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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.10 by root, Fri Aug 19 21:17:08 2011 UTC vs.
Revision 1.42 by root, Thu Sep 1 22:38:11 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	# available log levels in order:
		17	# fatal alert critical error warn note info debug trace
		18
		19	"Complex" uses (for speed sensitive code):
		20
16	use AnyEvent::Log;	21	use AnyEvent::Log;
17		22
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	23	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		24
20	$tracer->("i am here") if $trace;	25	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	26	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		27
23	# configuration	28	Configuration (also look at the EXAMPLES section):
24		29
25	# set logging for this package to maximum	30	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("all");	31	AnyEvent::Log::ctx->level ("error");
27		32
28	# set logging globally to anything below debug	33	# set logging level to suppress anything below "notice"
29	(AnyEvent::Log::ctx "")->level ("notice");	34	$AnyEvent::Log::FILTER->level ("notice");
30		35
31	# see also EXAMPLES, below	36	# send all critical and higher priority messages to syslog,
32		37	# regardless of (most) other settings
33	# disable logging for package "AnyEvent" and all packages below it	38	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
34	AnyEvent->AnyEvent::Log::ctx->level (0);	39	level => "critical",
35		40	log_to_syslog => "user",
36	# log everything below debug to a file, for the whole program	41	);
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		42
41	=head1 DESCRIPTION	43	=head1 DESCRIPTION
42		44
43	This module implements a relatively simple "logging framework". It doesn't	45	This module implements a relatively simple "logging framework". It doesn't
44	attempt to be "the" logging solution or even "a" logging solution for	46	attempt to be "the" logging solution or even "a" logging solution for
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	47	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	module more or less exposes the mechanism, with some extra spiff to allow	48	module more or less exposes the mechanism, with some extra spiff to allow
47	using it from other modules as well.	49	using it from other modules as well.
48		50
49	Remember that the default verbosity level is C<0>, so nothing will be	51	Remember that the default verbosity level is C<0> (C<off>), so nothing
50	logged, ever, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number	52	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
51	before starting your program, or change the logging level at runtime wiht	53	before starting your program, or change the logging level at runtime with
52	something like:	54	something like:
53		55
54	use AnyEvent;	56	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	57	$AnyEvent::Log::FILTER->level ("info");
56		58
57	The design goal behind this module was to keep it simple (and small),	59	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	60	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	61	extensive enough for the most common tasks, such as logging to multiple
60	targets, or being able to log into a database.	62	targets, or being able to log into a database.
61		63
		64	The module is also usable before AnyEvent itself is initialised, in which
		65	case some of the functionality might be reduced.
		66
		67	The amount of documentation might indicate otherwise, but the runtime part
		68	of the module is still just below 300 lines of code.
		69
		70	=head1 LOGGING LEVELS
		71
		72	Logging levels in this module range from C<1> (highest priority) to C<9>
		73	(lowest priority). Note that the lowest numerical value is the highest
		74	priority, so when this document says "higher priority" it means "lower
		75	numerical value".
		76
		77	Instead of specifying levels by name you can also specify them by aliases:
		78
		79	LVL NAME SYSLOG PERL NOTE
		80	1 fatal emerg exit system unusable, aborts program!
		81	2 alert failure in primary system
		82	3 critical crit failure in backup system
		83	4 error err die non-urgent program errors, a bug
		84	5 warn warning possible problem, not necessarily error
		85	6 note notice unusual conditions
		86	7 info normal messages, no action required
		87	8 debug debugging messages for development
		88	9 trace copious tracing output
		89
		90	As you can see, some logging levels have multiple aliases - the first one
		91	is the "official" name, the second one the "syslog" name (if it differs)
		92	and the third one the "perl" name, suggesting (only!) that you log C<die>
		93	messages at C<error> priority. The NOTE column tries to provide some
		94	rationale on how to chose a logging level.
		95
		96	As a rough guideline, levels 1..3 are primarily meant for users of
		97	the program (admins, staff), and are the only logged to STDERR by
		98	default. Levels 4..6 are meant for users and developers alike, while
		99	levels 7..9 are usually meant for developers.
		100
		101	You can normally only log a single message at highest priority level
		102	(C<1>, C<fatal>), because logging a fatal message will also quit the
		103	program - so use it sparingly :)
		104
		105	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		106	or C<all> - these are only valid in the methods they are documented for.
		107
62	=head1 LOGGING FUNCTIONS	108	=head1 LOGGING FUNCTIONS
63		109
64	These functions allow you to log messages. They always use the caller's	110	These functions allow you to log messages. They always use the caller's
65	package as a "logging module/source". Also, the main logging function is	111	package as a "logging context". Also, the main logging function C<log> is
66	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	112	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
67	loaded.	113	loaded.
68		114
69	=over 4	115	=over 4
70		116
…		…
74		120
75	use Carp ();	121	use Carp ();
76	use POSIX ();	122	use POSIX ();
77		123
78	use AnyEvent (); BEGIN { AnyEvent::common_sense }	124	use AnyEvent (); BEGIN { AnyEvent::common_sense }
79	use AnyEvent::Util ();	125	#use AnyEvent::Util (); need to load this in a delayed fashion, as it uses AE::log
		126
		127	our $VERSION = $AnyEvent::VERSION;
		128
		129	our ($COLLECT, $FILTER, $LOG);
80		130
81	our ($now_int, $now_str1, $now_str2);	131	our ($now_int, $now_str1, $now_str2);
82		132
83	# Format Time, not public - yet?	133	# Format Time, not public - yet?
84	sub ft($) {	134	sub ft($) {
…		…
89	if $now_int != $i;	139	if $now_int != $i;
90		140
91	"$now_str1$f$now_str2"	141	"$now_str1$f$now_str2"
92	}	142	}
93		143
94	our %CTX; # all logging contexts	144	our %CTX; # all package contexts
95		145
96	# creates a default package context object for the given package	146	# creates a default package context object for the given package
97	sub _pkg_ctx($) {	147	sub _pkg_ctx($) {
98	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	148	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
99		149
100	# link "parent" package	150	# link "parent" package
101	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "";	151	my $parent = $_[0] =~ /^(.+)::/
		152	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		153	: $COLLECT;
102		154
103	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
104	$ctx->[2]{$pkg+0} = $pkg;	155	$ctx->[2]{$parent+0} = $parent;
105		156
106	$ctx	157	$ctx
107	}	158	}
108		159
109	=item AnyEvent::Log::log $level, $msg[, @args]	160	=item AnyEvent::Log::log $level, $msg[, @args]
110		161
111	Requests logging of the given C<$msg> with the given log level (1..9).	162	Requests logging of the given C<$msg> with the given log level, and
112	You can also use the following strings as log level: C<fatal> (1),	163	returns true if the message was logged I<somewhere>.
113	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
114	C<info> (7), C<debug> (8), C<trace> (9).
115		164
116	For C<fatal> log levels, the program will abort.	165	For loglevel C<fatal>, the program will abort.
117		166
118	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	167	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
119	C<$msg> is interpreted as an sprintf format string.	168	C<$msg> is interpreted as an sprintf format string.
120		169
121	The C<$msg> should not end with C<\n>, but may if that is convenient for	170	The C<$msg> should not end with C<\n>, but may if that is convenient for
…		…
125	supposed to return the message. It will be called only then the message	174	supposed to return the message. It will be called only then the message
126	actually gets logged, which is useful if it is costly to create the	175	actually gets logged, which is useful if it is costly to create the
127	message in the first place.	176	message in the first place.
128		177
129	Whether the given message will be logged depends on the maximum log level	178	Whether the given message will be logged depends on the maximum log level
130	and the caller's package.	179	and the caller's package. The return value can be used to ensure that
		180	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		181	runtime error it tries to log it at C<die> level, but if that message is
		182	lost it simply uses warn.
131		183
132	Note that you can (and should) call this function as C<AnyEvent::log> or	184	Note that you can (and should) call this function as C<AnyEvent::log> or
133	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	185	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
134	need any additional functionality), as those functions will load the	186	need any additional functionality), as those functions will load the
135	logging module on demand only. They are also much shorter to write.	187	logging module on demand only. They are also much shorter to write.
136		188
137	Also, if you otpionally generate a lot of debug messages (such as when	189	Also, if you optionally generate a lot of debug messages (such as when
138	tracing some code), you should look into using a logger callback and a	190	tracing some code), you should look into using a logger callback and a
139	boolean enabler (see C<logger>, below).	191	boolean enabler (see C<logger>, below).
140		192
141	Example: log something at error level.	193	Example: log something at error level.
142		194
…		…
152		204
153	=cut	205	=cut
154		206
155	# also allow syslog equivalent names	207	# also allow syslog equivalent names
156	our %STR2LEVEL = (	208	our %STR2LEVEL = (
157	fatal => 1, emerg => 1,	209	fatal => 1, emerg => 1, exit => 1,
158	alert => 2,	210	alert => 2,
159	critical => 3, crit => 3,	211	critical => 3, crit => 3,
160	error => 4, err => 4,	212	error => 4, err => 4, die => 4,
161	warn => 5, warning => 5,	213	warn => 5, warning => 5,
162	note => 6, notice => 6,	214	note => 6, notice => 6,
163	info => 7,	215	info => 7,
164	debug => 8,	216	debug => 8,
165	trace => 9,	217	trace => 9,
166	);	218	);
167		219
168	sub now () { time }	220	our $TIME_EXACT;
		221
		222	sub exact_time($) {
		223	$TIME_EXACT = shift;
		224	*_ts = $AnyEvent::MODEL
		225	? $TIME_EXACT ? \&AE::now : \&AE::time
		226	: sub () { $TIME_EXACT ? do { require Time::HiRes; Time::HiRes::time () } : time };
		227	}
		228
		229	BEGIN {
		230	exact_time 0;
		231	}
169		232
170	AnyEvent::post_detect {	233	AnyEvent::post_detect {
171	*now = \&AE::now;	234	exact_time $TIME_EXACT;
172	};	235	};
173		236
174	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	237	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
175		238
176	# time, ctx, level, msg	239	# time, ctx, level, msg
177	sub _format($$$$) {	240	sub _format($$$$) {
178	my $pfx = ft $_[0];	241	my $ts = ft $_[0];
		242	my $ct = " ";
		243
179	my @res;	244	my @res;
180		245
181	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {	246	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {
182	push @res, "$pfx $_\n";	247	push @res, "$ts$ct$_\n";
183	$pfx = "\t";	248	$ct = " + ";
184	}	249	}
185		250
186	join "", @res	251	join "", @res
187	}	252	}
188		253
189	sub _log {	254	sub _log {
190	my ($ctx, $level, $format, @args) = @_;	255	my ($ctx, $level, $format, @args) = @_;
191		256
		257	$level = $level > 0 && $level <= 9
		258	? $level+0
192	$level = $level > 0 && $level <= 9 ? $level+0 : $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	259	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
193		260
194	my $mask = 1 << $level;	261	my $mask = 1 << $level;
195		262
196	my (@ctx, $now, $fmt);	263	my ($success, %seen, @ctx, $now, $fmt);
197		264
198	do {	265	do
		266	{
199	# skip if masked	267	# skip if masked
200	next unless $ctx->[1] & $mask;	268	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
201
202	if ($ctx->[3]) {	269	if ($ctx->[3]) {
203	# logging target found	270	# logging target found
204		271
205	# now get raw message, unless we have it already	272	# now get raw message, unless we have it already
206	unless ($now) {	273	unless ($now) {
207	$format = $format->() if ref $format;	274	$format = $format->() if ref $format;
208	$format = sprintf $format, @args if @args;	275	$format = sprintf $format, @args if @args;
209	$format =~ s/\n$//;	276	$format =~ s/\n$//;
210	$now = AE::now;	277	$now = _ts;
		278	};
		279
		280	# format msg
		281	my $str = $ctx->[4]
		282	? $ctx->[4]($now, $_[0], $level, $format)
		283	: ($fmt \|\|= _format $now, $_[0], $level, $format);
		284
		285	$success = 1;
		286
		287	$ctx->[3]($str)
		288	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		289	} else {
		290	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
		291	}
211	};	292	}
212
213	# format msg
214	my $str = $ctx->[4]
215	? $ctx->[4]($now, $_[0], $level, $format)
216	: $fmt \|\|= _format $now, $_[0], $level, $format;
217
218	$ctx->[3]($str)
219	and next;
220	}	293	}
221
222	# not masked, not consume - propagate to parent contexts
223	push @ctx, values %{ $ctx->[2] };
224	} while $ctx = pop @ctx;	294	while $ctx = pop @ctx;
225		295
226	exit 1 if $level <= 1;	296	exit 1 if $level <= 1;
		297
		298	$success
227	}	299	}
228		300
229	sub log($$;@) {	301	sub log($$;@) {
230	_log	302	_log
231	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	303	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
235	AnyEvent::log = AE::log = \&log;	307	AnyEvent::log = AE::log = \&log;
236		308
237	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	309	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
238		310
239	Creates a code reference that, when called, acts as if the	311	Creates a code reference that, when called, acts as if the
240	C<AnyEvent::Log::log> function was called at this point with the givne	312	C<AnyEvent::Log::log> function was called at this point with the given
241	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	313	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
242	the C<AnyEvent::Log::log> function:	314	the C<AnyEvent::Log::log> function:
243		315
244	my $debug_log = AnyEvent::Log::logger "debug";	316	my $debug_log = AnyEvent::Log::logger "debug";
245		317
…		…
270	# and later in your program	342	# and later in your program
271	$debug_log->("yo, stuff here") if $debug;	343	$debug_log->("yo, stuff here") if $debug;
272		344
273	$debug and $debug_log->("123");	345	$debug and $debug_log->("123");
274		346
275	Note: currently the enabled var is always true - that will be fixed in a
276	future version :)
277
278	=cut	347	=cut
279		348
280	our %LOGGER;	349	our %LOGGER;
281		350
282	# re-assess logging status for all loggers	351	# re-assess logging status for all loggers
283	sub _reassess {	352	sub _reassess {
		353	local $SIG{__DIE__};
		354	my $die = sub { die };
		355
284	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	356	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
285	my ($ctx, $level, $renabled) = @$_;	357	my ($ctx, $level, $renabled) = @$_;
286		358
287	# to detetc whether a message would be logged, we # actually	359	# to detect whether a message would be logged, we actually
288	# try to log one and die. this isn't # fast, but we can be	360	# try to log one and die. this isn't fast, but we can be
289	# sure that the logging decision is correct :)	361	# sure that the logging decision is correct :)
290		362
291	$$renabled = !eval {	363	$$renabled = !eval {
292	local $SIG{__DIE__};
293
294	_log $ctx, $level, sub { die };	364	_log $ctx, $level, $die;
295		365
296	1	366	1
297	};	367	};
298
299	$$renabled = 1; # TODO
300	}	368	}
301	}	369	}
302		370
303	sub _logger($;$) {	371	sub _logger {
304	my ($ctx, $level, $renabled) = @_;	372	my ($ctx, $level, $renabled) = @_;
305		373
306	$renabled \|\|= \my $enabled;
307
308	$$renabled = 1;	374	$$renabled = 1;
309		375
310	my $logger = [$ctx, $level, $renabled];	376	my $logger = [$ctx, $level, $renabled];
311		377
312	$LOGGER{$logger+0} = $logger;	378	$LOGGER{$logger+0} = $logger;
313		379
314	_reassess $logger+0;	380	_reassess $logger+0;
315		381
		382	require AnyEvent::Util;
316	my $guard = AnyEvent::Util::guard {	383	my $guard = AnyEvent::Util::guard (sub {
317	# "clean up"	384	# "clean up"
318	delete $LOGGER{$logger+0};	385	delete $LOGGER{$logger+0};
319	};	386	});
320		387
321	sub {	388	sub {
322	$guard if 0; # keep guard alive, but don't cause runtime overhead	389	$guard if 0; # keep guard alive, but don't cause runtime overhead
323		390
324	_log $ctx, $level, @_	391	_log $ctx, $level, @_
…		…
329	sub logger($;$) {	396	sub logger($;$) {
330	_logger	397	_logger
331	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	398	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
332	@_	399	@_
333	}	400	}
		401
		402	=item AnyEvent::Log::exact_time $on
		403
		404	By default, C<AnyEvent::Log> will use C<AE::now>, i.e. the cached
		405	eventloop time, for the log timestamps. After calling this function with a
		406	true value it will instead resort to C<AE::time>, i.e. fetch the current
		407	time on each log message. This only makes a difference for event loops
		408	that actually cache the time (such as L<EV> or L<AnyEvent::Loop>).
		409
		410	This setting can be changed at any time by calling this function.
		411
		412	Since C<AnyEvent::Log> has to work even before the L<AnyEvent> has been
		413	initialised, this switch will also decide whether to use C<CORE::time> or
		414	C<Time::HiRes::time> when logging a message before L<AnyEvent> becomes
		415	available.
334		416
335	=back	417	=back
336		418
337	=head1 LOGGING CONTEXTS	419	=head1 LOGGING CONTEXTS
338		420
…		…
351	timestamp, context, level and string message and formats it in the way	433	timestamp, context, level and string message and formats it in the way
352	it should be logged) and a logging callback (which is responsible for	434	it should be logged) and a logging callback (which is responsible for
353	actually logging the formatted message and telling C<AnyEvent::Log>	435	actually logging the formatted message and telling C<AnyEvent::Log>
354	whether it has consumed the message, or whether it should be propagated).	436	whether it has consumed the message, or whether it should be propagated).
355		437
356	For propagation, a context can have any number of attached I<parent	438	For propagation, a context can have any number of attached I<slave
357	contexts>. Any message that is neither masked by the logging mask nor	439	contexts>. Any message that is neither masked by the logging mask nor
358	masked by the logging callback returning true will be passed to all parent	440	masked by the logging callback returning true will be passed to all slave
359	contexts.	441	contexts.
		442
		443	Each call to a logging function will log the message at most once per
		444	context, so it does not matter (much) if there are cycles or if the
		445	message can arrive at the same context via multiple paths.
360		446
361	=head2 DEFAULTS	447	=head2 DEFAULTS
362		448
363	By default, all logging contexts have an full set of log levels ("all"), a	449	By default, all logging contexts have an full set of log levels ("all"), a
364	disabled logging callback and the default formatting callback.	450	disabled logging callback and the default formatting callback.
365		451
366	Package contexts have the package name as logging title by default.	452	Package contexts have the package name as logging title by default.
367		453
368	They have exactly one parent - the context of the "parent" package. The	454	They have exactly one slave - the context of the "parent" package. The
369	parent package is simply defined to be the package name without the last	455	parent package is simply defined to be the package name without the last
370	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	456	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
371	and C<AnyEvent> becomes the empty string.	457	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
		458	exception of the rule - just like the "parent" of any single-component
		459	package name in Perl is C<main>, the default slave of any top-level
		460	package context is C<$AnyEvent::Log::COLLECT>.
372		461
373	Since perl packages form only an approximate hierarchy, this parent	462	Since perl packages form only an approximate hierarchy, this slave
374	context can of course be removed.	463	context can of course be removed.
375		464
376	All other (anonymous) contexts have no parents and an empty title by	465	All other (anonymous) contexts have no slaves and an empty title by
377	default.	466	default.
378		467
379	When the module is first loaded, it configures the root context (the one	468	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
380	with the empty string) to simply dump all log messages to C<STDERR>,	469	context that simply logs everything via C<warn>, without propagating
381	and sets it's log level set to all levels up to the one specified by	470	anything anywhere by default. The purpose of this context is to provide
382	C<$ENV{PERL_ANYEVENT_VERBOSE}>.	471	a convenient place to override the global logging target or to attach
		472	additional log targets. It's not meant for filtering.
		473
		474	It then creates the C<$AnyEvent::Log::FILTER> context whose
		475	purpose is to suppress all messages with priority higher
		476	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
		477	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
		478	is to simply provide filtering according to some global log level.
		479
		480	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
		481	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
		482	leaves it at default config. Its purpose is simply to collect all log
		483	messages system-wide.
		484
		485	The hierarchy is then:
		486
		487	any package, eventually -> $COLLECT -> $FILTER -> $LOG
383		488
384	The effect of all this is that log messages, by default, wander up to the	489	The effect of all this is that log messages, by default, wander up to the
385	root context and will be logged to STDERR if their log level is less than	490	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
386	or equal to C<$ENV{PERL_ANYEVENT_VERBOSE}>.	491	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
		492	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
		493	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
387		494
		495	This makes it easy to set a global logging level (by modifying $FILTER),
		496	but still allow other contexts to send, for example, their debug and trace
		497	messages to the $LOG target despite the global logging level, or to attach
		498	additional log targets that log messages, regardless of the global logging
		499	level.
		500
		501	It also makes it easy to modify the default warn-logger ($LOG) to
		502	something that logs to a file, or to attach additional logging targets
		503	(such as loggign to a file) by attaching it to $FILTER.
		504
388	=head2 CREATING/FINDING A CONTEXT	505	=head2 CREATING/FINDING/DESTROYING CONTEXTS
389		506
390	=over 4	507	=over 4
391		508
392	=item $ctx = AnyEvent::Log::ctx [$pkg]	509	=item $ctx = AnyEvent::Log::ctx [$pkg]
393		510
…		…
411	: defined $pkg	528	: defined $pkg
412	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg	529	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg
413	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	530	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
414	}	531	}
415		532
416	# create default root context	533	=item AnyEvent::Log::reset
417	{	534
418	my $root = ctx undef;	535	Resets all package contexts and recreates the default hierarchy if
419	$root->[0] = "";	536	necessary, i.e. resets the logging subsystem to defaults, as much as
420	$root->title ("default");	537	possible. This process keeps references to contexts held by other parts of
421	$root->level ($AnyEvent::VERBOSE); undef $AnyEvent::VERBOSE;	538	the program intact.
422	$root->log_cb (sub {	539
423	print STDERR shift;	540	This can be used to implement config-file (re-)loading: before loading a
424	0	541	configuration, reset all contexts.
		542
		543	=cut
		544
		545	sub reset {
		546	# hard to kill complex data structures
		547	# we "recreate" all package loggers and reset the hierarchy
		548	while (my ($k, $v) = each %CTX) {
		549	@$v = ($k, (1 << 10) - 1 - 1, { });
		550
		551	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
425	});	552	}
426	$CTX{""} = $root;	553
		554	@$_ = ($_->[0], (1 << 10) - 1 - 1)
		555	for $LOG, $FILTER, $COLLECT;
		556
		557	#$LOG->slaves;
		558	$LOG->title ('$AnyEvent::Log::LOG');
		559	$LOG->log_to_warn;
		560
		561	$FILTER->slaves ($LOG);
		562	$FILTER->title ('$AnyEvent::Log::FILTER');
		563	$FILTER->level ($AnyEvent::VERBOSE);
		564
		565	$COLLECT->slaves ($FILTER);
		566	$COLLECT->title ('$AnyEvent::Log::COLLECT');
		567
		568	_reassess;
427	}	569	}
		570
		571	# create the default logger contexts
		572	$LOG = ctx undef;
		573	$FILTER = ctx undef;
		574	$COLLECT = ctx undef;
		575
		576	AnyEvent::Log::reset;
		577
		578	# hello, CPAN, please catch me
		579	package AnyEvent::Log::LOG;
		580	package AE::Log::LOG;
		581	package AnyEvent::Log::FILTER;
		582	package AE::Log::FILTER;
		583	package AnyEvent::Log::COLLECT;
		584	package AE::Log::COLLECT;
		585
		586	package AnyEvent::Log::Ctx;
		587
		588	# 0 1 2 3 4
		589	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
		590
		591	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
		592
		593	This is a convenience constructor that makes it simpler to construct
		594	anonymous logging contexts.
		595
		596	Each key-value pair results in an invocation of the method of the same
		597	name as the key with the value as parameter, unless the value is an
		598	arrayref, in which case it calls the method with the contents of the
		599	array. The methods are called in the same order as specified.
		600
		601	Example: create a new logging context and set both the default logging
		602	level, some slave contexts and a logging callback.
		603
		604	$ctx = new AnyEvent::Log::Ctx
		605	title => "dubious messages",
		606	level => "error",
		607	log_cb => sub { print STDOUT shift; 0 },
		608	slaves => [$ctx1, $ctx, $ctx2],
		609	;
428		610
429	=back	611	=back
430		612
431	=cut	613	=cut
432		614
433	package AnyEvent::Log::Ctx;	615	sub new {
		616	my $class = shift;
434		617
435	# 0 1 2 3 4	618	my $ctx = AnyEvent::Log::ctx undef;
436	# [$title, $level, %$parents, &$logcb, &$fmtcb]	619
		620	while (@_) {
		621	my ($k, $v) = splice @_, 0, 2;
		622	$ctx->$k (ref $v eq "ARRAY" ? @$v : $v);
		623	}
		624
		625	bless $ctx, $class # do we really support subclassing, hmm?
		626	}
		627
437		628
438	=head2 CONFIGURING A LOG CONTEXT	629	=head2 CONFIGURING A LOG CONTEXT
439		630
440	The following methods can be used to configure the logging context.	631	The following methods can be used to configure the logging context.
441		632
…		…
535	AnyEvent::Log::_reassess;	726	AnyEvent::Log::_reassess;
536	}	727	}
537		728
538	=back	729	=back
539		730
540	=head3 PARENT CONTEXTS	731	=head3 SLAVE CONTEXTS
541		732
542	The following methods attach and detach another logging context to a	733	The following methods attach and detach another logging context to a
543	logging context.	734	logging context.
544		735
545	Log messages are propagated to all parent contexts, unless the logging	736	Log messages are propagated to all slave contexts, unless the logging
546	callback consumes the message.	737	callback consumes the message.
547		738
548	=over 4	739	=over 4
549		740
550	=item $ctx->attach ($ctx2[, $ctx3...])	741	=item $ctx->attach ($ctx2[, $ctx3...])
551		742
552	Attaches the given contexts as parents to this context. It is not an error	743	Attaches the given contexts as slaves to this context. It is not an error
553	to add a context twice (the second add will be ignored).	744	to add a context twice (the second add will be ignored).
554		745
555	A context can be specified either as package name or as a context object.	746	A context can be specified either as package name or as a context object.
556		747
557	=item $ctx->detach ($ctx2[, $ctx3...])	748	=item $ctx->detach ($ctx2[, $ctx3...])
558		749
559	Removes the given parents from this context - it's not an error to attempt	750	Removes the given slaves from this context - it's not an error to attempt
560	to remove a context that hasn't been added.	751	to remove a context that hasn't been added.
561		752
562	A context can be specified either as package name or as a context object.	753	A context can be specified either as package name or as a context object.
		754
		755	=item $ctx->slaves ($ctx2[, $ctx3...])
		756
		757	Replaces all slaves attached to this context by the ones given.
563		758
564	=cut	759	=cut
565		760
566	sub attach {	761	sub attach {
567	my $ctx = shift;	762	my $ctx = shift;
…		…
575		770
576	delete $ctx->[2]{$_+0}	771	delete $ctx->[2]{$_+0}
577	for map { AnyEvent::Log::ctx $_ } @_;	772	for map { AnyEvent::Log::ctx $_ } @_;
578	}	773	}
579		774
		775	sub slaves {
		776	undef $_[0][2];
		777	&attach;
		778	}
		779
580	=back	780	=back
581		781
582	=head3 MESSAGE LOGGING	782	=head3 LOG TARGETS
583		783
584	The following methods configure how the logging context actually does	784	The following methods configure how the logging context actually does
585	the logging (which consists of formatting the message and printing it or	785	the logging (which consists of formatting the message and printing it or
586	whatever it wants to do with it) and also allows you to log messages	786	whatever it wants to do with it).
587	directly to a context, without going via your package context.
588		787
589	=over 4	788	=over 4
590		789
591	=item $ctx->log_cb ($cb->($str))	790	=item $ctx->log_cb ($cb->($str)
592		791
593	Replaces the logging callback on the context (C<undef> disables the	792	Replaces the logging callback on the context (C<undef> disables the
594	logging callback).	793	logging callback).
595		794
596	The logging callback is responsible for handling formatted log messages	795	The logging callback is responsible for handling formatted log messages
597	(see C<fmt_cb> below) - normally simple text strings that end with a	796	(see C<fmt_cb> below) - normally simple text strings that end with a
598	newline (and are possibly multiline themselves).	797	newline (and are possibly multiline themselves).
599		798
600	It also has to return true iff it has consumed the log message, and false	799	It also has to return true iff it has consumed the log message, and false
601	if it hasn't. Consuming a message means that it will not be sent to any	800	if it hasn't. Consuming a message means that it will not be sent to any
602	parent context. When in doubt, return C<0> from your logging callback.	801	slave context. When in doubt, return C<0> from your logging callback.
603		802
604	Example: a very simple logging callback, simply dump the message to STDOUT	803	Example: a very simple logging callback, simply dump the message to STDOUT
605	and do not consume it.	804	and do not consume it.
606		805
607	$ctx->log_cb (sub { print STDERR shift; 0 });	806	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
615	your program.	814	your program.
616		815
617	$ctx->levels ("debug", "trace");	816	$ctx->levels ("debug", "trace");
618	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	817	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
619		818
620	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	819	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
621		820
622	Replaces the formatting callback on the context (C<undef> restores the	821	Replaces the formatting callback on the context (C<undef> restores the
623	default formatter).	822	default formatter).
624		823
625	The callback is passed the (possibly fractional) timestamp, the original	824	The callback is passed the (possibly fractional) timestamp, the original
626	logging context, the (numeric) logging level and the raw message string and needs to	825	logging context, the (numeric) logging level and the raw message string
627	return a formatted log message. In most cases this will be a string, but	826	and needs to return a formatted log message. In most cases this will be a
628	it could just as well be an array reference that just stores the values.	827	string, but it could just as well be an array reference that just stores
		828	the values.
		829
		830	If, for some reason, you want to use C<caller> to find out more baout the
		831	logger then you should walk up the call stack until you are no longer
		832	inside the C<AnyEvent::Log> package.
629		833
630	Example: format just the raw message, with numeric log level in angle	834	Example: format just the raw message, with numeric log level in angle
631	brackets.	835	brackets.
632		836
633	$ctx->fmt_cb (sub {	837	$ctx->fmt_cb (sub {
…		…
650	"$msg->[3]";	854	"$msg->[3]";
651		855
652	0	856	0
653	});	857	});
654		858
		859	=item $ctx->log_to_warn
		860
		861	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		862	(usually this logs to STDERR).
		863
		864	=item $ctx->log_to_file ($path)
		865
		866	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		867
		868	=item $ctx->log_to_path ($path)
		869
		870	Same as C<< ->log_to_file >>, but opens the file for each message. This
		871	is much slower, but allows you to change/move/rename/delete the file at
		872	basically any time.
		873
		874	Needless(?) to say, if you do not want to be bitten by some evil person
		875	calling C<chdir>, the path should be absolute. Doesn't help with
		876	C<chroot>, but hey...
		877
		878	=item $ctx->log_to_syslog ([$facility])
		879
		880	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and
		881	all the others in the obvious way. If specified, then the C<$facility> is
		882	used as the facility (C<user>, C<auth>, C<local0> and so on). The default
		883	facility is C<user>.
		884
		885	Note that this function also sets a C<fmt_cb> - the logging part requires
		886	an array reference with [$level, $str] as input.
		887
655	=cut	888	=cut
656		889
657	sub log_cb {	890	sub log_cb {
658	my ($ctx, $cb) = @_;	891	my ($ctx, $cb) = @_;
659		892
…		…
664	my ($ctx, $cb) = @_;	897	my ($ctx, $cb) = @_;
665		898
666	$ctx->[4] = $cb;	899	$ctx->[4] = $cb;
667	}	900	}
668		901
		902	sub log_to_warn {
		903	my ($ctx, $path) = @_;
		904
		905	$ctx->log_cb (sub {
		906	warn shift;
		907	0
		908	});
		909	}
		910
		911	sub log_to_file {
		912	my ($ctx, $path) = @_;
		913
		914	open my $fh, ">>", $path
		915	or die "$path: $!";
		916
		917	$ctx->log_cb (sub {
		918	syswrite $fh, shift;
		919	0
		920	});
		921	}
		922
		923	sub log_to_path {
		924	my ($ctx, $path) = @_;
		925
		926	$ctx->log_cb (sub {
		927	open my $fh, ">>", $path
		928	or die "$path: $!";
		929
		930	syswrite $fh, shift;
		931	0
		932	});
		933	}
		934
		935	sub log_to_syslog {
		936	my ($ctx, $facility) = @_;
		937
		938	require Sys::Syslog;
		939
		940	$ctx->fmt_cb (sub {
		941	my $str = $_[3];
		942	$str =~ s/\n(?=.)/\n+ /g;
		943
		944	[$_[2], "($_[1][0]) $str"]
		945	});
		946
		947	$facility \|\|= "user";
		948
		949	$ctx->log_cb (sub {
		950	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		951
		952	Sys::Syslog::syslog ("$facility\|" . ($lvl - 1), $_)
		953	for split /\n/, $_[0][1];
		954
		955	0
		956	});
		957	}
		958
		959	=back
		960
		961	=head3 MESSAGE LOGGING
		962
		963	These methods allow you to log messages directly to a context, without
		964	going via your package context.
		965
		966	=over 4
		967
669	=item $ctx->log ($level, $msg[, @params])	968	=item $ctx->log ($level, $msg[, @params])
670		969
671	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	970	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
672		971
673	=item $logger = $ctx->logger ($level[, \$enabled])	972	=item $logger = $ctx->logger ($level[, \$enabled])
…		…
678	=cut	977	=cut
679		978
680	*log = \&AnyEvent::Log::_log;	979	*log = \&AnyEvent::Log::_log;
681	*logger = \&AnyEvent::Log::_logger;	980	*logger = \&AnyEvent::Log::_logger;
682		981
		982	=back
		983
		984	=cut
		985
		986	package AnyEvent::Log;
		987
		988	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		989
		990	Logging can also be configured by setting the environment variable
		991	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		992
		993	The value consists of one or more logging context specifications separated
		994	by C<:> or whitespace. Each logging specification in turn starts with a
		995	context name, followed by C<=>, followed by zero or more comma-separated
		996	configuration directives, here are some examples:
		997
		998	# set default logging level
		999	filter=warn
		1000
		1001	# log to file instead of to stderr
		1002	log=file=/tmp/mylog
		1003
		1004	# log to file in addition to stderr
		1005	log=+%file:%file=file=/tmp/mylog
		1006
		1007	# enable debug log messages, log warnings and above to syslog
		1008	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		1009
		1010	# log trace messages (only) from AnyEvent::Debug to file
		1011	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		1012
		1013	A context name in the log specification can be any of the following:
		1014
		1015	=over 4
		1016
		1017	=item C<collect>, C<filter>, C<log>
		1018
		1019	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		1020	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		1021
		1022	=item C<%name>
		1023
		1024	Context names starting with a C<%> are anonymous contexts created when the
		1025	name is first mentioned. The difference to package contexts is that by
		1026	default they have no attached slaves.
		1027
		1028	=item a perl package name
		1029
		1030	Any other string references the logging context associated with the given
		1031	Perl C<package>. In the unlikely case where you want to specify a package
		1032	context that matches on of the other context name forms, you can add a
		1033	C<::> to the package name to force interpretation as a package.
		1034
		1035	=back
		1036
		1037	The configuration specifications can be any number of the following:
		1038
		1039	=over 4
		1040
		1041	=item C<stderr>
		1042
		1043	Configures the context to use Perl's C<warn> function (which typically
		1044	logs to C<STDERR>). Works like C<log_to_warn>.
		1045
		1046	=item C<file=>I<path>
		1047
		1048	Configures the context to log to a file with the given path. Works like
		1049	C<log_to_file>.
		1050
		1051	=item C<path=>I<path>
		1052
		1053	Configures the context to log to a file with the given path. Works like
		1054	C<log_to_path>.
		1055
		1056	=item C<syslog> or C<syslog=>I<expr>
		1057
		1058	Configures the context to log to syslog. If I<expr> is given, then it is
		1059	evaluated in the L<Sys::Syslog> package, so you could use:
		1060
		1061	log=syslog=LOG_LOCAL0
		1062
		1063	=item C<nolog>
		1064
		1065	Configures the context to not log anything by itself, which is the
		1066	default. Same as C<< $ctx->log_cb (undef) >>.
		1067
		1068	=item C<0> or C<off>
		1069
		1070	Sets the logging level of the context ot C<0>, i.e. all messages will be
		1071	filtered out.
		1072
		1073	=item C<all>
		1074
		1075	Enables all logging levels, i.e. filtering will effectively be switched
		1076	off (the default).
		1077
		1078	=item C<only>
		1079
		1080	Disables all logging levels, and changes the interpretation of following
		1081	level specifications to enable the specified level only.
		1082
		1083	Example: only enable debug messages for a context.
		1084
		1085	context=only,debug
		1086
		1087	=item C<except>
		1088
		1089	Enables all logging levels, and changes the interpretation of following
		1090	level specifications to disable that level. Rarely used.
		1091
		1092	Example: enable all logging levels except fatal and trace (this is rather
		1093	nonsensical).
		1094
		1095	filter=exept,fatal,trace
		1096
		1097	=item C<level>
		1098
		1099	Enables all logging levels, and changes the interpretation of following
		1100	level specifications to be "that level or any higher priority
		1101	message". This is the default.
		1102
		1103	Example: log anything at or above warn level.
		1104
		1105	filter=warn
		1106
		1107	# or, more verbose
		1108	filter=only,level,warn
		1109
		1110	=item C<1>..C<9> or a logging level name (C<error>, C<debug> etc.)
		1111
		1112	A numeric loglevel or the name of a loglevel will be interpreted according
		1113	to the most recent C<only>, C<except> or C<level> directive. By default,
		1114	specifying a logging level enables that and any higher priority messages.
		1115
		1116	=item C<+>I<context>
		1117
		1118	Attaches the named context as slave to the context.
		1119
		1120	=item C<+>
		1121
		1122	A line C<+> detaches all contexts, i.e. clears the slave list from the
		1123	context. Anonymous (C<%name>) contexts have no attached slaves by default,
		1124	but package contexts have the parent context as slave by default.
		1125
		1126	Example: log messages from My::Module to a file, do not send them to the
		1127	default log collector.
		1128
		1129	My::Module=+,file=/tmp/mymodulelog
		1130
		1131	=back
		1132
		1133	Any character can be escaped by prefixing it with a C<\> (backslash), as
		1134	usual, so to log to a file containing a comma, colon, backslash and some
		1135	spaces in the filename, you would do this:
		1136
		1137	PERL_ANYEVENT_LOG='log=file=/some\ \:file\ with\,\ \\-escapes'
		1138
		1139	Since whitespace (which includes newlines) is allowed, it is fine to
		1140	specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
		1141
		1142	PERL_ANYEVENT_LOG="
		1143	filter=warn
		1144	AnyEvent::Debug=+%trace
		1145	%trace=only,trace,+log
		1146	" myprog
		1147
		1148	Also, in the unlikely case when you want to concatenate specifications,
		1149	use whitespace as separator, as C<::> will be interpreted as part of a
		1150	module name, an empty spec with two separators:
		1151
		1152	PERL_ANYEVENT_LOG="$PERL_ANYEVENT_LOG MyMod=debug"
		1153
		1154	=cut
		1155
		1156	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1157	my %anon;
		1158
		1159	my $pkg = sub {
		1160	$_[0] eq "log" ? $LOG
		1161	: $_[0] eq "filter" ? $FILTER
		1162	: $_[0] eq "collect" ? $COLLECT
		1163	: $_[0] =~ /^%(.+)$/ ? ($anon{$1} \|\|= ctx undef)
		1164	: $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
		1165	: die # never reached?
		1166	};
		1167
		1168	/\G[[:space:]]+/gc; # skip initial whitespace
		1169
		1170	while (/\G((?:[^:=[:space:]]+\|::\|\\.)+)=/gc) {
		1171	my $ctx = $pkg->($1);
		1172	my $level = "level";
		1173
		1174	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1175	for ("$1") {
		1176	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1177	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1178	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1179	} elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog ($1);
		1180	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1181	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1182	} elsif ($_ eq "+" ) { $ctx->slaves;
		1183	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1184	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1185	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1186	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1187	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1188	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1189	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1190	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1191	}
		1192	}
		1193
		1194	/\G,/gc or last;
		1195	}
		1196
		1197	/\G[:[:space:]]+/gc or last;
		1198	}
		1199
		1200	/\G[[:space:]]+/gc; # skip trailing whitespace
		1201
		1202	if (/\G(.+)/g) {
		1203	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1204	}
		1205	}
		1206
683	1;	1207	1;
		1208
		1209	=head1 EXAMPLES
		1210
		1211	This section shows some common configurations, both as code, and as
		1212	C<PERL_ANYEVENT_LOG> string.
		1213
		1214	=over 4
		1215
		1216	=item Setting the global logging level.
		1217
		1218	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1219	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1220	the root context at runtime:
		1221
		1222	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1223
		1224	PERL_ANYEVENT_LOG=log=warn
		1225
		1226	$AnyEvent::Log::FILTER->level ("warn");
		1227
		1228	=item Append all messages to a file instead of sending them to STDERR.
		1229
		1230	This is affected by the global logging level.
		1231
		1232	$AnyEvent::Log::LOG->log_to_file ($path);
		1233
		1234	PERL_ANYEVENT_LOG=log=file=/some/path
		1235
		1236	=item Write all messages with priority C<error> and higher to a file.
		1237
		1238	This writes them only when the global logging level allows it, because
		1239	it is attached to the default context which is invoked I<after> global
		1240	filtering.
		1241
		1242	$AnyEvent::Log::FILTER->attach
		1243	new AnyEvent::Log::Ctx log_to_file => $path);
		1244
		1245	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
		1246
		1247	This writes them regardless of the global logging level, because it is
		1248	attached to the toplevel context, which receives all messages I<before>
		1249	the global filtering.
		1250
		1251	$AnyEvent::Log::COLLECT->attach (
		1252	new AnyEvent::Log::Ctx log_to_file => $path);
		1253
		1254	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1255
		1256	In both cases, messages are still written to STDERR.
		1257
		1258	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
		1259
		1260	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
		1261	context - this simply circumvents the global filtering for trace messages.
		1262
		1263	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
		1264	$debug->attach ($AnyEvent::Log::LOG);
		1265
		1266	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1267
		1268	This of course works for any package, not just L<AnyEvent::Debug>, but
		1269	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1270	default.
684		1271
685	=back	1272	=back
686		1273
687	=head1 AUTHOR	1274	=head1 AUTHOR
688		1275
689	Marc Lehmann <schmorp@schmorp.de>	1276	Marc Lehmann <schmorp@schmorp.de>
690	http://home.schmorp.de/	1277	http://home.schmorp.de/
691		1278
692	=cut	1279	=cut
		1280

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.10 by root, Fri Aug 19 21:17:08 2011 UTC vs. Revision 1.42 by root, Thu Sep 1 22:38:11 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.10 by root, Fri Aug 19 21:17:08 2011 UTC vs.
Revision 1.42 by root, Thu Sep 1 22:38:11 2011 UTC