[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 1.24 by root, Sun Aug 21 03:24:59 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 use:
		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" use (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:
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");
		32
		33	# send all critical and higher priority messages to syslog,
		34	# regardless of (most) other settings
		35	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
		36	level => "critical",
		37	log_to_syslog => 0,
		38	);
30		39
31	# see also EXAMPLES, below	40	# see also EXAMPLES, below
32		41
33	=head1 DESCRIPTION	42	=head1 DESCRIPTION
34		43
…		…
36	attempt to be "the" logging solution or even "a" logging solution for	45	attempt to be "the" logging solution or even "a" logging solution for
37	AnyEvent - AnyEvent simply creates logging messages internally, and this	46	AnyEvent - AnyEvent simply creates logging messages internally, and this
38	module more or less exposes the mechanism, with some extra spiff to allow	47	module more or less exposes the mechanism, with some extra spiff to allow
39	using it from other modules as well.	48	using it from other modules as well.
40		49
41	Remember that the default verbosity level is C<0>, so nothing will be	50	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	51	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	52	before starting your program, or change the logging level at runtime with
44	something like:	53	something like:
45		54
46	use AnyEvent;	55	use AnyEvent::Log;
47	(AnyEvent::Log::ctx "")->level ("info");	56	AnyEvent::Log::FILTER->level ("info");
48		57
49	The design goal behind this module was to keep it simple (and small),	58	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	59	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	60	extensive enough for the most common tasks, such as logging to multiple
52	targets, or being able to log into a database.	61	targets, or being able to log into a database.
53		62
54	The amount of documentation might indicate otherwise, but the module is	63	The amount of documentation might indicate otherwise, but the module is
55	still just 240 lines or so.	64	still just below 300 lines of code.
		65
		66	=head1 LOGGING LEVELS
		67
		68	Logging levels in this module range from C<1> (highest priority) to C<9>
		69	(lowest priority). Note that the lowest numerical value is the highest
		70	priority, so when this document says "higher priority" it means "lower
		71	numerical value".
		72
		73	Instead of specifying levels by name you can also specify them by aliases:
		74
		75	LVL NAME SYSLOG PERL NOTE
		76	1 fatal emerg exit aborts program!
		77	2 alert
		78	3 critical crit
		79	4 error err die
		80	5 warn warning
		81	6 note notice
		82	7 info
		83	8 debug
		84	9 trace
		85
		86	As you can see, some logging levels have multiple aliases - the first one
		87	is the "official" name, the second one the "syslog" name (if it differs)
		88	and the third one the "perl" name, suggesting that you log C<die> messages
		89	at C<error> priority.
		90
		91	You can normally only log a single message at highest priority level
		92	(C<1>, C<fatal>), because logging a fatal message will also quit the
		93	program - so use it sparingly :)
		94
		95	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		96	or C<all> - these are only valid in the methods they are documented for.
56		97
57	=head1 LOGGING FUNCTIONS	98	=head1 LOGGING FUNCTIONS
58		99
59	These functions allow you to log messages. They always use the caller's	100	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	101	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	102	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
62	loaded.	103	loaded.
63		104
64	=over 4	105	=over 4
65		106
…		…
72		113
73	use AnyEvent (); BEGIN { AnyEvent::common_sense }	114	use AnyEvent (); BEGIN { AnyEvent::common_sense }
74	use AnyEvent::Util ();	115	use AnyEvent::Util ();
75		116
76	our $VERSION = $AnyEvent::VERSION;	117	our $VERSION = $AnyEvent::VERSION;
		118
		119	our ($COLLECT, $FILTER, $LOG);
77		120
78	our ($now_int, $now_str1, $now_str2);	121	our ($now_int, $now_str1, $now_str2);
79		122
80	# Format Time, not public - yet?	123	# Format Time, not public - yet?
81	sub ft($) {	124	sub ft($) {
…		…
86	if $now_int != $i;	129	if $now_int != $i;
87		130
88	"$now_str1$f$now_str2"	131	"$now_str1$f$now_str2"
89	}	132	}
90		133
91	our %CTX; # all logging contexts	134	our %CTX; # all package contexts
92		135
93	# creates a default package context object for the given package	136	# creates a default package context object for the given package
94	sub _pkg_ctx($) {	137	sub _pkg_ctx($) {
95	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	138	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
96		139
97	# link "parent" package	140	# link "parent" package
98	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	141	my $parent = $_[0] =~ /^(.+)::/
		142	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		143	: $COLLECT;
99		144
100	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
101	$ctx->[2]{$pkg+0} = $pkg;	145	$ctx->[2]{$parent+0} = $parent;
102		146
103	$ctx	147	$ctx
104	}	148	}
105		149
106	=item AnyEvent::Log::log $level, $msg[, @args]	150	=item AnyEvent::Log::log $level, $msg[, @args]
107		151
108	Requests logging of the given C<$msg> with the given log level (1..9).	152	Requests logging of the given C<$msg> with the given log level, and
109	You can also use the following strings as log level: C<fatal> (1),	153	returns true if the message was logged I<somewhere>.
110	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
111	C<info> (7), C<debug> (8), C<trace> (9).
112		154
113	For C<fatal> log levels, the program will abort.	155	For C<fatal> log levels, the program will abort.
114		156
115	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	157	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.	158	C<$msg> is interpreted as an sprintf format string.
…		…
122	supposed to return the message. It will be called only then the message	164	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	165	actually gets logged, which is useful if it is costly to create the
124	message in the first place.	166	message in the first place.
125		167
126	Whether the given message will be logged depends on the maximum log level	168	Whether the given message will be logged depends on the maximum log level
127	and the caller's package.	169	and the caller's package. The return value can be used to ensure that
		170	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		171	runtime error it tries to log it at C<die> level, but if that message is
		172	lost it simply uses warn.
128		173
129	Note that you can (and should) call this function as C<AnyEvent::log> or	174	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	175	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	176	need any additional functionality), as those functions will load the
132	logging module on demand only. They are also much shorter to write.	177	logging module on demand only. They are also much shorter to write.
…		…
149		194
150	=cut	195	=cut
151		196
152	# also allow syslog equivalent names	197	# also allow syslog equivalent names
153	our %STR2LEVEL = (	198	our %STR2LEVEL = (
154	fatal => 1, emerg => 1,	199	fatal => 1, emerg => 1, exit => 1,
155	alert => 2,	200	alert => 2,
156	critical => 3, crit => 3,	201	critical => 3, crit => 3,
157	error => 4, err => 4,	202	error => 4, err => 4, die => 4,
158	warn => 5, warning => 5,	203	warn => 5, warning => 5,
159	note => 6, notice => 6,	204	note => 6, notice => 6,
160	info => 7,	205	info => 7,
161	debug => 8,	206	debug => 8,
162	trace => 9,	207	trace => 9,
…		…
192	? $level+0	237	? $level+0
193	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	238	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
194		239
195	my $mask = 1 << $level;	240	my $mask = 1 << $level;
196		241
197	my (%seen, @ctx, $now, $fmt);	242	my ($success, %seen, @ctx, $now, $fmt);
198		243
199	do	244	do
200	{	245	{
201	# skip if masked	246	# skip if masked
202	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	247	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
212	};	257	};
213		258
214	# format msg	259	# format msg
215	my $str = $ctx->[4]	260	my $str = $ctx->[4]
216	? $ctx->[4]($now, $_[0], $level, $format)	261	? $ctx->[4]($now, $_[0], $level, $format)
217	: $fmt \|\|= _format $now, $_[0], $level, $format;	262	: ($fmt \|\|= _format $now, $_[0], $level, $format);
218		263
		264	$success = 1;
		265
219	$ctx->[3]($str);	266	$ctx->[3]($str)
		267	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		268	} else {
		269	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
220	}	270	}
221
222	# not masked, not consumed - propagate to parent contexts
223	push @ctx, values %{ $ctx->[2] };
224	}	271	}
225	}	272	}
226	while $ctx = pop @ctx;	273	while $ctx = pop @ctx;
227		274
228	exit 1 if $level <= 1;	275	exit 1 if $level <= 1;
		276
		277	$success
229	}	278	}
230		279
231	sub log($$;@) {	280	sub log($$;@) {
232	_log	281	_log
233	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	282	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
237	AnyEvent::log = AE::log = \&log;	286	AnyEvent::log = AE::log = \&log;
238		287
239	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	288	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
240		289
241	Creates a code reference that, when called, acts as if the	290	Creates a code reference that, when called, acts as if the
242	C<AnyEvent::Log::log> function was called at this point with the givne	291	C<AnyEvent::Log::log> function was called at this point with the given
243	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	292	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
244	the C<AnyEvent::Log::log> function:	293	the C<AnyEvent::Log::log> function:
245		294
246	my $debug_log = AnyEvent::Log::logger "debug";	295	my $debug_log = AnyEvent::Log::logger "debug";
247		296
…		…
347	timestamp, context, level and string message and formats it in the way	396	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	397	it should be logged) and a logging callback (which is responsible for
349	actually logging the formatted message and telling C<AnyEvent::Log>	398	actually logging the formatted message and telling C<AnyEvent::Log>
350	whether it has consumed the message, or whether it should be propagated).	399	whether it has consumed the message, or whether it should be propagated).
351		400
352	For propagation, a context can have any number of attached I<parent	401	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	402	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	403	masked by the logging callback returning true will be passed to all slave
355	contexts.	404	contexts.
356		405
357	Each call to a logging function will log the message at most once per	406	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	407	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.	408	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	412	By default, all logging contexts have an full set of log levels ("all"), a
364	disabled logging callback and the default formatting callback.	413	disabled logging callback and the default formatting callback.
365		414
366	Package contexts have the package name as logging title by default.	415	Package contexts have the package name as logging title by default.
367		416
368	They have exactly one parent - the context of the "parent" package. The	417	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	418	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>,	419	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
371	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	420	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	421	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	422	package name in Perl is C<main>, the default slave of any top-level
374	C<AnyEvent::Log::Top>.	423	package context is C<$AnyEvent::Log::COLLECT>.
375		424
376	Since perl packages form only an approximate hierarchy, this parent	425	Since perl packages form only an approximate hierarchy, this slave
377	context can of course be removed.	426	context can of course be removed.
378		427
379	All other (anonymous) contexts have no parents and an empty title by	428	All other (anonymous) contexts have no slaves and an empty title by
380	default.	429	default.
381		430
382	When the module is loaded it creates the default context called	431	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
383	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	432	context that simply logs everything via C<warn>, without propagating
384	which simply logs everything via C<warn> and doesn't propagate anything
385	anywhere by default. The purpose of the default context is to provide	433	anything anywhere by default. The purpose of this context is to provide
386	a convenient place to override the global logging target or to attach	434	a convenient place to override the global logging target or to attach
387	additional log targets. It's not meant for filtering.	435	additional log targets. It's not meant for filtering.
388		436
389	It then creates the root context called C<AnyEvent::Log::Root> (also	437	It then creates the C<$AnyEvent::Log::FILTER> context whose
390	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	438	purpose is to suppress all messages with priority higher
391	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	439	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
392	then attached the default logging context to it. The purpose of the root	440	C<$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.	441	is to simply provide filtering according to some global log level.
394		442
395	Finally it creates the top-level package context called	443	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
396	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	444	and attaches the C<$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	445	leaves it at default config. Its purpose is simply to collect all log
399	system-wide.	446	messages system-wide.
400		447
401	These three special contexts can also be referred to by the	448	The hierarchy is then:
402	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
403	C<AE::Log::Top>.
404		449
		450	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		451
405	The effect of all this is that log messages, by default, wander up	452	The effect of all this is that log messages, by default, wander up to the
406	to the root context where log messages with lower priority then	453	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		454	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	455	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
408	AnyEvent::Log::Default context to be passed to C<warn>.	456	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
409		457
410	Splitting the top level context into three contexts makes it easy to set	458	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	459	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	460	messages to the $LOG target despite the global logging level, or to attach
414	log targets that log messages, regardless of the global logging level.	461	additional log targets that log messages, regardless of the global logging
		462	level.
415		463
416	It also makes it easy to replace the default warn-logger by something that	464	It also makes it easy to modify the default warn-logger ($LOG) to
417	logs to a file, or to attach additional logging targets.	465	something that logs to a file, or to attach additional logging targets
		466	(such as loggign to a file) by attaching it to $FILTER.
418		467
419	=head2 CREATING/FINDING/DESTROYING CONTEXTS	468	=head2 CREATING/FINDING/DESTROYING CONTEXTS
420		469
421	=over 4	470	=over 4
422		471
…		…
456		505
457	=cut	506	=cut
458		507
459	sub reset {	508	sub reset {
460	# hard to kill complex data structures	509	# hard to kill complex data structures
461	# we recreate all package loggers and reset the hierarchy	510	# we "recreate" all package loggers and reset the hierarchy
462	while (my ($k, $v) = each %CTX) {	511	while (my ($k, $v) = each %CTX) {
463	@$v = ($k, (1 << 10) - 1 - 1, { });	512	@$v = ($k, (1 << 10) - 1 - 1, { });
464		513
465	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	514	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
466	$v->attach ($CTX{$pkg});
467	}	515	}
468		516
469	$AnyEvent::Log::Default->parents;	517	@$_ = ($_->[0], (1 << 10) - 1 - 1)
470	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	518	for $LOG, $FILTER, $COLLECT;
471	$AnyEvent::Log::Default->log_cb (sub {	519
		520	$LOG->slaves;
		521	$LOG->title ('$AnyEvent::Log::LOG');
		522	$LOG->log_cb (sub {
472	warn shift;	523	warn shift;
473	0	524	0
474	});	525	});
475	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
476		526
477	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	527	$FILTER->slaves ($LOG);
478	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	528	$FILTER->title ('$AnyEvent::Log::FILTER');
479	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	529	$FILTER->level ($AnyEvent::VERBOSE);
480	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
481		530
482	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	531	$COLLECT->slaves ($FILTER);
483	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	532	$COLLECT->title ('$AnyEvent::Log::COLLECT');
484	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;
485		533
486	_reassess;	534	_reassess;
487	}	535	}
488		536
489	# create the default logger contexts	537	# create the default logger contexts
490	$AnyEvent::Log::Default = ctx undef;	538	$LOG = ctx undef;
491	$AnyEvent::Log::Root = ctx undef;	539	$FILTER = ctx undef;
492	$AnyEvent::Log::Top = ctx undef;	540	$COLLECT = ctx undef;
493		541
494	AnyEvent::Log::reset;	542	AnyEvent::Log::reset;
495		543
496	# hello, CPAN, please catch me	544	# hello, CPAN, please catch me
497	package AnyEvent::Log::Default;
498	package AE::Log::Default;
499	package AnyEvent::Log::Root;
500	package AE::Log::Root;
501	package AnyEvent::Log::Top;	545	package AnyEvent::Log::LOG;
502	package AE::Log::Top;	546	package AE::Log::LOG;
		547	package AnyEvent::Log::FILTER;
		548	package AE::Log::FILTER;
		549	package AnyEvent::Log::COLLECT;
		550	package AE::Log::COLLECT;
503		551
504	package AnyEvent::Log::Ctx;	552	package AnyEvent::Log::Ctx;
505		553
506	# 0 1 2 3 4	554	# 0 1 2 3 4
507	# [$title, $level, %$parents, &$logcb, &$fmtcb]	555	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
508		556
509	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	557	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
510		558
511	This is a convenience constructor that makes it simpler to construct	559	This is a convenience constructor that makes it simpler to construct
512	anonymous logging contexts.	560	anonymous logging contexts.
…		…
515	name as the key with the value as parameter, unless the value is an	563	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	564	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.	565	array. The methods are called in the same order as specified.
518		566
519	Example: create a new logging context and set both the default logging	567	Example: create a new logging context and set both the default logging
520	level, some parent contexts and a logging callback.	568	level, some slave contexts and a logging callback.
521		569
522	$ctx = new AnyEvent::Log::Ctx	570	$ctx = new AnyEvent::Log::Ctx
523	title => "dubious messages",	571	title => "dubious messages",
524	level => "error",	572	level => "error",
525	log_cb => sub { print STDOUT shift; 0 },	573	log_cb => sub { print STDOUT shift; 0 },
526	parents => [$ctx1, $ctx, $ctx2],	574	slaves => [$ctx1, $ctx, $ctx2],
527	;	575	;
528		576
529	=back	577	=back
530		578
531	=cut	579	=cut
…		…
644	AnyEvent::Log::_reassess;	692	AnyEvent::Log::_reassess;
645	}	693	}
646		694
647	=back	695	=back
648		696
649	=head3 PARENT CONTEXTS	697	=head3 SLAVE CONTEXTS
650		698
651	The following methods attach and detach another logging context to a	699	The following methods attach and detach another logging context to a
652	logging context.	700	logging context.
653		701
654	Log messages are propagated to all parent contexts, unless the logging	702	Log messages are propagated to all slave contexts, unless the logging
655	callback consumes the message.	703	callback consumes the message.
656		704
657	=over 4	705	=over 4
658		706
659	=item $ctx->attach ($ctx2[, $ctx3...])	707	=item $ctx->attach ($ctx2[, $ctx3...])
660		708
661	Attaches the given contexts as parents to this context. It is not an error	709	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).	710	to add a context twice (the second add will be ignored).
663		711
664	A context can be specified either as package name or as a context object.	712	A context can be specified either as package name or as a context object.
665		713
666	=item $ctx->detach ($ctx2[, $ctx3...])	714	=item $ctx->detach ($ctx2[, $ctx3...])
667		715
668	Removes the given parents from this context - it's not an error to attempt	716	Removes the given slaves from this context - it's not an error to attempt
669	to remove a context that hasn't been added.	717	to remove a context that hasn't been added.
670		718
671	A context can be specified either as package name or as a context object.	719	A context can be specified either as package name or as a context object.
672		720
673	=item $ctx->parents ($ctx2[, $ctx3...])	721	=item $ctx->slaves ($ctx2[, $ctx3...])
674		722
675	Replaces all parents attached to this context by the ones given.	723	Replaces all slaves attached to this context by the ones given.
676		724
677	=cut	725	=cut
678		726
679	sub attach {	727	sub attach {
680	my $ctx = shift;	728	my $ctx = shift;
…		…
688		736
689	delete $ctx->[2]{$_+0}	737	delete $ctx->[2]{$_+0}
690	for map { AnyEvent::Log::ctx $_ } @_;	738	for map { AnyEvent::Log::ctx $_ } @_;
691	}	739	}
692		740
693	sub parents {	741	sub slaves {
694	undef $_[0][2];	742	undef $_[0][2];
695	&attach;	743	&attach;
696	}	744	}
697		745
698	=back	746	=back
699		747
700	=head3 MESSAGE LOGGING	748	=head3 LOG TARGETS
701		749
702	The following methods configure how the logging context actually does	750	The following methods configure how the logging context actually does
703	the logging (which consists of formatting the message and printing it or	751	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	752	whatever it wants to do with it).
705	directly to a context, without going via your package context.
706		753
707	=over 4	754	=over 4
708		755
709	=item $ctx->log_cb ($cb->($str))	756	=item $ctx->log_cb ($cb->($str)
710		757
711	Replaces the logging callback on the context (C<undef> disables the	758	Replaces the logging callback on the context (C<undef> disables the
712	logging callback).	759	logging callback).
713		760
714	The logging callback is responsible for handling formatted log messages	761	The logging callback is responsible for handling formatted log messages
715	(see C<fmt_cb> below) - normally simple text strings that end with a	762	(see C<fmt_cb> below) - normally simple text strings that end with a
716	newline (and are possibly multiline themselves).	763	newline (and are possibly multiline themselves).
717		764
718	It also has to return true iff it has consumed the log message, and false	765	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	766	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.	767	slave context. When in doubt, return C<0> from your logging callback.
721		768
722	Example: a very simple logging callback, simply dump the message to STDOUT	769	Example: a very simple logging callback, simply dump the message to STDOUT
723	and do not consume it.	770	and do not consume it.
724		771
725	$ctx->log_cb (sub { print STDERR shift; 0 });	772	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
733	your program.	780	your program.
734		781
735	$ctx->levels ("debug", "trace");	782	$ctx->levels ("debug", "trace");
736	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	783	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
737		784
738	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	785	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
739		786
740	Replaces the formatting callback on the context (C<undef> restores the	787	Replaces the formatting callback on the context (C<undef> restores the
741	default formatter).	788	default formatter).
742		789
743	The callback is passed the (possibly fractional) timestamp, the original	790	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	791	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	792	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.	793	string, but it could just as well be an array reference that just stores
		794	the values.
		795
		796	If, for some reaosn, you want to use C<caller> to find out more baout the
		797	logger then you should walk up the call stack until you are no longer
		798	inside the C<AnyEvent::Log> package.
747		799
748	Example: format just the raw message, with numeric log level in angle	800	Example: format just the raw message, with numeric log level in angle
749	brackets.	801	brackets.
750		802
751	$ctx->fmt_cb (sub {	803	$ctx->fmt_cb (sub {
…		…
768	"$msg->[3]";	820	"$msg->[3]";
769		821
770	0	822	0
771	});	823	});
772		824
		825	=item $ctx->log_to_file ($path)
		826
		827	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		828
		829	=item $ctx->log_to_path ($path)
		830
		831	Same as C<< ->log_to_file >>, but opens the file for each message. This
		832	is much slower, but allows you to change/move/rename/delete the file at
		833	basically any time.
		834
		835	=item $ctx->log_to_syslog ([$log_flags])
		836
		837	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		838	the others in the obvious way. If specified, then the C<$log_flags> are
		839	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		840	flags valid for Sys::Syslog::syslog, except for the priority levels.
		841
		842	Note that this function also sets a C<fmt_cb> - the logging part requires
		843	an array reference with [$level, $str] as input.
		844
773	=cut	845	=cut
774		846
775	sub log_cb {	847	sub log_cb {
776	my ($ctx, $cb) = @_;	848	my ($ctx, $cb) = @_;
777		849
…		…
782	my ($ctx, $cb) = @_;	854	my ($ctx, $cb) = @_;
783		855
784	$ctx->[4] = $cb;	856	$ctx->[4] = $cb;
785	}	857	}
786		858
787	=item $ctx->log ($level, $msg[, @params])	859	sub log_to_file {
788		860	my ($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		861
824	open my $fh, ">>", $path	862	open my $fh, ">>", $path
825	or die "$path: $!";	863	or die "$path: $!";
826		864
827	$AnyEvent::Log::Default->log_cb (sub {	865	$ctx->log_cb (sub {
828	syswrite $fh, shift;	866	syswrite $fh, shift;
829	0	867	0
830	});	868	});
		869	}
		870
		871	sub log_to_file {
		872	my ($ctx, $path) = @_;
		873
		874	$ctx->log_cb (sub {
		875	open my $fh, ">>", $path
		876	or die "$path: $!";
		877
		878	syswrite $fh, shift;
		879	0
		880	});
		881	}
		882
		883	sub log_to_syslog {
		884	my ($ctx, $flags) = @_;
		885
		886	require Sys::Syslog;
		887
		888	$ctx->fmt_cb (sub {
		889	my $str = $_[3];
		890	$str =~ s/\n(?=.)/\n+ /g;
		891
		892	[$_[2], "($_[1][0]) $str"]
		893	});
		894
		895	$ctx->log_cb (sub {
		896	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		897
		898	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		899	for split /\n/, $_[0][1];
		900
		901	0
		902	});
		903	}
		904
		905	=back
		906
		907	=head3 MESSAGE LOGGING
		908
		909	These methods allow you to log messages directly to a context, without
		910	going via your package context.
		911
		912	=over 4
		913
		914	=item $ctx->log ($level, $msg[, @params])
		915
		916	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		917
		918	=item $logger = $ctx->logger ($level[, \$enabled])
		919
		920	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		921	context.
		922
		923	=cut
		924
		925	*log = \&AnyEvent::Log::_log;
		926	*logger = \&AnyEvent::Log::_logger;
		927
		928	1;
		929
		930	=back
		931
		932	=head1 EXAMPLES
		933
		934	This section shows some common configurations.
		935
		936	=over 4
		937
		938	=item Setting the global logging level.
		939
		940	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
		941	running your program, or modify the log level of the root context:
		942
		943	PERL_ANYEVENT_VERBOSE=5 ./myprog
		944
		945	$AnyEvent::Log::FILTER->level ("warn");
		946
		947	=item Append all messages to a file instead of sending them to STDERR.
		948
		949	This is affected by the global logging level.
		950
		951	$AnyEvent::Log::LOG->log_to_file ($path); (sub {
831		952
832	=item Write all messages with priority C<error> and higher to a file.	953	=item Write all messages with priority C<error> and higher to a file.
833		954
834	This writes them only when the global logging level allows it, because	955	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	956	it is attached to the default context which is invoked I<after> global
836	filtering.	957	filtering.
837		958
838	open my $fh, ">>", $path	959	$AnyEvent::Log::FILTER->attach
839	or die "$path: $!";	960	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		961
844	This writes them regardless of the global logging level, because it is	962	This writes them regardless of the global logging level, because it is
845	attached to the toplevel context, which receives all messages I<before>	963	attached to the toplevel context, which receives all messages I<before>
846	the global filtering.	964	the global filtering.
847		965
848	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	966	$AnyEvent::Log::COLLECT->attach (
849	log_cb => sub { syswrite $fh, shift; 0 });	967	new AnyEvent::Log::Ctx log_to_file => $path);
850		968
851	In both cases, messages are still written to STDOUT.	969	In both cases, messages are still written to STDERR.
852		970
853	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	971	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
854		972
855	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	973	Attach the C<$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.	974	context - this simply circumvents the global filtering for trace messages.
858		975
859	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	976	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
860	$debug->attach ($AnyEvent::Log::Default);	977	$debug->attach ($AnyEvent::Log::LOG);
861	$debug->levels ("trace"); # not "level"!
862		978
863	This of course works for any package.	979	This of course works for any package, not just L<AnyEvent::Debug>, but
		980	assumes the log level for AnyEvent::Debug hasn't been changed from the
		981	default.
864		982
865	=back	983	=back
866		984
867	=head1 AUTHOR	985	=head1 AUTHOR
868		986

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.17 by root, Sat Aug 20 02:21:53 2011 UTC vs. Revision 1.24 by root, Sun Aug 21 03:24:59 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
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Revision 1.24 by root, Sun Aug 21 03:24:59 2011 UTC