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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.16 by root, Sat Aug 20 02:19:18 2011 UTC vs.
Revision 1.23 by root, Sun Aug 21 03:20:52 2011 UTC

…		…
8	use AnyEvent;	8	use AnyEvent;
9		9
10	AE::log debug => "hit my knee";	10	AE::log debug => "hit my knee";
11	AE::log warn => "it's a bit too hot";	11	AE::log warn => "it's a bit too hot";
12	AE::log error => "the flag was false!";	12	AE::log error => "the flag was false!";
13	AE::log fatal => "the bit toggled! run!";	13	AE::log fatal => "the bit toggled! run!"; # never returns
14		14
15	# "complex" use	15	# "complex" use (for speed sensitive code)
16	use AnyEvent::Log;	16	use AnyEvent::Log;
17		17
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		19
20	$tracer->("i am here") if $trace;	20	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		22
23	# configuration	23	# configuration
24		24
25	# set logging for this package to errors and higher only	25	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("error");	26	AnyEvent::Log::ctx->level ("error");
27		27
28	# set logging globally to anything below debug	28	# set logging level to suppress anything below "notice"
29	$AnyEvent::Log::Root->level ("notice");	29	$AnyEvent::Log::FILTER->level ("notice");
		30
		31	# send all critical and higher priority messages to syslog,
		32	# regardless of (most) other settings
		33	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
		34	level => "critical",
		35	log_to_syslog => 0,
		36	);
30		37
31	# see also EXAMPLES, below	38	# see also EXAMPLES, below
32		39
33	=head1 DESCRIPTION	40	=head1 DESCRIPTION
34		41
…		…
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
…		…
278		325
279	our %LOGGER;	326	our %LOGGER;
280		327
281	# re-assess logging status for all loggers	328	# re-assess logging status for all loggers
282	sub _reassess {	329	sub _reassess {
		330	local $SIG{__DIE__};
		331	my $die = sub { die };
		332
283	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	333	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
284	my ($ctx, $level, $renabled) = @$_;	334	my ($ctx, $level, $renabled) = @$_;
285		335
286	# to detect whether a message would be logged, we # actually	336	# to detect whether a message would be logged, we actually
287	# try to log one and die. this isn't fast, but we can be	337	# try to log one and die. this isn't fast, but we can be
288	# sure that the logging decision is correct :)	338	# sure that the logging decision is correct :)
289		339
290	$$renabled = !eval {	340	$$renabled = !eval {
291	local $SIG{__DIE__};
292
293	_log $ctx, $level, sub { die };	341	_log $ctx, $level, $die;
294		342
295	1	343	1
296	};	344	};
297
298	$$renabled = 1; # TODO
299	}	345	}
300	}	346	}
301		347
302	sub _logger {	348	sub _logger {
303	my ($ctx, $level, $renabled) = @_;	349	my ($ctx, $level, $renabled) = @_;
…		…
348	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
349	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
350	actually logging the formatted message and telling C<AnyEvent::Log>	396	actually logging the formatted message and telling C<AnyEvent::Log>
351	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).
352		398
353	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
354	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
355	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
356	contexts.	402	contexts.
357		403
358	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
359	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
360	message can arrive at the same context via multiple paths.	406	message can arrive at the same context via multiple paths.
…		…
364	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
365	disabled logging callback and the default formatting callback.	411	disabled logging callback and the default formatting callback.
366		412
367	Package contexts have the package name as logging title by default.	413	Package contexts have the package name as logging title by default.
368		414
369	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
370	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
371	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	417	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
372	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	418	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
373	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
374	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
375	C<AnyEvent::Log::Top>.	421	package context is C<$AnyEvent::Log::COLLECT>.
376		422
377	Since perl packages form only an approximate hierarchy, this parent	423	Since perl packages form only an approximate hierarchy, this slave
378	context can of course be removed.	424	context can of course be removed.
379		425
380	All other (anonymous) contexts have no parents and an empty title by	426	All other (anonymous) contexts have no slaves and an empty title by
381	default.	427	default.
382		428
383	When the module is loaded it creates the default context called	429	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
384	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	430	context that simply logs everything via C<warn>, without propagating
385	which simply logs everything via C<warn> and doesn't propagate anything
386	anywhere by default. The purpose of the default context is to provide	431	anything anywhere by default. The purpose of this context is to provide
387	a convenient place to override the global logging target or to attach	432	a convenient place to override the global logging target or to attach
388	additional log targets. It's not meant for filtering.	433	additional log targets. It's not meant for filtering.
389		434
390	It then creates the root context called C<AnyEvent::Log::Root> (also	435	It then creates the C<$AnyEvent::Log::FILTER> context whose
391	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	436	purpose is to suppress all messages with priority higher
392	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	437	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
393	then attached the default logging context to it. The purpose of the root	438	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
394	context is to simply provide filtering according to some global log level.	439	is to simply provide filtering according to some global log level.
395		440
396	Finally it creates the top-level package context called	441	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
397	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	442	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
398	C<$AnyEvent::Log::Top>) and attached the root context but otherwise leaves
399	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
400	system-wide.	444	messages system-wide.
401		445
402	These three special contexts can also be referred to by the	446	The hierarchy is then:
403	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
404	C<AE::Log::Top>.
405		447
		448	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		449
406	The effect of all this is that log messages, by default, wander up	450	The effect of all this is that log messages, by default, wander up to the
407	to the root context where log messages with lower priority then	451	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		452	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
408	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	453	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
409	AnyEvent::Log::Default context to be passed to C<warn>.	454	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
410		455
411	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),
412	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
413	other contexts to log, for example, their debug and trace messages to the
414	default target despite the global logging level, or to attach additional	458	messages to the $LOG target despite the global logging level, or to attach
415	log targets that log messages, regardless of the global logging level.	459	additional log targets that log messages, regardless of the global logging
		460	level.
416		461
417	It also makes it easy to replace the default warn-logger by something that	462	It also makes it easy to modify the default warn-logger ($LOG) to
418	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 $FILTER.
419		465
420	=head2 CREATING/FINDING/DESTROYING CONTEXTS	466	=head2 CREATING/FINDING/DESTROYING CONTEXTS
421		467
422	=over 4	468	=over 4
423		469
…		…
457		503
458	=cut	504	=cut
459		505
460	sub reset {	506	sub reset {
461	# hard to kill complex data structures	507	# hard to kill complex data structures
462	# we recreate all package loggers and reset the hierarchy	508	# we "recreate" all package loggers and reset the hierarchy
463	while (my ($k, $v) = each %CTX) {	509	while (my ($k, $v) = each %CTX) {
464	@$v = ($k, (1 << 10) - 1 - 1, { });	510	@$v = ($k, (1 << 10) - 1 - 1, { });
465		511
466	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	512	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
467	$v->attach ($CTX{$pkg});
468	}	513	}
469		514
470	$AnyEvent::Log::Default->parents;	515	@$_ = ($_->[0], (1 << 10) - 1 - 1)
471	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	516	for $LOG, $FILTER, $COLLECT;
472	$AnyEvent::Log::Default->log_cb (sub {	517
		518	$LOG->slaves;
		519	$LOG->title ('$AnyEvent::Log::LOG');
		520	$LOG->log_cb (sub {
473	warn shift;	521	warn shift;
474	0	522	0
475	});	523	});
476	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
477		524
478	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	525	$FILTER->slaves ($LOG);
479	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	526	$FILTER->title ('$AnyEvent::Log::FILTER');
480	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	527	$FILTER->level ($AnyEvent::VERBOSE);
481	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
482		528
483	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	529	$COLLECT->slaves ($FILTER);
484	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	530	$COLLECT->title ('$AnyEvent::Log::COLLECT');
485	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;
486		531
487	_reassess;	532	_reassess;
488	}	533	}
489		534
490	# create the default logger contexts	535	# create the default logger contexts
491	$AnyEvent::Log::Default = ctx undef;	536	$LOG = ctx undef;
492	$AnyEvent::Log::Root = ctx undef;	537	$FILTER = ctx undef;
493	$AnyEvent::Log::Top = ctx undef;	538	$COLLECT = ctx undef;
494		539
495	AnyEvent::Log::reset;	540	AnyEvent::Log::reset;
496		541
497	# hello, CPAN, please catch me	542	# hello, CPAN, please catch me
498	package AnyEvent::Log::Default;
499	package AE::Log::Default;
500	package AnyEvent::Log::Root;
501	package AE::Log::Root;
502	package AnyEvent::Log::Top;	543	package AnyEvent::Log::LOG;
503	package AE::Log::Top;	544	package AE::Log::LOG;
		545	package AnyEvent::Log::FILTER;
		546	package AE::Log::FILTER;
		547	package AnyEvent::Log::COLLECT;
		548	package AE::Log::COLLECT;
504		549
505	package AnyEvent::Log::Ctx;	550	package AnyEvent::Log::Ctx;
506		551
507	# 0 1 2 3 4	552	# 0 1 2 3 4
508	# [$title, $level, %$parents, &$logcb, &$fmtcb]	553	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
509		554
510	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	555	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
511		556
512	This is a convenience constructor that makes it simpler to construct	557	This is a convenience constructor that makes it simpler to construct
513	anonymous logging contexts.	558	anonymous logging contexts.
…		…
516	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
517	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
518	array. The methods are called in the same order as specified.	563	array. The methods are called in the same order as specified.
519		564
520	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
521	level, some parent contexts and a logging callback.	566	level, some slave contexts and a logging callback.
522		567
523	$ctx = new AnyEvent::Log::Ctx	568	$ctx = new AnyEvent::Log::Ctx
524	title => "dubious messages",	569	title => "dubious messages",
525	level => "error",	570	level => "error",
526	log_cb => sub { print STDOUT shift; 0 },	571	log_cb => sub { print STDOUT shift; 0 },
527	parents => [$ctx1, $ctx, $ctx2],	572	slaves => [$ctx1, $ctx, $ctx2],
528	;	573	;
529		574
530	=back	575	=back
531		576
532	=cut	577	=cut
…		…
645	AnyEvent::Log::_reassess;	690	AnyEvent::Log::_reassess;
646	}	691	}
647		692
648	=back	693	=back
649		694
650	=head3 PARENT CONTEXTS	695	=head3 SLAVE CONTEXTS
651		696
652	The following methods attach and detach another logging context to a	697	The following methods attach and detach another logging context to a
653	logging context.	698	logging context.
654		699
655	Log messages are propagated to all parent contexts, unless the logging	700	Log messages are propagated to all slave contexts, unless the logging
656	callback consumes the message.	701	callback consumes the message.
657		702
658	=over 4	703	=over 4
659		704
660	=item $ctx->attach ($ctx2[, $ctx3...])	705	=item $ctx->attach ($ctx2[, $ctx3...])
661		706
662	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
663	to add a context twice (the second add will be ignored).	708	to add a context twice (the second add will be ignored).
664		709
665	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.
666		711
667	=item $ctx->detach ($ctx2[, $ctx3...])	712	=item $ctx->detach ($ctx2[, $ctx3...])
668		713
669	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
670	to remove a context that hasn't been added.	715	to remove a context that hasn't been added.
671		716
672	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.
673		718
674	=item $ctx->parents ($ctx2[, $ctx3...])	719	=item $ctx->slaves ($ctx2[, $ctx3...])
675		720
676	Replaces all parents attached to this context by the ones given.	721	Replaces all slaves attached to this context by the ones given.
677		722
678	=cut	723	=cut
679		724
680	sub attach {	725	sub attach {
681	my $ctx = shift;	726	my $ctx = shift;
…		…
689		734
690	delete $ctx->[2]{$_+0}	735	delete $ctx->[2]{$_+0}
691	for map { AnyEvent::Log::ctx $_ } @_;	736	for map { AnyEvent::Log::ctx $_ } @_;
692	}	737	}
693		738
694	sub parents {	739	sub slaves {
695	undef $_[0][2];	740	undef $_[0][2];
696	&attach;	741	&attach;
697	}	742	}
698		743
699	=back	744	=back
700		745
701	=head3 MESSAGE LOGGING	746	=head3 LOG TARGETS
702		747
703	The following methods configure how the logging context actually does	748	The following methods configure how the logging context actually does
704	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
705	whatever it wants to do with it) and also allows you to log messages	750	whatever it wants to do with it).
706	directly to a context, without going via your package context.
707		751
708	=over 4	752	=over 4
709		753
710	=item $ctx->log_cb ($cb->($str))	754	=item $ctx->log_cb ($cb->($str)
711		755
712	Replaces the logging callback on the context (C<undef> disables the	756	Replaces the logging callback on the context (C<undef> disables the
713	logging callback).	757	logging callback).
714		758
715	The logging callback is responsible for handling formatted log messages	759	The logging callback is responsible for handling formatted log messages
716	(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
717	newline (and are possibly multiline themselves).	761	newline (and are possibly multiline themselves).
718		762
719	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
720	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
721	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.
722		766
723	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
724	and do not consume it.	768	and do not consume it.
725		769
726	$ctx->log_cb (sub { print STDERR shift; 0 });	770	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
734	your program.	778	your program.
735		779
736	$ctx->levels ("debug", "trace");	780	$ctx->levels ("debug", "trace");
737	$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
738		782
739	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	783	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
740		784
741	Replaces the formatting callback on the context (C<undef> restores the	785	Replaces the formatting callback on the context (C<undef> restores the
742	default formatter).	786	default formatter).
743		787
744	The callback is passed the (possibly fractional) timestamp, the original	788	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	789	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	790	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.	791	string, but it could just as well be an array reference that just stores
		792	the values.
		793
		794	If, for some reaosn, 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.
748		797
749	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
750	brackets.	799	brackets.
751		800
752	$ctx->fmt_cb (sub {	801	$ctx->fmt_cb (sub {
…		…
769	"$msg->[3]";	818	"$msg->[3]";
770		819
771	0	820	0
772	});	821	});
773		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, $str] as input.
		842
774	=cut	843	=cut
775		844
776	sub log_cb {	845	sub log_cb {
777	my ($ctx, $cb) = @_;	846	my ($ctx, $cb) = @_;
778		847
…		…
783	my ($ctx, $cb) = @_;	852	my ($ctx, $cb) = @_;
784		853
785	$ctx->[4] = $cb;	854	$ctx->[4] = $cb;
786	}	855	}
787		856
788	=item $ctx->log ($level, $msg[, @params])	857	sub log_to_file {
789		858	my ($ctx, $path) = @_;
790	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
791
792	=item $logger = $ctx->logger ($level[, \$enabled])
793
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		859
825	open my $fh, ">>", $path	860	open my $fh, ">>", $path
826	or die "$path: $!";	861	or die "$path: $!";
827		862
828	$AnyEvent::Log::Default->log_cb (sub {	863	$ctx->log_cb (sub {
829	syswrite $fh, shift;	864	syswrite $fh, shift;
830	0	865	0
831	});	866	});
		867	}
		868
		869	sub log_to_file {
		870	my ($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 {
832		950
833	=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.
834		952
835	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
836	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
837	filtering.	955	filtering.
838		956
839	open my $fh, ">>", $path	957	$AnyEvent::Log::FILTER->attach
840	or die "$path: $!";	958	new AnyEvent::Log::Ctx log_to_file => $path);
841
842	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx
843	log_cb => sub { syswrite $fh, shift; 0 });
844		959
845	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
846	attached to the toplevel context, which receives all messages I<before>	961	attached to the toplevel context, which receives all messages I<before>
847	the global filtering.	962	the global filtering.
848		963
849	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	964	$AnyEvent::Log::COLLECT->attach (
850	log_cb => sub { syswrite $fh, shift; 0 });	965	new AnyEvent::Log::Ctx log_to_file => $path);
851		966
852	In both cases, messages are still written to STDOUT.	967	In both cases, messages are still written to STDERR.
853		968
854	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	969	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
855		970
856	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	971	Attach the C<$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.	972	context - this simply circumvents the global filtering for trace messages.
859		973
860	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	974	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
861	$debug->attach ($AnyEvent::Log::Default);	975	$debug->attach ($AnyEvent::Log::LOG);
862	$debug->levels ("trace"); # not "level"!
863		976
864	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.
865		980
866	=back	981	=back
867		982
868	=head1 AUTHOR	983	=head1 AUTHOR
869		984

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.16 by root, Sat Aug 20 02:19:18 2011 UTC vs. Revision 1.23 by root, Sun Aug 21 03:20:52 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.16 by root, Sat Aug 20 02:19:18 2011 UTC vs.
Revision 1.23 by root, Sun Aug 21 03:20:52 2011 UTC