[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 1.31 by root, Thu Aug 25 03:08:48 2011 UTC

…		…
2		2
3	AnyEvent::Log - simple logging "framework"	3	AnyEvent::Log - simple logging "framework"
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	# simple use	7	Simple uses:
		8
8	use AnyEvent;	9	use AnyEvent;
9		10
10	AE::log debug => "hit my knee";	11	AE::log debug => "hit my knee";
11	AE::log warn => "it's a bit too hot";	12	AE::log warn => "it's a bit too hot";
12	AE::log error => "the flag was false!";	13	AE::log error => "the flag was false!";
13	AE::log fatal => "the bit toggled! run!";	14	AE::log fatal => "the bit toggled! run!"; # never returns
14		15
15	# "complex" use	16	"Complex" uses (for speed sensitive code):
		17
16	use AnyEvent::Log;	18	use AnyEvent::Log;
17		19
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	20	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		21
20	$tracer->("i am here") if $trace;	22	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	23	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		24
23	# configuration	25	Configuration (also look at the EXAMPLES section):
24		26
25	# set logging for this package to maximum	27	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("all");	28	AnyEvent::Log::ctx->level ("error");
27		29
28	# set logging globally to anything below debug	30	# set logging level to suppress anything below "notice"
29	(AnyEvent::Log::ctx "")->level ("notice");	31	$AnyEvent::Log::FILTER->level ("notice");
30		32
31	# see also EXAMPLES, below	33	# send all critical and higher priority messages to syslog,
32		34	# regardless of (most) other settings
33	# disable logging for package "AnyEvent" and all packages below it	35	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
34	AnyEvent->AnyEvent::Log::ctx->level (0);	36	level => "critical",
35		37	log_to_syslog => 0,
36	# log everything below debug to a file, for the whole program	38	);
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		39
41	=head1 DESCRIPTION	40	=head1 DESCRIPTION
42		41
43	This module implements a relatively simple "logging framework". It doesn't	42	This module implements a relatively simple "logging framework". It doesn't
44	attempt to be "the" logging solution or even "a" logging solution for	43	attempt to be "the" logging solution or even "a" logging solution for
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	44	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	module more or less exposes the mechanism, with some extra spiff to allow	45	module more or less exposes the mechanism, with some extra spiff to allow
47	using it from other modules as well.	46	using it from other modules as well.
48		47
49	Remember that the default verbosity level is C<0>, so nothing will be	48	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	49	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	50	before starting your program, or change the logging level at runtime with
52	something like:	51	something like:
53		52
54	use AnyEvent;	53	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	54	AnyEvent::Log::FILTER->level ("info");
56		55
57	The design goal behind this module was to keep it simple (and small),	56	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	57	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	58	extensive enough for the most common tasks, such as logging to multiple
60	targets, or being able to log into a database.	59	targets, or being able to log into a database.
61		60
62	The amount of documentation might indicate otherwise, but the module is	61	The amount of documentation might indicate otherwise, but the module is
63	still just 240 lines or so.	62	still just below 300 lines of code.
		63
		64	=head1 LOGGING LEVELS
		65
		66	Logging levels in this module range from C<1> (highest priority) to C<9>
		67	(lowest priority). Note that the lowest numerical value is the highest
		68	priority, so when this document says "higher priority" it means "lower
		69	numerical value".
		70
		71	Instead of specifying levels by name you can also specify them by aliases:
		72
		73	LVL NAME SYSLOG PERL NOTE
		74	1 fatal emerg exit aborts program!
		75	2 alert
		76	3 critical crit
		77	4 error err die
		78	5 warn warning
		79	6 note notice
		80	7 info
		81	8 debug
		82	9 trace
		83
		84	As you can see, some logging levels have multiple aliases - the first one
		85	is the "official" name, the second one the "syslog" name (if it differs)
		86	and the third one the "perl" name, suggesting that you log C<die> messages
		87	at C<error> priority.
		88
		89	You can normally only log a single message at highest priority level
		90	(C<1>, C<fatal>), because logging a fatal message will also quit the
		91	program - so use it sparingly :)
		92
		93	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		94	or C<all> - these are only valid in the methods they are documented for.
64		95
65	=head1 LOGGING FUNCTIONS	96	=head1 LOGGING FUNCTIONS
66		97
67	These functions allow you to log messages. They always use the caller's	98	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	99	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	100	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
70	loaded.	101	loaded.
71		102
72	=over 4	103	=over 4
73		104
…		…
80		111
81	use AnyEvent (); BEGIN { AnyEvent::common_sense }	112	use AnyEvent (); BEGIN { AnyEvent::common_sense }
82	use AnyEvent::Util ();	113	use AnyEvent::Util ();
83		114
84	our $VERSION = $AnyEvent::VERSION;	115	our $VERSION = $AnyEvent::VERSION;
		116
		117	our ($COLLECT, $FILTER, $LOG);
85		118
86	our ($now_int, $now_str1, $now_str2);	119	our ($now_int, $now_str1, $now_str2);
87		120
88	# Format Time, not public - yet?	121	# Format Time, not public - yet?
89	sub ft($) {	122	sub ft($) {
…		…
94	if $now_int != $i;	127	if $now_int != $i;
95		128
96	"$now_str1$f$now_str2"	129	"$now_str1$f$now_str2"
97	}	130	}
98		131
99	our %CTX; # all logging contexts	132	our %CTX; # all package contexts
100		133
101	# creates a default package context object for the given package	134	# creates a default package context object for the given package
102	sub _pkg_ctx($) {	135	sub _pkg_ctx($) {
103	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	136	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
104		137
105	# link "parent" package	138	# link "parent" package
106	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	139	my $parent = $_[0] =~ /^(.+)::/
		140	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		141	: $COLLECT;
107		142
108	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
109	$ctx->[2]{$pkg+0} = $pkg;	143	$ctx->[2]{$parent+0} = $parent;
110		144
111	$ctx	145	$ctx
112	}	146	}
113		147
114	=item AnyEvent::Log::log $level, $msg[, @args]	148	=item AnyEvent::Log::log $level, $msg[, @args]
115		149
116	Requests logging of the given C<$msg> with the given log level (1..9).	150	Requests logging of the given C<$msg> with the given log level, and
117	You can also use the following strings as log level: C<fatal> (1),	151	returns true if the message was logged I<somewhere>.
118	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
119	C<info> (7), C<debug> (8), C<trace> (9).
120		152
121	For C<fatal> log levels, the program will abort.	153	For C<fatal> log levels, the program will abort.
122		154
123	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	155	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.	156	C<$msg> is interpreted as an sprintf format string.
…		…
130	supposed to return the message. It will be called only then the message	162	supposed to return the message. It will be called only then the message
131	actually gets logged, which is useful if it is costly to create the	163	actually gets logged, which is useful if it is costly to create the
132	message in the first place.	164	message in the first place.
133		165
134	Whether the given message will be logged depends on the maximum log level	166	Whether the given message will be logged depends on the maximum log level
135	and the caller's package.	167	and the caller's package. The return value can be used to ensure that
		168	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		169	runtime error it tries to log it at C<die> level, but if that message is
		170	lost it simply uses warn.
136		171
137	Note that you can (and should) call this function as C<AnyEvent::log> or	172	Note that you can (and should) call this function as C<AnyEvent::log> or
138	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	173	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
139	need any additional functionality), as those functions will load the	174	need any additional functionality), as those functions will load the
140	logging module on demand only. They are also much shorter to write.	175	logging module on demand only. They are also much shorter to write.
…		…
157		192
158	=cut	193	=cut
159		194
160	# also allow syslog equivalent names	195	# also allow syslog equivalent names
161	our %STR2LEVEL = (	196	our %STR2LEVEL = (
162	fatal => 1, emerg => 1,	197	fatal => 1, emerg => 1, exit => 1,
163	alert => 2,	198	alert => 2,
164	critical => 3, crit => 3,	199	critical => 3, crit => 3,
165	error => 4, err => 4,	200	error => 4, err => 4, die => 4,
166	warn => 5, warning => 5,	201	warn => 5, warning => 5,
167	note => 6, notice => 6,	202	note => 6, notice => 6,
168	info => 7,	203	info => 7,
169	debug => 8,	204	debug => 8,
170	trace => 9,	205	trace => 9,
…		…
200	? $level+0	235	? $level+0
201	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	236	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
202		237
203	my $mask = 1 << $level;	238	my $mask = 1 << $level;
204		239
205	my (%seen, @ctx, $now, $fmt);	240	my ($success, %seen, @ctx, $now, $fmt);
206		241
207	do	242	do
208	{	243	{
209	# skip if masked	244	# skip if masked
210	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	245	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
214	# now get raw message, unless we have it already	249	# now get raw message, unless we have it already
215	unless ($now) {	250	unless ($now) {
216	$format = $format->() if ref $format;	251	$format = $format->() if ref $format;
217	$format = sprintf $format, @args if @args;	252	$format = sprintf $format, @args if @args;
218	$format =~ s/\n$//;	253	$format =~ s/\n$//;
219	$now = AE::now;	254	$now = now;
220	};	255	};
221		256
222	# format msg	257	# format msg
223	my $str = $ctx->[4]	258	my $str = $ctx->[4]
224	? $ctx->[4]($now, $_[0], $level, $format)	259	? $ctx->[4]($now, $_[0], $level, $format)
225	: $fmt \|\|= _format $now, $_[0], $level, $format;	260	: ($fmt \|\|= _format $now, $_[0], $level, $format);
226		261
		262	$success = 1;
		263
227	$ctx->[3]($str);	264	$ctx->[3]($str)
		265	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		266	} else {
		267	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
228	}	268	}
229
230	# not masked, not consumed - propagate to parent contexts
231	push @ctx, values %{ $ctx->[2] };
232	}	269	}
233	}	270	}
234	while $ctx = pop @ctx;	271	while $ctx = pop @ctx;
235		272
236	exit 1 if $level <= 1;	273	exit 1 if $level <= 1;
		274
		275	$success
237	}	276	}
238		277
239	sub log($$;@) {	278	sub log($$;@) {
240	_log	279	_log
241	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	280	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
245	AnyEvent::log = AE::log = \&log;	284	AnyEvent::log = AE::log = \&log;
246		285
247	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	286	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
248		287
249	Creates a code reference that, when called, acts as if the	288	Creates a code reference that, when called, acts as if the
250	C<AnyEvent::Log::log> function was called at this point with the givne	289	C<AnyEvent::Log::log> function was called at this point with the given
251	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	290	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
252	the C<AnyEvent::Log::log> function:	291	the C<AnyEvent::Log::log> function:
253		292
254	my $debug_log = AnyEvent::Log::logger "debug";	293	my $debug_log = AnyEvent::Log::logger "debug";
255		294
…		…
280	# and later in your program	319	# and later in your program
281	$debug_log->("yo, stuff here") if $debug;	320	$debug_log->("yo, stuff here") if $debug;
282		321
283	$debug and $debug_log->("123");	322	$debug and $debug_log->("123");
284		323
285	Note: currently the enabled var is always true - that will be fixed in a
286	future version :)
287
288	=cut	324	=cut
289		325
290	our %LOGGER;	326	our %LOGGER;
291		327
292	# re-assess logging status for all loggers	328	# re-assess logging status for all loggers
293	sub _reassess {	329	sub _reassess {
		330	local $SIG{__DIE__};
		331	my $die = sub { die };
		332
294	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	333	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
295	my ($ctx, $level, $renabled) = @$_;	334	my ($ctx, $level, $renabled) = @$_;
296		335
297	# to detect whether a message would be logged, we # actually	336	# 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	337	# try to log one and die. this isn't fast, but we can be
299	# sure that the logging decision is correct :)	338	# sure that the logging decision is correct :)
300		339
301	$$renabled = !eval {	340	$$renabled = !eval {
302	local $SIG{__DIE__};
303
304	_log $ctx, $level, sub { die };	341	_log $ctx, $level, $die;
305		342
306	1	343	1
307	};	344	};
308
309	$$renabled = 1; # TODO
310	}	345	}
311	}	346	}
312		347
313	sub _logger {	348	sub _logger {
314	my ($ctx, $level, $renabled) = @_;	349	my ($ctx, $level, $renabled) = @_;
…		…
359	timestamp, context, level and string message and formats it in the way	394	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	395	it should be logged) and a logging callback (which is responsible for
361	actually logging the formatted message and telling C<AnyEvent::Log>	396	actually logging the formatted message and telling C<AnyEvent::Log>
362	whether it has consumed the message, or whether it should be propagated).	397	whether it has consumed the message, or whether it should be propagated).
363		398
364	For propagation, a context can have any number of attached I<parent	399	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	400	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	401	masked by the logging callback returning true will be passed to all slave
367	contexts.	402	contexts.
368		403
369	Each call to a logging function will log the message at most once per	404	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	405	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.	406	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	410	By default, all logging contexts have an full set of log levels ("all"), a
376	disabled logging callback and the default formatting callback.	411	disabled logging callback and the default formatting callback.
377		412
378	Package contexts have the package name as logging title by default.	413	Package contexts have the package name as logging title by default.
379		414
380	They have exactly one parent - the context of the "parent" package. The	415	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	416	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>,	417	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
383	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	418	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	419	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	420	package name in Perl is C<main>, the default slave of any top-level
386	C<AnyEvent::Log::Top>.	421	package context is C<$AnyEvent::Log::COLLECT>.
387		422
388	Since perl packages form only an approximate hierarchy, this parent	423	Since perl packages form only an approximate hierarchy, this slave
389	context can of course be removed.	424	context can of course be removed.
390		425
391	All other (anonymous) contexts have no parents and an empty title by	426	All other (anonymous) contexts have no slaves and an empty title by
392	default.	427	default.
393		428
394	When the module is loaded it creates the default context called	429	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
395	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	430	context that simply logs everything via C<warn>, without propagating
396	which simply logs everything via C<warn> and doesn't propagate anything
397	anywhere by default. The purpose of the default context is to provide	431	anything anywhere by default. The purpose of this context is to provide
398	a convenient place to override the global logging target or to attach	432	a convenient place to override the global logging target or to attach
399	additional log targets. It's not meant for filtering.	433	additional log targets. It's not meant for filtering.
400		434
401	It then creates the root context called C<AnyEvent::Log::Root> (also	435	It then creates the C<$AnyEvent::Log::FILTER> context whose
402	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	436	purpose is to suppress all messages with priority higher
403	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	437	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
404	then attached the default logging context to it. The purpose of the root	438	C<$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.	439	is to simply provide filtering according to some global log level.
406		440
407	Finally it creates the top-level package context called	441	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
408	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	442	and attaches the C<$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	443	leaves it at default config. Its purpose is simply to collect all log
411	system-wide.	444	messages system-wide.
412		445
413	These three special contexts can also be referred to by the	446	The hierarchy is then:
414	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
415	C<AE::Log::Top>.
416		447
		448	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		449
417	The effect of all this is that log messages, by default, wander up	450	The effect of all this is that log messages, by default, wander up to the
418	to the root context where log messages with lower priority then	451	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		452	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	453	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
420	AnyEvent::Log::Default context to be passed to C<warn>.	454	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
421		455
422	Splitting the top level context into three contexts makes it easy to set	456	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	457	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	458	messages to the $LOG target despite the global logging level, or to attach
426	log targets that log messages, regardless of the global logging level.	459	additional log targets that log messages, regardless of the global logging
		460	level.
427		461
428	It also makes it easy to replace the default warn-logger by something that	462	It also makes it easy to modify the default warn-logger ($LOG) to
429	logs to a file, or to attach additional logging targets.	463	something that logs to a file, or to attach additional logging targets
		464	(such as loggign to a file) by attaching it to $FILTER.
430		465
431	=head2 CREATING/FINDING/DESTROYING CONTEXTS	466	=head2 CREATING/FINDING/DESTROYING CONTEXTS
432		467
433	=over 4	468	=over 4
434		469
…		…
456	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	491	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
457	}	492	}
458		493
459	=item AnyEvent::Log::reset	494	=item AnyEvent::Log::reset
460		495
461	Resets all package contexts contexts and recreates the default hierarchy	496	Resets all package contexts and recreates the default hierarchy if
462	if necessary, i.e. resets the logging subsystem to defaults.	497	necessary, i.e. resets the logging subsystem to defaults, as much as
		498	possible. This process keeps references to contexts held by other parts of
		499	the program intact.
463		500
464	This can be used to implement config-file (re-)loading: before loading a	501	This can be used to implement config-file (re-)loading: before loading a
465	configuration, reset all contexts.	502	configuration, reset all contexts.
466		503
467	Note that this currently destroys all logger callbacks - bug me if you
468	need this fixed :)
469
470	=cut	504	=cut
471		505
472	sub reset {	506	sub reset {
473	# hard to kill complex data structures	507	# hard to kill complex data structures
474	# we recreate all package loggers and reset the hierarchy	508	# we "recreate" all package loggers and reset the hierarchy
475	while (my ($k, $v) = each %CTX) {	509	while (my ($k, $v) = each %CTX) {
476	@$v = ($k, (1 << 10) - 1 - 1, { });	510	@$v = ($k, (1 << 10) - 1 - 1, { });
477		511
478	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	512	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
479	$v->attach ($CTX{$pkg});
480	}	513	}
481		514
482	$AnyEvent::Log::Default->parents;	515	@$_ = ($_->[0], (1 << 10) - 1 - 1)
483	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	516	for $LOG, $FILTER, $COLLECT;
484	$AnyEvent::Log::Default->log_cb (sub {
485	warn shift;
486	0
487	});
488	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
489		517
490	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	518	$LOG->slaves;
491	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	519	$LOG->title ('$AnyEvent::Log::LOG');
		520	$LOG->log_to_warn;
		521
		522	$FILTER->slaves ($LOG);
		523	$FILTER->title ('$AnyEvent::Log::FILTER');
492	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	524	$FILTER->level ($AnyEvent::VERBOSE);
493	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
494		525
495	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	526	$COLLECT->slaves ($FILTER);
496	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	527	$COLLECT->title ('$AnyEvent::Log::COLLECT');
497	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;
498		528
499	_reassess;	529	_reassess;
500	}	530	}
501		531
502	# create the default logger contexts	532	# create the default logger contexts
503	$AnyEvent::Log::Default = ctx undef;	533	$LOG = ctx undef;
504	$AnyEvent::Log::Root = ctx undef;	534	$FILTER = ctx undef;
505	$AnyEvent::Log::Top = ctx undef;	535	$COLLECT = ctx undef;
506		536
507	AnyEvent::Log::reset;	537	AnyEvent::Log::reset;
508		538
509	# hello, CPAN, please catch me	539	# hello, CPAN, please catch me
510	package AnyEvent::Log::Default;
511	package AE::Log::Default;
512	package AnyEvent::Log::Root;
513	package AE::Log::Root;
514	package AnyEvent::Log::Top;	540	package AnyEvent::Log::LOG;
515	package AE::Log::Top;	541	package AE::Log::LOG;
		542	package AnyEvent::Log::FILTER;
		543	package AE::Log::FILTER;
		544	package AnyEvent::Log::COLLECT;
		545	package AE::Log::COLLECT;
516		546
517	package AnyEvent::Log::Ctx;	547	package AnyEvent::Log::Ctx;
518		548
519	# 0 1 2 3 4	549	# 0 1 2 3 4
520	# [$title, $level, %$parents, &$logcb, &$fmtcb]	550	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
521		551
522	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	552	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
523		553
524	This is a convenience constructor that makes it simpler to construct	554	This is a convenience constructor that makes it simpler to construct
525	anonymous logging contexts.	555	anonymous logging contexts.
…		…
528	name as the key with the value as parameter, unless the value is an	558	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	559	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.	560	array. The methods are called in the same order as specified.
531		561
532	Example: create a new logging context and set both the default logging	562	Example: create a new logging context and set both the default logging
533	level, some parent contexts and a logging callback.	563	level, some slave contexts and a logging callback.
534		564
535	$ctx = new AnyEvent::Log::Ctx	565	$ctx = new AnyEvent::Log::Ctx
536	title => "dubious messages",	566	title => "dubious messages",
537	level => "error",	567	level => "error",
538	log_cb => sub { print STDOUT shift; 0 },	568	log_cb => sub { print STDOUT shift; 0 },
539	parents => [$ctx1, $ctx, $ctx2],	569	slaves => [$ctx1, $ctx, $ctx2],
540	;	570	;
541		571
542	=back	572	=back
543		573
544	=cut	574	=cut
…		…
657	AnyEvent::Log::_reassess;	687	AnyEvent::Log::_reassess;
658	}	688	}
659		689
660	=back	690	=back
661		691
662	=head3 PARENT CONTEXTS	692	=head3 SLAVE CONTEXTS
663		693
664	The following methods attach and detach another logging context to a	694	The following methods attach and detach another logging context to a
665	logging context.	695	logging context.
666		696
667	Log messages are propagated to all parent contexts, unless the logging	697	Log messages are propagated to all slave contexts, unless the logging
668	callback consumes the message.	698	callback consumes the message.
669		699
670	=over 4	700	=over 4
671		701
672	=item $ctx->attach ($ctx2[, $ctx3...])	702	=item $ctx->attach ($ctx2[, $ctx3...])
673		703
674	Attaches the given contexts as parents to this context. It is not an error	704	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).	705	to add a context twice (the second add will be ignored).
676		706
677	A context can be specified either as package name or as a context object.	707	A context can be specified either as package name or as a context object.
678		708
679	=item $ctx->detach ($ctx2[, $ctx3...])	709	=item $ctx->detach ($ctx2[, $ctx3...])
680		710
681	Removes the given parents from this context - it's not an error to attempt	711	Removes the given slaves from this context - it's not an error to attempt
682	to remove a context that hasn't been added.	712	to remove a context that hasn't been added.
683		713
684	A context can be specified either as package name or as a context object.	714	A context can be specified either as package name or as a context object.
685		715
686	=item $ctx->parents ($ctx2[, $ctx3...])	716	=item $ctx->slaves ($ctx2[, $ctx3...])
687		717
688	Replaces all parents attached to this context by the ones given.	718	Replaces all slaves attached to this context by the ones given.
689		719
690	=cut	720	=cut
691		721
692	sub attach {	722	sub attach {
693	my $ctx = shift;	723	my $ctx = shift;
…		…
701		731
702	delete $ctx->[2]{$_+0}	732	delete $ctx->[2]{$_+0}
703	for map { AnyEvent::Log::ctx $_ } @_;	733	for map { AnyEvent::Log::ctx $_ } @_;
704	}	734	}
705		735
706	sub parents {	736	sub slaves {
707	undef $_[0][2];	737	undef $_[0][2];
708	&attach;	738	&attach;
709	}	739	}
710		740
711	=back	741	=back
712		742
713	=head3 MESSAGE LOGGING	743	=head3 LOG TARGETS
714		744
715	The following methods configure how the logging context actually does	745	The following methods configure how the logging context actually does
716	the logging (which consists of formatting the message and printing it or	746	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	747	whatever it wants to do with it).
718	directly to a context, without going via your package context.
719		748
720	=over 4	749	=over 4
721		750
722	=item $ctx->log_cb ($cb->($str))	751	=item $ctx->log_cb ($cb->($str)
723		752
724	Replaces the logging callback on the context (C<undef> disables the	753	Replaces the logging callback on the context (C<undef> disables the
725	logging callback).	754	logging callback).
726		755
727	The logging callback is responsible for handling formatted log messages	756	The logging callback is responsible for handling formatted log messages
728	(see C<fmt_cb> below) - normally simple text strings that end with a	757	(see C<fmt_cb> below) - normally simple text strings that end with a
729	newline (and are possibly multiline themselves).	758	newline (and are possibly multiline themselves).
730		759
731	It also has to return true iff it has consumed the log message, and false	760	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	761	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.	762	slave context. When in doubt, return C<0> from your logging callback.
734		763
735	Example: a very simple logging callback, simply dump the message to STDOUT	764	Example: a very simple logging callback, simply dump the message to STDOUT
736	and do not consume it.	765	and do not consume it.
737		766
738	$ctx->log_cb (sub { print STDERR shift; 0 });	767	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
746	your program.	775	your program.
747		776
748	$ctx->levels ("debug", "trace");	777	$ctx->levels ("debug", "trace");
749	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	778	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
750		779
751	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	780	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
752		781
753	Replaces the formatting callback on the context (C<undef> restores the	782	Replaces the formatting callback on the context (C<undef> restores the
754	default formatter).	783	default formatter).
755		784
756	The callback is passed the (possibly fractional) timestamp, the original	785	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	786	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	787	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.	788	string, but it could just as well be an array reference that just stores
		789	the values.
		790
		791	If, for some reason, you want to use C<caller> to find out more baout the
		792	logger then you should walk up the call stack until you are no longer
		793	inside the C<AnyEvent::Log> package.
760		794
761	Example: format just the raw message, with numeric log level in angle	795	Example: format just the raw message, with numeric log level in angle
762	brackets.	796	brackets.
763		797
764	$ctx->fmt_cb (sub {	798	$ctx->fmt_cb (sub {
…		…
781	"$msg->[3]";	815	"$msg->[3]";
782		816
783	0	817	0
784	});	818	});
785		819
		820	=item $ctx->log_to_warn
		821
		822	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		823	(usually this logs to STDERR).
		824
		825	=item $ctx->log_to_file ($path)
		826
		827	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		828
		829	=item $ctx->log_to_path ($path)
		830
		831	Same as C<< ->log_to_file >>, but opens the file for each message. This
		832	is much slower, but allows you to change/move/rename/delete the file at
		833	basically any time.
		834
		835	Needless(?) to say, if you do not want to be bitten by some evil person
		836	calling C<chdir>, the path should be absolute. Doesn't help with
		837	C<chroot>, but hey...
		838
		839	=item $ctx->log_to_syslog ([$log_flags])
		840
		841	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		842	the others in the obvious way. If specified, then the C<$log_flags> are
		843	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		844	flags valid for Sys::Syslog::syslog, except for the priority levels.
		845
		846	Note that this function also sets a C<fmt_cb> - the logging part requires
		847	an array reference with [$level, $str] as input.
		848
786	=cut	849	=cut
787		850
788	sub log_cb {	851	sub log_cb {
789	my ($ctx, $cb) = @_;	852	my ($ctx, $cb) = @_;
790		853
…		…
795	my ($ctx, $cb) = @_;	858	my ($ctx, $cb) = @_;
796		859
797	$ctx->[4] = $cb;	860	$ctx->[4] = $cb;
798	}	861	}
799		862
800	=item $ctx->log ($level, $msg[, @params])	863	sub log_to_warn {
		864	my ($ctx, $path) = @_;
801		865
802	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	866	$ctx->log_cb (sub {
		867	warn shift;
		868	0
		869	});
		870	}
803		871
804	=item $logger = $ctx->logger ($level[, \$enabled])	872	sub log_to_file {
805		873	my ($ctx, $path) = @_;
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		874
837	open my $fh, ">>", $path	875	open my $fh, ">>", $path
838	or die "$path: $!";	876	or die "$path: $!";
839		877
840	$AnyEvent::Log::Default->log_cb (sub {	878	$ctx->log_cb (sub {
841	syswrite $fh, shift;	879	syswrite $fh, shift;
842	0	880	0
843	});	881	});
		882	}
		883
		884	sub log_to_path {
		885	my ($ctx, $path) = @_;
		886
		887	$ctx->log_cb (sub {
		888	open my $fh, ">>", $path
		889	or die "$path: $!";
		890
		891	syswrite $fh, shift;
		892	0
		893	});
		894	}
		895
		896	sub log_to_syslog {
		897	my ($ctx, $flags) = @_;
		898
		899	require Sys::Syslog;
		900
		901	$ctx->fmt_cb (sub {
		902	my $str = $_[3];
		903	$str =~ s/\n(?=.)/\n+ /g;
		904
		905	[$_[2], "($_[1][0]) $str"]
		906	});
		907
		908	$ctx->log_cb (sub {
		909	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		910
		911	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		912	for split /\n/, $_[0][1];
		913
		914	0
		915	});
		916	}
		917
		918	=back
		919
		920	=head3 MESSAGE LOGGING
		921
		922	These methods allow you to log messages directly to a context, without
		923	going via your package context.
		924
		925	=over 4
		926
		927	=item $ctx->log ($level, $msg[, @params])
		928
		929	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		930
		931	=item $logger = $ctx->logger ($level[, \$enabled])
		932
		933	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		934	context.
		935
		936	=cut
		937
		938	*log = \&AnyEvent::Log::_log;
		939	*logger = \&AnyEvent::Log::_logger;
		940
		941	=back
		942
		943	=cut
		944
		945	package AnyEvent::Log;
		946
		947	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		948
		949	Logging can also be configured by setting the environment variable
		950	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		951
		952	The value consists of one or more logging context specifications separated
		953	by C<:> or whitespace. Each logging specification in turn starts with a
		954	context name, followed by C<=>, followed by zero or more comma-separated
		955	configuration directives, here are some examples:
		956
		957	# set default logging level
		958	filter=warn
		959
		960	# log to file instead of to stderr
		961	log=file=/tmp/mylog
		962
		963	# log to file in addition to stderr
		964	log=+%file:%file=file=/tmp/mylog
		965
		966	# enable debug log messages, log warnings and above to syslog
		967	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		968
		969	# log trace messages (only) from AnyEvent::Debug to file
		970	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		971
		972	A context name in the log specification can be any of the following:
		973
		974	=over 4
		975
		976	=item C<collect>, C<filter>, C<log>
		977
		978	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		979	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		980
		981	=item C<%name>
		982
		983	Context names starting with a C<%> are anonymous contexts created when the
		984	name is first mentioned. The difference to package contexts is that by
		985	default they have no attached slaves.
		986
		987	=item a perl package name
		988
		989	Any other string references the logging context associated with the given
		990	Perl C<package>. In the unlikely case where you want to specify a package
		991	context that matches on of the other context name forms, you can add a
		992	C<::> to the package name to force interpretation as a package.
		993
		994	=back
		995
		996	The configuration specifications can be any number of the following:
		997
		998	=over 4
		999
		1000	=item C<stderr>
		1001
		1002	Configures the context to use Perl's C<warn> function (which typically
		1003	logs to C<STDERR>). Works like C<log_to_warn>.
		1004
		1005	=item C<file=>I<path>
		1006
		1007	Configures the context to log to a file with the given path. Works like
		1008	C<log_to_file>.
		1009
		1010	=item C<path=>I<path>
		1011
		1012	Configures the context to log to a file with the given path. Works like
		1013	C<log_to_path>.
		1014
		1015	=item C<syslog> or C<syslog=>I<expr>
		1016
		1017	Configured the context to log to syslog. If I<expr> is given, then it is
		1018	evaluated in the L<Sys::Syslog> package, so you could use:
		1019
		1020	log=syslog=LOG_LOCAL0
		1021
		1022	=item C<nolog>
		1023
		1024	Configures the context to not log anything by itself, which is the
		1025	default. Same as C<< $ctx->log_cb (undef) >>.
		1026
		1027	=item C<0> or C<off>
		1028
		1029	Sets the logging level of the context ot C<0>, i.e. all messages will be
		1030	filtered out.
		1031
		1032	=item C<all>
		1033
		1034	Enables all logging levels, i.e. filtering will effectively be switched
		1035	off (the default).
		1036
		1037	=item C<only>
		1038
		1039	Disables all logging levels, and changes the interpretation of following
		1040	level specifications to enable the specified level only.
		1041
		1042	Example: only enable debug messages for a context.
		1043
		1044	context=only,debug
		1045
		1046	=item C<except>
		1047
		1048	Enables all logging levels, and changes the interpretation of following
		1049	level specifications to disable that level. Rarely used.
		1050
		1051	Example: enable all logging levels except fatal and trace (this is rather
		1052	nonsensical).
		1053
		1054	filter=exept,fatal,trace
		1055
		1056	=item C<level>
		1057
		1058	Enables all logging levels, and changes the interpretation of following
		1059	level specifications to be "that level or any higher priority
		1060	message". This is the default.
		1061
		1062	Example: log anything at or above warn level.
		1063
		1064	filter=warn
		1065
		1066	# or, more verbose
		1067	filter=only,level,warn
		1068
		1069	=item C<1>..C<9>, a logging level name (C<error>, C<debug> etc.)
		1070
		1071	A numeric loglevel or the name of a loglevel will be interpreted according
		1072	to the most recent C<only>, C<except> or C<level> directive. By default,
		1073	specifying a logging level enables that and any higher priority messages.
		1074
		1075	=item C<+>I<context>
		1076
		1077	Adds/attaches the named context as slave to the context.
		1078
		1079	=item C<+>
		1080
		1081	A line C<+> clears the slave list form the context. Anonymous (C<%name>)
		1082	contexts have no slaves by default, but package contexts have the parent
		1083	context as slave by default.
		1084
		1085	Example: log messages from My::Module to a file, do not send them to the
		1086	default log collector.
		1087
		1088	My::Module=+,file=/tmp/mymodulelog
		1089
		1090	=back
		1091
		1092	Any character can be escaped by prefixing it with a C<\> (backslash), as
		1093	usual, so to log to a file containing a comma, colon, backslash and space in the
		1094	filename, you would do this:
		1095
		1096	PERL_ANYEVENT_LOG='log=file=/some\ \:file\ with\,\ \\-escapes'
		1097
		1098	Since whitespace (which includes newlines) is allowed, it is fine to
		1099	specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
		1100
		1101	PERL_ANYEVENT_LOG="
		1102	filter=warn
		1103	AnyEvent::Debug=+%trace
		1104	%trace=only,trace,+log
		1105	" myprog
		1106
		1107	Also, in the unlikely case when you want to concatenate specifications,
		1108	use whitespace as separator, as C<::> will be interpreted as part of a
		1109	module name, an empty spec with two separators:
		1110
		1111	PERL_ANYEVENT_LOG="$PERL_ANYEVENT_LOG MyMod=debug"
		1112
		1113	=cut
		1114
		1115	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1116	my %anon;
		1117
		1118	my $pkg = sub {
		1119	$_[0] eq "log" ? $LOG
		1120	: $_[0] eq "filter" ? $FILTER
		1121	: $_[0] eq "collect" ? $COLLECT
		1122	: $_[0] =~ /^%(.+)$/ ? ($anon{$1} \|\|= ctx undef)
		1123	: $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
		1124	: die # never reached?
		1125	};
		1126
		1127	/\G[[:space:]]+/gc; # skip initial whitespace
		1128
		1129	while (/\G((?:[^:=[:space:]]+\|::\|\\.)+)=/gc) {
		1130	my $ctx = $pkg->($1);
		1131	my $level = "level";
		1132
		1133	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1134	for ("$1") {
		1135	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1136	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1137	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1138	} elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog (eval "package Sys::Syslog; $1");
		1139	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1140	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1141	} elsif ($_ eq "+" ) { $ctx->slaves;
		1142	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1143	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1144	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1145	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1146	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1147	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1148	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1149	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1150	}
		1151	}
		1152
		1153	/\G,/gc or last;
		1154	}
		1155
		1156	/\G[:[:space:]]+/gc or last;
		1157	}
		1158
		1159	/\G[[:space:]]+/gc; # skip trailing whitespace
		1160
		1161	if (/\G(.+)/g) {
		1162	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1163	}
		1164	}
		1165
		1166	1;
		1167
		1168	=head1 EXAMPLES
		1169
		1170	This section shows some common configurations, both as code, and as
		1171	C<PERL_ANYEVENT_LOG> string.
		1172
		1173	=over 4
		1174
		1175	=item Setting the global logging level.
		1176
		1177	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1178	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1179	the root context at runtime:
		1180
		1181	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1182
		1183	PERL_ANYEVENT_LOG=log=warn
		1184
		1185	$AnyEvent::Log::FILTER->level ("warn");
		1186
		1187	=item Append all messages to a file instead of sending them to STDERR.
		1188
		1189	This is affected by the global logging level.
		1190
		1191	$AnyEvent::Log::LOG->log_to_file ($path);
		1192
		1193	PERL_ANYEVENT_LOG=log=file=/some/path
844		1194
845	=item Write all messages with priority C<error> and higher to a file.	1195	=item Write all messages with priority C<error> and higher to a file.
846		1196
847	This writes them only when the global logging level allows it, because	1197	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	1198	it is attached to the default context which is invoked I<after> global
849	filtering.	1199	filtering.
850		1200
851	open my $fh, ">>", $path	1201	$AnyEvent::Log::FILTER->attach
852	or die "$path: $!";	1202	new AnyEvent::Log::Ctx log_to_file => $path);
853		1203
854	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx	1204	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
855	log_cb => sub { syswrite $fh, shift; 0 });
856		1205
857	This writes them regardless of the global logging level, because it is	1206	This writes them regardless of the global logging level, because it is
858	attached to the toplevel context, which receives all messages I<before>	1207	attached to the toplevel context, which receives all messages I<before>
859	the global filtering.	1208	the global filtering.
860		1209
861	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	1210	$AnyEvent::Log::COLLECT->attach (
862	log_cb => sub { syswrite $fh, shift; 0 });	1211	new AnyEvent::Log::Ctx log_to_file => $path);
863		1212
		1213	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1214
864	In both cases, messages are still written to STDOUT.	1215	In both cases, messages are still written to STDERR.
865		1216
866	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	1217	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
867		1218
868	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	1219	Attach the C<$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.	1220	context - this simply circumvents the global filtering for trace messages.
871		1221
872	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	1222	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
873	$debug->attach ($AnyEvent::Log::Default);	1223	$debug->attach ($AnyEvent::Log::LOG);
874	$debug->levels ("trace"); # not "level"!
875		1224
876	This of course works for any package.	1225	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1226
		1227	This of course works for any package, not just L<AnyEvent::Debug>, but
		1228	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1229	default.
877		1230
878	=back	1231	=back
879		1232
880	=head1 AUTHOR	1233	=head1 AUTHOR
881		1234
882	Marc Lehmann <schmorp@schmorp.de>	1235	Marc Lehmann <schmorp@schmorp.de>
883	http://home.schmorp.de/	1236	http://home.schmorp.de/
884		1237
885	=cut	1238	=cut
		1239

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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 1.31 by root, Thu Aug 25 03:08:48 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 1.31 by root, Thu Aug 25 03:08:48 2011 UTC