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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.13 by root, Sat Aug 20 01:34:12 2011 UTC vs.
Revision 1.43 by root, Mon Sep 5 07:21:54 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, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number before	52	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
51	starting your program, or change the logging level at runtime with	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 : "AE::Log::Top";	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.
…		…
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 $TIME_EXACT;
172	};	235	};
173		236
174	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	237	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
175		238
176	# time, ctx, level, msg	239	# time, ctx, level, msg
…		…
186	}	249	}
187		250
188	join "", @res	251	join "", @res
189	}	252	}
190		253
		254	sub fatal_exit() {
		255	exit 1;
		256	}
		257
191	sub _log {	258	sub _log {
192	my ($ctx, $level, $format, @args) = @_;	259	my ($ctx, $level, $format, @args) = @_;
193		260
194	$level = $level > 0 && $level <= 9	261	$level = $level > 0 && $level <= 9
195	? $level+0	262	? $level+0
196	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	263	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
197		264
198	my $mask = 1 << $level;	265	my $mask = 1 << $level;
199		266
200	my (%seen, @ctx, $now, $fmt);	267	my ($success, %seen, @ctx, $now, $fmt);
201		268
202	do	269	do
203	{	270	{
204	# skip if masked	271	# skip if masked
205	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	272	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
209	# now get raw message, unless we have it already	276	# now get raw message, unless we have it already
210	unless ($now) {	277	unless ($now) {
211	$format = $format->() if ref $format;	278	$format = $format->() if ref $format;
212	$format = sprintf $format, @args if @args;	279	$format = sprintf $format, @args if @args;
213	$format =~ s/\n$//;	280	$format =~ s/\n$//;
214	$now = AE::now;	281	$now = _ts;
215	};	282	};
216		283
217	# format msg	284	# format msg
218	my $str = $ctx->[4]	285	my $str = $ctx->[4]
219	? $ctx->[4]($now, $_[0], $level, $format)	286	? $ctx->[4]($now, $_[0], $level, $format)
220	: $fmt \|\|= _format $now, $_[0], $level, $format;	287	: ($fmt \|\|= _format $now, $_[0], $level, $format);
221		288
		289	$success = 1;
		290
222	$ctx->[3]($str);	291	$ctx->[3]($str)
		292	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		293	} else {
		294	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
223	}	295	}
224
225	# not masked, not consumed - propagate to parent contexts
226	push @ctx, values %{ $ctx->[2] };
227	}	296	}
228	}	297	}
229	while $ctx = pop @ctx;	298	while $ctx = pop @ctx;
230		299
231	exit 1 if $level <= 1;	300	fatal_exit if $level <= 1;
		301
		302	$success
232	}	303	}
233		304
234	sub log($$;@) {	305	sub log($$;@) {
235	_log	306	_log
236	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	307	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
237	@_;	308	@_;
238	}	309	}
239		310
240	AnyEvent::log = AE::log = \&log;
241
242	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	311	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
243		312
244	Creates a code reference that, when called, acts as if the	313	Creates a code reference that, when called, acts as if the
245	C<AnyEvent::Log::log> function was called at this point with the givne	314	C<AnyEvent::Log::log> function was called at this point with the given
246	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	315	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
247	the C<AnyEvent::Log::log> function:	316	the C<AnyEvent::Log::log> function:
248		317
249	my $debug_log = AnyEvent::Log::logger "debug";	318	my $debug_log = AnyEvent::Log::logger "debug";
250		319
…		…
275	# and later in your program	344	# and later in your program
276	$debug_log->("yo, stuff here") if $debug;	345	$debug_log->("yo, stuff here") if $debug;
277		346
278	$debug and $debug_log->("123");	347	$debug and $debug_log->("123");
279		348
280	Note: currently the enabled var is always true - that will be fixed in a
281	future version :)
282
283	=cut	349	=cut
284		350
285	our %LOGGER;	351	our %LOGGER;
286		352
287	# re-assess logging status for all loggers	353	# re-assess logging status for all loggers
288	sub _reassess {	354	sub _reassess {
		355	local $SIG{__DIE__};
		356	my $die = sub { die };
		357
289	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	358	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
290	my ($ctx, $level, $renabled) = @$_;	359	my ($ctx, $level, $renabled) = @$_;
291		360
292	# to detect whether a message would be logged, we # actually	361	# to detect whether a message would be logged, we actually
293	# try to log one and die. this isn't fast, but we can be	362	# try to log one and die. this isn't fast, but we can be
294	# sure that the logging decision is correct :)	363	# sure that the logging decision is correct :)
295		364
296	$$renabled = !eval {	365	$$renabled = !eval {
297	local $SIG{__DIE__};
298
299	_log $ctx, $level, sub { die };	366	_log $ctx, $level, $die;
300		367
301	1	368	1
302	};	369	};
303
304	$$renabled = 1; # TODO
305	}	370	}
306	}	371	}
307		372
308	sub _logger($;$) {	373	sub _logger {
309	my ($ctx, $level, $renabled) = @_;	374	my ($ctx, $level, $renabled) = @_;
310		375
311	$renabled \|\|= \my $enabled;
312
313	$$renabled = 1;	376	$$renabled = 1;
314		377
315	my $logger = [$ctx, $level, $renabled];	378	my $logger = [$ctx, $level, $renabled];
316		379
317	$LOGGER{$logger+0} = $logger;	380	$LOGGER{$logger+0} = $logger;
318		381
319	_reassess $logger+0;	382	_reassess $logger+0;
320		383
		384	require AnyEvent::Util unless $AnyEvent::Util::VERSION;
321	my $guard = AnyEvent::Util::guard {	385	my $guard = AnyEvent::Util::guard (sub {
322	# "clean up"	386	# "clean up"
323	delete $LOGGER{$logger+0};	387	delete $LOGGER{$logger+0};
324	};	388	});
325		389
326	sub {	390	sub {
327	$guard if 0; # keep guard alive, but don't cause runtime overhead	391	$guard if 0; # keep guard alive, but don't cause runtime overhead
328		392
329	_log $ctx, $level, @_	393	_log $ctx, $level, @_
…		…
334	sub logger($;$) {	398	sub logger($;$) {
335	_logger	399	_logger
336	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	400	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
337	@_	401	@_
338	}	402	}
		403
		404	=item AnyEvent::Log::exact_time $on
		405
		406	By default, C<AnyEvent::Log> will use C<AE::now>, i.e. the cached
		407	eventloop time, for the log timestamps. After calling this function with a
		408	true value it will instead resort to C<AE::time>, i.e. fetch the current
		409	time on each log message. This only makes a difference for event loops
		410	that actually cache the time (such as L<EV> or L<AnyEvent::Loop>).
		411
		412	This setting can be changed at any time by calling this function.
		413
		414	Since C<AnyEvent::Log> has to work even before the L<AnyEvent> has been
		415	initialised, this switch will also decide whether to use C<CORE::time> or
		416	C<Time::HiRes::time> when logging a message before L<AnyEvent> becomes
		417	available.
339		418
340	=back	419	=back
341		420
342	=head1 LOGGING CONTEXTS	421	=head1 LOGGING CONTEXTS
343		422
…		…
356	timestamp, context, level and string message and formats it in the way	435	timestamp, context, level and string message and formats it in the way
357	it should be logged) and a logging callback (which is responsible for	436	it should be logged) and a logging callback (which is responsible for
358	actually logging the formatted message and telling C<AnyEvent::Log>	437	actually logging the formatted message and telling C<AnyEvent::Log>
359	whether it has consumed the message, or whether it should be propagated).	438	whether it has consumed the message, or whether it should be propagated).
360		439
361	For propagation, a context can have any number of attached I<parent	440	For propagation, a context can have any number of attached I<slave
362	contexts>. Any message that is neither masked by the logging mask nor	441	contexts>. Any message that is neither masked by the logging mask nor
363	masked by the logging callback returning true will be passed to all parent	442	masked by the logging callback returning true will be passed to all slave
364	contexts.	443	contexts.
365		444
366	Each call to a logging function will log the message at most once per	445	Each call to a logging function will log the message at most once per
367	context, so it does not matter (much) if there are cycles or if the	446	context, so it does not matter (much) if there are cycles or if the
368	message can arrive at the same context via multiple paths.	447	message can arrive at the same context via multiple paths.
…		…
372	By default, all logging contexts have an full set of log levels ("all"), a	451	By default, all logging contexts have an full set of log levels ("all"), a
373	disabled logging callback and the default formatting callback.	452	disabled logging callback and the default formatting callback.
374		453
375	Package contexts have the package name as logging title by default.	454	Package contexts have the package name as logging title by default.
376		455
377	They have exactly one parent - the context of the "parent" package. The	456	They have exactly one slave - the context of the "parent" package. The
378	parent package is simply defined to be the package name without the last	457	parent package is simply defined to be the package name without the last
379	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	458	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
380	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	459	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
381	exception of the rule - just like the parent of any package name in	460	exception of the rule - just like the "parent" of any single-component
382	Perl is C<main>, the default parent of any top-level package context is	461	package name in Perl is C<main>, the default slave of any top-level
383	C<AnyEvent::Log::Top>.	462	package context is C<$AnyEvent::Log::COLLECT>.
384		463
385	Since perl packages form only an approximate hierarchy, this parent	464	Since perl packages form only an approximate hierarchy, this slave
386	context can of course be removed.	465	context can of course be removed.
387		466
388	All other (anonymous) contexts have no parents and an empty title by	467	All other (anonymous) contexts have no slaves and an empty title by
389	default.	468	default.
390		469
391	When the module is loaded it creates the default context called	470	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
392	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	471	context that simply logs everything via C<warn>, without propagating
393	which simply logs everything to STDERR and doesn't propagate anything
394	anywhere by default. The purpose of the default context is to provide	472	anything anywhere by default. The purpose of this context is to provide
395	a convenient place to override the global logging target or to attach	473	a convenient place to override the global logging target or to attach
396	additional log targets. It's not meant for filtering.	474	additional log targets. It's not meant for filtering.
397		475
398	It then creates the root context called C<AnyEvent::Log::Root> (also	476	It then creates the C<$AnyEvent::Log::FILTER> context whose
399	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	477	purpose is to suppress all messages with priority higher
400	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	478	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
401	then attached the default logging context to it. The purpose of the root	479	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
402	context is to simply provide filtering according to some global log level.	480	is to simply provide filtering according to some global log level.
403		481
404	Finally it creates the top-level package context called	482	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
405	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	483	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
406	C<$AnyEvent::Log::Top>) and attached the root context but otherwise leaves
407	it at default config. It's purpose is simply to collect all log messages	484	leaves it at default config. Its purpose is simply to collect all log
408	system-wide.	485	messages system-wide.
409		486
410	These three special contexts can also be referred to by the	487	The hierarchy is then:
411	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
412	C<AE::Log::Top>.
413		488
		489	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		490
414	The effect of all this is that log messages, by default, wander up	491	The effect of all this is that log messages, by default, wander up to the
415	to the root context where log messages with lower priority then	492	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		493	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
416	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	494	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
417	AnyEvent::Log::Default context to be logged to STDERR.	495	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
418		496
419	Splitting the top level context into three contexts makes it easy to set	497	This makes it easy to set a global logging level (by modifying $FILTER),
420	a global logging level (by modifying the root context), but still allow	498	but still allow other contexts to send, for example, their debug and trace
421	other contexts to log, for example, their debug and trace messages to the
422	default target despite the global logging level, or to attach additional	499	messages to the $LOG target despite the global logging level, or to attach
423	log targets that log messages, regardless of the global logging level.	500	additional log targets that log messages, regardless of the global logging
		501	level.
424		502
425	It also makes it easy to replace the default STDERR-logger by something	503	It also makes it easy to modify the default warn-logger ($LOG) to
426	that logs to a file, or to attach additional logging targets.	504	something that logs to a file, or to attach additional logging targets
		505	(such as loggign to a file) by attaching it to $FILTER.
427		506
428	=head2 CREATING/FINDING/DESTROYING CONTEXTS	507	=head2 CREATING/FINDING/DESTROYING CONTEXTS
429		508
430	=over 4	509	=over 4
431		510
…		…
453	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	532	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
454	}	533	}
455		534
456	=item AnyEvent::Log::reset	535	=item AnyEvent::Log::reset
457		536
458	Deletes all contexts and recreates the default hierarchy, i.e. resets the	537	Resets all package contexts and recreates the default hierarchy if
459	logging subsystem to defaults.	538	necessary, i.e. resets the logging subsystem to defaults, as much as
		539	possible. This process keeps references to contexts held by other parts of
		540	the program intact.
460		541
461	This can be used to implement config-file (re-)loading: before loading a	542	This can be used to implement config-file (re-)loading: before loading a
462	configuration, reset all contexts.	543	configuration, reset all contexts.
463		544
464	=cut	545	=cut
465		546
		547	our $ORIG_VERBOSE = $AnyEvent::VERBOSE;
		548	$AnyEvent::VERBOSE = 9;
		549
466	sub reset {	550	sub reset {
467	@$_ = () for values %CTX; # just to be sure - to kill circular logging dependencies	551	# hard to kill complex data structures
468	%CTX = ();	552	# we "recreate" all package loggers and reset the hierarchy
		553	while (my ($k, $v) = each %CTX) {
		554	@$v = ($k, (1 << 10) - 1 - 1, { });
469		555
470	my $default = ctx undef;	556	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
471	$default->title ("AnyEvent::Log::Default");
472	$default->log_cb (sub {
473	print STDERR shift;
474	0
475	});	557	}
476	$AnyEvent::Log::Default = $CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $default;
477		558
478	my $root = ctx undef;	559	@$_ = ($_->[0], (1 << 10) - 1 - 1)
479	$root->title ("AnyEvent::Log::Root");	560	for $LOG, $FILTER, $COLLECT;
480	$root->level ($AnyEvent::VERBOSE);
481	$root->attach ($default);
482	$AnyEvent::Log::Root = $CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $root;
483		561
484	my $top = ctx undef;	562	#$LOG->slaves;
485	$top->title ("AnyEvent::Log::Top");	563	$LOG->title ('$AnyEvent::Log::LOG');
486	$top->attach ($root);	564	$LOG->log_to_warn;
487	$AnyEvent::Log::Top = $CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $top;	565
		566	$FILTER->slaves ($LOG);
		567	$FILTER->title ('$AnyEvent::Log::FILTER');
		568	$FILTER->level ($ORIG_VERBOSE);
		569
		570	$COLLECT->slaves ($FILTER);
		571	$COLLECT->title ('$AnyEvent::Log::COLLECT');
		572
		573	_reassess;
488	}	574	}
		575
		576	# override AE::log/logger
		577	AnyEvent::log = AE::log = \&log;
		578	AnyEvent::logger = AE::logger = \&logger;
		579
		580	# convert AnyEvent loggers to AnyEvent::Log loggers
		581	$_->[0] = ctx $_->[0] # convert "pkg" to "ctx"
		582	for values %LOGGER;
		583
		584	# create the default logger contexts
		585	$LOG = ctx undef;
		586	$FILTER = ctx undef;
		587	$COLLECT = ctx undef;
489		588
490	AnyEvent::Log::reset;	589	AnyEvent::Log::reset;
491		590
492	# hello, CPAN, please catch me	591	# hello, CPAN, please catch me
493	package AnyEvent::Log::Default;
494	package AE::Log::Default;
495	package AnyEvent::Log::Root;
496	package AE::Log::Root;
497	package AnyEvent::Log::Top;	592	package AnyEvent::Log::LOG;
498	package AE::Log::Top;	593	package AE::Log::LOG;
		594	package AnyEvent::Log::FILTER;
		595	package AE::Log::FILTER;
		596	package AnyEvent::Log::COLLECT;
		597	package AE::Log::COLLECT;
499		598
500	package AnyEvent::Log::Ctx;	599	package AnyEvent::Log::Ctx;
501		600
502	# 0 1 2 3 4	601	# 0 1 2 3 4
503	# [$title, $level, %$parents, &$logcb, &$fmtcb]	602	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
504		603
505	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	604	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
506		605
507	This is a convenience constructor that makes it simpler to construct	606	This is a convenience constructor that makes it simpler to construct
508	anonymous logging contexts.	607	anonymous logging contexts.
…		…
511	name as the key with the value as parameter, unless the value is an	610	name as the key with the value as parameter, unless the value is an
512	arrayref, in which case it calls the method with the contents of the	611	arrayref, in which case it calls the method with the contents of the
513	array. The methods are called in the same order as specified.	612	array. The methods are called in the same order as specified.
514		613
515	Example: create a new logging context and set both the default logging	614	Example: create a new logging context and set both the default logging
516	level, some parent contexts and a logging callback.	615	level, some slave contexts and a logging callback.
517		616
518	$ctx = new AnyEvent::Log::Ctx	617	$ctx = new AnyEvent::Log::Ctx
519	title => "dubious messages",	618	title => "dubious messages",
520	level => "error",	619	level => "error",
521	log_cb => sub { print STDOUT shift; 0 },	620	log_cb => sub { print STDOUT shift; 0 },
522	parents => [$ctx1, $ctx, $ctx2],	621	slaves => [$ctx1, $ctx, $ctx2],
523	;	622	;
524		623
525	=back	624	=back
526		625
527	=cut	626	=cut
…		…
640	AnyEvent::Log::_reassess;	739	AnyEvent::Log::_reassess;
641	}	740	}
642		741
643	=back	742	=back
644		743
645	=head3 PARENT CONTEXTS	744	=head3 SLAVE CONTEXTS
646		745
647	The following methods attach and detach another logging context to a	746	The following methods attach and detach another logging context to a
648	logging context.	747	logging context.
649		748
650	Log messages are propagated to all parent contexts, unless the logging	749	Log messages are propagated to all slave contexts, unless the logging
651	callback consumes the message.	750	callback consumes the message.
652		751
653	=over 4	752	=over 4
654		753
655	=item $ctx->attach ($ctx2[, $ctx3...])	754	=item $ctx->attach ($ctx2[, $ctx3...])
656		755
657	Attaches the given contexts as parents to this context. It is not an error	756	Attaches the given contexts as slaves to this context. It is not an error
658	to add a context twice (the second add will be ignored).	757	to add a context twice (the second add will be ignored).
659		758
660	A context can be specified either as package name or as a context object.	759	A context can be specified either as package name or as a context object.
661		760
662	=item $ctx->detach ($ctx2[, $ctx3...])	761	=item $ctx->detach ($ctx2[, $ctx3...])
663		762
664	Removes the given parents from this context - it's not an error to attempt	763	Removes the given slaves from this context - it's not an error to attempt
665	to remove a context that hasn't been added.	764	to remove a context that hasn't been added.
666		765
667	A context can be specified either as package name or as a context object.	766	A context can be specified either as package name or as a context object.
668		767
669	=item $ctx->parents ($ctx2[, $ctx3...])	768	=item $ctx->slaves ($ctx2[, $ctx3...])
670		769
671	Replaces all parents attached to this context by the ones given.	770	Replaces all slaves attached to this context by the ones given.
672		771
673	=cut	772	=cut
674		773
675	sub attach {	774	sub attach {
676	my $ctx = shift;	775	my $ctx = shift;
…		…
684		783
685	delete $ctx->[2]{$_+0}	784	delete $ctx->[2]{$_+0}
686	for map { AnyEvent::Log::ctx $_ } @_;	785	for map { AnyEvent::Log::ctx $_ } @_;
687	}	786	}
688		787
689	sub parents {	788	sub slaves {
690	undef $_[0][2];	789	undef $_[0][2];
691	&attach;	790	&attach;
692	}	791	}
693		792
694	=back	793	=back
695		794
696	=head3 MESSAGE LOGGING	795	=head3 LOG TARGETS
697		796
698	The following methods configure how the logging context actually does	797	The following methods configure how the logging context actually does
699	the logging (which consists of formatting the message and printing it or	798	the logging (which consists of formatting the message and printing it or
700	whatever it wants to do with it) and also allows you to log messages	799	whatever it wants to do with it).
701	directly to a context, without going via your package context.
702		800
703	=over 4	801	=over 4
704		802
705	=item $ctx->log_cb ($cb->($str))	803	=item $ctx->log_cb ($cb->($str)
706		804
707	Replaces the logging callback on the context (C<undef> disables the	805	Replaces the logging callback on the context (C<undef> disables the
708	logging callback).	806	logging callback).
709		807
710	The logging callback is responsible for handling formatted log messages	808	The logging callback is responsible for handling formatted log messages
711	(see C<fmt_cb> below) - normally simple text strings that end with a	809	(see C<fmt_cb> below) - normally simple text strings that end with a
712	newline (and are possibly multiline themselves).	810	newline (and are possibly multiline themselves).
713		811
714	It also has to return true iff it has consumed the log message, and false	812	It also has to return true iff it has consumed the log message, and false
715	if it hasn't. Consuming a message means that it will not be sent to any	813	if it hasn't. Consuming a message means that it will not be sent to any
716	parent context. When in doubt, return C<0> from your logging callback.	814	slave context. When in doubt, return C<0> from your logging callback.
717		815
718	Example: a very simple logging callback, simply dump the message to STDOUT	816	Example: a very simple logging callback, simply dump the message to STDOUT
719	and do not consume it.	817	and do not consume it.
720		818
721	$ctx->log_cb (sub { print STDERR shift; 0 });	819	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
729	your program.	827	your program.
730		828
731	$ctx->levels ("debug", "trace");	829	$ctx->levels ("debug", "trace");
732	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	830	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
733		831
734	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	832	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
735		833
736	Replaces the formatting callback on the context (C<undef> restores the	834	Replaces the formatting callback on the context (C<undef> restores the
737	default formatter).	835	default formatter).
738		836
739	The callback is passed the (possibly fractional) timestamp, the original	837	The callback is passed the (possibly fractional) timestamp, the original
740	logging context, the (numeric) logging level and the raw message string and needs to	838	logging context, the (numeric) logging level and the raw message string
741	return a formatted log message. In most cases this will be a string, but	839	and needs to return a formatted log message. In most cases this will be a
742	it could just as well be an array reference that just stores the values.	840	string, but it could just as well be an array reference that just stores
		841	the values.
		842
		843	If, for some reason, you want to use C<caller> to find out more baout the
		844	logger then you should walk up the call stack until you are no longer
		845	inside the C<AnyEvent::Log> package.
743		846
744	Example: format just the raw message, with numeric log level in angle	847	Example: format just the raw message, with numeric log level in angle
745	brackets.	848	brackets.
746		849
747	$ctx->fmt_cb (sub {	850	$ctx->fmt_cb (sub {
…		…
764	"$msg->[3]";	867	"$msg->[3]";
765		868
766	0	869	0
767	});	870	});
768		871
		872	=item $ctx->log_to_warn
		873
		874	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		875	(usually this logs to STDERR).
		876
		877	=item $ctx->log_to_file ($path)
		878
		879	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		880
		881	=item $ctx->log_to_path ($path)
		882
		883	Same as C<< ->log_to_file >>, but opens the file for each message. This
		884	is much slower, but allows you to change/move/rename/delete the file at
		885	basically any time.
		886
		887	Needless(?) to say, if you do not want to be bitten by some evil person
		888	calling C<chdir>, the path should be absolute. Doesn't help with
		889	C<chroot>, but hey...
		890
		891	=item $ctx->log_to_syslog ([$facility])
		892
		893	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and
		894	all the others in the obvious way. If specified, then the C<$facility> is
		895	used as the facility (C<user>, C<auth>, C<local0> and so on). The default
		896	facility is C<user>.
		897
		898	Note that this function also sets a C<fmt_cb> - the logging part requires
		899	an array reference with [$level, $str] as input.
		900
769	=cut	901	=cut
770		902
771	sub log_cb {	903	sub log_cb {
772	my ($ctx, $cb) = @_;	904	my ($ctx, $cb) = @_;
773		905
…		…
778	my ($ctx, $cb) = @_;	910	my ($ctx, $cb) = @_;
779		911
780	$ctx->[4] = $cb;	912	$ctx->[4] = $cb;
781	}	913	}
782		914
783	=item $ctx->log ($level, $msg[, @params])	915	sub log_to_warn {
		916	my ($ctx, $path) = @_;
784		917
785	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	918	$ctx->log_cb (sub {
		919	warn shift;
		920	0
		921	});
		922	}
786		923
787	=item $logger = $ctx->logger ($level[, \$enabled])	924	sub log_to_file {
788		925	my ($ctx, $path) = @_;
789	Same as C<AnyEvent::Log::logger>, but uses the given context as log
790	context.
791
792	=cut
793
794	*log = \&AnyEvent::Log::_log;
795	*logger = \&AnyEvent::Log::_logger;
796
797	1;
798
799	=back
800
801	=head1 EXAMPLES
802
803	This section shows some common configurations.
804
805	=over 4
806
807	=item Setting the global logging level.
808
809	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
810	running your program, or modify the log level of the root context:
811
812	PERL_ANYEVENT_VERBOSE=5 ./myprog
813
814	$AnyEvent::Log::Root->level ("warn");
815
816	=item Append all messages to a file instead of sending them to STDERR.
817
818	This is affected by the global logging level.
819		926
820	open my $fh, ">>", $path	927	open my $fh, ">>", $path
821	or die "$path: $!";	928	or die "$path: $!";
822		929
823	$AnyEvent::Log::Default->log_cb (sub {	930	$ctx->log_cb (sub {
824	syswrite $fh, shift;	931	syswrite $fh, shift;
825	0	932	0
826	});	933	});
		934	}
		935
		936	sub log_to_path {
		937	my ($ctx, $path) = @_;
		938
		939	$ctx->log_cb (sub {
		940	open my $fh, ">>", $path
		941	or die "$path: $!";
		942
		943	syswrite $fh, shift;
		944	0
		945	});
		946	}
		947
		948	sub log_to_syslog {
		949	my ($ctx, $facility) = @_;
		950
		951	require Sys::Syslog;
		952
		953	$ctx->fmt_cb (sub {
		954	my $str = $_[3];
		955	$str =~ s/\n(?=.)/\n+ /g;
		956
		957	[$_[2], "($_[1][0]) $str"]
		958	});
		959
		960	$facility \|\|= "user";
		961
		962	$ctx->log_cb (sub {
		963	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		964
		965	Sys::Syslog::syslog ("$facility\|" . ($lvl - 1), $_)
		966	for split /\n/, $_[0][1];
		967
		968	0
		969	});
		970	}
		971
		972	=back
		973
		974	=head3 MESSAGE LOGGING
		975
		976	These methods allow you to log messages directly to a context, without
		977	going via your package context.
		978
		979	=over 4
		980
		981	=item $ctx->log ($level, $msg[, @params])
		982
		983	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		984
		985	=item $logger = $ctx->logger ($level[, \$enabled])
		986
		987	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		988	context.
		989
		990	=cut
		991
		992	*log = \&AnyEvent::Log::_log;
		993	*logger = \&AnyEvent::Log::_logger;
		994
		995	=back
		996
		997	=cut
		998
		999	package AnyEvent::Log;
		1000
		1001	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		1002
		1003	Logging can also be configured by setting the environment variable
		1004	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		1005
		1006	The value consists of one or more logging context specifications separated
		1007	by C<:> or whitespace. Each logging specification in turn starts with a
		1008	context name, followed by C<=>, followed by zero or more comma-separated
		1009	configuration directives, here are some examples:
		1010
		1011	# set default logging level
		1012	filter=warn
		1013
		1014	# log to file instead of to stderr
		1015	log=file=/tmp/mylog
		1016
		1017	# log to file in addition to stderr
		1018	log=+%file:%file=file=/tmp/mylog
		1019
		1020	# enable debug log messages, log warnings and above to syslog
		1021	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		1022
		1023	# log trace messages (only) from AnyEvent::Debug to file
		1024	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		1025
		1026	A context name in the log specification can be any of the following:
		1027
		1028	=over 4
		1029
		1030	=item C<collect>, C<filter>, C<log>
		1031
		1032	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		1033	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		1034
		1035	=item C<%name>
		1036
		1037	Context names starting with a C<%> are anonymous contexts created when the
		1038	name is first mentioned. The difference to package contexts is that by
		1039	default they have no attached slaves.
		1040
		1041	=item a perl package name
		1042
		1043	Any other string references the logging context associated with the given
		1044	Perl C<package>. In the unlikely case where you want to specify a package
		1045	context that matches on of the other context name forms, you can add a
		1046	C<::> to the package name to force interpretation as a package.
		1047
		1048	=back
		1049
		1050	The configuration specifications can be any number of the following:
		1051
		1052	=over 4
		1053
		1054	=item C<stderr>
		1055
		1056	Configures the context to use Perl's C<warn> function (which typically
		1057	logs to C<STDERR>). Works like C<log_to_warn>.
		1058
		1059	=item C<file=>I<path>
		1060
		1061	Configures the context to log to a file with the given path. Works like
		1062	C<log_to_file>.
		1063
		1064	=item C<path=>I<path>
		1065
		1066	Configures the context to log to a file with the given path. Works like
		1067	C<log_to_path>.
		1068
		1069	=item C<syslog> or C<syslog=>I<expr>
		1070
		1071	Configures the context to log to syslog. If I<expr> is given, then it is
		1072	evaluated in the L<Sys::Syslog> package, so you could use:
		1073
		1074	log=syslog=LOG_LOCAL0
		1075
		1076	=item C<nolog>
		1077
		1078	Configures the context to not log anything by itself, which is the
		1079	default. Same as C<< $ctx->log_cb (undef) >>.
		1080
		1081	=item C<0> or C<off>
		1082
		1083	Sets the logging level of the context ot C<0>, i.e. all messages will be
		1084	filtered out.
		1085
		1086	=item C<all>
		1087
		1088	Enables all logging levels, i.e. filtering will effectively be switched
		1089	off (the default).
		1090
		1091	=item C<only>
		1092
		1093	Disables all logging levels, and changes the interpretation of following
		1094	level specifications to enable the specified level only.
		1095
		1096	Example: only enable debug messages for a context.
		1097
		1098	context=only,debug
		1099
		1100	=item C<except>
		1101
		1102	Enables all logging levels, and changes the interpretation of following
		1103	level specifications to disable that level. Rarely used.
		1104
		1105	Example: enable all logging levels except fatal and trace (this is rather
		1106	nonsensical).
		1107
		1108	filter=exept,fatal,trace
		1109
		1110	=item C<level>
		1111
		1112	Enables all logging levels, and changes the interpretation of following
		1113	level specifications to be "that level or any higher priority
		1114	message". This is the default.
		1115
		1116	Example: log anything at or above warn level.
		1117
		1118	filter=warn
		1119
		1120	# or, more verbose
		1121	filter=only,level,warn
		1122
		1123	=item C<1>..C<9> or a logging level name (C<error>, C<debug> etc.)
		1124
		1125	A numeric loglevel or the name of a loglevel will be interpreted according
		1126	to the most recent C<only>, C<except> or C<level> directive. By default,
		1127	specifying a logging level enables that and any higher priority messages.
		1128
		1129	=item C<+>I<context>
		1130
		1131	Attaches the named context as slave to the context.
		1132
		1133	=item C<+>
		1134
		1135	A line C<+> detaches all contexts, i.e. clears the slave list from the
		1136	context. Anonymous (C<%name>) contexts have no attached slaves by default,
		1137	but package contexts have the parent context as slave by default.
		1138
		1139	Example: log messages from My::Module to a file, do not send them to the
		1140	default log collector.
		1141
		1142	My::Module=+,file=/tmp/mymodulelog
		1143
		1144	=back
		1145
		1146	Any character can be escaped by prefixing it with a C<\> (backslash), as
		1147	usual, so to log to a file containing a comma, colon, backslash and some
		1148	spaces in the filename, you would do this:
		1149
		1150	PERL_ANYEVENT_LOG='log=file=/some\ \:file\ with\,\ \\-escapes'
		1151
		1152	Since whitespace (which includes newlines) is allowed, it is fine to
		1153	specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
		1154
		1155	PERL_ANYEVENT_LOG="
		1156	filter=warn
		1157	AnyEvent::Debug=+%trace
		1158	%trace=only,trace,+log
		1159	" myprog
		1160
		1161	Also, in the unlikely case when you want to concatenate specifications,
		1162	use whitespace as separator, as C<::> will be interpreted as part of a
		1163	module name, an empty spec with two separators:
		1164
		1165	PERL_ANYEVENT_LOG="$PERL_ANYEVENT_LOG MyMod=debug"
		1166
		1167	=cut
		1168
		1169	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1170	my %anon;
		1171
		1172	my $pkg = sub {
		1173	$_[0] eq "log" ? $LOG
		1174	: $_[0] eq "filter" ? $FILTER
		1175	: $_[0] eq "collect" ? $COLLECT
		1176	: $_[0] =~ /^%(.+)$/ ? ($anon{$1} \|\|= ctx undef)
		1177	: $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
		1178	: die # never reached?
		1179	};
		1180
		1181	/\G[[:space:]]+/gc; # skip initial whitespace
		1182
		1183	while (/\G((?:[^:=[:space:]]+\|::\|\\.)+)=/gc) {
		1184	my $ctx = $pkg->($1);
		1185	my $level = "level";
		1186
		1187	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1188	for ("$1") {
		1189	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1190	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1191	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1192	} elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog ($1);
		1193	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1194	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1195	} elsif ($_ eq "+" ) { $ctx->slaves;
		1196	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1197	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1198	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1199	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1200	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1201	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1202	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1203	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1204	}
		1205	}
		1206
		1207	/\G,/gc or last;
		1208	}
		1209
		1210	/\G[:[:space:]]+/gc or last;
		1211	}
		1212
		1213	/\G[[:space:]]+/gc; # skip trailing whitespace
		1214
		1215	if (/\G(.+)/g) {
		1216	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1217	}
		1218	}
		1219
		1220	1;
		1221
		1222	=head1 EXAMPLES
		1223
		1224	This section shows some common configurations, both as code, and as
		1225	C<PERL_ANYEVENT_LOG> string.
		1226
		1227	=over 4
		1228
		1229	=item Setting the global logging level.
		1230
		1231	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1232	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1233	the root context at runtime:
		1234
		1235	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1236
		1237	PERL_ANYEVENT_LOG=log=warn
		1238
		1239	$AnyEvent::Log::FILTER->level ("warn");
		1240
		1241	=item Append all messages to a file instead of sending them to STDERR.
		1242
		1243	This is affected by the global logging level.
		1244
		1245	$AnyEvent::Log::LOG->log_to_file ($path);
		1246
		1247	PERL_ANYEVENT_LOG=log=file=/some/path
827		1248
828	=item Write all messages with priority C<error> and higher to a file.	1249	=item Write all messages with priority C<error> and higher to a file.
829		1250
830	This writes them only when the global logging level allows it, because	1251	This writes them only when the global logging level allows it, because
831	it is attached to the default context which is invoked I<after> global	1252	it is attached to the default context which is invoked I<after> global
832	filtering.	1253	filtering.
833		1254
834	open my $fh, ">>", $path	1255	$AnyEvent::Log::FILTER->attach (
835	or die "$path: $!";	1256	new AnyEvent::Log::Ctx log_to_file => $path);
836		1257
837	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx	1258	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
838	log_cb => sub { syswrite $fh, shift; 0 });
839		1259
840	This writes them regardless of the global logging level, because it is	1260	This writes them regardless of the global logging level, because it is
841	attached to the toplevel context, which receives all messages I<before>	1261	attached to the toplevel context, which receives all messages I<before>
842	the global filtering.	1262	the global filtering.
843		1263
844	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	1264	$AnyEvent::Log::COLLECT->attach (
845	log_cb => sub { syswrite $fh, shift; 0 });	1265	new AnyEvent::Log::Ctx log_to_file => $path);
846		1266
		1267	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1268
847	In both cases, messages are still written to STDOUT.	1269	In both cases, messages are still written to STDERR.
848		1270
849	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	1271	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
850		1272
851	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	1273	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
852	context and increase the C<AnyEvent::Debug> logging level - this simply
853	circumvents the global filtering for trace messages.	1274	context - this simply circumvents the global filtering for trace messages.
854		1275
855	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	1276	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
856	$debug->attach ($AnyEvent::Log::Default);	1277	$debug->attach ($AnyEvent::Log::LOG);
857	$debug->levels ("trace"); # not "level"!
858		1278
859	This of course works for any package.	1279	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1280
		1281	This of course works for any package, not just L<AnyEvent::Debug>, but
		1282	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1283	default.
860		1284
861	=back	1285	=back
862		1286
863	=head1 AUTHOR	1287	=head1 AUTHOR
864		1288
865	Marc Lehmann <schmorp@schmorp.de>	1289	Marc Lehmann <schmorp@schmorp.de>
866	http://home.schmorp.de/	1290	http://home.schmorp.de/
867		1291
868	=cut	1292	=cut
		1293

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.13 by root, Sat Aug 20 01:34:12 2011 UTC vs. Revision 1.43 by root, Mon Sep 5 07:21:54 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.13 by root, Sat Aug 20 01:34:12 2011 UTC vs.
Revision 1.43 by root, Mon Sep 5 07:21:54 2011 UTC