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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.9 by root, Fri Aug 19 19:59:53 2011 UTC vs.
Revision 1.29 by root, Thu Aug 25 00:14:32 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	#TODO: config	25	Configuration (also look at the EXAMPLES section):
24	#TODO: ctx () becomes caller[0]...	26
		27	# set logging for the current package to errors and higher only
		28	AnyEvent::Log::ctx->level ("error");
		29
		30	# set logging level to suppress anything below "notice"
		31	$AnyEvent::Log::FILTER->level ("notice");
		32
		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	);
25		39
26	=head1 DESCRIPTION	40	=head1 DESCRIPTION
27		41
28	This module implements a relatively simple "logging framework". It doesn't	42	This module implements a relatively simple "logging framework". It doesn't
29	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
30	AnyEvent - AnyEvent simply creates logging messages internally, and this	44	AnyEvent - AnyEvent simply creates logging messages internally, and this
31	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
32	using it from other modules as well.	46	using it from other modules as well.
33		47
34	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
35	logged, ever, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number	49	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
36	before starting your program, or change the logging level at runtime wiht	50	before starting your program, or change the logging level at runtime with
37	something like:	51	something like:
38		52
39	use AnyEvent;	53	use AnyEvent::Log;
40	(AnyEvent::Log::ctx "")->level ("info");	54	AnyEvent::Log::FILTER->level ("info");
		55
		56	The design goal behind this module was to keep it simple (and small),
		57	but make it powerful enough to be potentially useful for any module, and
		58	extensive enough for the most common tasks, such as logging to multiple
		59	targets, or being able to log into a database.
		60
		61	The amount of documentation might indicate otherwise, but the module is
		62	still just below 300 lines of code.
		63
		64	=head1 LOGGING LEVELS
		65
		66	Logging levels in this module range from C<1> (highest priority) to C<9>
		67	(lowest priority). Note that the lowest numerical value is the highest
		68	priority, so when this document says "higher priority" it means "lower
		69	numerical value".
		70
		71	Instead of specifying levels by name you can also specify them by aliases:
		72
		73	LVL NAME SYSLOG PERL NOTE
		74	1 fatal emerg exit aborts program!
		75	2 alert
		76	3 critical crit
		77	4 error err die
		78	5 warn warning
		79	6 note notice
		80	7 info
		81	8 debug
		82	9 trace
		83
		84	As you can see, some logging levels have multiple aliases - the first one
		85	is the "official" name, the second one the "syslog" name (if it differs)
		86	and the third one the "perl" name, suggesting that you log C<die> messages
		87	at C<error> priority.
		88
		89	You can normally only log a single message at highest priority level
		90	(C<1>, C<fatal>), because logging a fatal message will also quit the
		91	program - so use it sparingly :)
		92
		93	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		94	or C<all> - these are only valid in the methods they are documented for.
41		95
42	=head1 LOGGING FUNCTIONS	96	=head1 LOGGING FUNCTIONS
43		97
44	These functions allow you to log messages. They always use the caller's	98	These functions allow you to log messages. They always use the caller's
45	package as a "logging module/source". Also, the main logging function is	99	package as a "logging context". Also, the main logging function C<log> is
46	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	100	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
47	loaded.	101	loaded.
48		102
49	=over 4	103	=over 4
50		104
…		…
55	use Carp ();	109	use Carp ();
56	use POSIX ();	110	use POSIX ();
57		111
58	use AnyEvent (); BEGIN { AnyEvent::common_sense }	112	use AnyEvent (); BEGIN { AnyEvent::common_sense }
59	use AnyEvent::Util ();	113	use AnyEvent::Util ();
		114
		115	our $VERSION = $AnyEvent::VERSION;
		116
		117	our ($COLLECT, $FILTER, $LOG);
60		118
61	our ($now_int, $now_str1, $now_str2);	119	our ($now_int, $now_str1, $now_str2);
62		120
63	# Format Time, not public - yet?	121	# Format Time, not public - yet?
64	sub ft($) {	122	sub ft($) {
…		…
69	if $now_int != $i;	127	if $now_int != $i;
70		128
71	"$now_str1$f$now_str2"	129	"$now_str1$f$now_str2"
72	}	130	}
73		131
74	our %CTX; # all logging contexts	132	our %CTX; # all package contexts
75
76	my $default_log_cb = sub { 0 };
77		133
78	# creates a default package context object for the given package	134	# creates a default package context object for the given package
79	sub _pkg_ctx($) {	135	sub _pkg_ctx($) {
80	my $ctx = bless [$_[0], 0, {}, $default_log_cb], "AnyEvent::Log::Ctx";	136	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
81		137
82	# link "parent" package	138	# link "parent" package
83	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "";	139	my $parent = $_[0] =~ /^(.+)::/
		140	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		141	: $COLLECT;
84		142
85	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
86	$ctx->[2]{$pkg+0} = $pkg;	143	$ctx->[2]{$parent+0} = $parent;
87		144
88	$ctx	145	$ctx
89	}	146	}
90		147
91	=item AnyEvent::Log::log $level, $msg[, @args]	148	=item AnyEvent::Log::log $level, $msg[, @args]
92		149
93	Requests logging of the given C<$msg> with the given log level (1..9).	150	Requests logging of the given C<$msg> with the given log level, and
94	You can also use the following strings as log level: C<fatal> (1),	151	returns true if the message was logged I<somewhere>.
95	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
96	C<info> (7), C<debug> (8), C<trace> (9).
97		152
98	For C<fatal> log levels, the program will abort.	153	For C<fatal> log levels, the program will abort.
99		154
100	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	155	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
101	C<$msg> is interpreted as an sprintf format string.	156	C<$msg> is interpreted as an sprintf format string.
…		…
107	supposed to return the message. It will be called only then the message	162	supposed to return the message. It will be called only then the message
108	actually gets logged, which is useful if it is costly to create the	163	actually gets logged, which is useful if it is costly to create the
109	message in the first place.	164	message in the first place.
110		165
111	Whether the given message will be logged depends on the maximum log level	166	Whether the given message will be logged depends on the maximum log level
112	and the caller's package.	167	and the caller's package. The return value can be used to ensure that
		168	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		169	runtime error it tries to log it at C<die> level, but if that message is
		170	lost it simply uses warn.
113		171
114	Note that you can (and should) call this function as C<AnyEvent::log> or	172	Note that you can (and should) call this function as C<AnyEvent::log> or
115	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	173	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
116	need any additional functionality), as those functions will load the	174	need any additional functionality), as those functions will load the
117	logging module on demand only. They are also much shorter to write.	175	logging module on demand only. They are also much shorter to write.
118		176
119	Also, if you otpionally generate a lot of debug messages (such as when	177	Also, if you optionally generate a lot of debug messages (such as when
120	tracing some code), you should look into using a logger callback and a	178	tracing some code), you should look into using a logger callback and a
121	boolean enabler (see C<logger>, below).	179	boolean enabler (see C<logger>, below).
122		180
123	Example: log something at error level.	181	Example: log something at error level.
124		182
…		…
134		192
135	=cut	193	=cut
136		194
137	# also allow syslog equivalent names	195	# also allow syslog equivalent names
138	our %STR2LEVEL = (	196	our %STR2LEVEL = (
139	fatal => 1, emerg => 1,	197	fatal => 1, emerg => 1, exit => 1,
140	alert => 2,	198	alert => 2,
141	critical => 3, crit => 3,	199	critical => 3, crit => 3,
142	error => 4, err => 4,	200	error => 4, err => 4, die => 4,
143	warn => 5, warning => 5,	201	warn => 5, warning => 5,
144	note => 6, notice => 6,	202	note => 6, notice => 6,
145	info => 7,	203	info => 7,
146	debug => 8,	204	debug => 8,
147	trace => 9,	205	trace => 9,
148	);	206	);
149		207
150	sub now () { time }	208	sub now () { time }
		209
151	AnyEvent::post_detect {	210	AnyEvent::post_detect {
152	*now = \&AE::now;	211	*now = \&AE::now;
153	};	212	};
154		213
155	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	214	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
156		215
157	# time, ctx, level, msg	216	# time, ctx, level, msg
158	sub _format($$$$) {	217	sub _format($$$$) {
159	my $pfx = ft $_[0];	218	my $ts = ft $_[0];
		219	my $ct = " ";
160		220
161	join "",	221	my @res;
162	map "$pfx $_\n",	222
163	split /\n/,
164	sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]	223	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {
		224	push @res, "$ts$ct$_\n";
		225	$ct = " + ";
		226	}
		227
		228	join "", @res
165	}	229	}
166		230
167	sub _log {	231	sub _log {
168	my ($ctx, $level, $format, @args) = @_;	232	my ($ctx, $level, $format, @args) = @_;
169		233
		234	$level = $level > 0 && $level <= 9
		235	? $level+0
170	$level = $level > 0 && $level <= 9 ? $level+0 : $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	236	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
171		237
172	my $mask = 1 << $level;	238	my $mask = 1 << $level;
173	my $now = AE::now;
174		239
175	my (@ctx, $did_format, $fmt);	240	my ($success, %seen, @ctx, $now, $fmt);
176		241
177	do {	242	do
178	if ($ctx->[1] & $mask) {	243	{
		244	# skip if masked
		245	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
		246	if ($ctx->[3]) {
179	# logging target found	247	# logging target found
180		248
181	# get raw message	249	# now get raw message, unless we have it already
182	unless ($did_format) {	250	unless ($now) {
183	$format = $format->() if ref $format;	251	$format = $format->() if ref $format;
184	$format = sprintf $format, @args if @args;	252	$format = sprintf $format, @args if @args;
185	$format =~ s/\n$//;	253	$format =~ s/\n$//;
186	$did_format = 1;	254	$now = AE::now;
		255	};
		256
		257	# format msg
		258	my $str = $ctx->[4]
		259	? $ctx->[4]($now, $_[0], $level, $format)
		260	: ($fmt \|\|= _format $now, $_[0], $level, $format);
		261
		262	$success = 1;
		263
		264	$ctx->[3]($str)
		265	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		266	} else {
		267	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
		268	}
187	};	269	}
188
189	# format msg
190	my $str = $ctx->[4]
191	? $ctx->[4]($now, $_[0], $level, $format)
192	: $fmt \|\|= _format $now, $_[0], $level, $format;
193
194	$ctx->[3]($str)
195	and next;
196	}	270	}
197
198	# not consume - push parent contexts
199	push @ctx, values %{ $ctx->[2] };
200	} while $ctx = pop @ctx;	271	while $ctx = pop @ctx;
201		272
202	exit 1 if $level <= 1;	273	exit 1 if $level <= 1;
		274
		275	$success
203	}	276	}
204		277
205	sub log($$;@) {	278	sub log($$;@) {
206	_log	279	_log
207	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	280	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
211	AnyEvent::log = AE::log = \&log;	284	AnyEvent::log = AE::log = \&log;
212		285
213	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	286	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
214		287
215	Creates a code reference that, when called, acts as if the	288	Creates a code reference that, when called, acts as if the
216	C<AnyEvent::Log::log> function was called at this point with the givne	289	C<AnyEvent::Log::log> function was called at this point with the given
217	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	290	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
218	the C<AnyEvent::Log::log> function:	291	the C<AnyEvent::Log::log> function:
219		292
220	my $debug_log = AnyEvent::Log::logger "debug";	293	my $debug_log = AnyEvent::Log::logger "debug";
221		294
…		…
246	# and later in your program	319	# and later in your program
247	$debug_log->("yo, stuff here") if $debug;	320	$debug_log->("yo, stuff here") if $debug;
248		321
249	$debug and $debug_log->("123");	322	$debug and $debug_log->("123");
250		323
251	Note: currently the enabled var is always true - that will be fixed in a
252	future version :)
253
254	=cut	324	=cut
255		325
256	our %LOGGER;	326	our %LOGGER;
257		327
258	# re-assess logging status for all loggers	328	# re-assess logging status for all loggers
259	sub _reassess {	329	sub _reassess {
		330	local $SIG{__DIE__};
		331	my $die = sub { die };
		332
260	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	333	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
261	my ($ctx, $level, $renabled) = @$_;	334	my ($ctx, $level, $renabled) = @$_;
262		335
263	# to detetc whether a message would be logged, we # actually	336	# to detect whether a message would be logged, we actually
264	# try to log one and die. this isn't # fast, but we can be	337	# try to log one and die. this isn't fast, but we can be
265	# sure that the logging decision is correct :)	338	# sure that the logging decision is correct :)
266		339
267	$$renabled = !eval {	340	$$renabled = !eval {
268	local $SIG{__DIE__};
269
270	_log $ctx, $level, sub { die };	341	_log $ctx, $level, $die;
271		342
272	1	343	1
273	};	344	};
274
275	$$renabled = 1; # TODO
276	}	345	}
277	}	346	}
278		347
279	sub _logger($;$) {	348	sub _logger {
280	my ($ctx, $level, $renabled) = @_;	349	my ($ctx, $level, $renabled) = @_;
281
282	$renabled \|\|= \my $enabled;
283		350
284	$$renabled = 1;	351	$$renabled = 1;
285		352
286	my $logger = [$ctx, $level, $renabled];	353	my $logger = [$ctx, $level, $renabled];
287		354
…		…
306	_logger	373	_logger
307	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	374	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
308	@_	375	@_
309	}	376	}
310		377
311	#TODO
312
313	=back	378	=back
314		379
315	=head1 LOGGING CONTEXTS	380	=head1 LOGGING CONTEXTS
316		381
317	This module associates every log message with a so-called I<logging	382	This module associates every log message with a so-called I<logging
318	context>, based on the package of the caller. Every perl package has its	383	context>, based on the package of the caller. Every perl package has its
319	own logging context.	384	own logging context.
320		385
321	A logging context has two major responsibilities: logging the message and	386	A logging context has three major responsibilities: filtering, logging and
322	propagating the message to other contexts.	387	propagating the message.
323		388
324	For logging, the context stores a set of logging levels that it	389	For the first purpose, filtering, each context has a set of logging
325	potentially wishes to log, a formatting callback that takes the timestamp,	390	levels, called the log level mask. Messages not in the set will be ignored
		391	by this context (masked).
		392
		393	For logging, the context stores a formatting callback (which takes the
326	context, level and string emssage and formats it in the way it should be	394	timestamp, context, level and string message and formats it in the way
327	logged, and a logging callback, which is responsible for actually logging	395	it should be logged) and a logging callback (which is responsible for
328	the formatted message and telling C<AnyEvent::Log> whether it has consumed	396	actually logging the formatted message and telling C<AnyEvent::Log>
329	the message, or whether it should be propagated.	397	whether it has consumed the message, or whether it should be propagated).
330		398
331	For propagation, a context can have any number of attached I<parent	399	For propagation, a context can have any number of attached I<slave
332	contexts>. They will be ignored if the logging callback consumes the	400	contexts>. Any message that is neither masked by the logging mask nor
333	message, but in all other cases, the log message will be passed to all	401	masked by the logging callback returning true will be passed to all slave
334	parent contexts attached to a context.	402	contexts.
		403
		404	Each call to a logging function will log the message at most once per
		405	context, so it does not matter (much) if there are cycles or if the
		406	message can arrive at the same context via multiple paths.
335		407
336	=head2 DEFAULTS	408	=head2 DEFAULTS
337		409
338	By default, all logging contexts have an empty set of log levels, a	410	By default, all logging contexts have an full set of log levels ("all"), a
339	disabled logging callback and the default formatting callback.	411	disabled logging callback and the default formatting callback.
340		412
341	Package contexts have the package name as logging title by default.	413	Package contexts have the package name as logging title by default.
342		414
343	They have exactly one parent - the context of the "parent" package. The	415	They have exactly one slave - the context of the "parent" package. The
344	parent package is simply defined to be the package name without the last	416	parent package is simply defined to be the package name without the last
345	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	417	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
346	and C<AnyEvent> becomes the empty string.	418	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
		419	exception of the rule - just like the "parent" of any single-component
		420	package name in Perl is C<main>, the default slave of any top-level
		421	package context is C<$AnyEvent::Log::COLLECT>.
347		422
348	Since perl packages form only an approximate hierarchy, this parent	423	Since perl packages form only an approximate hierarchy, this slave
349	context can of course be removed.	424	context can of course be removed.
350		425
351	All other (anonymous) contexts have no parents and an empty title by	426	All other (anonymous) contexts have no slaves and an empty title by
352	default.	427	default.
353		428
354	When the module is first loaded, it configures the root context (the one	429	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
355	with the empty string) to simply dump all log messages to C<STDERR>,	430	context that simply logs everything via C<warn>, without propagating
356	and sets it's log level set to all levels up to the one specified by	431	anything anywhere by default. The purpose of this context is to provide
357	C<$ENV{PERL_ANYEVENT_VERBOSE}>.	432	a convenient place to override the global logging target or to attach
		433	additional log targets. It's not meant for filtering.
358		434
		435	It then creates the C<$AnyEvent::Log::FILTER> context whose
		436	purpose is to suppress all messages with priority higher
		437	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
		438	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
		439	is to simply provide filtering according to some global log level.
		440
		441	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
		442	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
		443	leaves it at default config. Its purpose is simply to collect all log
		444	messages system-wide.
		445
		446	The hierarchy is then:
		447
		448	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		449
359	The effetc of all this is that log messages, by default, wander up to the	450	The effect of all this is that log messages, by default, wander up to the
360	root context and will be logged to STDERR if their log level is less than	451	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
361	or equal to C<$ENV{PERL_ANYEVENT_VERBOSE}>.	452	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
		453	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
		454	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
362		455
		456	This makes it easy to set a global logging level (by modifying $FILTER),
		457	but still allow other contexts to send, for example, their debug and trace
		458	messages to the $LOG target despite the global logging level, or to attach
		459	additional log targets that log messages, regardless of the global logging
		460	level.
		461
		462	It also makes it easy to modify the default warn-logger ($LOG) to
		463	something that logs to a file, or to attach additional logging targets
		464	(such as loggign to a file) by attaching it to $FILTER.
		465
363	=head2 CREATING/FINDING A CONTEXT	466	=head2 CREATING/FINDING/DESTROYING CONTEXTS
364		467
365	=over 4	468	=over 4
366		469
367	=item $ctx = AnyEvent::Log::ctx [$pkg]	470	=item $ctx = AnyEvent::Log::ctx [$pkg]
368		471
…		…
383		486
384	ref $pkg	487	ref $pkg
385	? $pkg	488	? $pkg
386	: defined $pkg	489	: defined $pkg
387	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg	490	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg
388	: bless [undef, 0, undef, $default_log_cb], "AnyEvent::Log::Ctx"	491	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
389	}	492	}
390		493
391	# create default root context	494	=item AnyEvent::Log::reset
392	{	495
393	my $root = ctx undef;	496	Resets all package contexts and recreates the default hierarchy if
394	$root->[0] = "";	497	necessary, i.e. resets the logging subsystem to defaults, as much as
395	$root->title ("default");	498	possible. This process keeps references to contexts held by other parts of
396	$root->level ($AnyEvent::VERBOSE); undef $AnyEvent::VERBOSE;	499	the program intact.
397	$root->log_cb (sub {	500
398	print STDERR shift;	501	This can be used to implement config-file (re-)loading: before loading a
399	0	502	configuration, reset all contexts.
		503
		504	=cut
		505
		506	sub reset {
		507	# hard to kill complex data structures
		508	# we "recreate" all package loggers and reset the hierarchy
		509	while (my ($k, $v) = each %CTX) {
		510	@$v = ($k, (1 << 10) - 1 - 1, { });
		511
		512	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
400	});	513	}
401	$CTX{""} = $root;	514
		515	@$_ = ($_->[0], (1 << 10) - 1 - 1)
		516	for $LOG, $FILTER, $COLLECT;
		517
		518	$LOG->slaves;
		519	$LOG->title ('$AnyEvent::Log::LOG');
		520	$LOG->log_to_warn;
		521
		522	$FILTER->slaves ($LOG);
		523	$FILTER->title ('$AnyEvent::Log::FILTER');
		524	$FILTER->level ($AnyEvent::VERBOSE);
		525
		526	$COLLECT->slaves ($FILTER);
		527	$COLLECT->title ('$AnyEvent::Log::COLLECT');
		528
		529	_reassess;
402	}	530	}
		531
		532	# create the default logger contexts
		533	$LOG = ctx undef;
		534	$FILTER = ctx undef;
		535	$COLLECT = ctx undef;
		536
		537	AnyEvent::Log::reset;
		538
		539	# hello, CPAN, please catch me
		540	package AnyEvent::Log::LOG;
		541	package AE::Log::LOG;
		542	package AnyEvent::Log::FILTER;
		543	package AE::Log::FILTER;
		544	package AnyEvent::Log::COLLECT;
		545	package AE::Log::COLLECT;
		546
		547	package AnyEvent::Log::Ctx;
		548
		549	# 0 1 2 3 4
		550	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
		551
		552	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
		553
		554	This is a convenience constructor that makes it simpler to construct
		555	anonymous logging contexts.
		556
		557	Each key-value pair results in an invocation of the method of the same
		558	name as the key with the value as parameter, unless the value is an
		559	arrayref, in which case it calls the method with the contents of the
		560	array. The methods are called in the same order as specified.
		561
		562	Example: create a new logging context and set both the default logging
		563	level, some slave contexts and a logging callback.
		564
		565	$ctx = new AnyEvent::Log::Ctx
		566	title => "dubious messages",
		567	level => "error",
		568	log_cb => sub { print STDOUT shift; 0 },
		569	slaves => [$ctx1, $ctx, $ctx2],
		570	;
403		571
404	=back	572	=back
405		573
406	=cut	574	=cut
407		575
408	package AnyEvent::Log::Ctx;	576	sub new {
		577	my $class = shift;
409		578
410	# 0 1 2 3 4	579	my $ctx = AnyEvent::Log::ctx undef;
411	# [$title, $level, %$parents, &$logcb, &$fmtcb]	580
		581	while (@_) {
		582	my ($k, $v) = splice @_, 0, 2;
		583	$ctx->$k (ref $v eq "ARRAY" ? @$v : $v);
		584	}
		585
		586	bless $ctx, $class # do we really support subclassing, hmm?
		587	}
		588
412		589
413	=head2 CONFIGURING A LOG CONTEXT	590	=head2 CONFIGURING A LOG CONTEXT
414		591
415	The following methods can be used to configure the logging context.	592	The following methods can be used to configure the logging context.
416		593
…		…
432		609
433	=back	610	=back
434		611
435	=head3 LOGGING LEVELS	612	=head3 LOGGING LEVELS
436		613
437	The following methods deal with the logging level set associated wiht the log context.	614	The following methods deal with the logging level set associated with the
		615	log context.
438		616
439	The most common method to use is probably C<< $ctx->level ($level) >>,	617	The most common method to use is probably C<< $ctx->level ($level) >>,
440	which configures the specified and any higher priority levels.	618	which configures the specified and any higher priority levels.
441		619
		620	All functions which accept a list of levels also accept the special string
		621	C<all> which expands to all logging levels.
		622
442	=over 4	623	=over 4
443		624
444	=item $ctx->levels ($level[, $level...)	625	=item $ctx->levels ($level[, $level...)
445		626
446	Enables logging fot the given levels and disables it for all others.	627	Enables logging for the given levels and disables it for all others.
447		628
448	=item $ctx->level ($level)	629	=item $ctx->level ($level)
449		630
450	Enables logging for the given level and all lower level (higher priority)	631	Enables logging for the given level and all lower level (higher priority)
451	ones. Specifying a level of C<0> or C<off> disables all logging for this	632	ones. In addition to normal logging levels, specifying a level of C<0> or
452	level.	633	C<off> disables all logging for this level.
453		634
454	Example: log warnings, errors and higher priority messages.	635	Example: log warnings, errors and higher priority messages.
455		636
456	$ctx->level ("warn");	637	$ctx->level ("warn");
457	$ctx->level (5); # same thing, just numeric	638	$ctx->level (5); # same thing, just numeric
…		…
465	Disables logging for the given levels, leaving all others unchanged.	646	Disables logging for the given levels, leaving all others unchanged.
466		647
467	=cut	648	=cut
468		649
469	sub _lvl_lst {	650	sub _lvl_lst {
		651	map {
		652	$_ > 0 && $_ <= 9 ? $_+0
		653	: $_ eq "all" ? (1 .. 9)
470	map { $_ > 0 && $_ <= 9 ? $_+0 : $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught" }	654	: $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught"
471	@_	655	} @_
472	}	656	}
473		657
474	our $NOP_CB = sub { 0 };	658	our $NOP_CB = sub { 0 };
475		659
476	sub levels {	660	sub levels {
…		…
481	AnyEvent::Log::_reassess;	665	AnyEvent::Log::_reassess;
482	}	666	}
483		667
484	sub level {	668	sub level {
485	my $ctx = shift;	669	my $ctx = shift;
486	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[0];	670	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[-1];
		671
487	$ctx->[1] = ((1 << $lvl) - 1) << 1;	672	$ctx->[1] = ((1 << $lvl) - 1) << 1;
488	AnyEvent::Log::_reassess;	673	AnyEvent::Log::_reassess;
489	}	674	}
490		675
491	sub enable {	676	sub enable {
…		…
502	AnyEvent::Log::_reassess;	687	AnyEvent::Log::_reassess;
503	}	688	}
504		689
505	=back	690	=back
506		691
507	=head3 PARENT CONTEXTS	692	=head3 SLAVE CONTEXTS
508		693
509	The following methods attach and detach another logging context to a	694	The following methods attach and detach another logging context to a
510	logging context.	695	logging context.
511		696
512	Log messages are propagated to all parent contexts, unless the logging	697	Log messages are propagated to all slave contexts, unless the logging
513	callback consumes the message.	698	callback consumes the message.
514		699
515	=over 4	700	=over 4
516		701
517	=item $ctx->attach ($ctx2[, $ctx3...])	702	=item $ctx->attach ($ctx2[, $ctx3...])
518		703
519	Attaches the given contexts as parents to this context. It is not an error	704	Attaches the given contexts as slaves to this context. It is not an error
520	to add a context twice (the second add will be ignored).	705	to add a context twice (the second add will be ignored).
521		706
522	A context can be specified either as package name or as a context object.	707	A context can be specified either as package name or as a context object.
523		708
524	=item $ctx->detach ($ctx2[, $ctx3...])	709	=item $ctx->detach ($ctx2[, $ctx3...])
525		710
526	Removes the given parents from this context - it's not an error to attempt	711	Removes the given slaves from this context - it's not an error to attempt
527	to remove a context that hasn't been added.	712	to remove a context that hasn't been added.
528		713
529	A context can be specified either as package name or as a context object.	714	A context can be specified either as package name or as a context object.
		715
		716	=item $ctx->slaves ($ctx2[, $ctx3...])
		717
		718	Replaces all slaves attached to this context by the ones given.
530		719
531	=cut	720	=cut
532		721
533	sub attach {	722	sub attach {
534	my $ctx = shift;	723	my $ctx = shift;
…		…
542		731
543	delete $ctx->[2]{$_+0}	732	delete $ctx->[2]{$_+0}
544	for map { AnyEvent::Log::ctx $_ } @_;	733	for map { AnyEvent::Log::ctx $_ } @_;
545	}	734	}
546		735
		736	sub slaves {
		737	undef $_[0][2];
		738	&attach;
		739	}
		740
547	=back	741	=back
548		742
549	=head3 MESSAGE LOGGING	743	=head3 LOG TARGETS
550		744
551	The following methods configure how the logging context actually does	745	The following methods configure how the logging context actually does
552	the logging (which consists of foratting the message and printing it or	746	the logging (which consists of formatting the message and printing it or
553	whatever it wants to do with it) and also allows you to log messages	747	whatever it wants to do with it).
554	directly to a context, without going via your package context.
555		748
556	=over 4	749	=over 4
557		750
558	=item $ctx->log_cb ($cb->($str))	751	=item $ctx->log_cb ($cb->($str)
559		752
560	Replaces the logging callback on the context (C<undef> disables the	753	Replaces the logging callback on the context (C<undef> disables the
561	logging callback).	754	logging callback).
562		755
563	The logging callback is responsible for handling formatted log messages	756	The logging callback is responsible for handling formatted log messages
564	(see C<fmt_cb> below) - normally simple text strings that end with a	757	(see C<fmt_cb> below) - normally simple text strings that end with a
565	newline (and are possibly multiline themselves).	758	newline (and are possibly multiline themselves).
566		759
567	It also has to return true iff it has consumed the log message, and false	760	It also has to return true iff it has consumed the log message, and false
568	if it hasn't. Consuming a message means that it will not be sent to any	761	if it hasn't. Consuming a message means that it will not be sent to any
569	parent context. When in doubt, return C<0> from your logging callback.	762	slave context. When in doubt, return C<0> from your logging callback.
570		763
571	Example: a very simple logging callback, simply dump the message to STDOUT	764	Example: a very simple logging callback, simply dump the message to STDOUT
572	and do not consume it.	765	and do not consume it.
573		766
574	$ctx->log_cb (sub { print STDERR shift; 0 });	767	$ctx->log_cb (sub { print STDERR shift; 0 });
575		768
		769	You can filter messages by having a log callback that simply returns C<1>
		770	and does not do anything with the message, but this counts as "message
		771	being logged" and might not be very efficient.
		772
		773	Example: propagate all messages except for log levels "debug" and
		774	"trace". The messages will still be generated, though, which can slow down
		775	your program.
		776
		777	$ctx->levels ("debug", "trace");
		778	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
		779
576	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	780	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
577		781
578	Replaces the fornatting callback on the cobntext (C<undef> restores the	782	Replaces the formatting callback on the context (C<undef> restores the
579	default formatter).	783	default formatter).
580		784
581	The callback is passed the (possibly fractional) timestamp, the original	785	The callback is passed the (possibly fractional) timestamp, the original
582	logging context, the (numeric) logging level and the raw message string and needs to	786	logging context, the (numeric) logging level and the raw message string
583	return a formatted log message. In most cases this will be a string, but	787	and needs to return a formatted log message. In most cases this will be a
584	it could just as well be an array reference that just stores the values.	788	string, but it could just as well be an array reference that just stores
		789	the values.
		790
		791	If, for some reason, you want to use C<caller> to find out more baout the
		792	logger then you should walk up the call stack until you are no longer
		793	inside the C<AnyEvent::Log> package.
585		794
586	Example: format just the raw message, with numeric log level in angle	795	Example: format just the raw message, with numeric log level in angle
587	brackets.	796	brackets.
588		797
589	$ctx->fmt_cb (sub {	798	$ctx->fmt_cb (sub {
…		…
606	"$msg->[3]";	815	"$msg->[3]";
607		816
608	0	817	0
609	});	818	});
610		819
		820	=item $ctx->log_to_warn
		821
		822	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		823	(usually this logs to STDERR).
		824
		825	=item $ctx->log_to_file ($path)
		826
		827	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		828
		829	=item $ctx->log_to_path ($path)
		830
		831	Same as C<< ->log_to_file >>, but opens the file for each message. This
		832	is much slower, but allows you to change/move/rename/delete the file at
		833	basically any time.
		834
		835	Needless(?) to say, if you do not want to be bitten by some evil person
		836	calling C<chdir>, the path should be absolute. Doesn't help with
		837	C<chroot>, but hey...
		838
		839	=item $ctx->log_to_syslog ([$log_flags])
		840
		841	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		842	the others in the obvious way. If specified, then the C<$log_flags> are
		843	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		844	flags valid for Sys::Syslog::syslog, except for the priority levels.
		845
		846	Note that this function also sets a C<fmt_cb> - the logging part requires
		847	an array reference with [$level, $str] as input.
		848
611	=cut	849	=cut
612		850
613	sub log_cb {	851	sub log_cb {
614	my ($ctx, $cb) = @_;	852	my ($ctx, $cb) = @_;
615		853
616	$ctx->[3] = $cb \|\| $default_log_cb;	854	$ctx->[3] = $cb;
617	}	855	}
618		856
619	sub fmt_cb {	857	sub fmt_cb {
620	my ($ctx, $cb) = @_;	858	my ($ctx, $cb) = @_;
621		859
622	$ctx->[4] = $cb;	860	$ctx->[4] = $cb;
623	}	861	}
624		862
		863	sub log_to_warn {
		864	my ($ctx, $path) = @_;
		865
		866	$ctx->log_cb (sub {
		867	warn shift;
		868	0
		869	});
		870	}
		871
		872	sub log_to_file {
		873	my ($ctx, $path) = @_;
		874
		875	open my $fh, ">>", $path
		876	or die "$path: $!";
		877
		878	$ctx->log_cb (sub {
		879	syswrite $fh, shift;
		880	0
		881	});
		882	}
		883
		884	sub log_to_path {
		885	my ($ctx, $path) = @_;
		886
		887	$ctx->log_cb (sub {
		888	open my $fh, ">>", $path
		889	or die "$path: $!";
		890
		891	syswrite $fh, shift;
		892	0
		893	});
		894	}
		895
		896	sub log_to_syslog {
		897	my ($ctx, $flags) = @_;
		898
		899	require Sys::Syslog;
		900
		901	$ctx->fmt_cb (sub {
		902	my $str = $_[3];
		903	$str =~ s/\n(?=.)/\n+ /g;
		904
		905	[$_[2], "($_[1][0]) $str"]
		906	});
		907
		908	$ctx->log_cb (sub {
		909	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		910
		911	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		912	for split /\n/, $_[0][1];
		913
		914	0
		915	});
		916	}
		917
		918	=back
		919
		920	=head3 MESSAGE LOGGING
		921
		922	These methods allow you to log messages directly to a context, without
		923	going via your package context.
		924
		925	=over 4
		926
625	=item $ctx->log ($level, $msg[, @params])	927	=item $ctx->log ($level, $msg[, @params])
626		928
627	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	929	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
628		930
629	=item $logger = $ctx->logger ($level[, \$enabled])	931	=item $logger = $ctx->logger ($level[, \$enabled])
…		…
634	=cut	936	=cut
635		937
636	*log = \&AnyEvent::Log::_log;	938	*log = \&AnyEvent::Log::_log;
637	*logger = \&AnyEvent::Log::_logger;	939	*logger = \&AnyEvent::Log::_logger;
638		940
		941	=back
		942
		943	=cut
		944
		945	package AnyEvent::Log;
		946
		947	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		948
		949	Logging can also be configured by setting the environment variable
		950	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		951
		952	The value consists of one or more logging context specifications separated
		953	by C<:> or whitespace. Each logging specification in turn starts with a
		954	context name, followed by C<=>, followed by zero or more comma-separated
		955	configuration directives, here are some examples:
		956
		957	# set default logging level
		958	filter=warn
		959
		960	# log to file instead of to stderr
		961	log=file=/tmp/mylog
		962
		963	# log to file in addition to stderr
		964	log=+%file:%file=file=/tmp/mylog
		965
		966	# enable debug log messages, log warnings and above to syslog
		967	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		968
		969	# log trace messages (only) from AnyEvent::Debug to file
		970	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		971
		972	Since whitespace (which includes newlines) is allowed, it is fine to
		973	specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
		974
		975	PERL_ANYEVENT_LOG="
		976	filter=warn
		977	AnyEvent::Debug=+%trace
		978	%trace=only,trace,+log
		979	" myprog
		980
		981	A context name in the log specification can be any of the following:
		982
		983	=over 4
		984
		985	=item C<collect>, C<filter>, C<log>
		986
		987	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		988	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		989
		990	=item C<%name>
		991
		992	Context names starting with a C<%> are anonymous contexts created when the
		993	name is first mentioned. The difference to package contexts is that by
		994	default they have no attached slaves.
		995
		996	=item a perl package name
		997
		998	Any other string references the logging context associated with the given
		999	Perl C<package>. In the unlikely case where you want to specify a package
		1000	context that matches on of the other context name forms, you can add a
		1001	C<::> to the package name to force interpretation as a package.
		1002
		1003	=back
		1004
		1005	The configuration specifications can be any number of the following:
		1006
		1007	=over 4
		1008
		1009	=item C<stderr>
		1010
		1011	Configures the context to use Perl's C<warn> function (which typically
		1012	logs to C<STDERR>). Works like C<log_to_warn>.
		1013
		1014	=item C<file=>I<path>
		1015
		1016	Configures the context to log to a file with the given path. Works like
		1017	C<log_to_file>.
		1018
		1019	=item C<path=>I<path>
		1020
		1021	Configures the context to log to a file with the given path. Works like
		1022	C<log_to_path>.
		1023
		1024	=item C<syslog> or C<syslog=>I<expr>
		1025
		1026	Configured the context to log to syslog. If I<expr> is given, then it is
		1027	evaluated in the L<Sys::Syslog> package, so you could use:
		1028
		1029	log=syslog=LOG_LOCAL0
		1030
		1031	=item C<nolog>
		1032
		1033	Configures the context to not log anything by itself, which is the
		1034	default. Same as C<< $ctx->log_cb (undef) >>.
		1035
		1036	=item C<0> or C<off>
		1037
		1038	Sets the logging level of the context ot C<0>, i.e. all messages will be
		1039	filtered out.
		1040
		1041	=item C<all>
		1042
		1043	Enables all logging levels, i.e. filtering will effectively be switched
		1044	off (the default).
		1045
		1046	=item C<only>
		1047
		1048	Disables all logging levels, and changes the interpretation of following
		1049	level specifications to enable the specified level only.
		1050
		1051	Example: only enable debug messages for a context.
		1052
		1053	context=only,debug
		1054
		1055	=item C<except>
		1056
		1057	Enables all logging levels, and changes the interpretation of following
		1058	level specifications to disable that level. Rarely used.
		1059
		1060	Example: enable all logging levels except fatal and trace (this is rather
		1061	nonsensical).
		1062
		1063	filter=exept,fatal,trace
		1064
		1065	=item C<level>
		1066
		1067	Enables all logging levels, and changes the interpretation of following
		1068	level specifications to be "that level or any higher priority
		1069	message". This is the default.
		1070
		1071	Example: log anything at or above warn level.
		1072
		1073	filter=warn
		1074
		1075	# or, more verbose
		1076	filter=only,level,warn
		1077
		1078	=item C<1>..C<9>, a logging level name (C<error>, C<debug> etc.)
		1079
		1080	A numeric loglevel or the name of a loglevel will be interpreted according
		1081	to the most recent C<only>, C<except> or C<level> directive. By default,
		1082	specifying a logging level enables that and any higher priority messages.
		1083
		1084	=item C<+>I<context>
		1085
		1086	Adds/attaches the named context as slave to the context.
		1087
		1088	=item C<+>
		1089
		1090	A line C<+> clears the slave list form the context. Anonymous (C<%name>)
		1091	contexts have no slaves by default, but package contexts have the parent
		1092	context as slave by default.
		1093
		1094	Example: log messages from My::Module to a file, do not send them to the
		1095	default log collector.
		1096
		1097	My::Module=+,file=/tmp/mymodulelog
		1098
		1099	=back
		1100
		1101	=cut
		1102
		1103	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1104	my %anon;
		1105
		1106	my $pkg = sub {
		1107	$_[0] eq "log" ? $LOG
		1108	: $_[0] eq "filter" ? $FILTER
		1109	: $_[0] eq "collect" ? $COLLECT
		1110	: $_[0] =~ /^%(.+)$/ ? ($anon{$1} \|\|= ctx undef)
		1111	: $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
		1112	: die # never reached?
		1113	};
		1114
		1115	/\G[[:space:]]+/gc; # skip initial whitespace
		1116
		1117	while (/\G((?:[^:=[:space:]]+\|::\|\\.)+)=/gc) {
		1118	my $ctx = $pkg->($1);
		1119	my $level = "level";
		1120
		1121	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1122	for ("$1") {
		1123	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1124	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1125	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1126	} elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog (eval "package Sys::Syslog; $1");
		1127	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1128	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1129	} elsif ($_ eq "+" ) { $ctx->slaves;
		1130	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1131	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1132	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1133	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1134	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1135	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1136	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1137	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1138	}
		1139	}
		1140
		1141	/\G,/gc or last;
		1142	}
		1143
		1144	/\G[:[:space:]]+/gc or last;
		1145	}
		1146
		1147	/\G[[:space:]]+/gc; # skip trailing whitespace
		1148
		1149	if (/\G(.+)/g) {
		1150	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1151	}
		1152	}
		1153
639	1;	1154	1;
		1155
		1156	=head1 EXAMPLES
		1157
		1158	This section shows some common configurations, both as code, and as
		1159	C<PERL_ANYEVENT_LOG> string.
		1160
		1161	=over 4
		1162
		1163	=item Setting the global logging level.
		1164
		1165	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1166	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1167	the root context at runtime:
		1168
		1169	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1170
		1171	PERL_ANYEVENT_LOG=log=warn
		1172
		1173	$AnyEvent::Log::FILTER->level ("warn");
		1174
		1175	=item Append all messages to a file instead of sending them to STDERR.
		1176
		1177	This is affected by the global logging level.
		1178
		1179	$AnyEvent::Log::LOG->log_to_file ($path);
		1180
		1181	PERL_ANYEVENT_LOG=log=file=/some/path
		1182
		1183	=item Write all messages with priority C<error> and higher to a file.
		1184
		1185	This writes them only when the global logging level allows it, because
		1186	it is attached to the default context which is invoked I<after> global
		1187	filtering.
		1188
		1189	$AnyEvent::Log::FILTER->attach
		1190	new AnyEvent::Log::Ctx log_to_file => $path);
		1191
		1192	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
		1193
		1194	This writes them regardless of the global logging level, because it is
		1195	attached to the toplevel context, which receives all messages I<before>
		1196	the global filtering.
		1197
		1198	$AnyEvent::Log::COLLECT->attach (
		1199	new AnyEvent::Log::Ctx log_to_file => $path);
		1200
		1201	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1202
		1203	In both cases, messages are still written to STDERR.
		1204
		1205	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
		1206
		1207	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
		1208	context - this simply circumvents the global filtering for trace messages.
		1209
		1210	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
		1211	$debug->attach ($AnyEvent::Log::LOG);
		1212
		1213	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1214
		1215	This of course works for any package, not just L<AnyEvent::Debug>, but
		1216	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1217	default.
640		1218
641	=back	1219	=back
642		1220
643	=head1 AUTHOR	1221	=head1 AUTHOR
644		1222
645	Marc Lehmann <schmorp@schmorp.de>	1223	Marc Lehmann <schmorp@schmorp.de>
646	http://home.schmorp.de/	1224	http://home.schmorp.de/
647		1225
648	=cut	1226	=cut
		1227

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.9 by root, Fri Aug 19 19:59:53 2011 UTC vs. Revision 1.29 by root, Thu Aug 25 00:14:32 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.9 by root, Fri Aug 19 19:59:53 2011 UTC vs.
Revision 1.29 by root, Thu Aug 25 00:14:32 2011 UTC