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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.7 by root, Thu Aug 18 18:02:11 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 uses:
		8
		9	use AnyEvent;
		10
		11	AE::log debug => "hit my knee";
		12	AE::log warn => "it's a bit too hot";
		13	AE::log error => "the flag was false!";
		14	AE::log fatal => "the bit toggled! run!"; # never returns
		15
		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
7	use AnyEvent::Log;	21	use AnyEvent::Log;
		22
		23	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
		24
		25	$tracer->("i am here") if $trace;
		26	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
		27
		28	Configuration (also look at the EXAMPLES section):
		29
		30	# set logging for the current package to errors and higher only
		31	AnyEvent::Log::ctx->level ("error");
		32
		33	# set logging level to suppress anything below "notice"
		34	$AnyEvent::Log::FILTER->level ("notice");
		35
		36	# send all critical and higher priority messages to syslog,
		37	# regardless of (most) other settings
		38	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
		39	level => "critical",
		40	log_to_syslog => "user",
		41	);
8		42
9	=head1 DESCRIPTION	43	=head1 DESCRIPTION
10		44
11	This module implements a relatively simple "logging framework". It doesn't	45	This module implements a relatively simple "logging framework". It doesn't
12	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
13	AnyEvent - AnyEvent simply creates logging messages internally, and this	47	AnyEvent - AnyEvent simply creates logging messages internally, and this
14	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
15	using it from other modules as well.	49	using it from other modules as well.
16		50
17	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
18	logged, ever, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number	52	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
19	before starting your program.#TODO	53	before starting your program, or change the logging level at runtime with
		54	something like:
20		55
21	Possible future extensions are to allow custom log targets (where the	56	use AnyEvent::Log;
22	level is an object), log filtering based on package, formatting, aliasing	57	$AnyEvent::Log::FILTER->level ("info");
23	or package groups.
24		58
		59	The design goal behind this module was to keep it simple (and small),
		60	but make it powerful enough to be potentially useful for any module, and
		61	extensive enough for the most common tasks, such as logging to multiple
		62	targets, or being able to log into a database.
		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
25	=head1 LOG FUNCTIONS	108	=head1 LOGGING FUNCTIONS
26		109
27	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
28	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
29	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
30	loaded.	113	loaded.
31		114
32	=over 4	115	=over 4
33		116
…		…
37		120
38	use Carp ();	121	use Carp ();
39	use POSIX ();	122	use POSIX ();
40		123
41	use AnyEvent (); BEGIN { AnyEvent::common_sense }	124	use AnyEvent (); BEGIN { AnyEvent::common_sense }
42	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, $LOG);
43		130
44	our ($now_int, $now_str1, $now_str2);	131	our ($now_int, $now_str1, $now_str2);
45		132
46	# Format Time, not public - yet?	133	# Format Time, not public - yet?
47	sub ft($) {	134	sub ft($) {
…		…
52	if $now_int != $i;	139	if $now_int != $i;
53		140
54	"$now_str1$f$now_str2"	141	"$now_str1$f$now_str2"
55	}	142	}
56		143
57	our %CTX; # all logging contexts	144	our %CTX; # all package contexts
		145
		146	# creates a default package context object for the given package
		147	sub _pkg_ctx($) {
		148	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
		149
		150	# link "parent" package
		151	my $parent = $_[0] =~ /^(.+)::/
		152	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		153	: $COLLECT;
		154
		155	$ctx->[2]{$parent+0} = $parent;
		156
		157	$ctx
		158	}
58		159
59	=item AnyEvent::Log::log $level, $msg[, @args]	160	=item AnyEvent::Log::log $level, $msg[, @args]
60		161
61	Requests logging of the given C<$msg> with the given log level (1..9).	162	Requests logging of the given C<$msg> with the given log level, and
62	You can also use the following strings as log level: C<fatal> (1),	163	returns true if the message was logged I<somewhere>.
63	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
64	C<info> (7), C<debug> (8), C<trace> (9).
65		164
66	For C<fatal> log levels, the program will abort.	165	For loglevel C<fatal>, the program will abort.
67		166
68	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	167	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
69	C<$msg> is interpreted as an sprintf format string.	168	C<$msg> is interpreted as an sprintf format string.
70		169
71	The C<$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
…		…
75	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
76	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
77	message in the first place.	176	message in the first place.
78		177
79	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
80	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.
81		183
82	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
83	C<AE::log>, without C<use>-ing this module if possible, as those functions	185	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
84	will laod the logging module on demand only.	186	need any additional functionality), as those functions will load the
		187	logging module on demand only. They are also much shorter to write.
		188
		189	Also, if you optionally generate a lot of debug messages (such as when
		190	tracing some code), you should look into using a logger callback and a
		191	boolean enabler (see C<logger>, below).
85		192
86	Example: log something at error level.	193	Example: log something at error level.
87		194
88	AE::log error => "something";	195	AE::log error => "something";
89		196
…		…
97		204
98	=cut	205	=cut
99		206
100	# also allow syslog equivalent names	207	# also allow syslog equivalent names
101	our %STR2LEVEL = (	208	our %STR2LEVEL = (
102	fatal => 1, emerg => 1,	209	fatal => 1, emerg => 1, exit => 1,
103	alert => 2,	210	alert => 2,
104	critical => 3, crit => 3,	211	critical => 3, crit => 3,
105	error => 4, err => 4,	212	error => 4, err => 4, die => 4,
106	warn => 5, warning => 5,	213	warn => 5, warning => 5,
107	note => 6, notice => 6,	214	note => 6, notice => 6,
108	info => 7,	215	info => 7,
109	debug => 8,	216	debug => 8,
110	trace => 9,	217	trace => 9,
111	);	218	);
112		219
113	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	}
		232
114	AnyEvent::post_detect {	233	AnyEvent::post_detect {
115	*now = \&AE::now;	234	exact_time $TIME_EXACT;
116	};	235	};
117		236
118	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);
119		238
		239	# time, ctx, level, msg
		240	sub _format($$$$) {
		241	my $ts = ft $_[0];
		242	my $ct = " ";
		243
		244	my @res;
		245
		246	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {
		247	push @res, "$ts$ct$_\n";
		248	$ct = " + ";
		249	}
		250
		251	join "", @res
		252	}
		253
		254	sub fatal_exit() {
		255	exit 1;
		256	}
		257
120	sub _log {	258	sub _log {
121	my ($pkg, $targ, $msg, @args) = @_;	259	my ($ctx, $level, $format, @args) = @_;
122		260
123	my $level = ref $targ ? die "Can't use reference as logging level (yet)"	261	$level = $level > 0 && $level <= 9
124	: $targ > 0 && $targ <= 9 ? $targ+0	262	? $level+0
125	: $STR2LEVEL{$targ} \|\| Carp::croak "$targ: not a valid logging level, caught";	263	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
126		264
127	#TODO: find actual targets, see if we even have to log	265	my $mask = 1 << $level;
128		266
129	return unless $level <= $AnyEvent::VERBOSE;	267	my ($success, %seen, @ctx, $now, $fmt);
130		268
131	$msg = $msg->() if ref $msg;	269	do
132	$msg = sprintf $msg, @args if @args;	270	{
133	$msg =~ s/\n$//;	271	# skip if masked
		272	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
		273	if ($ctx->[3]) {
		274	# logging target found
134		275
135	# now we have a message, log it	276	# now get raw message, unless we have it already
		277	unless ($now) {
		278	$format = $format->() if ref $format;
		279	$format = sprintf $format, @args if @args;
		280	$format =~ s/\n$//;
		281	$now = _ts;
		282	};
136		283
137	# TODO: writers/processors/filters/formatters?	284	# format msg
		285	my $str = $ctx->[4]
		286	? $ctx->[4]($now, $_[0], $level, $format)
		287	: ($fmt \|\|= _format $now, $_[0], $level, $format);
138		288
139	$msg = sprintf "%-5s %s: %s", $LEVEL2STR[$level], $pkg, $msg;	289	$success = 1;
140	my $pfx = ft now;
141		290
142	for (split /\n/, $msg) {	291	$ctx->[3]($str)
143	printf STDERR "$pfx $_\n";	292	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
144	$pfx = "\t";	293	} else {
145	}	294	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
		295	}
		296	}
		297	}
		298	while $ctx = pop @ctx;
146		299
147	exit 1 if $level <= 1;	300	fatal_exit if $level <= 1;
		301
		302	$success
148	}	303	}
149		304
150	sub log($$;@) {	305	sub log($$;@) {
151	_log +(caller)[0], @_;	306	_log
		307	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
		308	@_;
152	}	309	}
153
154	AnyEvent::log = AE::log = \&log;
155		310
156	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	311	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
157		312
158	Creates a code reference that, when called, acts as if the	313	Creates a code reference that, when called, acts as if the
159	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
160	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
161	the C<AnyEvent::Log::log> function:	316	the C<AnyEvent::Log::log> function:
162		317
163	my $debug_log = AnyEvent::Log::logger "debug";	318	my $debug_log = AnyEvent::Log::logger "debug";
164		319
…		…
189	# and later in your program	344	# and later in your program
190	$debug_log->("yo, stuff here") if $debug;	345	$debug_log->("yo, stuff here") if $debug;
191		346
192	$debug and $debug_log->("123");	347	$debug and $debug_log->("123");
193		348
194	Note: currently the enabled var is always true - that will be fixed in a
195	future version :)
196
197	=cut	349	=cut
198		350
199	our %LOGGER;	351	our %LOGGER;
200		352
201	# re-assess logging status for all loggers	353	# re-assess logging status for all loggers
202	sub _reassess {	354	sub _reassess {
		355	local $SIG{__DIE__};
		356	my $die = sub { die };
		357
203	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	358	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
204	my ($pkg, $level, $renabled) = @$_;	359	my ($ctx, $level, $renabled) = @$_;
205		360
206	# to detetc whether a message would be logged, we # actually	361	# to detect whether a message would be logged, we actually
207	# 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
208	# sure that the logging decision is correct :)	363	# sure that the logging decision is correct :)
209		364
210	$$renabled = !eval {	365	$$renabled = !eval {
211	local $SIG{__DIE__};
212
213	_log $pkg, $level, sub { die };	366	_log $ctx, $level, $die;
214		367
215	1	368	1
216	};	369	};
217
218	$$renabled = 1; # TODO
219	}	370	}
220	}	371	}
221		372
222	sub logger($;$) {	373	sub _logger {
223	my ($level, $renabled) = @_;	374	my ($ctx, $level, $renabled) = @_;
224
225	$renabled \|\|= \my $enabled;
226	my $pkg = (caller)[0];
227		375
228	$$renabled = 1;	376	$$renabled = 1;
229		377
230	my $logger = [$pkg, $level, $renabled];	378	my $logger = [$ctx, $level, $renabled];
231		379
232	$LOGGER{$logger+0} = $logger;	380	$LOGGER{$logger+0} = $logger;
233		381
234	_reassess $logger+0;	382	_reassess $logger+0;
235		383
		384	require AnyEvent::Util unless $AnyEvent::Util::VERSION;
236	my $guard = AnyEvent::Util::guard {	385	my $guard = AnyEvent::Util::guard (sub {
237	# "clean up"	386	# "clean up"
238	delete $LOGGER{$logger+0};	387	delete $LOGGER{$logger+0};
239	};	388	});
240		389
241	sub {	390	sub {
242	$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
243		392
244	_log $pkg, $level, @_	393	_log $ctx, $level, @_
245	if $$renabled;	394	if $$renabled;
246	}	395	}
247	}	396	}
248		397
249	#TODO	398	sub logger($;$) {
		399	_logger
		400	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
		401	@_
		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.
250		418
251	=back	419	=back
252		420
253	=head1 CONFIGURATION FUNCTIONALITY	421	=head1 LOGGING CONTEXTS
254		422
255	None, yet, except for C<PERL_ANYEVENT_VERBOSE>, described in the L<AnyEvent> manpage.	423	This module associates every log message with a so-called I<logging
256	#TODO	424	context>, based on the package of the caller. Every perl package has its
		425	own logging context.
		426
		427	A logging context has three major responsibilities: filtering, logging and
		428	propagating the message.
		429
		430	For the first purpose, filtering, each context has a set of logging
		431	levels, called the log level mask. Messages not in the set will be ignored
		432	by this context (masked).
		433
		434	For logging, the context stores a formatting callback (which takes the
		435	timestamp, context, level and string message and formats it in the way
		436	it should be logged) and a logging callback (which is responsible for
		437	actually logging the formatted message and telling C<AnyEvent::Log>
		438	whether it has consumed the message, or whether it should be propagated).
		439
		440	For propagation, a context can have any number of attached I<slave
		441	contexts>. Any message that is neither masked by the logging mask nor
		442	masked by the logging callback returning true will be passed to all slave
		443	contexts.
		444
		445	Each call to a logging function will log the message at most once per
		446	context, so it does not matter (much) if there are cycles or if the
		447	message can arrive at the same context via multiple paths.
		448
		449	=head2 DEFAULTS
		450
		451	By default, all logging contexts have an full set of log levels ("all"), a
		452	disabled logging callback and the default formatting callback.
		453
		454	Package contexts have the package name as logging title by default.
		455
		456	They have exactly one slave - the context of the "parent" package. The
		457	parent package is simply defined to be the package name without the last
		458	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
		459	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
		460	exception of the rule - just like the "parent" of any single-component
		461	package name in Perl is C<main>, the default slave of any top-level
		462	package context is C<$AnyEvent::Log::COLLECT>.
		463
		464	Since perl packages form only an approximate hierarchy, this slave
		465	context can of course be removed.
		466
		467	All other (anonymous) contexts have no slaves and an empty title by
		468	default.
		469
		470	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
		471	context that simply logs everything via C<warn>, without propagating
		472	anything anywhere by default. The purpose of this context is to provide
		473	a convenient place to override the global logging target or to attach
		474	additional log targets. It's not meant for filtering.
		475
		476	It then creates the C<$AnyEvent::Log::FILTER> context whose
		477	purpose is to suppress all messages with priority higher
		478	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
		479	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
		480	is to simply provide filtering according to some global log level.
		481
		482	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
		483	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
		484	leaves it at default config. Its purpose is simply to collect all log
		485	messages system-wide.
		486
		487	The hierarchy is then:
		488
		489	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		490
		491	The effect of all this is that log messages, by default, wander up to the
		492	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		493	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
		494	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
		495	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
		496
		497	This makes it easy to set a global logging level (by modifying $FILTER),
		498	but still allow other contexts to send, for example, their debug and trace
		499	messages to the $LOG target despite the global logging level, or to attach
		500	additional log targets that log messages, regardless of the global logging
		501	level.
		502
		503	It also makes it easy to modify the default warn-logger ($LOG) to
		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.
		506
		507	=head2 CREATING/FINDING/DESTROYING CONTEXTS
257		508
258	=over 4	509	=over 4
259		510
260	=item $ctx = AnyEvent::Log::cfg [$pkg]	511	=item $ctx = AnyEvent::Log::ctx [$pkg]
261		512
262	Returns a I<config> object for the given package name (or previously	513	This function creates or returns a logging context (which is an object).
263	created package-less configuration). If no package name, or C<undef>, is	514
		515	If a package name is given, then the context for that packlage is
		516	returned. If it is called without any arguments, then the context for the
		517	callers package is returned (i.e. the same context as a C<AE::log> call
		518	would use).
		519
264	given, then it creates a new anonymous context that is not tied to any	520	If C<undef> is given, then it creates a new anonymous context that is not
265	package.	521	tied to any package and is destroyed when no longer referenced.
266		522
267	=cut	523	=cut
268		524
269	sub cfg(;$) {	525	sub ctx(;$) {
270	my $name = shift;	526	my $pkg = @_ ? shift : (caller)[0];
271		527
272	my $ctx = defined $name ? $CTX{$name} : undef;	528	ref $pkg
		529	? $pkg
		530	: defined $pkg
		531	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg
		532	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
		533	}
273		534
274	unless ($ctx) {	535	=item AnyEvent::Log::reset
275	$ctx = bless {}, "AnyEvent::Log::Ctx";	536
276	$name = -$ctx unless defined $name;	537	Resets all package contexts and recreates the default hierarchy if
277	$ctx->{name} = $name;	538	necessary, i.e. resets the logging subsystem to defaults, as much as
278	$CTX{$name} = $ctx;	539	possible. This process keeps references to contexts held by other parts of
		540	the program intact.
		541
		542	This can be used to implement config-file (re-)loading: before loading a
		543	configuration, reset all contexts.
		544
		545	=cut
		546
		547	our $ORIG_VERBOSE = $AnyEvent::VERBOSE;
		548	$AnyEvent::VERBOSE = 9;
		549
		550	sub reset {
		551	# hard to kill complex data structures
		552	# we "recreate" all package loggers and reset the hierarchy
		553	while (my ($k, $v) = each %CTX) {
		554	@$v = ($k, (1 << 10) - 1 - 1, { });
		555
		556	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
279	}	557	}
280		558
281	$ctx	559	@$_ = ($_->[0], (1 << 10) - 1 - 1)
		560	for $LOG, $FILTER, $COLLECT;
		561
		562	#$LOG->slaves;
		563	$LOG->title ('$AnyEvent::Log::LOG');
		564	$LOG->log_to_warn;
		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;
282	}	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	$COLLECT = ctx undef;
		588
		589	AnyEvent::Log::reset;
		590
		591	# hello, CPAN, please catch me
		592	package AnyEvent::Log::LOG;
		593	package AE::Log::LOG;
		594	package AnyEvent::Log::FILTER;
		595	package AE::Log::FILTER;
		596	package AnyEvent::Log::COLLECT;
		597	package AE::Log::COLLECT;
283		598
284	package AnyEvent::Log::Ctx;	599	package AnyEvent::Log::Ctx;
285		600
286	sub DESTROY {	601	# 0 1 2 3 4
287	# if only one member is remaining (name!) then delete this context	602	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
288	delete $CTX{$_[0]{name}}	603
289	if 1 == scalar keys %{ $_[0] };	604	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
		605
		606	This is a convenience constructor that makes it simpler to construct
		607	anonymous logging contexts.
		608
		609	Each key-value pair results in an invocation of the method of the same
		610	name as the key with the value as parameter, unless the value is an
		611	arrayref, in which case it calls the method with the contents of the
		612	array. The methods are called in the same order as specified.
		613
		614	Example: create a new logging context and set both the default logging
		615	level, some slave contexts and a logging callback.
		616
		617	$ctx = new AnyEvent::Log::Ctx
		618	title => "dubious messages",
		619	level => "error",
		620	log_cb => sub { print STDOUT shift; 0 },
		621	slaves => [$ctx1, $ctx, $ctx2],
		622	;
		623
		624	=back
		625
		626	=cut
		627
		628	sub new {
		629	my $class = shift;
		630
		631	my $ctx = AnyEvent::Log::ctx undef;
		632
		633	while (@_) {
		634	my ($k, $v) = splice @_, 0, 2;
		635	$ctx->$k (ref $v eq "ARRAY" ? @$v : $v);
		636	}
		637
		638	bless $ctx, $class # do we really support subclassing, hmm?
		639	}
		640
		641
		642	=head2 CONFIGURING A LOG CONTEXT
		643
		644	The following methods can be used to configure the logging context.
		645
		646	=over 4
		647
		648	=item $ctx->title ([$new_title])
		649
		650	Returns the title of the logging context - this is the package name, for
		651	package contexts, and a user defined string for all others.
		652
		653	If C<$new_title> is given, then it replaces the package name or title.
		654
		655	=cut
		656
		657	sub title {
		658	$_[0][0] = $_[1] if @_ > 1;
		659	$_[0][0]
		660	}
		661
		662	=back
		663
		664	=head3 LOGGING LEVELS
		665
		666	The following methods deal with the logging level set associated with the
		667	log context.
		668
		669	The most common method to use is probably C<< $ctx->level ($level) >>,
		670	which configures the specified and any higher priority levels.
		671
		672	All functions which accept a list of levels also accept the special string
		673	C<all> which expands to all logging levels.
		674
		675	=over 4
		676
		677	=item $ctx->levels ($level[, $level...)
		678
		679	Enables logging for the given levels and disables it for all others.
		680
		681	=item $ctx->level ($level)
		682
		683	Enables logging for the given level and all lower level (higher priority)
		684	ones. In addition to normal logging levels, specifying a level of C<0> or
		685	C<off> disables all logging for this level.
		686
		687	Example: log warnings, errors and higher priority messages.
		688
		689	$ctx->level ("warn");
		690	$ctx->level (5); # same thing, just numeric
		691
		692	=item $ctx->enable ($level[, $level...])
		693
		694	Enables logging for the given levels, leaving all others unchanged.
		695
		696	=item $ctx->disable ($level[, $level...])
		697
		698	Disables logging for the given levels, leaving all others unchanged.
		699
		700	=cut
		701
		702	sub _lvl_lst {
		703	map {
		704	$_ > 0 && $_ <= 9 ? $_+0
		705	: $_ eq "all" ? (1 .. 9)
		706	: $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught"
		707	} @_
		708	}
		709
		710	our $NOP_CB = sub { 0 };
		711
		712	sub levels {
		713	my $ctx = shift;
		714	$ctx->[1] = 0;
		715	$ctx->[1] \|= 1 << $_
		716	for &_lvl_lst;
		717	AnyEvent::Log::_reassess;
		718	}
		719
		720	sub level {
		721	my $ctx = shift;
		722	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[-1];
		723
		724	$ctx->[1] = ((1 << $lvl) - 1) << 1;
		725	AnyEvent::Log::_reassess;
		726	}
		727
		728	sub enable {
		729	my $ctx = shift;
		730	$ctx->[1] \|= 1 << $_
		731	for &_lvl_lst;
		732	AnyEvent::Log::_reassess;
		733	}
		734
		735	sub disable {
		736	my $ctx = shift;
		737	$ctx->[1] &= ~(1 << $_)
		738	for &_lvl_lst;
		739	AnyEvent::Log::_reassess;
		740	}
		741
		742	=back
		743
		744	=head3 SLAVE CONTEXTS
		745
		746	The following methods attach and detach another logging context to a
		747	logging context.
		748
		749	Log messages are propagated to all slave contexts, unless the logging
		750	callback consumes the message.
		751
		752	=over 4
		753
		754	=item $ctx->attach ($ctx2[, $ctx3...])
		755
		756	Attaches the given contexts as slaves to this context. It is not an error
		757	to add a context twice (the second add will be ignored).
		758
		759	A context can be specified either as package name or as a context object.
		760
		761	=item $ctx->detach ($ctx2[, $ctx3...])
		762
		763	Removes the given slaves from this context - it's not an error to attempt
		764	to remove a context that hasn't been added.
		765
		766	A context can be specified either as package name or as a context object.
		767
		768	=item $ctx->slaves ($ctx2[, $ctx3...])
		769
		770	Replaces all slaves attached to this context by the ones given.
		771
		772	=cut
		773
		774	sub attach {
		775	my $ctx = shift;
		776
		777	$ctx->[2]{$_+0} = $_
		778	for map { AnyEvent::Log::ctx $_ } @_;
		779	}
		780
		781	sub detach {
		782	my $ctx = shift;
		783
		784	delete $ctx->[2]{$_+0}
		785	for map { AnyEvent::Log::ctx $_ } @_;
		786	}
		787
		788	sub slaves {
		789	undef $_[0][2];
		790	&attach;
		791	}
		792
		793	=back
		794
		795	=head3 LOG TARGETS
		796
		797	The following methods configure how the logging context actually does
		798	the logging (which consists of formatting the message and printing it or
		799	whatever it wants to do with it).
		800
		801	=over 4
		802
		803	=item $ctx->log_cb ($cb->($str)
		804
		805	Replaces the logging callback on the context (C<undef> disables the
		806	logging callback).
		807
		808	The logging callback is responsible for handling formatted log messages
		809	(see C<fmt_cb> below) - normally simple text strings that end with a
		810	newline (and are possibly multiline themselves).
		811
		812	It also has to return true iff it has consumed the log message, and false
		813	if it hasn't. Consuming a message means that it will not be sent to any
		814	slave context. When in doubt, return C<0> from your logging callback.
		815
		816	Example: a very simple logging callback, simply dump the message to STDOUT
		817	and do not consume it.
		818
		819	$ctx->log_cb (sub { print STDERR shift; 0 });
		820
		821	You can filter messages by having a log callback that simply returns C<1>
		822	and does not do anything with the message, but this counts as "message
		823	being logged" and might not be very efficient.
		824
		825	Example: propagate all messages except for log levels "debug" and
		826	"trace". The messages will still be generated, though, which can slow down
		827	your program.
		828
		829	$ctx->levels ("debug", "trace");
		830	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
		831
		832	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
		833
		834	Replaces the formatting callback on the context (C<undef> restores the
		835	default formatter).
		836
		837	The callback is passed the (possibly fractional) timestamp, the original
		838	logging context, the (numeric) logging level and the raw message string
		839	and needs to return a formatted log message. In most cases this will be a
		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.
		846
		847	Example: format just the raw message, with numeric log level in angle
		848	brackets.
		849
		850	$ctx->fmt_cb (sub {
		851	my ($time, $ctx, $lvl, $msg) = @_;
		852
		853	"<$lvl>$msg\n"
		854	});
		855
		856	Example: return an array reference with just the log values, and use
		857	C<PApp::SQL::sql_exec> to store the emssage in a database.
		858
		859	$ctx->fmt_cb (sub { \@_ });
		860	$ctx->log_cb (sub {
		861	my ($msg) = @_;
		862
		863	sql_exec "insert into log (when, subsys, prio, msg) values (?, ?, ?, ?)",
		864	$msg->[0] + 0,
		865	"$msg->[1]",
		866	$msg->[2] + 0,
		867	"$msg->[3]";
		868
		869	0
		870	});
		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, $str] as input.
		900
		901	=cut
		902
		903	sub log_cb {
		904	my ($ctx, $cb) = @_;
		905
		906	$ctx->[3] = $cb;
		907	}
		908
		909	sub fmt_cb {
		910	my ($ctx, $cb) = @_;
		911
		912	$ctx->[4] = $cb;
		913	}
		914
		915	sub log_to_warn {
		916	my ($ctx, $path) = @_;
		917
		918	$ctx->log_cb (sub {
		919	warn shift;
		920	0
		921	});
		922	}
		923
		924	sub log_to_file {
		925	my ($ctx, $path) = @_;
		926
		927	open my $fh, ">>", $path
		928	or die "$path: $!";
		929
		930	$ctx->log_cb (sub {
		931	syswrite $fh, shift;
		932	0
		933	});
		934	}
		935
		936	sub log_to_path {
		937	my ($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	}
290	}	1218	}
291		1219
292	1;	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
		1248
		1249	=item Write all messages with priority C<error> and higher to a file.
		1250
		1251	This writes them only when the global logging level allows it, because
		1252	it is attached to the default context which is invoked I<after> global
		1253	filtering.
		1254
		1255	$AnyEvent::Log::FILTER->attach (
		1256	new AnyEvent::Log::Ctx log_to_file => $path);
		1257
		1258	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
		1259
		1260	This writes them regardless of the global logging level, because it is
		1261	attached to the toplevel context, which receives all messages I<before>
		1262	the global filtering.
		1263
		1264	$AnyEvent::Log::COLLECT->attach (
		1265	new AnyEvent::Log::Ctx log_to_file => $path);
		1266
		1267	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1268
		1269	In both cases, messages are still written to STDERR.
		1270
		1271	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
		1272
		1273	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
		1274	context - this simply circumvents the global filtering for trace messages.
		1275
		1276	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
		1277	$debug->attach ($AnyEvent::Log::LOG);
		1278
		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.
293		1284
294	=back	1285	=back
295		1286
296	=head1 AUTHOR	1287	=head1 AUTHOR
297		1288
298	Marc Lehmann <schmorp@schmorp.de>	1289	Marc Lehmann <schmorp@schmorp.de>
299	http://home.schmorp.de/	1290	http://home.schmorp.de/
300		1291
301	=cut	1292	=cut
		1293

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.7 by root, Thu Aug 18 18:02:11 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 1.7 by root, Thu Aug 18 18:02:11 2011 UTC vs.
Revision 1.43 by root, Mon Sep 5 07:21:54 2011 UTC