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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.15 by root, Sat Aug 20 02:16:59 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 maximum	25	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("all");	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::ctx "")->level ("notice");	29	$AnyEvent::Log::FILTER->level ("notice");
30		30
31	# see also EXAMPLES, below	31	# see also EXAMPLES, below
32
33	# disable logging for package "AnyEvent" and all packages below it
34	AnyEvent->AnyEvent::Log::ctx->level (0);
35
36	# log everything below debug to a file, for the whole program
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		32
41	=head1 DESCRIPTION	33	=head1 DESCRIPTION
42		34
43	This module implements a relatively simple "logging framework". It doesn't	35	This module implements a relatively simple "logging framework". It doesn't
44	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
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	37	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	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
47	using it from other modules as well.	39	using it from other modules as well.
48		40
49	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
50	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
51	starting your program, or change the logging level at runtime with	43	before starting your program, or change the logging level at runtime with
52	something like:	44	something like:
53		45
54	use AnyEvent;	46	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	47	AnyEvent::Log::FILTER->level ("info");
56		48
57	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),
58	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
59	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
60	targets, or being able to log into a database.	52	targets, or being able to log into a database.
61		53
62	The amount of documentation might indicate otherwise, but the module is	54	The amount of documentation might indicate otherwise, but the module is
63	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.
64		88
65	=head1 LOGGING FUNCTIONS	89	=head1 LOGGING FUNCTIONS
66		90
67	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
68	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
69	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
70	loaded.	94	loaded.
71		95
72	=over 4	96	=over 4
73		97
…		…
80		104
81	use AnyEvent (); BEGIN { AnyEvent::common_sense }	105	use AnyEvent (); BEGIN { AnyEvent::common_sense }
82	use AnyEvent::Util ();	106	use AnyEvent::Util ();
83		107
84	our $VERSION = $AnyEvent::VERSION;	108	our $VERSION = $AnyEvent::VERSION;
		109
		110	our ($COLLECT, $FILTER, $LOG);
85		111
86	our ($now_int, $now_str1, $now_str2);	112	our ($now_int, $now_str1, $now_str2);
87		113
88	# Format Time, not public - yet?	114	# Format Time, not public - yet?
89	sub ft($) {	115	sub ft($) {
…		…
94	if $now_int != $i;	120	if $now_int != $i;
95		121
96	"$now_str1$f$now_str2"	122	"$now_str1$f$now_str2"
97	}	123	}
98		124
99	our %CTX; # all logging contexts	125	our %CTX; # all package contexts
100		126
101	# creates a default package context object for the given package	127	# creates a default package context object for the given package
102	sub _pkg_ctx($) {	128	sub _pkg_ctx($) {
103	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	129	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
104		130
105	# link "parent" package	131	# link "parent" package
106	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	132	my $parent = $_[0] =~ /^(.+)::/
		133	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		134	: $COLLECT;
107		135
108	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
109	$ctx->[2]{$pkg+0} = $pkg;	136	$ctx->[2]{$parent+0} = $parent;
110		137
111	$ctx	138	$ctx
112	}	139	}
113		140
114	=item AnyEvent::Log::log $level, $msg[, @args]	141	=item AnyEvent::Log::log $level, $msg[, @args]
115		142
116	Requests logging of the given C<$msg> with the given log level (1..9).	143	Requests logging of the given C<$msg> with the given log level.
117	You can also use the following strings as log level: C<fatal> (1),
118	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
119	C<info> (7), C<debug> (8), C<trace> (9).
120		144
121	For C<fatal> log levels, the program will abort.	145	For C<fatal> log levels, the program will abort.
122		146
123	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	147	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
124	C<$msg> is interpreted as an sprintf format string.	148	C<$msg> is interpreted as an sprintf format string.
…		…
157		181
158	=cut	182	=cut
159		183
160	# also allow syslog equivalent names	184	# also allow syslog equivalent names
161	our %STR2LEVEL = (	185	our %STR2LEVEL = (
162	fatal => 1, emerg => 1,	186	fatal => 1, emerg => 1, exit => 1,
163	alert => 2,	187	alert => 2,
164	critical => 3, crit => 3,	188	critical => 3, crit => 3,
165	error => 4, err => 4,	189	error => 4, err => 4, die => 4,
166	warn => 5, warning => 5,	190	warn => 5, warning => 5,
167	note => 6, notice => 6,	191	note => 6, notice => 6,
168	info => 7,	192	info => 7,
169	debug => 8,	193	debug => 8,
170	trace => 9,	194	trace => 9,
…		…
220	};	244	};
221		245
222	# format msg	246	# format msg
223	my $str = $ctx->[4]	247	my $str = $ctx->[4]
224	? $ctx->[4]($now, $_[0], $level, $format)	248	? $ctx->[4]($now, $_[0], $level, $format)
225	: $fmt \|\|= _format $now, $_[0], $level, $format;	249	: ($fmt \|\|= _format $now, $_[0], $level, $format);
226		250
227	$ctx->[3]($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
228	}	255	}
229
230	# not masked, not consumed - propagate to parent contexts
231	push @ctx, values %{ $ctx->[2] };
232	}	256	}
233	}	257	}
234	while $ctx = pop @ctx;	258	while $ctx = pop @ctx;
235		259
236	exit 1 if $level <= 1;	260	exit 1 if $level <= 1;
…		…
280	# and later in your program	304	# and later in your program
281	$debug_log->("yo, stuff here") if $debug;	305	$debug_log->("yo, stuff here") if $debug;
282		306
283	$debug and $debug_log->("123");	307	$debug and $debug_log->("123");
284		308
285	Note: currently the enabled var is always true - that will be fixed in a
286	future version :)
287
288	=cut	309	=cut
289		310
290	our %LOGGER;	311	our %LOGGER;
291		312
292	# re-assess logging status for all loggers	313	# re-assess logging status for all loggers
293	sub _reassess {	314	sub _reassess {
		315	local $SIG{__DIE__};
		316	my $die = sub { die };
		317
294	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	318	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
295	my ($ctx, $level, $renabled) = @$_;	319	my ($ctx, $level, $renabled) = @$_;
296		320
297	# to detect whether a message would be logged, we # actually	321	# to detect whether a message would be logged, we actually
298	# 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
299	# sure that the logging decision is correct :)	323	# sure that the logging decision is correct :)
300		324
301	$$renabled = !eval {	325	$$renabled = !eval {
302	local $SIG{__DIE__};
303
304	_log $ctx, $level, sub { die };	326	_log $ctx, $level, $die;
305		327
306	1	328	1
307	};	329	};
308
309	$$renabled = 1; # TODO
310	}	330	}
311	}	331	}
312		332
313	sub _logger {	333	sub _logger {
314	my ($ctx, $level, $renabled) = @_;	334	my ($ctx, $level, $renabled) = @_;
…		…
359	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
360	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
361	actually logging the formatted message and telling C<AnyEvent::Log>	381	actually logging the formatted message and telling C<AnyEvent::Log>
362	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).
363		383
364	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
365	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
366	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
367	contexts.	387	contexts.
368		388
369	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
370	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
371	message can arrive at the same context via multiple paths.	391	message can arrive at the same context via multiple paths.
…		…
375	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
376	disabled logging callback and the default formatting callback.	396	disabled logging callback and the default formatting callback.
377		397
378	Package contexts have the package name as logging title by default.	398	Package contexts have the package name as logging title by default.
379		399
380	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
381	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
382	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	402	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
383	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	403	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
384	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
385	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
386	C<AnyEvent::Log::Top>.	406	package context is C<$AnyEvent::Log::COLLECT>.
387		407
388	Since perl packages form only an approximate hierarchy, this parent	408	Since perl packages form only an approximate hierarchy, this slave
389	context can of course be removed.	409	context can of course be removed.
390		410
391	All other (anonymous) contexts have no parents and an empty title by	411	All other (anonymous) contexts have no slaves and an empty title by
392	default.	412	default.
393		413
394	When the module is loaded it creates the default context called	414	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
395	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	415	context that simply logs everything via C<warn>, without propagating
396	which simply logs everything via C<warn> and doesn't propagate anything
397	anywhere by default. The purpose of the default context is to provide	416	anything anywhere by default. The purpose of this context is to provide
398	a convenient place to override the global logging target or to attach	417	a convenient place to override the global logging target or to attach
399	additional log targets. It's not meant for filtering.	418	additional log targets. It's not meant for filtering.
400		419
401	It then creates the root context called C<AnyEvent::Log::Root> (also	420	It then creates the C<$AnyEvent::Log::FILTER> context whose
402	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	421	purpose is to suppress all messages with priority higher
403	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	422	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
404	then attached the default logging context to it. The purpose of the root	423	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
405	context is to simply provide filtering according to some global log level.	424	is to simply provide filtering according to some global log level.
406		425
407	Finally it creates the top-level package context called	426	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
408	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	427	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
409	C<$AnyEvent::Log::Top>) and attached the root context but otherwise leaves
410	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
411	system-wide.	429	messages system-wide.
412		430
413	These three special contexts can also be referred to by the	431	The hierarchy is then:
414	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
415	C<AE::Log::Top>.
416		432
		433	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		434
417	The effect of all this is that log messages, by default, wander up	435	The effect of all this is that log messages, by default, wander up to the
418	to the root context where log messages with lower priority then	436	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		437	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
419	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	438	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
420	AnyEvent::Log::Default context to be passed to C<warn>.	439	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
421		440
422	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),
423	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
424	other contexts to log, for example, their debug and trace messages to the
425	default target despite the global logging level, or to attach additional	443	messages to the $LOG target despite the global logging level, or to attach
426	log targets that log messages, regardless of the global logging level.	444	additional log targets that log messages, regardless of the global logging
		445	level.
427		446
428	It also makes it easy to replace the default warn-logger by something that	447	It also makes it easy to modify the default warn-logger ($LOG) to
429	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 $FILTER.
430		450
431	=head2 CREATING/FINDING/DESTROYING CONTEXTS	451	=head2 CREATING/FINDING/DESTROYING CONTEXTS
432		452
433	=over 4	453	=over 4
434		454
…		…
456	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	476	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
457	}	477	}
458		478
459	=item AnyEvent::Log::reset	479	=item AnyEvent::Log::reset
460		480
461	Resets all package contexts contexts and recreates the default hierarchy	481	Resets all package contexts and recreates the default hierarchy if
462	if necessary, i.e. resets the logging subsystem to defaults.	482	necessary, i.e. resets the logging subsystem to defaults, as much as
		483	possible. This process keeps references to contexts held by other parts of
		484	the program intact.
463		485
464	This can be used to implement config-file (re-)loading: before loading a	486	This can be used to implement config-file (re-)loading: before loading a
465	configuration, reset all contexts.	487	configuration, reset all contexts.
466		488
467	Note that this currently destroys all logger callbacks - bug me if you
468	need this fixed :)
469
470	=cut	489	=cut
471		490
472	sub reset {	491	sub reset {
473	# hard to kill complex data structures	492	# hard to kill complex data structures
474	# we recreate all package loggers and reset the hierarchy	493	# we "recreate" all package loggers and reset the hierarchy
475	while (my ($k, $v) = each %CTX) {	494	while (my ($k, $v) = each %CTX) {
476	@$v = ($k, (1 << 10) - 1 - 1, { });	495	@$v = ($k, (1 << 10) - 1 - 1, { });
477		496
478	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	497	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
479	$v->attach ($CTX{$pkg});
480	}	498	}
481		499
482	$AnyEvent::Log::Default->parents;	500	@$_ = ($_->[0], (1 << 10) - 1 - 1)
483	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	501	for $LOG, $FILTER, $COLLECT;
484	$AnyEvent::Log::Default->log_cb (sub {	502
		503	$LOG->slaves;
		504	$LOG->title ('$AnyEvent::Log::LOG');
		505	$LOG->log_cb (sub {
485	warn shift;	506	warn shift;
486	0	507	0
487	});	508	});
488	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
489		509
490	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	510	$FILTER->slaves ($LOG);
491	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	511	$FILTER->title ('$AnyEvent::Log::FILTER');
492	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	512	$FILTER->level ($AnyEvent::VERBOSE);
493	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
494		513
495	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	514	$COLLECT->slaves ($FILTER);
496	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	515	$COLLECT->title ('$AnyEvent::Log::COLLECT');
497	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;
498		516
499	_reassess;	517	_reassess;
500	}	518	}
501		519
502	# create the default logger contexts	520	# create the default logger contexts
503	$AnyEvent::Log::Default = ctx undef;	521	$LOG = ctx undef;
504	$AnyEvent::Log::Root = ctx undef;	522	$FILTER = ctx undef;
505	$AnyEvent::Log::Top = ctx undef;	523	$COLLECT = ctx undef;
506		524
507	AnyEvent::Log::reset;	525	AnyEvent::Log::reset;
508		526
509	# hello, CPAN, please catch me	527	# hello, CPAN, please catch me
510	package AnyEvent::Log::Default;
511	package AE::Log::Default;
512	package AnyEvent::Log::Root;
513	package AE::Log::Root;
514	package AnyEvent::Log::Top;	528	package AnyEvent::Log::LOG;
515	package AE::Log::Top;	529	package AE::Log::LOG;
		530	package AnyEvent::Log::FILTER;
		531	package AE::Log::FILTER;
		532	package AnyEvent::Log::COLLECT;
		533	package AE::Log::COLLECT;
516		534
517	package AnyEvent::Log::Ctx;	535	package AnyEvent::Log::Ctx;
518		536
519	# 0 1 2 3 4	537	# 0 1 2 3 4
520	# [$title, $level, %$parents, &$logcb, &$fmtcb]	538	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
521		539
522	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	540	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
523		541
524	This is a convenience constructor that makes it simpler to construct	542	This is a convenience constructor that makes it simpler to construct
525	anonymous logging contexts.	543	anonymous logging contexts.
…		…
528	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
529	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
530	array. The methods are called in the same order as specified.	548	array. The methods are called in the same order as specified.
531		549
532	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
533	level, some parent contexts and a logging callback.	551	level, some slave contexts and a logging callback.
534		552
535	$ctx = new AnyEvent::Log::Ctx	553	$ctx = new AnyEvent::Log::Ctx
536	title => "dubious messages",	554	title => "dubious messages",
537	level => "error",	555	level => "error",
538	log_cb => sub { print STDOUT shift; 0 },	556	log_cb => sub { print STDOUT shift; 0 },
539	parents => [$ctx1, $ctx, $ctx2],	557	slaves => [$ctx1, $ctx, $ctx2],
540	;	558	;
541		559
542	=back	560	=back
543		561
544	=cut	562	=cut
…		…
657	AnyEvent::Log::_reassess;	675	AnyEvent::Log::_reassess;
658	}	676	}
659		677
660	=back	678	=back
661		679
662	=head3 PARENT CONTEXTS	680	=head3 SLAVE CONTEXTS
663		681
664	The following methods attach and detach another logging context to a	682	The following methods attach and detach another logging context to a
665	logging context.	683	logging context.
666		684
667	Log messages are propagated to all parent contexts, unless the logging	685	Log messages are propagated to all slave contexts, unless the logging
668	callback consumes the message.	686	callback consumes the message.
669		687
670	=over 4	688	=over 4
671		689
672	=item $ctx->attach ($ctx2[, $ctx3...])	690	=item $ctx->attach ($ctx2[, $ctx3...])
673		691
674	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
675	to add a context twice (the second add will be ignored).	693	to add a context twice (the second add will be ignored).
676		694
677	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.
678		696
679	=item $ctx->detach ($ctx2[, $ctx3...])	697	=item $ctx->detach ($ctx2[, $ctx3...])
680		698
681	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
682	to remove a context that hasn't been added.	700	to remove a context that hasn't been added.
683		701
684	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.
685		703
686	=item $ctx->parents ($ctx2[, $ctx3...])	704	=item $ctx->slaves ($ctx2[, $ctx3...])
687		705
688	Replaces all parents attached to this context by the ones given.	706	Replaces all slaves attached to this context by the ones given.
689		707
690	=cut	708	=cut
691		709
692	sub attach {	710	sub attach {
693	my $ctx = shift;	711	my $ctx = shift;
…		…
701		719
702	delete $ctx->[2]{$_+0}	720	delete $ctx->[2]{$_+0}
703	for map { AnyEvent::Log::ctx $_ } @_;	721	for map { AnyEvent::Log::ctx $_ } @_;
704	}	722	}
705		723
706	sub parents {	724	sub slaves {
707	undef $_[0][2];	725	undef $_[0][2];
708	&attach;	726	&attach;
709	}	727	}
710		728
711	=back	729	=back
712		730
713	=head3 MESSAGE LOGGING	731	=head3 LOG TARGETS
714		732
715	The following methods configure how the logging context actually does	733	The following methods configure how the logging context actually does
716	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
717	whatever it wants to do with it) and also allows you to log messages	735	whatever it wants to do with it).
718	directly to a context, without going via your package context.
719		736
720	=over 4	737	=over 4
721		738
722	=item $ctx->log_cb ($cb->($str))	739	=item $ctx->log_cb ($cb->($str, $orig_ctx, $level))
723		740
724	Replaces the logging callback on the context (C<undef> disables the	741	Replaces the logging callback on the context (C<undef> disables the
725	logging callback).	742	logging callback).
726		743
727	The logging callback is responsible for handling formatted log messages	744	The logging callback is responsible for handling formatted log messages
728	(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
729	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.
730		749
731	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
732	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
733	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.
734		753
735	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
736	and do not consume it.	755	and do not consume it.
737		756
738	$ctx->log_cb (sub { print STDERR shift; 0 });	757	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
746	your program.	765	your program.
747		766
748	$ctx->levels ("debug", "trace");	767	$ctx->levels ("debug", "trace");
749	$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
750		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
751	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	793	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
752		794
753	Replaces the formatting callback on the context (C<undef> restores the	795	Replaces the formatting callback on the context (C<undef> restores the
754	default formatter).	796	default formatter).
755		797
756	The callback is passed the (possibly fractional) timestamp, the original	798	The callback is passed the (possibly fractional) timestamp, the original
757	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
758	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
759	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.
760		807
761	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
762	brackets.	809	brackets.
763		810
764	$ctx->fmt_cb (sub {	811	$ctx->fmt_cb (sub {
…		…
795	my ($ctx, $cb) = @_;	842	my ($ctx, $cb) = @_;
796		843
797	$ctx->[4] = $cb;	844	$ctx->[4] = $cb;
798	}	845	}
799		846
800	=item $ctx->log ($level, $msg[, @params])	847	sub log_to_file {
801		848	my ($ctx, $path) = @_;
802	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
803
804	=item $logger = $ctx->logger ($level[, \$enabled])
805
806	Same as C<AnyEvent::Log::logger>, but uses the given context as log
807	context.
808
809	=cut
810
811	*log = \&AnyEvent::Log::_log;
812	*logger = \&AnyEvent::Log::_logger;
813
814	1;
815
816	=back
817
818	=head1 EXAMPLES
819
820	This section shows some common configurations.
821
822	=over 4
823
824	=item Setting the global logging level.
825
826	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
827	running your program, or modify the log level of the root context:
828
829	PERL_ANYEVENT_VERBOSE=5 ./myprog
830
831	$AnyEvent::Log::Root->level ("warn");
832
833	=item Append all messages to a file instead of sending them to STDERR.
834
835	This is affected by the global logging level.
836		849
837	open my $fh, ">>", $path	850	open my $fh, ">>", $path
838	or die "$path: $!";	851	or die "$path: $!";
839		852
840	$AnyEvent::Log::Default->log_cb (sub {	853	$ctx->log_cb (sub {
841	syswrite $fh, shift;	854	syswrite $fh, shift;
842	0	855	0
843	});	856	});
		857	}
		858
		859	sub log_to_file {
		860	my ($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 {
844		933
845	=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.
846		935
847	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
848	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
849	filtering.	938	filtering.
850		939
851	open my $fh, ">>", $path	940	$AnyEvent::Log::FILTER->attach
852	or die "$path: $!";	941	new AnyEvent::Log::Ctx log_to_file => $path);
853
854	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx
855	log_cb => sub { syswrite $fh, shift; 0 });
856		942
857	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
858	attached to the toplevel context, which receives all messages I<before>	944	attached to the toplevel context, which receives all messages I<before>
859	the global filtering.	945	the global filtering.
860		946
861	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	947	$AnyEvent::Log::COLLECT->attach (
862	log_cb => sub { syswrite $fh, shift; 0 });	948	new AnyEvent::Log::Ctx log_to_file => $path);
863		949
864	In both cases, messages are still written to STDOUT.	950	In both cases, messages are still written to STDERR.
865		951
866	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	952	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
867		953
868	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	954	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
869	context and increase the C<AnyEvent::Debug> logging level - this simply
870	circumvents the global filtering for trace messages.	955	context - this simply circumvents the global filtering for trace messages.
871		956
872	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	957	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
873	$debug->attach ($AnyEvent::Log::Default);	958	$debug->attach ($AnyEvent::Log::LOG);
874	$debug->levels ("trace"); # not "level"!
875		959
876	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.
877		963
878	=back	964	=back
879		965
880	=head1 AUTHOR	966	=head1 AUTHOR
881		967

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.15 by root, Sat Aug 20 02:16:59 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):
Revision 1.15 by root, Sat Aug 20 02:16:59 2011 UTC vs.
Revision 1.20 by root, Sat Aug 20 22:27:07 2011 UTC