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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.17 by root, Sat Aug 20 02:21:53 2011 UTC vs.
Revision 1.26 by root, Sun Aug 21 03:29:19 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 debug => "hit my knee";
11	AE::log warn => "it's a bit too hot";	12	AE::log warn => "it's a bit too hot";
12	AE::log error => "the flag was false!";	13	AE::log error => "the flag was false!";
13	AE::log fatal => "the bit toggled! run!";	14	AE::log fatal => "the bit toggled! run!"; # never returns
14		15
15	# "complex" use	16	"Complex" uses (for speed sensitive code):
		17
16	use AnyEvent::Log;	18	use AnyEvent::Log;
17		19
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	20	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		21
20	$tracer->("i am here") if $trace;	22	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	23	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		24
23	# configuration	25	Configuration (also look at the EXAMPLES section):
24		26
25	# set logging for this package to errors and higher only	27	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("error");	28	AnyEvent::Log::ctx->level ("error");
27		29
28	# set logging globally to anything below debug	30	# set logging level to suppress anything below "notice"
29	$AnyEvent::Log::Root->level ("notice");	31	$AnyEvent::Log::FILTER->level ("notice");
30		32
31	# see also EXAMPLES, below	33	# send all critical and higher priority messages to syslog,
		34	# regardless of (most) other settings
		35	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
		36	level => "critical",
		37	log_to_syslog => 0,
		38	);
32		39
33	=head1 DESCRIPTION	40	=head1 DESCRIPTION
34		41
35	This module implements a relatively simple "logging framework". It doesn't	42	This module implements a relatively simple "logging framework". It doesn't
36	attempt to be "the" logging solution or even "a" logging solution for	43	attempt to be "the" logging solution or even "a" logging solution for
37	AnyEvent - AnyEvent simply creates logging messages internally, and this	44	AnyEvent - AnyEvent simply creates logging messages internally, and this
38	module more or less exposes the mechanism, with some extra spiff to allow	45	module more or less exposes the mechanism, with some extra spiff to allow
39	using it from other modules as well.	46	using it from other modules as well.
40		47
41	Remember that the default verbosity level is C<0>, so nothing will be	48	Remember that the default verbosity level is C<0> (C<off>), so nothing
42	logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number before	49	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
43	starting your program, or change the logging level at runtime with	50	before starting your program, or change the logging level at runtime with
44	something like:	51	something like:
45		52
46	use AnyEvent;	53	use AnyEvent::Log;
47	(AnyEvent::Log::ctx "")->level ("info");	54	AnyEvent::Log::FILTER->level ("info");
48		55
49	The design goal behind this module was to keep it simple (and small),	56	The design goal behind this module was to keep it simple (and small),
50	but make it powerful enough to be potentially useful for any module, and	57	but make it powerful enough to be potentially useful for any module, and
51	extensive enough for the most common tasks, such as logging to multiple	58	extensive enough for the most common tasks, such as logging to multiple
52	targets, or being able to log into a database.	59	targets, or being able to log into a database.
53		60
54	The amount of documentation might indicate otherwise, but the module is	61	The amount of documentation might indicate otherwise, but the module is
55	still just 240 lines or so.	62	still just below 300 lines of code.
		63
		64	=head1 LOGGING LEVELS
		65
		66	Logging levels in this module range from C<1> (highest priority) to C<9>
		67	(lowest priority). Note that the lowest numerical value is the highest
		68	priority, so when this document says "higher priority" it means "lower
		69	numerical value".
		70
		71	Instead of specifying levels by name you can also specify them by aliases:
		72
		73	LVL NAME SYSLOG PERL NOTE
		74	1 fatal emerg exit aborts program!
		75	2 alert
		76	3 critical crit
		77	4 error err die
		78	5 warn warning
		79	6 note notice
		80	7 info
		81	8 debug
		82	9 trace
		83
		84	As you can see, some logging levels have multiple aliases - the first one
		85	is the "official" name, the second one the "syslog" name (if it differs)
		86	and the third one the "perl" name, suggesting that you log C<die> messages
		87	at C<error> priority.
		88
		89	You can normally only log a single message at highest priority level
		90	(C<1>, C<fatal>), because logging a fatal message will also quit the
		91	program - so use it sparingly :)
		92
		93	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		94	or C<all> - these are only valid in the methods they are documented for.
56		95
57	=head1 LOGGING FUNCTIONS	96	=head1 LOGGING FUNCTIONS
58		97
59	These functions allow you to log messages. They always use the caller's	98	These functions allow you to log messages. They always use the caller's
60	package as a "logging module/source". Also, the main logging function is	99	package as a "logging context". Also, the main logging function C<log> is
61	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	100	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
62	loaded.	101	loaded.
63		102
64	=over 4	103	=over 4
65		104
…		…
72		111
73	use AnyEvent (); BEGIN { AnyEvent::common_sense }	112	use AnyEvent (); BEGIN { AnyEvent::common_sense }
74	use AnyEvent::Util ();	113	use AnyEvent::Util ();
75		114
76	our $VERSION = $AnyEvent::VERSION;	115	our $VERSION = $AnyEvent::VERSION;
		116
		117	our ($COLLECT, $FILTER, $LOG);
77		118
78	our ($now_int, $now_str1, $now_str2);	119	our ($now_int, $now_str1, $now_str2);
79		120
80	# Format Time, not public - yet?	121	# Format Time, not public - yet?
81	sub ft($) {	122	sub ft($) {
…		…
86	if $now_int != $i;	127	if $now_int != $i;
87		128
88	"$now_str1$f$now_str2"	129	"$now_str1$f$now_str2"
89	}	130	}
90		131
91	our %CTX; # all logging contexts	132	our %CTX; # all package contexts
92		133
93	# creates a default package context object for the given package	134	# creates a default package context object for the given package
94	sub _pkg_ctx($) {	135	sub _pkg_ctx($) {
95	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	136	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
96		137
97	# link "parent" package	138	# link "parent" package
98	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	139	my $parent = $_[0] =~ /^(.+)::/
		140	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		141	: $COLLECT;
99		142
100	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
101	$ctx->[2]{$pkg+0} = $pkg;	143	$ctx->[2]{$parent+0} = $parent;
102		144
103	$ctx	145	$ctx
104	}	146	}
105		147
106	=item AnyEvent::Log::log $level, $msg[, @args]	148	=item AnyEvent::Log::log $level, $msg[, @args]
107		149
108	Requests logging of the given C<$msg> with the given log level (1..9).	150	Requests logging of the given C<$msg> with the given log level, and
109	You can also use the following strings as log level: C<fatal> (1),	151	returns true if the message was logged I<somewhere>.
110	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
111	C<info> (7), C<debug> (8), C<trace> (9).
112		152
113	For C<fatal> log levels, the program will abort.	153	For C<fatal> log levels, the program will abort.
114		154
115	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	155	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
116	C<$msg> is interpreted as an sprintf format string.	156	C<$msg> is interpreted as an sprintf format string.
…		…
122	supposed to return the message. It will be called only then the message	162	supposed to return the message. It will be called only then the message
123	actually gets logged, which is useful if it is costly to create the	163	actually gets logged, which is useful if it is costly to create the
124	message in the first place.	164	message in the first place.
125		165
126	Whether the given message will be logged depends on the maximum log level	166	Whether the given message will be logged depends on the maximum log level
127	and the caller's package.	167	and the caller's package. The return value can be used to ensure that
		168	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		169	runtime error it tries to log it at C<die> level, but if that message is
		170	lost it simply uses warn.
128		171
129	Note that you can (and should) call this function as C<AnyEvent::log> or	172	Note that you can (and should) call this function as C<AnyEvent::log> or
130	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	173	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
131	need any additional functionality), as those functions will load the	174	need any additional functionality), as those functions will load the
132	logging module on demand only. They are also much shorter to write.	175	logging module on demand only. They are also much shorter to write.
…		…
149		192
150	=cut	193	=cut
151		194
152	# also allow syslog equivalent names	195	# also allow syslog equivalent names
153	our %STR2LEVEL = (	196	our %STR2LEVEL = (
154	fatal => 1, emerg => 1,	197	fatal => 1, emerg => 1, exit => 1,
155	alert => 2,	198	alert => 2,
156	critical => 3, crit => 3,	199	critical => 3, crit => 3,
157	error => 4, err => 4,	200	error => 4, err => 4, die => 4,
158	warn => 5, warning => 5,	201	warn => 5, warning => 5,
159	note => 6, notice => 6,	202	note => 6, notice => 6,
160	info => 7,	203	info => 7,
161	debug => 8,	204	debug => 8,
162	trace => 9,	205	trace => 9,
…		…
192	? $level+0	235	? $level+0
193	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	236	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
194		237
195	my $mask = 1 << $level;	238	my $mask = 1 << $level;
196		239
197	my (%seen, @ctx, $now, $fmt);	240	my ($success, %seen, @ctx, $now, $fmt);
198		241
199	do	242	do
200	{	243	{
201	# skip if masked	244	# skip if masked
202	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	245	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
212	};	255	};
213		256
214	# format msg	257	# format msg
215	my $str = $ctx->[4]	258	my $str = $ctx->[4]
216	? $ctx->[4]($now, $_[0], $level, $format)	259	? $ctx->[4]($now, $_[0], $level, $format)
217	: $fmt \|\|= _format $now, $_[0], $level, $format;	260	: ($fmt \|\|= _format $now, $_[0], $level, $format);
218		261
		262	$success = 1;
		263
219	$ctx->[3]($str);	264	$ctx->[3]($str)
		265	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		266	} else {
		267	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
220	}	268	}
221
222	# not masked, not consumed - propagate to parent contexts
223	push @ctx, values %{ $ctx->[2] };
224	}	269	}
225	}	270	}
226	while $ctx = pop @ctx;	271	while $ctx = pop @ctx;
227		272
228	exit 1 if $level <= 1;	273	exit 1 if $level <= 1;
		274
		275	$success
229	}	276	}
230		277
231	sub log($$;@) {	278	sub log($$;@) {
232	_log	279	_log
233	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	280	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
237	AnyEvent::log = AE::log = \&log;	284	AnyEvent::log = AE::log = \&log;
238		285
239	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	286	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
240		287
241	Creates a code reference that, when called, acts as if the	288	Creates a code reference that, when called, acts as if the
242	C<AnyEvent::Log::log> function was called at this point with the givne	289	C<AnyEvent::Log::log> function was called at this point with the given
243	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	290	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
244	the C<AnyEvent::Log::log> function:	291	the C<AnyEvent::Log::log> function:
245		292
246	my $debug_log = AnyEvent::Log::logger "debug";	293	my $debug_log = AnyEvent::Log::logger "debug";
247		294
…		…
347	timestamp, context, level and string message and formats it in the way	394	timestamp, context, level and string message and formats it in the way
348	it should be logged) and a logging callback (which is responsible for	395	it should be logged) and a logging callback (which is responsible for
349	actually logging the formatted message and telling C<AnyEvent::Log>	396	actually logging the formatted message and telling C<AnyEvent::Log>
350	whether it has consumed the message, or whether it should be propagated).	397	whether it has consumed the message, or whether it should be propagated).
351		398
352	For propagation, a context can have any number of attached I<parent	399	For propagation, a context can have any number of attached I<slave
353	contexts>. Any message that is neither masked by the logging mask nor	400	contexts>. Any message that is neither masked by the logging mask nor
354	masked by the logging callback returning true will be passed to all parent	401	masked by the logging callback returning true will be passed to all slave
355	contexts.	402	contexts.
356		403
357	Each call to a logging function will log the message at most once per	404	Each call to a logging function will log the message at most once per
358	context, so it does not matter (much) if there are cycles or if the	405	context, so it does not matter (much) if there are cycles or if the
359	message can arrive at the same context via multiple paths.	406	message can arrive at the same context via multiple paths.
…		…
363	By default, all logging contexts have an full set of log levels ("all"), a	410	By default, all logging contexts have an full set of log levels ("all"), a
364	disabled logging callback and the default formatting callback.	411	disabled logging callback and the default formatting callback.
365		412
366	Package contexts have the package name as logging title by default.	413	Package contexts have the package name as logging title by default.
367		414
368	They have exactly one parent - the context of the "parent" package. The	415	They have exactly one slave - the context of the "parent" package. The
369	parent package is simply defined to be the package name without the last	416	parent package is simply defined to be the package name without the last
370	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	417	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
371	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	418	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
372	exception of the rule - just like the parent of any package name in	419	exception of the rule - just like the "parent" of any single-component
373	Perl is C<main>, the default parent of any top-level package context is	420	package name in Perl is C<main>, the default slave of any top-level
374	C<AnyEvent::Log::Top>.	421	package context is C<$AnyEvent::Log::COLLECT>.
375		422
376	Since perl packages form only an approximate hierarchy, this parent	423	Since perl packages form only an approximate hierarchy, this slave
377	context can of course be removed.	424	context can of course be removed.
378		425
379	All other (anonymous) contexts have no parents and an empty title by	426	All other (anonymous) contexts have no slaves and an empty title by
380	default.	427	default.
381		428
382	When the module is loaded it creates the default context called	429	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
383	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	430	context that simply logs everything via C<warn>, without propagating
384	which simply logs everything via C<warn> and doesn't propagate anything
385	anywhere by default. The purpose of the default context is to provide	431	anything anywhere by default. The purpose of this context is to provide
386	a convenient place to override the global logging target or to attach	432	a convenient place to override the global logging target or to attach
387	additional log targets. It's not meant for filtering.	433	additional log targets. It's not meant for filtering.
388		434
389	It then creates the root context called C<AnyEvent::Log::Root> (also	435	It then creates the C<$AnyEvent::Log::FILTER> context whose
390	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	436	purpose is to suppress all messages with priority higher
391	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	437	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
392	then attached the default logging context to it. The purpose of the root	438	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
393	context is to simply provide filtering according to some global log level.	439	is to simply provide filtering according to some global log level.
394		440
395	Finally it creates the top-level package context called	441	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
396	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	442	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
397	C<$AnyEvent::Log::Top>) and attached the root context but otherwise leaves
398	it at default config. It's purpose is simply to collect all log messages	443	leaves it at default config. Its purpose is simply to collect all log
399	system-wide.	444	messages system-wide.
400		445
401	These three special contexts can also be referred to by the	446	The hierarchy is then:
402	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
403	C<AE::Log::Top>.
404		447
		448	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		449
405	The effect of all this is that log messages, by default, wander up	450	The effect of all this is that log messages, by default, wander up to the
406	to the root context where log messages with lower priority then	451	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		452	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
407	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	453	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
408	AnyEvent::Log::Default context to be passed to C<warn>.	454	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
409		455
410	Splitting the top level context into three contexts makes it easy to set	456	This makes it easy to set a global logging level (by modifying $FILTER),
411	a global logging level (by modifying the root context), but still allow	457	but still allow other contexts to send, for example, their debug and trace
412	other contexts to log, for example, their debug and trace messages to the
413	default target despite the global logging level, or to attach additional	458	messages to the $LOG target despite the global logging level, or to attach
414	log targets that log messages, regardless of the global logging level.	459	additional log targets that log messages, regardless of the global logging
		460	level.
415		461
416	It also makes it easy to replace the default warn-logger by something that	462	It also makes it easy to modify the default warn-logger ($LOG) to
417	logs to a file, or to attach additional logging targets.	463	something that logs to a file, or to attach additional logging targets
		464	(such as loggign to a file) by attaching it to $FILTER.
418		465
419	=head2 CREATING/FINDING/DESTROYING CONTEXTS	466	=head2 CREATING/FINDING/DESTROYING CONTEXTS
420		467
421	=over 4	468	=over 4
422		469
…		…
456		503
457	=cut	504	=cut
458		505
459	sub reset {	506	sub reset {
460	# hard to kill complex data structures	507	# hard to kill complex data structures
461	# we recreate all package loggers and reset the hierarchy	508	# we "recreate" all package loggers and reset the hierarchy
462	while (my ($k, $v) = each %CTX) {	509	while (my ($k, $v) = each %CTX) {
463	@$v = ($k, (1 << 10) - 1 - 1, { });	510	@$v = ($k, (1 << 10) - 1 - 1, { });
464		511
465	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	512	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
466	$v->attach ($CTX{$pkg});
467	}	513	}
468		514
469	$AnyEvent::Log::Default->parents;	515	@$_ = ($_->[0], (1 << 10) - 1 - 1)
470	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	516	for $LOG, $FILTER, $COLLECT;
471	$AnyEvent::Log::Default->log_cb (sub {	517
		518	$LOG->slaves;
		519	$LOG->title ('$AnyEvent::Log::LOG');
		520	$LOG->log_cb (sub {
472	warn shift;	521	warn shift;
473	0	522	0
474	});	523	});
475	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
476		524
477	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	525	$FILTER->slaves ($LOG);
478	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	526	$FILTER->title ('$AnyEvent::Log::FILTER');
479	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	527	$FILTER->level ($AnyEvent::VERBOSE);
480	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
481		528
482	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	529	$COLLECT->slaves ($FILTER);
483	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	530	$COLLECT->title ('$AnyEvent::Log::COLLECT');
484	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;
485		531
486	_reassess;	532	_reassess;
487	}	533	}
488		534
489	# create the default logger contexts	535	# create the default logger contexts
490	$AnyEvent::Log::Default = ctx undef;	536	$LOG = ctx undef;
491	$AnyEvent::Log::Root = ctx undef;	537	$FILTER = ctx undef;
492	$AnyEvent::Log::Top = ctx undef;	538	$COLLECT = ctx undef;
493		539
494	AnyEvent::Log::reset;	540	AnyEvent::Log::reset;
495		541
496	# hello, CPAN, please catch me	542	# hello, CPAN, please catch me
497	package AnyEvent::Log::Default;
498	package AE::Log::Default;
499	package AnyEvent::Log::Root;
500	package AE::Log::Root;
501	package AnyEvent::Log::Top;	543	package AnyEvent::Log::LOG;
502	package AE::Log::Top;	544	package AE::Log::LOG;
		545	package AnyEvent::Log::FILTER;
		546	package AE::Log::FILTER;
		547	package AnyEvent::Log::COLLECT;
		548	package AE::Log::COLLECT;
503		549
504	package AnyEvent::Log::Ctx;	550	package AnyEvent::Log::Ctx;
505		551
506	# 0 1 2 3 4	552	# 0 1 2 3 4
507	# [$title, $level, %$parents, &$logcb, &$fmtcb]	553	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
508		554
509	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	555	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
510		556
511	This is a convenience constructor that makes it simpler to construct	557	This is a convenience constructor that makes it simpler to construct
512	anonymous logging contexts.	558	anonymous logging contexts.
…		…
515	name as the key with the value as parameter, unless the value is an	561	name as the key with the value as parameter, unless the value is an
516	arrayref, in which case it calls the method with the contents of the	562	arrayref, in which case it calls the method with the contents of the
517	array. The methods are called in the same order as specified.	563	array. The methods are called in the same order as specified.
518		564
519	Example: create a new logging context and set both the default logging	565	Example: create a new logging context and set both the default logging
520	level, some parent contexts and a logging callback.	566	level, some slave contexts and a logging callback.
521		567
522	$ctx = new AnyEvent::Log::Ctx	568	$ctx = new AnyEvent::Log::Ctx
523	title => "dubious messages",	569	title => "dubious messages",
524	level => "error",	570	level => "error",
525	log_cb => sub { print STDOUT shift; 0 },	571	log_cb => sub { print STDOUT shift; 0 },
526	parents => [$ctx1, $ctx, $ctx2],	572	slaves => [$ctx1, $ctx, $ctx2],
527	;	573	;
528		574
529	=back	575	=back
530		576
531	=cut	577	=cut
…		…
644	AnyEvent::Log::_reassess;	690	AnyEvent::Log::_reassess;
645	}	691	}
646		692
647	=back	693	=back
648		694
649	=head3 PARENT CONTEXTS	695	=head3 SLAVE CONTEXTS
650		696
651	The following methods attach and detach another logging context to a	697	The following methods attach and detach another logging context to a
652	logging context.	698	logging context.
653		699
654	Log messages are propagated to all parent contexts, unless the logging	700	Log messages are propagated to all slave contexts, unless the logging
655	callback consumes the message.	701	callback consumes the message.
656		702
657	=over 4	703	=over 4
658		704
659	=item $ctx->attach ($ctx2[, $ctx3...])	705	=item $ctx->attach ($ctx2[, $ctx3...])
660		706
661	Attaches the given contexts as parents to this context. It is not an error	707	Attaches the given contexts as slaves to this context. It is not an error
662	to add a context twice (the second add will be ignored).	708	to add a context twice (the second add will be ignored).
663		709
664	A context can be specified either as package name or as a context object.	710	A context can be specified either as package name or as a context object.
665		711
666	=item $ctx->detach ($ctx2[, $ctx3...])	712	=item $ctx->detach ($ctx2[, $ctx3...])
667		713
668	Removes the given parents from this context - it's not an error to attempt	714	Removes the given slaves from this context - it's not an error to attempt
669	to remove a context that hasn't been added.	715	to remove a context that hasn't been added.
670		716
671	A context can be specified either as package name or as a context object.	717	A context can be specified either as package name or as a context object.
672		718
673	=item $ctx->parents ($ctx2[, $ctx3...])	719	=item $ctx->slaves ($ctx2[, $ctx3...])
674		720
675	Replaces all parents attached to this context by the ones given.	721	Replaces all slaves attached to this context by the ones given.
676		722
677	=cut	723	=cut
678		724
679	sub attach {	725	sub attach {
680	my $ctx = shift;	726	my $ctx = shift;
…		…
688		734
689	delete $ctx->[2]{$_+0}	735	delete $ctx->[2]{$_+0}
690	for map { AnyEvent::Log::ctx $_ } @_;	736	for map { AnyEvent::Log::ctx $_ } @_;
691	}	737	}
692		738
693	sub parents {	739	sub slaves {
694	undef $_[0][2];	740	undef $_[0][2];
695	&attach;	741	&attach;
696	}	742	}
697		743
698	=back	744	=back
699		745
700	=head3 MESSAGE LOGGING	746	=head3 LOG TARGETS
701		747
702	The following methods configure how the logging context actually does	748	The following methods configure how the logging context actually does
703	the logging (which consists of formatting the message and printing it or	749	the logging (which consists of formatting the message and printing it or
704	whatever it wants to do with it) and also allows you to log messages	750	whatever it wants to do with it).
705	directly to a context, without going via your package context.
706		751
707	=over 4	752	=over 4
708		753
709	=item $ctx->log_cb ($cb->($str))	754	=item $ctx->log_cb ($cb->($str)
710		755
711	Replaces the logging callback on the context (C<undef> disables the	756	Replaces the logging callback on the context (C<undef> disables the
712	logging callback).	757	logging callback).
713		758
714	The logging callback is responsible for handling formatted log messages	759	The logging callback is responsible for handling formatted log messages
715	(see C<fmt_cb> below) - normally simple text strings that end with a	760	(see C<fmt_cb> below) - normally simple text strings that end with a
716	newline (and are possibly multiline themselves).	761	newline (and are possibly multiline themselves).
717		762
718	It also has to return true iff it has consumed the log message, and false	763	It also has to return true iff it has consumed the log message, and false
719	if it hasn't. Consuming a message means that it will not be sent to any	764	if it hasn't. Consuming a message means that it will not be sent to any
720	parent context. When in doubt, return C<0> from your logging callback.	765	slave context. When in doubt, return C<0> from your logging callback.
721		766
722	Example: a very simple logging callback, simply dump the message to STDOUT	767	Example: a very simple logging callback, simply dump the message to STDOUT
723	and do not consume it.	768	and do not consume it.
724		769
725	$ctx->log_cb (sub { print STDERR shift; 0 });	770	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
733	your program.	778	your program.
734		779
735	$ctx->levels ("debug", "trace");	780	$ctx->levels ("debug", "trace");
736	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	781	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
737		782
738	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	783	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
739		784
740	Replaces the formatting callback on the context (C<undef> restores the	785	Replaces the formatting callback on the context (C<undef> restores the
741	default formatter).	786	default formatter).
742		787
743	The callback is passed the (possibly fractional) timestamp, the original	788	The callback is passed the (possibly fractional) timestamp, the original
744	logging context, the (numeric) logging level and the raw message string and needs to	789	logging context, the (numeric) logging level and the raw message string
745	return a formatted log message. In most cases this will be a string, but	790	and needs to return a formatted log message. In most cases this will be a
746	it could just as well be an array reference that just stores the values.	791	string, but it could just as well be an array reference that just stores
		792	the values.
		793
		794	If, for some reason, you want to use C<caller> to find out more baout the
		795	logger then you should walk up the call stack until you are no longer
		796	inside the C<AnyEvent::Log> package.
747		797
748	Example: format just the raw message, with numeric log level in angle	798	Example: format just the raw message, with numeric log level in angle
749	brackets.	799	brackets.
750		800
751	$ctx->fmt_cb (sub {	801	$ctx->fmt_cb (sub {
…		…
768	"$msg->[3]";	818	"$msg->[3]";
769		819
770	0	820	0
771	});	821	});
772		822
		823	=item $ctx->log_to_file ($path)
		824
		825	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		826
		827	=item $ctx->log_to_path ($path)
		828
		829	Same as C<< ->log_to_file >>, but opens the file for each message. This
		830	is much slower, but allows you to change/move/rename/delete the file at
		831	basically any time.
		832
		833	=item $ctx->log_to_syslog ([$log_flags])
		834
		835	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		836	the others in the obvious way. If specified, then the C<$log_flags> are
		837	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		838	flags valid for Sys::Syslog::syslog, except for the priority levels.
		839
		840	Note that this function also sets a C<fmt_cb> - the logging part requires
		841	an array reference with [$level, $str] as input.
		842
773	=cut	843	=cut
774		844
775	sub log_cb {	845	sub log_cb {
776	my ($ctx, $cb) = @_;	846	my ($ctx, $cb) = @_;
777		847
…		…
782	my ($ctx, $cb) = @_;	852	my ($ctx, $cb) = @_;
783		853
784	$ctx->[4] = $cb;	854	$ctx->[4] = $cb;
785	}	855	}
786		856
787	=item $ctx->log ($level, $msg[, @params])	857	sub log_to_file {
788		858	my ($ctx, $path) = @_;
789	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
790
791	=item $logger = $ctx->logger ($level[, \$enabled])
792
793	Same as C<AnyEvent::Log::logger>, but uses the given context as log
794	context.
795
796	=cut
797
798	*log = \&AnyEvent::Log::_log;
799	*logger = \&AnyEvent::Log::_logger;
800
801	1;
802
803	=back
804
805	=head1 EXAMPLES
806
807	This section shows some common configurations.
808
809	=over 4
810
811	=item Setting the global logging level.
812
813	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
814	running your program, or modify the log level of the root context:
815
816	PERL_ANYEVENT_VERBOSE=5 ./myprog
817
818	$AnyEvent::Log::Root->level ("warn");
819
820	=item Append all messages to a file instead of sending them to STDERR.
821
822	This is affected by the global logging level.
823		859
824	open my $fh, ">>", $path	860	open my $fh, ">>", $path
825	or die "$path: $!";	861	or die "$path: $!";
826		862
827	$AnyEvent::Log::Default->log_cb (sub {	863	$ctx->log_cb (sub {
828	syswrite $fh, shift;	864	syswrite $fh, shift;
829	0	865	0
830	});	866	});
		867	}
		868
		869	sub log_to_file {
		870	my ($ctx, $path) = @_;
		871
		872	$ctx->log_cb (sub {
		873	open my $fh, ">>", $path
		874	or die "$path: $!";
		875
		876	syswrite $fh, shift;
		877	0
		878	});
		879	}
		880
		881	sub log_to_syslog {
		882	my ($ctx, $flags) = @_;
		883
		884	require Sys::Syslog;
		885
		886	$ctx->fmt_cb (sub {
		887	my $str = $_[3];
		888	$str =~ s/\n(?=.)/\n+ /g;
		889
		890	[$_[2], "($_[1][0]) $str"]
		891	});
		892
		893	$ctx->log_cb (sub {
		894	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		895
		896	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		897	for split /\n/, $_[0][1];
		898
		899	0
		900	});
		901	}
		902
		903	=back
		904
		905	=head3 MESSAGE LOGGING
		906
		907	These methods allow you to log messages directly to a context, without
		908	going via your package context.
		909
		910	=over 4
		911
		912	=item $ctx->log ($level, $msg[, @params])
		913
		914	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		915
		916	=item $logger = $ctx->logger ($level[, \$enabled])
		917
		918	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		919	context.
		920
		921	=cut
		922
		923	*log = \&AnyEvent::Log::_log;
		924	*logger = \&AnyEvent::Log::_logger;
		925
		926	1;
		927
		928	=back
		929
		930	=head1 EXAMPLES
		931
		932	This section shows some common configurations.
		933
		934	=over 4
		935
		936	=item Setting the global logging level.
		937
		938	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
		939	running your program, or modify the log level of the root context:
		940
		941	PERL_ANYEVENT_VERBOSE=5 ./myprog
		942
		943	$AnyEvent::Log::FILTER->level ("warn");
		944
		945	=item Append all messages to a file instead of sending them to STDERR.
		946
		947	This is affected by the global logging level.
		948
		949	$AnyEvent::Log::LOG->log_to_file ($path); (sub {
831		950
832	=item Write all messages with priority C<error> and higher to a file.	951	=item Write all messages with priority C<error> and higher to a file.
833		952
834	This writes them only when the global logging level allows it, because	953	This writes them only when the global logging level allows it, because
835	it is attached to the default context which is invoked I<after> global	954	it is attached to the default context which is invoked I<after> global
836	filtering.	955	filtering.
837		956
838	open my $fh, ">>", $path	957	$AnyEvent::Log::FILTER->attach
839	or die "$path: $!";	958	new AnyEvent::Log::Ctx log_to_file => $path);
840
841	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx
842	log_cb => sub { syswrite $fh, shift; 0 });
843		959
844	This writes them regardless of the global logging level, because it is	960	This writes them regardless of the global logging level, because it is
845	attached to the toplevel context, which receives all messages I<before>	961	attached to the toplevel context, which receives all messages I<before>
846	the global filtering.	962	the global filtering.
847		963
848	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	964	$AnyEvent::Log::COLLECT->attach (
849	log_cb => sub { syswrite $fh, shift; 0 });	965	new AnyEvent::Log::Ctx log_to_file => $path);
850		966
851	In both cases, messages are still written to STDOUT.	967	In both cases, messages are still written to STDERR.
852		968
853	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	969	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
854		970
855	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	971	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
856	context and increase the C<AnyEvent::Debug> logging level - this simply
857	circumvents the global filtering for trace messages.	972	context - this simply circumvents the global filtering for trace messages.
858		973
859	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	974	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
860	$debug->attach ($AnyEvent::Log::Default);	975	$debug->attach ($AnyEvent::Log::LOG);
861	$debug->levels ("trace"); # not "level"!
862		976
863	This of course works for any package.	977	This of course works for any package, not just L<AnyEvent::Debug>, but
		978	assumes the log level for AnyEvent::Debug hasn't been changed from the
		979	default.
864		980
865	=back	981	=back
866		982
867	=head1 AUTHOR	983	=head1 AUTHOR
868		984

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.17 by root, Sat Aug 20 02:21:53 2011 UTC vs. Revision 1.26 by root, Sun Aug 21 03:29:19 2011 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.17 by root, Sat Aug 20 02:21:53 2011 UTC vs.
Revision 1.26 by root, Sun Aug 21 03:29:19 2011 UTC