context actually does	733	The following methods configure how the logging context actually does
704	the logging (which consists of formatting the message and printing it or	734	the logging (which consists of formatting the message and printing it or
705	whatever it wants to do with it) and also allows you to log messages	735	whatever it wants to do with it).
706	directly to a context, without going via your package context.
707		736
708	=over 4	737	=over 4
709		738
710	=item $ctx->log_cb ($cb->($str))	739	=item $ctx->log_cb ($cb->($str, $orig_ctx, $level))
711		740
712	Replaces the logging callback on the context (C<undef> disables the	741	Replaces the logging callback on the context (C<undef> disables the
713	logging callback).	742	logging callback).
714		743
715	The logging callback is responsible for handling formatted log messages	744	The logging callback is responsible for handling formatted log messages
716	(see C<fmt_cb> below) - normally simple text strings that end with a	745	(see C<fmt_cb> below) - normally simple text strings that end with a
717	newline (and are possibly multiline themselves).	746	newline (and are possibly multiline themselves). In addition to the
		747	message, which is often the only argument you need to look at, it is
		748	passed the numeric log level and originating context.
718		749
719	It also has to return true iff it has consumed the log message, and false	750	It also has to return true iff it has consumed the log message, and false
720	if it hasn't. Consuming a message means that it will not be sent to any	751	if it hasn't. Consuming a message means that it will not be sent to any
721	parent context. When in doubt, return C<0> from your logging callback.	752	slave context. When in doubt, return C<0> from your logging callback.
722		753
723	Example: a very simple logging callback, simply dump the message to STDOUT	754	Example: a very simple logging callback, simply dump the message to STDOUT
724	and do not consume it.	755	and do not consume it.
725		756
726	$ctx->log_cb (sub { print STDERR shift; 0 });	757	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
734	your program.	765	your program.
735		766
736	$ctx->levels ("debug", "trace");	767	$ctx->levels ("debug", "trace");
737	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	768	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
738		769
		770	=item $ctx->log_to_file ($path)
		771
		772	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		773
		774	=item $ctx->log_to_path ($path)
		775
		776	Same as C<< ->log_to_file >>, but opens the file for each message. This
		777	is much slower, but allows you to change/move/rename/delete the file at
		778	basically any time.
		779
		780	=item $ctx->log_to_syslog ([$log_flags])
		781
		782	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		783	the others in the obvious way. If specified, then the C<$log_flags> are
		784	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		785	flags valid for Sys::Syslog::syslog, except for the priority levels.
		786
		787	Note that the default logging format includes a verbose timestamp, which
		788	is not so suited for syslog, so a simpler C<fmt_cb> might be useful:
		789
		790	$ctx->log_to_syslog;
		791	$ctx->fmt_cb (sub { "($_[1][0]) $_[3]" });
		792
739	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	793	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
740		794
741	Replaces the formatting callback on the context (C<undef> restores the	795	Replaces the formatting callback on the context (C<undef> restores the
742	default formatter).	796	default formatter).
743		797
744	The callback is passed the (possibly fractional) timestamp, the original	798	The callback is passed the (possibly fractional) timestamp, the original
745	logging context, the (numeric) logging level and the raw message string and needs to	799	logging context, the (numeric) logging level and the raw message string
746	return a formatted log message. In most cases this will be a string, but	800	and needs to return a formatted log message. In most cases this will be a
747	it could just as well be an array reference that just stores the values.	801	string, but it could just as well be an array reference that just stores
		802	the values.
		803
		804	If, for some reaosn, you want to use C<caller> to find out more baout the
		805	logger then you should walk up the call stack until you are no longer
		806	inside the C<AnyEvent::Log> package.
748		807
749	Example: format just the raw message, with numeric log level in angle	808	Example: format just the raw message, with numeric log level in angle
750	brackets.	809	brackets.
751		810
752	$ctx->fmt_cb (sub {	811	$ctx->fmt_cb (sub {
…		…
783	my ($ctx, $cb) = @_;	842	my ($ctx, $cb) = @_;
784		843
785	$ctx->[4] = $cb;	844	$ctx->[4] = $cb;
786	}	845	}
787		846
788	=item $ctx->log ($level, $msg[, @params])	847	sub log_to_file {
789		848	my ($ctx, $path) = @_;
790	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
791
792	=item $logger = $ctx->logger ($level[, \$enabled])
793
794	Same as C<AnyEvent::Log::logger>, but uses the given context as log
795	context.
796
797	=cut
798
799	*log = \&AnyEvent::Log::_log;
800	*logger = \&AnyEvent::Log::_logger;
801
802	1;
803
804	=back
805
806	=head1 EXAMPLES
807
808	This section shows some common configurations.
809
810	=over 4
811
812	=item Setting the global logging level.
813
814	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
815	running your program, or modify the log level of the root context:
816
817	PERL_ANYEVENT_VERBOSE=5 ./myprog
818
819	$AnyEvent::Log::Root->level ("warn");
820
821	=item Append all messages to a file instead of sending them to STDERR.
822
823	This is affected by the global logging level.
824		849
825	open my $fh, ">>", $path	850	open my $fh, ">>", $path
826	or die "$path: $!";	851	or die "$path: $!";
827		852
828	$AnyEvent::Log::Default->log_cb (sub {	853	$ctx->log_cb (sub {
829	syswrite $fh, shift;	854	syswrite $fh, shift;
830	0	855	0
831	});	856	});
		857	}
		858
		859	sub log_to_file {
		860	my ($ctx, $path) = @_;
		861
		862	$ctx->log_cb (sub {
		863	open my $fh, ">>", $path
		864	or die "$path: $!";
		865
		866	syswrite $fh, shift;
		867	0
		868	});
		869	}
		870
		871	sub log_to_syslog {
		872	my ($ctx, $flags) = @_;
		873
		874	require Sys::Syslog;
		875
		876	$ctx->log_cb (sub {
		877	my $lvl = $_[2] < 9 ? $_[2] : 8;
		878
		879	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		880	for split /\n/, shift;
		881
		882	0
		883	});
		884	}
		885
		886	=back
		887
		888	=head3 MESSAGE LOGGING
		889
		890	These methods allow you to log messages directly to a context, without
		891	going via your package context.
		892
		893	=over 4
		894
		895	=item $ctx->log ($level, $msg[, @params])
		896
		897	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		898
		899	=item $logger = $ctx->logger ($level[, \$enabled])
		900
		901	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		902	context.
		903
		904	=cut
		905
		906	*log = \&AnyEvent::Log::_log;
		907	*logger = \&AnyEvent::Log::_logger;
		908
		909	1;
		910
		911	=back
		912
		913	=head1 EXAMPLES
		914
		915	This section shows some common configurations.
		916
		917	=over 4
		918
		919	=item Setting the global logging level.
		920
		921	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
		922	running your program, or modify the log level of the root context:
		923
		924	PERL_ANYEVENT_VERBOSE=5 ./myprog
		925
		926	$AnyEvent::Log::FILTER->level ("warn");
		927
		928	=item Append all messages to a file instead of sending them to STDERR.
		929
		930	This is affected by the global logging level.
		931
		932	$AnyEvent::Log::LOG->log_to_file ($path); (sub {
832		933
833	=item Write all messages with priority C<error> and higher to a file.	934	=item Write all messages with priority C<error> and higher to a file.
834		935
835	This writes them only when the global logging level allows it, because	936	This writes them only when the global logging level allows it, because
836	it is attached to the default context which is invoked I<after> global	937	it is attached to the default context which is invoked I<after> global
837	filtering.	938	filtering.
838		939
839	open my $fh, ">>", $path	940	$AnyEvent::Log::FILTER->attach
840	or die "$path: $!";	941	new AnyEvent::Log::Ctx log_to_file => $path);
841
842	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx
843	log_cb => sub { syswrite $fh, shift; 0 });
844		942
845	This writes them regardless of the global logging level, because it is	943	This writes them regardless of the global logging level, because it is
846	attached to the toplevel context, which receives all messages I<before>	944	attached to the toplevel context, which receives all messages I<before>
847	the global filtering.	945	the global filtering.
848		946
849	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	947	$AnyEvent::Log::COLLECT->attach (
850	log_cb => sub { syswrite $fh, shift; 0 });	948	new AnyEvent::Log::Ctx log_to_file => $path);
851		949
852	In both cases, messages are still written to STDOUT.	950	In both cases, messages are still written to STDERR.
853		951
854	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	952	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
855		953
856	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	954	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
857	context and increase the C<AnyEvent::Debug> logging level - this simply
858	circumvents the global filtering for trace messages.	955	context - this simply circumvents the global filtering for trace messages.
859		956
860	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	957	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
861	$debug->attach ($AnyEvent::Log::Default);	958	$debug->attach ($AnyEvent::Log::LOG);
862	$debug->levels ("trace"); # not "level"!
863		959
864	This of course works for any package.	960	This of course works for any package, not just L<AnyEvent::Debug>, but
		961	assumes the log level for AnyEvent::Debug hasn't been changed from the
		962	default.
865		963
866	=back	964	=back
867		965
868	=head1 AUTHOR	966	=head1 AUTHOR
869		967

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.16 by root, Sat Aug 20 02:19:18 2011 UTC vs. Revision 1.20 by root, Sat Aug 20 22:27:07 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
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Revision 1.20 by root, Sat Aug 20 22:27:07 2011 UTC