[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 1.39 by root, Fri Aug 26 00:37:26 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 errors and higher only	27	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("error");	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::Root->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,
		34	# regardless of (most) other settings
		35	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
		36	level => "critical",
		37	log_to_syslog => 0,
		38	);
32		39
33	=head1 DESCRIPTION	40	=head1 DESCRIPTION
34		41
35	This module implements a relatively simple "logging framework". It doesn't	42	This module implements a relatively simple "logging framework". It doesn't
36	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
37	AnyEvent - AnyEvent simply creates logging messages internally, and this	44	AnyEvent - AnyEvent simply creates logging messages internally, and this
38	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
39	using it from other modules as well.	46	using it from other modules as well.
40		47
41	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
42	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
43	starting your program, or change the logging level at runtime with	50	before starting your program, or change the logging level at runtime with
44	something like:	51	something like:
45		52
46	use AnyEvent;	53	use AnyEvent::Log;
47	(AnyEvent::Log::ctx "")->level ("info");	54	$AnyEvent::Log::FILTER->level ("info");
48		55
49	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),
50	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
51	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
52	targets, or being able to log into a database.	59	targets, or being able to log into a database.
53		60
		61	The module is also usable before AnyEvent itself is initialised, in which
		62	case some of the functionality might be reduced.
		63
54	The amount of documentation might indicate otherwise, but the module is	64	The amount of documentation might indicate otherwise, but the runtime part
55	still just 240 lines or so.	65	of the module is still just below 300 lines of code.
		66
		67	=head1 LOGGING LEVELS
		68
		69	Logging levels in this module range from C<1> (highest priority) to C<9>
		70	(lowest priority). Note that the lowest numerical value is the highest
		71	priority, so when this document says "higher priority" it means "lower
		72	numerical value".
		73
		74	Instead of specifying levels by name you can also specify them by aliases:
		75
		76	LVL NAME SYSLOG PERL NOTE
		77	1 fatal emerg exit aborts program!
		78	2 alert
		79	3 critical crit
		80	4 error err die
		81	5 warn warning
		82	6 note notice
		83	7 info
		84	8 debug
		85	9 trace
		86
		87	As you can see, some logging levels have multiple aliases - the first one
		88	is the "official" name, the second one the "syslog" name (if it differs)
		89	and the third one the "perl" name, suggesting that you log C<die> messages
		90	at C<error> priority.
		91
		92	You can normally only log a single message at highest priority level
		93	(C<1>, C<fatal>), because logging a fatal message will also quit the
		94	program - so use it sparingly :)
		95
		96	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		97	or C<all> - these are only valid in the methods they are documented for.
56		98
57	=head1 LOGGING FUNCTIONS	99	=head1 LOGGING FUNCTIONS
58		100
59	These functions allow you to log messages. They always use the caller's	101	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	102	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	103	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
62	loaded.	104	loaded.
63		105
64	=over 4	106	=over 4
65		107
…		…
69		111
70	use Carp ();	112	use Carp ();
71	use POSIX ();	113	use POSIX ();
72		114
73	use AnyEvent (); BEGIN { AnyEvent::common_sense }	115	use AnyEvent (); BEGIN { AnyEvent::common_sense }
74	use AnyEvent::Util ();	116	#use AnyEvent::Util (); need to load this in a delayed fashion, as it uses AE::log
75		117
76	our $VERSION = $AnyEvent::VERSION;	118	our $VERSION = $AnyEvent::VERSION;
		119
		120	our ($COLLECT, $FILTER, $LOG);
77		121
78	our ($now_int, $now_str1, $now_str2);	122	our ($now_int, $now_str1, $now_str2);
79		123
80	# Format Time, not public - yet?	124	# Format Time, not public - yet?
81	sub ft($) {	125	sub ft($) {
…		…
86	if $now_int != $i;	130	if $now_int != $i;
87		131
88	"$now_str1$f$now_str2"	132	"$now_str1$f$now_str2"
89	}	133	}
90		134
91	our %CTX; # all logging contexts	135	our %CTX; # all package contexts
92		136
93	# creates a default package context object for the given package	137	# creates a default package context object for the given package
94	sub _pkg_ctx($) {	138	sub _pkg_ctx($) {
95	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	139	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
96		140
97	# link "parent" package	141	# link "parent" package
98	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	142	my $parent = $_[0] =~ /^(.+)::/
		143	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		144	: $COLLECT;
99		145
100	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
101	$ctx->[2]{$pkg+0} = $pkg;	146	$ctx->[2]{$parent+0} = $parent;
102		147
103	$ctx	148	$ctx
104	}	149	}
105		150
106	=item AnyEvent::Log::log $level, $msg[, @args]	151	=item AnyEvent::Log::log $level, $msg[, @args]
107		152
108	Requests logging of the given C<$msg> with the given log level (1..9).	153	Requests logging of the given C<$msg> with the given log level, and
109	You can also use the following strings as log level: C<fatal> (1),	154	returns true if the message was logged I<somewhere>.
110	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
111	C<info> (7), C<debug> (8), C<trace> (9).
112		155
113	For C<fatal> log levels, the program will abort.	156	For C<fatal> log levels, the program will abort.
114		157
115	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	158	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.	159	C<$msg> is interpreted as an sprintf format string.
…		…
122	supposed to return the message. It will be called only then the message	165	supposed to return the message. It will be called only then the message
123	actually gets logged, which is useful if it is costly to create the	166	actually gets logged, which is useful if it is costly to create the
124	message in the first place.	167	message in the first place.
125		168
126	Whether the given message will be logged depends on the maximum log level	169	Whether the given message will be logged depends on the maximum log level
127	and the caller's package.	170	and the caller's package. The return value can be used to ensure that
		171	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		172	runtime error it tries to log it at C<die> level, but if that message is
		173	lost it simply uses warn.
128		174
129	Note that you can (and should) call this function as C<AnyEvent::log> or	175	Note that you can (and should) call this function as C<AnyEvent::log> or
130	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	176	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
131	need any additional functionality), as those functions will load the	177	need any additional functionality), as those functions will load the
132	logging module on demand only. They are also much shorter to write.	178	logging module on demand only. They are also much shorter to write.
…		…
149		195
150	=cut	196	=cut
151		197
152	# also allow syslog equivalent names	198	# also allow syslog equivalent names
153	our %STR2LEVEL = (	199	our %STR2LEVEL = (
154	fatal => 1, emerg => 1,	200	fatal => 1, emerg => 1, exit => 1,
155	alert => 2,	201	alert => 2,
156	critical => 3, crit => 3,	202	critical => 3, crit => 3,
157	error => 4, err => 4,	203	error => 4, err => 4, die => 4,
158	warn => 5, warning => 5,	204	warn => 5, warning => 5,
159	note => 6, notice => 6,	205	note => 6, notice => 6,
160	info => 7,	206	info => 7,
161	debug => 8,	207	debug => 8,
162	trace => 9,	208	trace => 9,
163	);	209	);
164		210
165	sub now () { time }	211	our $TIME_EXACT;
		212
		213	sub exact_time($) {
		214	$TIME_EXACT = shift;
		215	*_ts = $AnyEvent::MODEL
		216	? $TIME_EXACT ? \&AE::now : \&AE::time
		217	: sub () { $TIME_EXACT ? do { require Time::HiRes; Time::HiRes::time () } : time };
		218	}
		219
		220	BEGIN {
		221	exact_time 0;
		222	}
166		223
167	AnyEvent::post_detect {	224	AnyEvent::post_detect {
168	*now = \&AE::now;	225	exact_time $TIME_EXACT;
169	};	226	};
170		227
171	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	228	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
172		229
173	# time, ctx, level, msg	230	# time, ctx, level, msg
…		…
192	? $level+0	249	? $level+0
193	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	250	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
194		251
195	my $mask = 1 << $level;	252	my $mask = 1 << $level;
196		253
197	my (%seen, @ctx, $now, $fmt);	254	my ($success, %seen, @ctx, $now, $fmt);
198		255
199	do	256	do
200	{	257	{
201	# skip if masked	258	# skip if masked
202	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	259	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
206	# now get raw message, unless we have it already	263	# now get raw message, unless we have it already
207	unless ($now) {	264	unless ($now) {
208	$format = $format->() if ref $format;	265	$format = $format->() if ref $format;
209	$format = sprintf $format, @args if @args;	266	$format = sprintf $format, @args if @args;
210	$format =~ s/\n$//;	267	$format =~ s/\n$//;
211	$now = AE::now;	268	$now = _ts;
212	};	269	};
213		270
214	# format msg	271	# format msg
215	my $str = $ctx->[4]	272	my $str = $ctx->[4]
216	? $ctx->[4]($now, $_[0], $level, $format)	273	? $ctx->[4]($now, $_[0], $level, $format)
217	: $fmt \|\|= _format $now, $_[0], $level, $format;	274	: ($fmt \|\|= _format $now, $_[0], $level, $format);
218		275
		276	$success = 1;
		277
219	$ctx->[3]($str);	278	$ctx->[3]($str)
		279	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		280	} else {
		281	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
220	}	282	}
221
222	# not masked, not consumed - propagate to parent contexts
223	push @ctx, values %{ $ctx->[2] };
224	}	283	}
225	}	284	}
226	while $ctx = pop @ctx;	285	while $ctx = pop @ctx;
227		286
228	exit 1 if $level <= 1;	287	exit 1 if $level <= 1;
		288
		289	$success
229	}	290	}
230		291
231	sub log($$;@) {	292	sub log($$;@) {
232	_log	293	_log
233	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	294	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
237	AnyEvent::log = AE::log = \&log;	298	AnyEvent::log = AE::log = \&log;
238		299
239	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	300	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
240		301
241	Creates a code reference that, when called, acts as if the	302	Creates a code reference that, when called, acts as if the
242	C<AnyEvent::Log::log> function was called at this point with the givne	303	C<AnyEvent::Log::log> function was called at this point with the given
243	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	304	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
244	the C<AnyEvent::Log::log> function:	305	the C<AnyEvent::Log::log> function:
245		306
246	my $debug_log = AnyEvent::Log::logger "debug";	307	my $debug_log = AnyEvent::Log::logger "debug";
247		308
…		…
278		339
279	our %LOGGER;	340	our %LOGGER;
280		341
281	# re-assess logging status for all loggers	342	# re-assess logging status for all loggers
282	sub _reassess {	343	sub _reassess {
		344	local $SIG{__DIE__};
		345	my $die = sub { die };
		346
283	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	347	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
284	my ($ctx, $level, $renabled) = @$_;	348	my ($ctx, $level, $renabled) = @$_;
285		349
286	# to detect whether a message would be logged, we # actually	350	# 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	351	# try to log one and die. this isn't fast, but we can be
288	# sure that the logging decision is correct :)	352	# sure that the logging decision is correct :)
289		353
290	$$renabled = !eval {	354	$$renabled = !eval {
291	local $SIG{__DIE__};
292
293	_log $ctx, $level, sub { die };	355	_log $ctx, $level, $die;
294		356
295	1	357	1
296	};	358	};
297
298	$$renabled = 1; # TODO
299	}	359	}
300	}	360	}
301		361
302	sub _logger {	362	sub _logger {
303	my ($ctx, $level, $renabled) = @_;	363	my ($ctx, $level, $renabled) = @_;
…		…
308		368
309	$LOGGER{$logger+0} = $logger;	369	$LOGGER{$logger+0} = $logger;
310		370
311	_reassess $logger+0;	371	_reassess $logger+0;
312		372
		373	require AnyEvent::Util;
313	my $guard = AnyEvent::Util::guard {	374	my $guard = AnyEvent::Util::guard (sub {
314	# "clean up"	375	# "clean up"
315	delete $LOGGER{$logger+0};	376	delete $LOGGER{$logger+0};
316	};	377	});
317		378
318	sub {	379	sub {
319	$guard if 0; # keep guard alive, but don't cause runtime overhead	380	$guard if 0; # keep guard alive, but don't cause runtime overhead
320		381
321	_log $ctx, $level, @_	382	_log $ctx, $level, @_
…		…
326	sub logger($;$) {	387	sub logger($;$) {
327	_logger	388	_logger
328	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	389	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
329	@_	390	@_
330	}	391	}
		392
		393	=item AnyEvent::Log::exact_time $on
		394
		395	By default, C<AnyEvent::Log> will use C<AE::now>, i.e. the cached
		396	eventloop time, for the log timestamps. After calling this function with a
		397	true value it will instead resort to C<AE::time>, i.e. fetch the current
		398	time on each log message. This only makes a difference for event loops
		399	that actually cache the time (such as L<EV> or L<AnyEvent::Loop>).
		400
		401	This setting can be changed at any time by calling this function.
		402
		403	Since C<AnyEvent::Log> has to work even before the L<AnyEvent> has been
		404	initialised, this switch will also decide whether to use C<CORE::time> or
		405	C<Time::HiRes::time> when logging a message before L<AnyEvent> becomes
		406	available.
331		407
332	=back	408	=back
333		409
334	=head1 LOGGING CONTEXTS	410	=head1 LOGGING CONTEXTS
335		411
…		…
348	timestamp, context, level and string message and formats it in the way	424	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	425	it should be logged) and a logging callback (which is responsible for
350	actually logging the formatted message and telling C<AnyEvent::Log>	426	actually logging the formatted message and telling C<AnyEvent::Log>
351	whether it has consumed the message, or whether it should be propagated).	427	whether it has consumed the message, or whether it should be propagated).
352		428
353	For propagation, a context can have any number of attached I<parent	429	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	430	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	431	masked by the logging callback returning true will be passed to all slave
356	contexts.	432	contexts.
357		433
358	Each call to a logging function will log the message at most once per	434	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	435	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.	436	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	440	By default, all logging contexts have an full set of log levels ("all"), a
365	disabled logging callback and the default formatting callback.	441	disabled logging callback and the default formatting callback.
366		442
367	Package contexts have the package name as logging title by default.	443	Package contexts have the package name as logging title by default.
368		444
369	They have exactly one parent - the context of the "parent" package. The	445	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	446	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>,	447	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
372	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	448	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	449	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	450	package name in Perl is C<main>, the default slave of any top-level
375	C<AnyEvent::Log::Top>.	451	package context is C<$AnyEvent::Log::COLLECT>.
376		452
377	Since perl packages form only an approximate hierarchy, this parent	453	Since perl packages form only an approximate hierarchy, this slave
378	context can of course be removed.	454	context can of course be removed.
379		455
380	All other (anonymous) contexts have no parents and an empty title by	456	All other (anonymous) contexts have no slaves and an empty title by
381	default.	457	default.
382		458
383	When the module is loaded it creates the default context called	459	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
384	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	460	context that simply logs everything via C<warn>, without propagating
385	which simply logs everything via C<warn> and doesn't propagate anything
386	anywhere by default. The purpose of the default context is to provide	461	anything anywhere by default. The purpose of this context is to provide
387	a convenient place to override the global logging target or to attach	462	a convenient place to override the global logging target or to attach
388	additional log targets. It's not meant for filtering.	463	additional log targets. It's not meant for filtering.
389		464
390	It then creates the root context called C<AnyEvent::Log::Root> (also	465	It then creates the C<$AnyEvent::Log::FILTER> context whose
391	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	466	purpose is to suppress all messages with priority higher
392	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	467	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
393	then attached the default logging context to it. The purpose of the root	468	C<$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.	469	is to simply provide filtering according to some global log level.
395		470
396	Finally it creates the top-level package context called	471	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
397	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	472	and attaches the C<$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	473	leaves it at default config. Its purpose is simply to collect all log
400	system-wide.	474	messages system-wide.
401		475
402	These three special contexts can also be referred to by the	476	The hierarchy is then:
403	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
404	C<AE::Log::Top>.
405		477
		478	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		479
406	The effect of all this is that log messages, by default, wander up	480	The effect of all this is that log messages, by default, wander up to the
407	to the root context where log messages with lower priority then	481	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		482	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	483	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
409	AnyEvent::Log::Default context to be passed to C<warn>.	484	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
410		485
411	Splitting the top level context into three contexts makes it easy to set	486	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	487	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	488	messages to the $LOG target despite the global logging level, or to attach
415	log targets that log messages, regardless of the global logging level.	489	additional log targets that log messages, regardless of the global logging
		490	level.
416		491
417	It also makes it easy to replace the default warn-logger by something that	492	It also makes it easy to modify the default warn-logger ($LOG) to
418	logs to a file, or to attach additional logging targets.	493	something that logs to a file, or to attach additional logging targets
		494	(such as loggign to a file) by attaching it to $FILTER.
419		495
420	=head2 CREATING/FINDING/DESTROYING CONTEXTS	496	=head2 CREATING/FINDING/DESTROYING CONTEXTS
421		497
422	=over 4	498	=over 4
423		499
…		…
457		533
458	=cut	534	=cut
459		535
460	sub reset {	536	sub reset {
461	# hard to kill complex data structures	537	# hard to kill complex data structures
462	# we recreate all package loggers and reset the hierarchy	538	# we "recreate" all package loggers and reset the hierarchy
463	while (my ($k, $v) = each %CTX) {	539	while (my ($k, $v) = each %CTX) {
464	@$v = ($k, (1 << 10) - 1 - 1, { });	540	@$v = ($k, (1 << 10) - 1 - 1, { });
465		541
466	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	542	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
467	$v->attach ($CTX{$pkg});
468	}	543	}
469		544
470	$AnyEvent::Log::Default->parents;	545	@$_ = ($_->[0], (1 << 10) - 1 - 1)
471	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	546	for $LOG, $FILTER, $COLLECT;
472	$AnyEvent::Log::Default->log_cb (sub {
473	warn shift;
474	0
475	});
476	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
477		547
478	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	548	#$LOG->slaves;
479	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	549	$LOG->title ('$AnyEvent::Log::LOG');
		550	$LOG->log_to_warn;
		551
		552	$FILTER->slaves ($LOG);
		553	$FILTER->title ('$AnyEvent::Log::FILTER');
480	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	554	$FILTER->level ($AnyEvent::VERBOSE);
481	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
482		555
483	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	556	$COLLECT->slaves ($FILTER);
484	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	557	$COLLECT->title ('$AnyEvent::Log::COLLECT');
485	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;
486		558
487	_reassess;	559	_reassess;
488	}	560	}
489		561
490	# create the default logger contexts	562	# create the default logger contexts
491	$AnyEvent::Log::Default = ctx undef;	563	$LOG = ctx undef;
492	$AnyEvent::Log::Root = ctx undef;	564	$FILTER = ctx undef;
493	$AnyEvent::Log::Top = ctx undef;	565	$COLLECT = ctx undef;
494		566
495	AnyEvent::Log::reset;	567	AnyEvent::Log::reset;
496		568
497	# hello, CPAN, please catch me	569	# hello, CPAN, please catch me
498	package AnyEvent::Log::Default;
499	package AE::Log::Default;
500	package AnyEvent::Log::Root;
501	package AE::Log::Root;
502	package AnyEvent::Log::Top;	570	package AnyEvent::Log::LOG;
503	package AE::Log::Top;	571	package AE::Log::LOG;
		572	package AnyEvent::Log::FILTER;
		573	package AE::Log::FILTER;
		574	package AnyEvent::Log::COLLECT;
		575	package AE::Log::COLLECT;
504		576
505	package AnyEvent::Log::Ctx;	577	package AnyEvent::Log::Ctx;
506		578
507	# 0 1 2 3 4	579	# 0 1 2 3 4
508	# [$title, $level, %$parents, &$logcb, &$fmtcb]	580	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
509		581
510	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	582	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
511		583
512	This is a convenience constructor that makes it simpler to construct	584	This is a convenience constructor that makes it simpler to construct
513	anonymous logging contexts.	585	anonymous logging contexts.
…		…
516	name as the key with the value as parameter, unless the value is an	588	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	589	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.	590	array. The methods are called in the same order as specified.
519		591
520	Example: create a new logging context and set both the default logging	592	Example: create a new logging context and set both the default logging
521	level, some parent contexts and a logging callback.	593	level, some slave contexts and a logging callback.
522		594
523	$ctx = new AnyEvent::Log::Ctx	595	$ctx = new AnyEvent::Log::Ctx
524	title => "dubious messages",	596	title => "dubious messages",
525	level => "error",	597	level => "error",
526	log_cb => sub { print STDOUT shift; 0 },	598	log_cb => sub { print STDOUT shift; 0 },
527	parents => [$ctx1, $ctx, $ctx2],	599	slaves => [$ctx1, $ctx, $ctx2],
528	;	600	;
529		601
530	=back	602	=back
531		603
532	=cut	604	=cut
…		…
645	AnyEvent::Log::_reassess;	717	AnyEvent::Log::_reassess;
646	}	718	}
647		719
648	=back	720	=back
649		721
650	=head3 PARENT CONTEXTS	722	=head3 SLAVE CONTEXTS
651		723
652	The following methods attach and detach another logging context to a	724	The following methods attach and detach another logging context to a
653	logging context.	725	logging context.
654		726
655	Log messages are propagated to all parent contexts, unless the logging	727	Log messages are propagated to all slave contexts, unless the logging
656	callback consumes the message.	728	callback consumes the message.
657		729
658	=over 4	730	=over 4
659		731
660	=item $ctx->attach ($ctx2[, $ctx3...])	732	=item $ctx->attach ($ctx2[, $ctx3...])
661		733
662	Attaches the given contexts as parents to this context. It is not an error	734	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).	735	to add a context twice (the second add will be ignored).
664		736
665	A context can be specified either as package name or as a context object.	737	A context can be specified either as package name or as a context object.
666		738
667	=item $ctx->detach ($ctx2[, $ctx3...])	739	=item $ctx->detach ($ctx2[, $ctx3...])
668		740
669	Removes the given parents from this context - it's not an error to attempt	741	Removes the given slaves from this context - it's not an error to attempt
670	to remove a context that hasn't been added.	742	to remove a context that hasn't been added.
671		743
672	A context can be specified either as package name or as a context object.	744	A context can be specified either as package name or as a context object.
673		745
674	=item $ctx->parents ($ctx2[, $ctx3...])	746	=item $ctx->slaves ($ctx2[, $ctx3...])
675		747
676	Replaces all parents attached to this context by the ones given.	748	Replaces all slaves attached to this context by the ones given.
677		749
678	=cut	750	=cut
679		751
680	sub attach {	752	sub attach {
681	my $ctx = shift;	753	my $ctx = shift;
…		…
689		761
690	delete $ctx->[2]{$_+0}	762	delete $ctx->[2]{$_+0}
691	for map { AnyEvent::Log::ctx $_ } @_;	763	for map { AnyEvent::Log::ctx $_ } @_;
692	}	764	}
693		765
694	sub parents {	766	sub slaves {
695	undef $_[0][2];	767	undef $_[0][2];
696	&attach;	768	&attach;
697	}	769	}
698		770
699	=back	771	=back
700		772
701	=head3 MESSAGE LOGGING	773	=head3 LOG TARGETS
702		774
703	The following methods configure how the logging context actually does	775	The following methods configure how the logging context actually does
704	the logging (which consists of formatting the message and printing it or	776	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	777	whatever it wants to do with it).
706	directly to a context, without going via your package context.
707		778
708	=over 4	779	=over 4
709		780
710	=item $ctx->log_cb ($cb->($str))	781	=item $ctx->log_cb ($cb->($str)
711		782
712	Replaces the logging callback on the context (C<undef> disables the	783	Replaces the logging callback on the context (C<undef> disables the
713	logging callback).	784	logging callback).
714		785
715	The logging callback is responsible for handling formatted log messages	786	The logging callback is responsible for handling formatted log messages
716	(see C<fmt_cb> below) - normally simple text strings that end with a	787	(see C<fmt_cb> below) - normally simple text strings that end with a
717	newline (and are possibly multiline themselves).	788	newline (and are possibly multiline themselves).
718		789
719	It also has to return true iff it has consumed the log message, and false	790	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	791	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.	792	slave context. When in doubt, return C<0> from your logging callback.
722		793
723	Example: a very simple logging callback, simply dump the message to STDOUT	794	Example: a very simple logging callback, simply dump the message to STDOUT
724	and do not consume it.	795	and do not consume it.
725		796
726	$ctx->log_cb (sub { print STDERR shift; 0 });	797	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
734	your program.	805	your program.
735		806
736	$ctx->levels ("debug", "trace");	807	$ctx->levels ("debug", "trace");
737	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	808	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
738		809
739	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	810	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
740		811
741	Replaces the formatting callback on the context (C<undef> restores the	812	Replaces the formatting callback on the context (C<undef> restores the
742	default formatter).	813	default formatter).
743		814
744	The callback is passed the (possibly fractional) timestamp, the original	815	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	816	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	817	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.	818	string, but it could just as well be an array reference that just stores
		819	the values.
		820
		821	If, for some reason, you want to use C<caller> to find out more baout the
		822	logger then you should walk up the call stack until you are no longer
		823	inside the C<AnyEvent::Log> package.
748		824
749	Example: format just the raw message, with numeric log level in angle	825	Example: format just the raw message, with numeric log level in angle
750	brackets.	826	brackets.
751		827
752	$ctx->fmt_cb (sub {	828	$ctx->fmt_cb (sub {
…		…
769	"$msg->[3]";	845	"$msg->[3]";
770		846
771	0	847	0
772	});	848	});
773		849
		850	=item $ctx->log_to_warn
		851
		852	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		853	(usually this logs to STDERR).
		854
		855	=item $ctx->log_to_file ($path)
		856
		857	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		858
		859	=item $ctx->log_to_path ($path)
		860
		861	Same as C<< ->log_to_file >>, but opens the file for each message. This
		862	is much slower, but allows you to change/move/rename/delete the file at
		863	basically any time.
		864
		865	Needless(?) to say, if you do not want to be bitten by some evil person
		866	calling C<chdir>, the path should be absolute. Doesn't help with
		867	C<chroot>, but hey...
		868
		869	=item $ctx->log_to_syslog ([$log_flags])
		870
		871	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		872	the others in the obvious way. If specified, then the C<$log_flags> are
		873	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		874	flags valid for Sys::Syslog::syslog, except for the priority levels.
		875
		876	Note that this function also sets a C<fmt_cb> - the logging part requires
		877	an array reference with [$level, $str] as input.
		878
774	=cut	879	=cut
775		880
776	sub log_cb {	881	sub log_cb {
777	my ($ctx, $cb) = @_;	882	my ($ctx, $cb) = @_;
778		883
…		…
783	my ($ctx, $cb) = @_;	888	my ($ctx, $cb) = @_;
784		889
785	$ctx->[4] = $cb;	890	$ctx->[4] = $cb;
786	}	891	}
787		892
788	=item $ctx->log ($level, $msg[, @params])	893	sub log_to_warn {
		894	my ($ctx, $path) = @_;
789		895
790	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	896	$ctx->log_cb (sub {
		897	warn shift;
		898	0
		899	});
		900	}
791		901
792	=item $logger = $ctx->logger ($level[, \$enabled])	902	sub log_to_file {
793		903	my ($ctx, $path) = @_;
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		904
825	open my $fh, ">>", $path	905	open my $fh, ">>", $path
826	or die "$path: $!";	906	or die "$path: $!";
827		907
828	$AnyEvent::Log::Default->log_cb (sub {	908	$ctx->log_cb (sub {
829	syswrite $fh, shift;	909	syswrite $fh, shift;
830	0	910	0
831	});	911	});
		912	}
		913
		914	sub log_to_path {
		915	my ($ctx, $path) = @_;
		916
		917	$ctx->log_cb (sub {
		918	open my $fh, ">>", $path
		919	or die "$path: $!";
		920
		921	syswrite $fh, shift;
		922	0
		923	});
		924	}
		925
		926	sub log_to_syslog {
		927	my ($ctx, $flags) = @_;
		928
		929	require Sys::Syslog;
		930
		931	$ctx->fmt_cb (sub {
		932	my $str = $_[3];
		933	$str =~ s/\n(?=.)/\n+ /g;
		934
		935	[$_[2], "($_[1][0]) $str"]
		936	});
		937
		938	$ctx->log_cb (sub {
		939	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		940
		941	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		942	for split /\n/, $_[0][1];
		943
		944	0
		945	});
		946	}
		947
		948	=back
		949
		950	=head3 MESSAGE LOGGING
		951
		952	These methods allow you to log messages directly to a context, without
		953	going via your package context.
		954
		955	=over 4
		956
		957	=item $ctx->log ($level, $msg[, @params])
		958
		959	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		960
		961	=item $logger = $ctx->logger ($level[, \$enabled])
		962
		963	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		964	context.
		965
		966	=cut
		967
		968	*log = \&AnyEvent::Log::_log;
		969	*logger = \&AnyEvent::Log::_logger;
		970
		971	=back
		972
		973	=cut
		974
		975	package AnyEvent::Log;
		976
		977	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		978
		979	Logging can also be configured by setting the environment variable
		980	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		981
		982	The value consists of one or more logging context specifications separated
		983	by C<:> or whitespace. Each logging specification in turn starts with a
		984	context name, followed by C<=>, followed by zero or more comma-separated
		985	configuration directives, here are some examples:
		986
		987	# set default logging level
		988	filter=warn
		989
		990	# log to file instead of to stderr
		991	log=file=/tmp/mylog
		992
		993	# log to file in addition to stderr
		994	log=+%file:%file=file=/tmp/mylog
		995
		996	# enable debug log messages, log warnings and above to syslog
		997	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		998
		999	# log trace messages (only) from AnyEvent::Debug to file
		1000	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		1001
		1002	A context name in the log specification can be any of the following:
		1003
		1004	=over 4
		1005
		1006	=item C<collect>, C<filter>, C<log>
		1007
		1008	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		1009	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		1010
		1011	=item C<%name>
		1012
		1013	Context names starting with a C<%> are anonymous contexts created when the
		1014	name is first mentioned. The difference to package contexts is that by
		1015	default they have no attached slaves.
		1016
		1017	=item a perl package name
		1018
		1019	Any other string references the logging context associated with the given
		1020	Perl C<package>. In the unlikely case where you want to specify a package
		1021	context that matches on of the other context name forms, you can add a
		1022	C<::> to the package name to force interpretation as a package.
		1023
		1024	=back
		1025
		1026	The configuration specifications can be any number of the following:
		1027
		1028	=over 4
		1029
		1030	=item C<stderr>
		1031
		1032	Configures the context to use Perl's C<warn> function (which typically
		1033	logs to C<STDERR>). Works like C<log_to_warn>.
		1034
		1035	=item C<file=>I<path>
		1036
		1037	Configures the context to log to a file with the given path. Works like
		1038	C<log_to_file>.
		1039
		1040	=item C<path=>I<path>
		1041
		1042	Configures the context to log to a file with the given path. Works like
		1043	C<log_to_path>.
		1044
		1045	=item C<syslog> or C<syslog=>I<expr>
		1046
		1047	Configures the context to log to syslog. If I<expr> is given, then it is
		1048	evaluated in the L<Sys::Syslog> package, so you could use:
		1049
		1050	log=syslog=LOG_LOCAL0
		1051
		1052	=item C<nolog>
		1053
		1054	Configures the context to not log anything by itself, which is the
		1055	default. Same as C<< $ctx->log_cb (undef) >>.
		1056
		1057	=item C<0> or C<off>
		1058
		1059	Sets the logging level of the context ot C<0>, i.e. all messages will be
		1060	filtered out.
		1061
		1062	=item C<all>
		1063
		1064	Enables all logging levels, i.e. filtering will effectively be switched
		1065	off (the default).
		1066
		1067	=item C<only>
		1068
		1069	Disables all logging levels, and changes the interpretation of following
		1070	level specifications to enable the specified level only.
		1071
		1072	Example: only enable debug messages for a context.
		1073
		1074	context=only,debug
		1075
		1076	=item C<except>
		1077
		1078	Enables all logging levels, and changes the interpretation of following
		1079	level specifications to disable that level. Rarely used.
		1080
		1081	Example: enable all logging levels except fatal and trace (this is rather
		1082	nonsensical).
		1083
		1084	filter=exept,fatal,trace
		1085
		1086	=item C<level>
		1087
		1088	Enables all logging levels, and changes the interpretation of following
		1089	level specifications to be "that level or any higher priority
		1090	message". This is the default.
		1091
		1092	Example: log anything at or above warn level.
		1093
		1094	filter=warn
		1095
		1096	# or, more verbose
		1097	filter=only,level,warn
		1098
		1099	=item C<1>..C<9> or a logging level name (C<error>, C<debug> etc.)
		1100
		1101	A numeric loglevel or the name of a loglevel will be interpreted according
		1102	to the most recent C<only>, C<except> or C<level> directive. By default,
		1103	specifying a logging level enables that and any higher priority messages.
		1104
		1105	=item C<+>I<context>
		1106
		1107	Attaches the named context as slave to the context.
		1108
		1109	=item C<+>
		1110
		1111	A line C<+> detaches all contexts, i.e. clears the slave list from the
		1112	context. Anonymous (C<%name>) contexts have no attached slaves by default,
		1113	but package contexts have the parent context as slave by default.
		1114
		1115	Example: log messages from My::Module to a file, do not send them to the
		1116	default log collector.
		1117
		1118	My::Module=+,file=/tmp/mymodulelog
		1119
		1120	=back
		1121
		1122	Any character can be escaped by prefixing it with a C<\> (backslash), as
		1123	usual, so to log to a file containing a comma, colon, backslash and some
		1124	spaces in the filename, you would do this:
		1125
		1126	PERL_ANYEVENT_LOG='log=file=/some\ \:file\ with\,\ \\-escapes'
		1127
		1128	Since whitespace (which includes newlines) is allowed, it is fine to
		1129	specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
		1130
		1131	PERL_ANYEVENT_LOG="
		1132	filter=warn
		1133	AnyEvent::Debug=+%trace
		1134	%trace=only,trace,+log
		1135	" myprog
		1136
		1137	Also, in the unlikely case when you want to concatenate specifications,
		1138	use whitespace as separator, as C<::> will be interpreted as part of a
		1139	module name, an empty spec with two separators:
		1140
		1141	PERL_ANYEVENT_LOG="$PERL_ANYEVENT_LOG MyMod=debug"
		1142
		1143	=cut
		1144
		1145	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1146	my %anon;
		1147
		1148	my $pkg = sub {
		1149	$_[0] eq "log" ? $LOG
		1150	: $_[0] eq "filter" ? $FILTER
		1151	: $_[0] eq "collect" ? $COLLECT
		1152	: $_[0] =~ /^%(.+)$/ ? ($anon{$1} \|\|= ctx undef)
		1153	: $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
		1154	: die # never reached?
		1155	};
		1156
		1157	/\G[[:space:]]+/gc; # skip initial whitespace
		1158
		1159	while (/\G((?:[^:=[:space:]]+\|::\|\\.)+)=/gc) {
		1160	my $ctx = $pkg->($1);
		1161	my $level = "level";
		1162
		1163	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1164	for ("$1") {
		1165	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1166	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1167	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1168	} elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog (eval "package Sys::Syslog; $1");
		1169	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1170	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1171	} elsif ($_ eq "+" ) { $ctx->slaves;
		1172	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1173	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1174	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1175	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1176	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1177	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1178	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1179	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1180	}
		1181	}
		1182
		1183	/\G,/gc or last;
		1184	}
		1185
		1186	/\G[:[:space:]]+/gc or last;
		1187	}
		1188
		1189	/\G[[:space:]]+/gc; # skip trailing whitespace
		1190
		1191	if (/\G(.+)/g) {
		1192	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1193	}
		1194	}
		1195
		1196	1;
		1197
		1198	=head1 EXAMPLES
		1199
		1200	This section shows some common configurations, both as code, and as
		1201	C<PERL_ANYEVENT_LOG> string.
		1202
		1203	=over 4
		1204
		1205	=item Setting the global logging level.
		1206
		1207	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1208	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1209	the root context at runtime:
		1210
		1211	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1212
		1213	PERL_ANYEVENT_LOG=log=warn
		1214
		1215	$AnyEvent::Log::FILTER->level ("warn");
		1216
		1217	=item Append all messages to a file instead of sending them to STDERR.
		1218
		1219	This is affected by the global logging level.
		1220
		1221	$AnyEvent::Log::LOG->log_to_file ($path);
		1222
		1223	PERL_ANYEVENT_LOG=log=file=/some/path
832		1224
833	=item Write all messages with priority C<error> and higher to a file.	1225	=item Write all messages with priority C<error> and higher to a file.
834		1226
835	This writes them only when the global logging level allows it, because	1227	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	1228	it is attached to the default context which is invoked I<after> global
837	filtering.	1229	filtering.
838		1230
839	open my $fh, ">>", $path	1231	$AnyEvent::Log::FILTER->attach
840	or die "$path: $!";	1232	new AnyEvent::Log::Ctx log_to_file => $path);
841		1233
842	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx	1234	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
843	log_cb => sub { syswrite $fh, shift; 0 });
844		1235
845	This writes them regardless of the global logging level, because it is	1236	This writes them regardless of the global logging level, because it is
846	attached to the toplevel context, which receives all messages I<before>	1237	attached to the toplevel context, which receives all messages I<before>
847	the global filtering.	1238	the global filtering.
848		1239
849	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	1240	$AnyEvent::Log::COLLECT->attach (
850	log_cb => sub { syswrite $fh, shift; 0 });	1241	new AnyEvent::Log::Ctx log_to_file => $path);
851		1242
		1243	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1244
852	In both cases, messages are still written to STDOUT.	1245	In both cases, messages are still written to STDERR.
853		1246
854	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	1247	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
855		1248
856	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	1249	Attach the C<$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.	1250	context - this simply circumvents the global filtering for trace messages.
859		1251
860	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	1252	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
861	$debug->attach ($AnyEvent::Log::Default);	1253	$debug->attach ($AnyEvent::Log::LOG);
862	$debug->levels ("trace"); # not "level"!
863		1254
864	This of course works for any package.	1255	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1256
		1257	This of course works for any package, not just L<AnyEvent::Debug>, but
		1258	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1259	default.
865		1260
866	=back	1261	=back
867		1262
868	=head1 AUTHOR	1263	=head1 AUTHOR
869		1264
870	Marc Lehmann <schmorp@schmorp.de>	1265	Marc Lehmann <schmorp@schmorp.de>
871	http://home.schmorp.de/	1266	http://home.schmorp.de/
872		1267
873	=cut	1268	=cut
		1269

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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 1.39 by root, Fri Aug 26 00:37:26 2011 UTC

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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 1.39 by root, Fri Aug 26 00:37:26 2011 UTC