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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.14 by root, Sat Aug 20 01:49:27 2011 UTC vs.
Revision 1.44 by root, Mon Sep 26 11:32:19 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 trace => "going to call function abc";
11	AE::log warn => "it's a bit too hot";	12	AE::log debug => "the function returned 3";
12	AE::log error => "the flag was false!";	13	AE::log info => "file soandso successfully deleted";
13	AE::log fatal => "the bit toggled! run!";	14	AE::log note => "wanted to create config, but config was alraedy created";
		15	AE::log warn => "couldn't delete the file";
		16	AE::log error => "failed to retrieve data";
		17	AE::log crit => "the battery temperature is too hot";
		18	AE::log alert => "the battery died";
		19	AE::log fatal => "no config found, cannot continue"; # never returns
14		20
15	# "complex" use	21	Log level overview:
		22
		23	LVL NAME SYSLOG PERL NOTE
		24	1 fatal emerg exit system unusable, aborts program!
		25	2 alert failure in primary system
		26	3 critical crit failure in backup system
		27	4 error err die non-urgent program errors, a bug
		28	5 warn warning possible problem, not necessarily error
		29	6 note notice unusual conditions
		30	7 info normal messages, no action required
		31	8 debug debugging messages for development
		32	9 trace copious tracing output
		33
		34	"Complex" uses (for speed sensitive code, e.g. trace/debug messages):
		35
16	use AnyEvent::Log;	36	use AnyEvent::Log;
17		37
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	38	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		39
20	$tracer->("i am here") if $trace;	40	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	41	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		42
23	# configuration	43	Configuration (also look at the EXAMPLES section):
24		44
25	# set logging for this package to maximum	45	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("all");	46	AnyEvent::Log::ctx->level ("error");
27		47
28	# set logging globally to anything below debug	48	# set logging level to suppress anything below "notice"
29	(AnyEvent::Log::ctx "")->level ("notice");	49	$AnyEvent::Log::FILTER->level ("notice");
30		50
31	# see also EXAMPLES, below	51	# send all critical and higher priority messages to syslog,
32		52	# regardless of (most) other settings
33	# disable logging for package "AnyEvent" and all packages below it	53	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
34	AnyEvent->AnyEvent::Log::ctx->level (0);	54	level => "critical",
35		55	log_to_syslog => "user",
36	# log everything below debug to a file, for the whole program	56	);
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		57
41	=head1 DESCRIPTION	58	=head1 DESCRIPTION
42		59
43	This module implements a relatively simple "logging framework". It doesn't	60	This module implements a relatively simple "logging framework". It doesn't
44	attempt to be "the" logging solution or even "a" logging solution for	61	attempt to be "the" logging solution or even "a" logging solution for
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	62	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	module more or less exposes the mechanism, with some extra spiff to allow	63	module more or less exposes the mechanism, with some extra spiff to allow
47	using it from other modules as well.	64	using it from other modules as well.
48		65
49	Remember that the default verbosity level is C<0>, so nothing will be	66	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	67	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	68	before starting your program, or change the logging level at runtime with
52	something like:	69	something like:
53		70
54	use AnyEvent;	71	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	72	$AnyEvent::Log::FILTER->level ("info");
56		73
57	The design goal behind this module was to keep it simple (and small),	74	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	75	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	76	extensive enough for the most common tasks, such as logging to multiple
60	targets, or being able to log into a database.	77	targets, or being able to log into a database.
61		78
		79	The module is also usable before AnyEvent itself is initialised, in which
		80	case some of the functionality might be reduced.
		81
62	The amount of documentation might indicate otherwise, but the module is	82	The amount of documentation might indicate otherwise, but the runtime part
63	still just 240 lines or so.	83	of the module is still just below 300 lines of code.
		84
		85	=head1 LOGGING LEVELS
		86
		87	Logging levels in this module range from C<1> (highest priority) to C<9>
		88	(lowest priority). Note that the lowest numerical value is the highest
		89	priority, so when this document says "higher priority" it means "lower
		90	numerical value".
		91
		92	Instead of specifying levels by name you can also specify them by aliases:
		93
		94	LVL NAME SYSLOG PERL NOTE
		95	1 fatal emerg exit system unusable, aborts program!
		96	2 alert failure in primary system
		97	3 critical crit failure in backup system
		98	4 error err die non-urgent program errors, a bug
		99	5 warn warning possible problem, not necessarily error
		100	6 note notice unusual conditions
		101	7 info normal messages, no action required
		102	8 debug debugging messages for development
		103	9 trace copious tracing output
		104
		105	As you can see, some logging levels have multiple aliases - the first one
		106	is the "official" name, the second one the "syslog" name (if it differs)
		107	and the third one the "perl" name, suggesting (only!) that you log C<die>
		108	messages at C<error> priority. The NOTE column tries to provide some
		109	rationale on how to chose a logging level.
		110
		111	As a rough guideline, levels 1..3 are primarily meant for users of
		112	the program (admins, staff), and are the only logged to STDERR by
		113	default. Levels 4..6 are meant for users and developers alike, while
		114	levels 7..9 are usually meant for developers.
		115
		116	You can normally only log a single message at highest priority level
		117	(C<1>, C<fatal>), because logging a fatal message will also quit the
		118	program - so use it sparingly :)
		119
		120	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		121	or C<all> - these are only valid in the methods they are documented for.
64		122
65	=head1 LOGGING FUNCTIONS	123	=head1 LOGGING FUNCTIONS
66		124
67	These functions allow you to log messages. They always use the caller's	125	These functions allow you to log messages. They always use the caller's
68	package as a "logging module/source". Also, the main logging function is	126	package as a "logging context". Also, the main logging function C<log> is
69	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	127	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
70	loaded.	128	loaded.
71		129
72	=over 4	130	=over 4
73		131
…		…
77		135
78	use Carp ();	136	use Carp ();
79	use POSIX ();	137	use POSIX ();
80		138
81	use AnyEvent (); BEGIN { AnyEvent::common_sense }	139	use AnyEvent (); BEGIN { AnyEvent::common_sense }
82	use AnyEvent::Util ();	140	#use AnyEvent::Util (); need to load this in a delayed fashion, as it uses AE::log
83		141
84	our $VERSION = $AnyEvent::VERSION;	142	our $VERSION = $AnyEvent::VERSION;
		143
		144	our ($COLLECT, $FILTER, $LOG);
85		145
86	our ($now_int, $now_str1, $now_str2);	146	our ($now_int, $now_str1, $now_str2);
87		147
88	# Format Time, not public - yet?	148	# Format Time, not public - yet?
89	sub ft($) {	149	sub ft($) {
…		…
94	if $now_int != $i;	154	if $now_int != $i;
95		155
96	"$now_str1$f$now_str2"	156	"$now_str1$f$now_str2"
97	}	157	}
98		158
99	our %CTX; # all logging contexts	159	our %CTX; # all package contexts
100		160
101	# creates a default package context object for the given package	161	# creates a default package context object for the given package
102	sub _pkg_ctx($) {	162	sub _pkg_ctx($) {
103	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	163	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
104		164
105	# link "parent" package	165	# link "parent" package
106	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	166	my $parent = $_[0] =~ /^(.+)::/
		167	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		168	: $COLLECT;
107		169
108	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
109	$ctx->[2]{$pkg+0} = $pkg;	170	$ctx->[2]{$parent+0} = $parent;
110		171
111	$ctx	172	$ctx
112	}	173	}
113		174
114	=item AnyEvent::Log::log $level, $msg[, @args]	175	=item AnyEvent::Log::log $level, $msg[, @args]
115		176
116	Requests logging of the given C<$msg> with the given log level (1..9).	177	Requests logging of the given C<$msg> with the given log level, and
117	You can also use the following strings as log level: C<fatal> (1),	178	returns true if the message was logged I<somewhere>.
118	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
119	C<info> (7), C<debug> (8), C<trace> (9).
120		179
121	For C<fatal> log levels, the program will abort.	180	For loglevel C<fatal>, the program will abort.
122		181
123	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	182	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
124	C<$msg> is interpreted as an sprintf format string.	183	C<$msg> is interpreted as an sprintf format string.
125		184
126	The C<$msg> should not end with C<\n>, but may if that is convenient for	185	The C<$msg> should not end with C<\n>, but may if that is convenient for
…		…
130	supposed to return the message. It will be called only then the message	189	supposed to return the message. It will be called only then the message
131	actually gets logged, which is useful if it is costly to create the	190	actually gets logged, which is useful if it is costly to create the
132	message in the first place.	191	message in the first place.
133		192
134	Whether the given message will be logged depends on the maximum log level	193	Whether the given message will be logged depends on the maximum log level
135	and the caller's package.	194	and the caller's package. The return value can be used to ensure that
		195	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		196	runtime error it tries to log it at C<die> level, but if that message is
		197	lost it simply uses warn.
136		198
137	Note that you can (and should) call this function as C<AnyEvent::log> or	199	Note that you can (and should) call this function as C<AnyEvent::log> or
138	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	200	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
139	need any additional functionality), as those functions will load the	201	need any additional functionality), as those functions will load the
140	logging module on demand only. They are also much shorter to write.	202	logging module on demand only. They are also much shorter to write.
…		…
157		219
158	=cut	220	=cut
159		221
160	# also allow syslog equivalent names	222	# also allow syslog equivalent names
161	our %STR2LEVEL = (	223	our %STR2LEVEL = (
162	fatal => 1, emerg => 1,	224	fatal => 1, emerg => 1, exit => 1,
163	alert => 2,	225	alert => 2,
164	critical => 3, crit => 3,	226	critical => 3, crit => 3,
165	error => 4, err => 4,	227	error => 4, err => 4, die => 4,
166	warn => 5, warning => 5,	228	warn => 5, warning => 5,
167	note => 6, notice => 6,	229	note => 6, notice => 6,
168	info => 7,	230	info => 7,
169	debug => 8,	231	debug => 8,
170	trace => 9,	232	trace => 9,
171	);	233	);
172		234
173	sub now () { time }	235	our $TIME_EXACT;
		236
		237	sub exact_time($) {
		238	$TIME_EXACT = shift;
		239	*_ts = $AnyEvent::MODEL
		240	? $TIME_EXACT ? \&AE::now : \&AE::time
		241	: sub () { $TIME_EXACT ? do { require Time::HiRes; Time::HiRes::time () } : time };
		242	}
		243
		244	BEGIN {
		245	exact_time 0;
		246	}
174		247
175	AnyEvent::post_detect {	248	AnyEvent::post_detect {
176	*now = \&AE::now;	249	exact_time $TIME_EXACT;
177	};	250	};
178		251
179	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	252	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
180		253
181	# time, ctx, level, msg	254	# time, ctx, level, msg
…		…
191	}	264	}
192		265
193	join "", @res	266	join "", @res
194	}	267	}
195		268
		269	sub fatal_exit() {
		270	exit 1;
		271	}
		272
196	sub _log {	273	sub _log {
197	my ($ctx, $level, $format, @args) = @_;	274	my ($ctx, $level, $format, @args) = @_;
198		275
199	$level = $level > 0 && $level <= 9	276	$level = $level > 0 && $level <= 9
200	? $level+0	277	? $level+0
201	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	278	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
202		279
203	my $mask = 1 << $level;	280	my $mask = 1 << $level;
204		281
205	my (%seen, @ctx, $now, $fmt);	282	my ($success, %seen, @ctx, $now, $fmt);
206		283
207	do	284	do
208	{	285	{
209	# skip if masked	286	# skip if masked
210	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	287	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
214	# now get raw message, unless we have it already	291	# now get raw message, unless we have it already
215	unless ($now) {	292	unless ($now) {
216	$format = $format->() if ref $format;	293	$format = $format->() if ref $format;
217	$format = sprintf $format, @args if @args;	294	$format = sprintf $format, @args if @args;
218	$format =~ s/\n$//;	295	$format =~ s/\n$//;
219	$now = AE::now;	296	$now = _ts;
220	};	297	};
221		298
222	# format msg	299	# format msg
223	my $str = $ctx->[4]	300	my $str = $ctx->[4]
224	? $ctx->[4]($now, $_[0], $level, $format)	301	? $ctx->[4]($now, $_[0], $level, $format)
225	: $fmt \|\|= _format $now, $_[0], $level, $format;	302	: ($fmt \|\|= _format $now, $_[0], $level, $format);
226		303
		304	$success = 1;
		305
227	$ctx->[3]($str);	306	$ctx->[3]($str)
		307	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		308	} else {
		309	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
228	}	310	}
229
230	# not masked, not consumed - propagate to parent contexts
231	push @ctx, values %{ $ctx->[2] };
232	}	311	}
233	}	312	}
234	while $ctx = pop @ctx;	313	while $ctx = pop @ctx;
235		314
236	exit 1 if $level <= 1;	315	fatal_exit if $level <= 1;
		316
		317	$success
237	}	318	}
238		319
239	sub log($$;@) {	320	sub log($$;@) {
240	_log	321	_log
241	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	322	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
242	@_;	323	@_;
243	}	324	}
244		325
245	AnyEvent::log = AE::log = \&log;
246
247	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	326	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
248		327
249	Creates a code reference that, when called, acts as if the	328	Creates a code reference that, when called, acts as if the
250	C<AnyEvent::Log::log> function was called at this point with the givne	329	C<AnyEvent::Log::log> function was called at this point with the given
251	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	330	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
252	the C<AnyEvent::Log::log> function:	331	the C<AnyEvent::Log::log> function:
253		332
254	my $debug_log = AnyEvent::Log::logger "debug";	333	my $debug_log = AnyEvent::Log::logger "debug";
255		334
…		…
280	# and later in your program	359	# and later in your program
281	$debug_log->("yo, stuff here") if $debug;	360	$debug_log->("yo, stuff here") if $debug;
282		361
283	$debug and $debug_log->("123");	362	$debug and $debug_log->("123");
284		363
285	Note: currently the enabled var is always true - that will be fixed in a
286	future version :)
287
288	=cut	364	=cut
289		365
290	our %LOGGER;	366	our %LOGGER;
291		367
292	# re-assess logging status for all loggers	368	# re-assess logging status for all loggers
293	sub _reassess {	369	sub _reassess {
		370	local $SIG{__DIE__};
		371	my $die = sub { die };
		372
294	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	373	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
295	my ($ctx, $level, $renabled) = @$_;	374	my ($ctx, $level, $renabled) = @$_;
296		375
297	# to detect whether a message would be logged, we # actually	376	# to detect whether a message would be logged, we actually
298	# try to log one and die. this isn't fast, but we can be	377	# try to log one and die. this isn't fast, but we can be
299	# sure that the logging decision is correct :)	378	# sure that the logging decision is correct :)
300		379
301	$$renabled = !eval {	380	$$renabled = !eval {
302	local $SIG{__DIE__};
303
304	_log $ctx, $level, sub { die };	381	_log $ctx, $level, $die;
305		382
306	1	383	1
307	};	384	};
308
309	$$renabled = 1; # TODO
310	}	385	}
311	}	386	}
312		387
313	sub _logger($;$) {	388	sub _logger {
314	my ($ctx, $level, $renabled) = @_;	389	my ($ctx, $level, $renabled) = @_;
315		390
316	$renabled \|\|= \my $enabled;
317
318	$$renabled = 1;	391	$$renabled = 1;
319		392
320	my $logger = [$ctx, $level, $renabled];	393	my $logger = [$ctx, $level, $renabled];
321		394
322	$LOGGER{$logger+0} = $logger;	395	$LOGGER{$logger+0} = $logger;
323		396
324	_reassess $logger+0;	397	_reassess $logger+0;
325		398
		399	require AnyEvent::Util unless $AnyEvent::Util::VERSION;
326	my $guard = AnyEvent::Util::guard {	400	my $guard = AnyEvent::Util::guard (sub {
327	# "clean up"	401	# "clean up"
328	delete $LOGGER{$logger+0};	402	delete $LOGGER{$logger+0};
329	};	403	});
330		404
331	sub {	405	sub {
332	$guard if 0; # keep guard alive, but don't cause runtime overhead	406	$guard if 0; # keep guard alive, but don't cause runtime overhead
333		407
334	_log $ctx, $level, @_	408	_log $ctx, $level, @_
…		…
339	sub logger($;$) {	413	sub logger($;$) {
340	_logger	414	_logger
341	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	415	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
342	@_	416	@_
343	}	417	}
		418
		419	=item AnyEvent::Log::exact_time $on
		420
		421	By default, C<AnyEvent::Log> will use C<AE::now>, i.e. the cached
		422	eventloop time, for the log timestamps. After calling this function with a
		423	true value it will instead resort to C<AE::time>, i.e. fetch the current
		424	time on each log message. This only makes a difference for event loops
		425	that actually cache the time (such as L<EV> or L<AnyEvent::Loop>).
		426
		427	This setting can be changed at any time by calling this function.
		428
		429	Since C<AnyEvent::Log> has to work even before the L<AnyEvent> has been
		430	initialised, this switch will also decide whether to use C<CORE::time> or
		431	C<Time::HiRes::time> when logging a message before L<AnyEvent> becomes
		432	available.
344		433
345	=back	434	=back
346		435
347	=head1 LOGGING CONTEXTS	436	=head1 LOGGING CONTEXTS
348		437
…		…
361	timestamp, context, level and string message and formats it in the way	450	timestamp, context, level and string message and formats it in the way
362	it should be logged) and a logging callback (which is responsible for	451	it should be logged) and a logging callback (which is responsible for
363	actually logging the formatted message and telling C<AnyEvent::Log>	452	actually logging the formatted message and telling C<AnyEvent::Log>
364	whether it has consumed the message, or whether it should be propagated).	453	whether it has consumed the message, or whether it should be propagated).
365		454
366	For propagation, a context can have any number of attached I<parent	455	For propagation, a context can have any number of attached I<slave
367	contexts>. Any message that is neither masked by the logging mask nor	456	contexts>. Any message that is neither masked by the logging mask nor
368	masked by the logging callback returning true will be passed to all parent	457	masked by the logging callback returning true will be passed to all slave
369	contexts.	458	contexts.
370		459
371	Each call to a logging function will log the message at most once per	460	Each call to a logging function will log the message at most once per
372	context, so it does not matter (much) if there are cycles or if the	461	context, so it does not matter (much) if there are cycles or if the
373	message can arrive at the same context via multiple paths.	462	message can arrive at the same context via multiple paths.
…		…
377	By default, all logging contexts have an full set of log levels ("all"), a	466	By default, all logging contexts have an full set of log levels ("all"), a
378	disabled logging callback and the default formatting callback.	467	disabled logging callback and the default formatting callback.
379		468
380	Package contexts have the package name as logging title by default.	469	Package contexts have the package name as logging title by default.
381		470
382	They have exactly one parent - the context of the "parent" package. The	471	They have exactly one slave - the context of the "parent" package. The
383	parent package is simply defined to be the package name without the last	472	parent package is simply defined to be the package name without the last
384	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	473	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
385	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	474	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
386	exception of the rule - just like the parent of any package name in	475	exception of the rule - just like the "parent" of any single-component
387	Perl is C<main>, the default parent of any top-level package context is	476	package name in Perl is C<main>, the default slave of any top-level
388	C<AnyEvent::Log::Top>.	477	package context is C<$AnyEvent::Log::COLLECT>.
389		478
390	Since perl packages form only an approximate hierarchy, this parent	479	Since perl packages form only an approximate hierarchy, this slave
391	context can of course be removed.	480	context can of course be removed.
392		481
393	All other (anonymous) contexts have no parents and an empty title by	482	All other (anonymous) contexts have no slaves and an empty title by
394	default.	483	default.
395		484
396	When the module is loaded it creates the default context called	485	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
397	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	486	context that simply logs everything via C<warn>, without propagating
398	which simply logs everything to STDERR and doesn't propagate anything
399	anywhere by default. The purpose of the default context is to provide	487	anything anywhere by default. The purpose of this context is to provide
400	a convenient place to override the global logging target or to attach	488	a convenient place to override the global logging target or to attach
401	additional log targets. It's not meant for filtering.	489	additional log targets. It's not meant for filtering.
402		490
403	It then creates the root context called C<AnyEvent::Log::Root> (also	491	It then creates the C<$AnyEvent::Log::FILTER> context whose
404	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	492	purpose is to suppress all messages with priority higher
405	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	493	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
406	then attached the default logging context to it. The purpose of the root	494	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
407	context is to simply provide filtering according to some global log level.	495	is to simply provide filtering according to some global log level.
408		496
409	Finally it creates the top-level package context called	497	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
410	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	498	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
411	C<$AnyEvent::Log::Top>) and attached the root context but otherwise leaves
412	it at default config. It's purpose is simply to collect all log messages	499	leaves it at default config. Its purpose is simply to collect all log
413	system-wide.	500	messages system-wide.
414		501
415	These three special contexts can also be referred to by the	502	The hierarchy is then:
416	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
417	C<AE::Log::Top>.
418		503
		504	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		505
419	The effect of all this is that log messages, by default, wander up	506	The effect of all this is that log messages, by default, wander up to the
420	to the root context where log messages with lower priority then	507	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		508	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
421	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	509	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
422	AnyEvent::Log::Default context to be logged to STDERR.	510	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
423		511
424	Splitting the top level context into three contexts makes it easy to set	512	This makes it easy to set a global logging level (by modifying $FILTER),
425	a global logging level (by modifying the root context), but still allow	513	but still allow other contexts to send, for example, their debug and trace
426	other contexts to log, for example, their debug and trace messages to the
427	default target despite the global logging level, or to attach additional	514	messages to the $LOG target despite the global logging level, or to attach
428	log targets that log messages, regardless of the global logging level.	515	additional log targets that log messages, regardless of the global logging
		516	level.
429		517
430	It also makes it easy to replace the default STDERR-logger by something	518	It also makes it easy to modify the default warn-logger ($LOG) to
431	that logs to a file, or to attach additional logging targets.	519	something that logs to a file, or to attach additional logging targets
		520	(such as loggign to a file) by attaching it to $FILTER.
432		521
433	=head2 CREATING/FINDING/DESTROYING CONTEXTS	522	=head2 CREATING/FINDING/DESTROYING CONTEXTS
434		523
435	=over 4	524	=over 4
436		525
…		…
458	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	547	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
459	}	548	}
460		549
461	=item AnyEvent::Log::reset	550	=item AnyEvent::Log::reset
462		551
463	Deletes all contexts and recreates the default hierarchy, i.e. resets the	552	Resets all package contexts and recreates the default hierarchy if
464	logging subsystem to defaults.	553	necessary, i.e. resets the logging subsystem to defaults, as much as
		554	possible. This process keeps references to contexts held by other parts of
		555	the program intact.
465		556
466	This can be used to implement config-file (re-)loading: before loading a	557	This can be used to implement config-file (re-)loading: before loading a
467	configuration, reset all contexts.	558	configuration, reset all contexts.
468		559
469	=cut	560	=cut
470		561
		562	our $ORIG_VERBOSE = $AnyEvent::VERBOSE;
		563	$AnyEvent::VERBOSE = 9;
		564
471	sub reset {	565	sub reset {
472	@$_ = () for values %CTX; # just to be sure - to kill circular logging dependencies	566	# hard to kill complex data structures
473	%CTX = ();	567	# we "recreate" all package loggers and reset the hierarchy
		568	while (my ($k, $v) = each %CTX) {
		569	@$v = ($k, (1 << 10) - 1 - 1, { });
474		570
475	my $default = ctx undef;	571	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
476	$default->title ("AnyEvent::Log::Default");
477	$default->log_cb (sub {
478	print STDERR shift;
479	0
480	});	572	}
481	$AnyEvent::Log::Default = $CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $default;
482		573
483	my $root = ctx undef;	574	@$_ = ($_->[0], (1 << 10) - 1 - 1)
484	$root->title ("AnyEvent::Log::Root");	575	for $LOG, $FILTER, $COLLECT;
485	$root->level ($AnyEvent::VERBOSE);
486	$root->attach ($default);
487	$AnyEvent::Log::Root = $CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $root;
488		576
489	my $top = ctx undef;	577	#$LOG->slaves;
490	$top->title ("AnyEvent::Log::Top");	578	$LOG->title ('$AnyEvent::Log::LOG');
491	$top->attach ($root);	579	$LOG->log_to_warn;
492	$AnyEvent::Log::Top = $CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $top;	580
		581	$FILTER->slaves ($LOG);
		582	$FILTER->title ('$AnyEvent::Log::FILTER');
		583	$FILTER->level ($ORIG_VERBOSE);
		584
		585	$COLLECT->slaves ($FILTER);
		586	$COLLECT->title ('$AnyEvent::Log::COLLECT');
		587
		588	_reassess;
493	}	589	}
		590
		591	# override AE::log/logger
		592	AnyEvent::log = AE::log = \&log;
		593	AnyEvent::logger = AE::logger = \&logger;
		594
		595	# convert AnyEvent loggers to AnyEvent::Log loggers
		596	$_->[0] = ctx $_->[0] # convert "pkg" to "ctx"
		597	for values %LOGGER;
		598
		599	# create the default logger contexts
		600	$LOG = ctx undef;
		601	$FILTER = ctx undef;
		602	$COLLECT = ctx undef;
494		603
495	AnyEvent::Log::reset;	604	AnyEvent::Log::reset;
496		605
497	# hello, CPAN, please catch me	606	# hello, CPAN, please catch me
498	package AnyEvent::Log::Default;
499	package AE::Log::Default;
500	package AnyEvent::Log::Root;
501	package AE::Log::Root;
502	package AnyEvent::Log::Top;	607	package AnyEvent::Log::LOG;
503	package AE::Log::Top;	608	package AE::Log::LOG;
		609	package AnyEvent::Log::FILTER;
		610	package AE::Log::FILTER;
		611	package AnyEvent::Log::COLLECT;
		612	package AE::Log::COLLECT;
504		613
505	package AnyEvent::Log::Ctx;	614	package AnyEvent::Log::Ctx;
506		615
507	# 0 1 2 3 4	616	# 0 1 2 3 4
508	# [$title, $level, %$parents, &$logcb, &$fmtcb]	617	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
509		618
510	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	619	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
511		620
512	This is a convenience constructor that makes it simpler to construct	621	This is a convenience constructor that makes it simpler to construct
513	anonymous logging contexts.	622	anonymous logging contexts.
…		…
516	name as the key with the value as parameter, unless the value is an	625	name as the key with the value as parameter, unless the value is an
517	arrayref, in which case it calls the method with the contents of the	626	arrayref, in which case it calls the method with the contents of the
518	array. The methods are called in the same order as specified.	627	array. The methods are called in the same order as specified.
519		628
520	Example: create a new logging context and set both the default logging	629	Example: create a new logging context and set both the default logging
521	level, some parent contexts and a logging callback.	630	level, some slave contexts and a logging callback.
522		631
523	$ctx = new AnyEvent::Log::Ctx	632	$ctx = new AnyEvent::Log::Ctx
524	title => "dubious messages",	633	title => "dubious messages",
525	level => "error",	634	level => "error",
526	log_cb => sub { print STDOUT shift; 0 },	635	log_cb => sub { print STDOUT shift; 0 },
527	parents => [$ctx1, $ctx, $ctx2],	636	slaves => [$ctx1, $ctx, $ctx2],
528	;	637	;
529		638
530	=back	639	=back
531		640
532	=cut	641	=cut
…		…
645	AnyEvent::Log::_reassess;	754	AnyEvent::Log::_reassess;
646	}	755	}
647		756
648	=back	757	=back
649		758
650	=head3 PARENT CONTEXTS	759	=head3 SLAVE CONTEXTS
651		760
652	The following methods attach and detach another logging context to a	761	The following methods attach and detach another logging context to a
653	logging context.	762	logging context.
654		763
655	Log messages are propagated to all parent contexts, unless the logging	764	Log messages are propagated to all slave contexts, unless the logging
656	callback consumes the message.	765	callback consumes the message.
657		766
658	=over 4	767	=over 4
659		768
660	=item $ctx->attach ($ctx2[, $ctx3...])	769	=item $ctx->attach ($ctx2[, $ctx3...])
661		770
662	Attaches the given contexts as parents to this context. It is not an error	771	Attaches the given contexts as slaves to this context. It is not an error
663	to add a context twice (the second add will be ignored).	772	to add a context twice (the second add will be ignored).
664		773
665	A context can be specified either as package name or as a context object.	774	A context can be specified either as package name or as a context object.
666		775
667	=item $ctx->detach ($ctx2[, $ctx3...])	776	=item $ctx->detach ($ctx2[, $ctx3...])
668		777
669	Removes the given parents from this context - it's not an error to attempt	778	Removes the given slaves from this context - it's not an error to attempt
670	to remove a context that hasn't been added.	779	to remove a context that hasn't been added.
671		780
672	A context can be specified either as package name or as a context object.	781	A context can be specified either as package name or as a context object.
673		782
674	=item $ctx->parents ($ctx2[, $ctx3...])	783	=item $ctx->slaves ($ctx2[, $ctx3...])
675		784
676	Replaces all parents attached to this context by the ones given.	785	Replaces all slaves attached to this context by the ones given.
677		786
678	=cut	787	=cut
679		788
680	sub attach {	789	sub attach {
681	my $ctx = shift;	790	my $ctx = shift;
…		…
689		798
690	delete $ctx->[2]{$_+0}	799	delete $ctx->[2]{$_+0}
691	for map { AnyEvent::Log::ctx $_ } @_;	800	for map { AnyEvent::Log::ctx $_ } @_;
692	}	801	}
693		802
694	sub parents {	803	sub slaves {
695	undef $_[0][2];	804	undef $_[0][2];
696	&attach;	805	&attach;
697	}	806	}
698		807
699	=back	808	=back
700		809
701	=head3 MESSAGE LOGGING	810	=head3 LOG TARGETS
702		811
703	The following methods configure how the logging context actually does	812	The following methods configure how the logging context actually does
704	the logging (which consists of formatting the message and printing it or	813	the logging (which consists of formatting the message and printing it or
705	whatever it wants to do with it) and also allows you to log messages	814	whatever it wants to do with it).
706	directly to a context, without going via your package context.
707		815
708	=over 4	816	=over 4
709		817
710	=item $ctx->log_cb ($cb->($str))	818	=item $ctx->log_cb ($cb->($str)
711		819
712	Replaces the logging callback on the context (C<undef> disables the	820	Replaces the logging callback on the context (C<undef> disables the
713	logging callback).	821	logging callback).
714		822
715	The logging callback is responsible for handling formatted log messages	823	The logging callback is responsible for handling formatted log messages
716	(see C<fmt_cb> below) - normally simple text strings that end with a	824	(see C<fmt_cb> below) - normally simple text strings that end with a
717	newline (and are possibly multiline themselves).	825	newline (and are possibly multiline themselves).
718		826
719	It also has to return true iff it has consumed the log message, and false	827	It also has to return true iff it has consumed the log message, and false
720	if it hasn't. Consuming a message means that it will not be sent to any	828	if it hasn't. Consuming a message means that it will not be sent to any
721	parent context. When in doubt, return C<0> from your logging callback.	829	slave context. When in doubt, return C<0> from your logging callback.
722		830
723	Example: a very simple logging callback, simply dump the message to STDOUT	831	Example: a very simple logging callback, simply dump the message to STDOUT
724	and do not consume it.	832	and do not consume it.
725		833
726	$ctx->log_cb (sub { print STDERR shift; 0 });	834	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
734	your program.	842	your program.
735		843
736	$ctx->levels ("debug", "trace");	844	$ctx->levels ("debug", "trace");
737	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	845	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
738		846
739	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	847	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
740		848
741	Replaces the formatting callback on the context (C<undef> restores the	849	Replaces the formatting callback on the context (C<undef> restores the
742	default formatter).	850	default formatter).
743		851
744	The callback is passed the (possibly fractional) timestamp, the original	852	The callback is passed the (possibly fractional) timestamp, the original
745	logging context, the (numeric) logging level and the raw message string and needs to	853	logging context, the (numeric) logging level and the raw message string
746	return a formatted log message. In most cases this will be a string, but	854	and needs to return a formatted log message. In most cases this will be a
747	it could just as well be an array reference that just stores the values.	855	string, but it could just as well be an array reference that just stores
		856	the values.
		857
		858	If, for some reason, you want to use C<caller> to find out more baout the
		859	logger then you should walk up the call stack until you are no longer
		860	inside the C<AnyEvent::Log> package.
748		861
749	Example: format just the raw message, with numeric log level in angle	862	Example: format just the raw message, with numeric log level in angle
750	brackets.	863	brackets.
751		864
752	$ctx->fmt_cb (sub {	865	$ctx->fmt_cb (sub {
…		…
769	"$msg->[3]";	882	"$msg->[3]";
770		883
771	0	884	0
772	});	885	});
773		886
		887	=item $ctx->log_to_warn
		888
		889	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		890	(usually this logs to STDERR).
		891
		892	=item $ctx->log_to_file ($path)
		893
		894	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		895
		896	=item $ctx->log_to_path ($path)
		897
		898	Same as C<< ->log_to_file >>, but opens the file for each message. This
		899	is much slower, but allows you to change/move/rename/delete the file at
		900	basically any time.
		901
		902	Needless(?) to say, if you do not want to be bitten by some evil person
		903	calling C<chdir>, the path should be absolute. Doesn't help with
		904	C<chroot>, but hey...
		905
		906	=item $ctx->log_to_syslog ([$facility])
		907
		908	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and
		909	all the others in the obvious way. If specified, then the C<$facility> is
		910	used as the facility (C<user>, C<auth>, C<local0> and so on). The default
		911	facility is C<user>.
		912
		913	Note that this function also sets a C<fmt_cb> - the logging part requires
		914	an array reference with [$level, $str] as input.
		915
774	=cut	916	=cut
775		917
776	sub log_cb {	918	sub log_cb {
777	my ($ctx, $cb) = @_;	919	my ($ctx, $cb) = @_;
778		920
…		…
783	my ($ctx, $cb) = @_;	925	my ($ctx, $cb) = @_;
784		926
785	$ctx->[4] = $cb;	927	$ctx->[4] = $cb;
786	}	928	}
787		929
788	=item $ctx->log ($level, $msg[, @params])	930	sub log_to_warn {
		931	my ($ctx, $path) = @_;
789		932
790	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	933	$ctx->log_cb (sub {
		934	warn shift;
		935	0
		936	});
		937	}
791		938
792	=item $logger = $ctx->logger ($level[, \$enabled])	939	sub log_to_file {
793		940	my ($ctx, $path) = @_;
794	Same as C<AnyEvent::Log::logger>, but uses the given context as log
795	context.
796
797	=cut
798
799	*log = \&AnyEvent::Log::_log;
800	*logger = \&AnyEvent::Log::_logger;
801
802	1;
803
804	=back
805
806	=head1 EXAMPLES
807
808	This section shows some common configurations.
809
810	=over 4
811
812	=item Setting the global logging level.
813
814	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
815	running your program, or modify the log level of the root context:
816
817	PERL_ANYEVENT_VERBOSE=5 ./myprog
818
819	$AnyEvent::Log::Root->level ("warn");
820
821	=item Append all messages to a file instead of sending them to STDERR.
822
823	This is affected by the global logging level.
824		941
825	open my $fh, ">>", $path	942	open my $fh, ">>", $path
826	or die "$path: $!";	943	or die "$path: $!";
827		944
828	$AnyEvent::Log::Default->log_cb (sub {	945	$ctx->log_cb (sub {
829	syswrite $fh, shift;	946	syswrite $fh, shift;
830	0	947	0
831	});	948	});
		949	}
		950
		951	sub log_to_path {
		952	my ($ctx, $path) = @_;
		953
		954	$ctx->log_cb (sub {
		955	open my $fh, ">>", $path
		956	or die "$path: $!";
		957
		958	syswrite $fh, shift;
		959	0
		960	});
		961	}
		962
		963	sub log_to_syslog {
		964	my ($ctx, $facility) = @_;
		965
		966	require Sys::Syslog;
		967
		968	$ctx->fmt_cb (sub {
		969	my $str = $_[3];
		970	$str =~ s/\n(?=.)/\n+ /g;
		971
		972	[$_[2], "($_[1][0]) $str"]
		973	});
		974
		975	$facility \|\|= "user";
		976
		977	$ctx->log_cb (sub {
		978	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		979
		980	Sys::Syslog::syslog ("$facility\|" . ($lvl - 1), $_)
		981	for split /\n/, $_[0][1];
		982
		983	0
		984	});
		985	}
		986
		987	=back
		988
		989	=head3 MESSAGE LOGGING
		990
		991	These methods allow you to log messages directly to a context, without
		992	going via your package context.
		993
		994	=over 4
		995
		996	=item $ctx->log ($level, $msg[, @params])
		997
		998	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		999
		1000	=item $logger = $ctx->logger ($level[, \$enabled])
		1001
		1002	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		1003	context.
		1004
		1005	=cut
		1006
		1007	*log = \&AnyEvent::Log::_log;
		1008	*logger = \&AnyEvent::Log::_logger;
		1009
		1010	=back
		1011
		1012	=cut
		1013
		1014	package AnyEvent::Log;
		1015
		1016	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		1017
		1018	Logging can also be configured by setting the environment variable
		1019	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		1020
		1021	The value consists of one or more logging context specifications separated
		1022	by C<:> or whitespace. Each logging specification in turn starts with a
		1023	context name, followed by C<=>, followed by zero or more comma-separated
		1024	configuration directives, here are some examples:
		1025
		1026	# set default logging level
		1027	filter=warn
		1028
		1029	# log to file instead of to stderr
		1030	log=file=/tmp/mylog
		1031
		1032	# log to file in addition to stderr
		1033	log=+%file:%file=file=/tmp/mylog
		1034
		1035	# enable debug log messages, log warnings and above to syslog
		1036	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		1037
		1038	# log trace messages (only) from AnyEvent::Debug to file
		1039	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		1040
		1041	A context name in the log specification can be any of the following:
		1042
		1043	=over 4
		1044
		1045	=item C<collect>, C<filter>, C<log>
		1046
		1047	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		1048	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		1049
		1050	=item C<%name>
		1051
		1052	Context names starting with a C<%> are anonymous contexts created when the
		1053	name is first mentioned. The difference to package contexts is that by
		1054	default they have no attached slaves.
		1055
		1056	=item a perl package name
		1057
		1058	Any other string references the logging context associated with the given
		1059	Perl C<package>. In the unlikely case where you want to specify a package
		1060	context that matches on of the other context name forms, you can add a
		1061	C<::> to the package name to force interpretation as a package.
		1062
		1063	=back
		1064
		1065	The configuration specifications can be any number of the following:
		1066
		1067	=over 4
		1068
		1069	=item C<stderr>
		1070
		1071	Configures the context to use Perl's C<warn> function (which typically
		1072	logs to C<STDERR>). Works like C<log_to_warn>.
		1073
		1074	=item C<file=>I<path>
		1075
		1076	Configures the context to log to a file with the given path. Works like
		1077	C<log_to_file>.
		1078
		1079	=item C<path=>I<path>
		1080
		1081	Configures the context to log to a file with the given path. Works like
		1082	C<log_to_path>.
		1083
		1084	=item C<syslog> or C<syslog=>I<expr>
		1085
		1086	Configures the context to log to syslog. If I<expr> is given, then it is
		1087	evaluated in the L<Sys::Syslog> package, so you could use:
		1088
		1089	log=syslog=LOG_LOCAL0
		1090
		1091	=item C<nolog>
		1092
		1093	Configures the context to not log anything by itself, which is the
		1094	default. Same as C<< $ctx->log_cb (undef) >>.
		1095
		1096	=item C<0> or C<off>
		1097
		1098	Sets the logging level of the context ot C<0>, i.e. all messages will be
		1099	filtered out.
		1100
		1101	=item C<all>
		1102
		1103	Enables all logging levels, i.e. filtering will effectively be switched
		1104	off (the default).
		1105
		1106	=item C<only>
		1107
		1108	Disables all logging levels, and changes the interpretation of following
		1109	level specifications to enable the specified level only.
		1110
		1111	Example: only enable debug messages for a context.
		1112
		1113	context=only,debug
		1114
		1115	=item C<except>
		1116
		1117	Enables all logging levels, and changes the interpretation of following
		1118	level specifications to disable that level. Rarely used.
		1119
		1120	Example: enable all logging levels except fatal and trace (this is rather
		1121	nonsensical).
		1122
		1123	filter=exept,fatal,trace
		1124
		1125	=item C<level>
		1126
		1127	Enables all logging levels, and changes the interpretation of following
		1128	level specifications to be "that level or any higher priority
		1129	message". This is the default.
		1130
		1131	Example: log anything at or above warn level.
		1132
		1133	filter=warn
		1134
		1135	# or, more verbose
		1136	filter=only,level,warn
		1137
		1138	=item C<1>..C<9> or a logging level name (C<error>, C<debug> etc.)
		1139
		1140	A numeric loglevel or the name of a loglevel will be interpreted according
		1141	to the most recent C<only>, C<except> or C<level> directive. By default,
		1142	specifying a logging level enables that and any higher priority messages.
		1143
		1144	=item C<+>I<context>
		1145
		1146	Attaches the named context as slave to the context.
		1147
		1148	=item C<+>
		1149
		1150	A line C<+> detaches all contexts, i.e. clears the slave list from the
		1151	context. Anonymous (C<%name>) contexts have no attached slaves by default,
		1152	but package contexts have the parent context as slave by default.
		1153
		1154	Example: log messages from My::Module to a file, do not send them to the
		1155	default log collector.
		1156
		1157	My::Module=+,file=/tmp/mymodulelog
		1158
		1159	=back
		1160
		1161	Any character can be escaped by prefixing it with a C<\> (backslash), as
		1162	usual, so to log to a file containing a comma, colon, backslash and some
		1163	spaces in the filename, you would do this:
		1164
		1165	PERL_ANYEVENT_LOG='log=file=/some\ \:file\ with\,\ \\-escapes'
		1166
		1167	Since whitespace (which includes newlines) is allowed, it is fine to
		1168	specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
		1169
		1170	PERL_ANYEVENT_LOG="
		1171	filter=warn
		1172	AnyEvent::Debug=+%trace
		1173	%trace=only,trace,+log
		1174	" myprog
		1175
		1176	Also, in the unlikely case when you want to concatenate specifications,
		1177	use whitespace as separator, as C<::> will be interpreted as part of a
		1178	module name, an empty spec with two separators:
		1179
		1180	PERL_ANYEVENT_LOG="$PERL_ANYEVENT_LOG MyMod=debug"
		1181
		1182	=cut
		1183
		1184	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1185	my %anon;
		1186
		1187	my $pkg = sub {
		1188	$_[0] eq "log" ? $LOG
		1189	: $_[0] eq "filter" ? $FILTER
		1190	: $_[0] eq "collect" ? $COLLECT
		1191	: $_[0] =~ /^%(.+)$/ ? ($anon{$1} \|\|= ctx undef)
		1192	: $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
		1193	: die # never reached?
		1194	};
		1195
		1196	/\G[[:space:]]+/gc; # skip initial whitespace
		1197
		1198	while (/\G((?:[^:=[:space:]]+\|::\|\\.)+)=/gc) {
		1199	my $ctx = $pkg->($1);
		1200	my $level = "level";
		1201
		1202	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1203	for ("$1") {
		1204	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1205	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1206	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1207	} elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog ($1);
		1208	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1209	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1210	} elsif ($_ eq "+" ) { $ctx->slaves;
		1211	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1212	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1213	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1214	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1215	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1216	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1217	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1218	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1219	}
		1220	}
		1221
		1222	/\G,/gc or last;
		1223	}
		1224
		1225	/\G[:[:space:]]+/gc or last;
		1226	}
		1227
		1228	/\G[[:space:]]+/gc; # skip trailing whitespace
		1229
		1230	if (/\G(.+)/g) {
		1231	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1232	}
		1233	}
		1234
		1235	1;
		1236
		1237	=head1 EXAMPLES
		1238
		1239	This section shows some common configurations, both as code, and as
		1240	C<PERL_ANYEVENT_LOG> string.
		1241
		1242	=over 4
		1243
		1244	=item Setting the global logging level.
		1245
		1246	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1247	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1248	the root context at runtime:
		1249
		1250	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1251
		1252	PERL_ANYEVENT_LOG=log=warn
		1253
		1254	$AnyEvent::Log::FILTER->level ("warn");
		1255
		1256	=item Append all messages to a file instead of sending them to STDERR.
		1257
		1258	This is affected by the global logging level.
		1259
		1260	$AnyEvent::Log::LOG->log_to_file ($path);
		1261
		1262	PERL_ANYEVENT_LOG=log=file=/some/path
832		1263
833	=item Write all messages with priority C<error> and higher to a file.	1264	=item Write all messages with priority C<error> and higher to a file.
834		1265
835	This writes them only when the global logging level allows it, because	1266	This writes them only when the global logging level allows it, because
836	it is attached to the default context which is invoked I<after> global	1267	it is attached to the default context which is invoked I<after> global
837	filtering.	1268	filtering.
838		1269
839	open my $fh, ">>", $path	1270	$AnyEvent::Log::FILTER->attach (
840	or die "$path: $!";	1271	new AnyEvent::Log::Ctx log_to_file => $path);
841		1272
842	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx	1273	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
843	log_cb => sub { syswrite $fh, shift; 0 });
844		1274
845	This writes them regardless of the global logging level, because it is	1275	This writes them regardless of the global logging level, because it is
846	attached to the toplevel context, which receives all messages I<before>	1276	attached to the toplevel context, which receives all messages I<before>
847	the global filtering.	1277	the global filtering.
848		1278
849	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	1279	$AnyEvent::Log::COLLECT->attach (
850	log_cb => sub { syswrite $fh, shift; 0 });	1280	new AnyEvent::Log::Ctx log_to_file => $path);
851		1281
		1282	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1283
852	In both cases, messages are still written to STDOUT.	1284	In both cases, messages are still written to STDERR.
853		1285
854	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	1286	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
855		1287
856	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	1288	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
857	context and increase the C<AnyEvent::Debug> logging level - this simply
858	circumvents the global filtering for trace messages.	1289	context - this simply circumvents the global filtering for trace messages.
859		1290
860	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	1291	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
861	$debug->attach ($AnyEvent::Log::Default);	1292	$debug->attach ($AnyEvent::Log::LOG);
862	$debug->levels ("trace"); # not "level"!
863		1293
864	This of course works for any package.	1294	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1295
		1296	This of course works for any package, not just L<AnyEvent::Debug>, but
		1297	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1298	default.
865		1299
866	=back	1300	=back
867		1301
868	=head1 AUTHOR	1302	=head1 AUTHOR
869		1303
870	Marc Lehmann <schmorp@schmorp.de>	1304	Marc Lehmann <schmorp@schmorp.de>
871	http://home.schmorp.de/	1305	http://home.schmorp.de/
872		1306
873	=cut	1307	=cut
		1308

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.14 by root, Sat Aug 20 01:49:27 2011 UTC vs. Revision 1.44 by root, Mon Sep 26 11:32:19 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.14 by root, Sat Aug 20 01:49:27 2011 UTC vs.
Revision 1.44 by root, Mon Sep 26 11:32:19 2011 UTC