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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.11 by root, Sat Aug 20 01:03:09 2011 UTC vs.
Revision 1.28 by root, Thu Aug 25 00:08:10 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 maximum	27	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("all");	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::ctx "")->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,
32		34	# regardless of (most) other settings
33	# disable logging for package "AnyEvent" and all packages below it	35	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
34	AnyEvent->AnyEvent::Log::ctx->level (0);	36	level => "critical",
35		37	log_to_syslog => 0,
36	# log everything below debug to a file, for the whole program	38	);
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		39
41	=head1 DESCRIPTION	40	=head1 DESCRIPTION
42		41
43	This module implements a relatively simple "logging framework". It doesn't	42	This module implements a relatively simple "logging framework". It doesn't
44	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
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	44	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	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
47	using it from other modules as well.	46	using it from other modules as well.
48		47
49	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
50	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
51	starting your program, or change the logging level at runtime with	50	before starting your program, or change the logging level at runtime with
52	something like:	51	something like:
53		52
54	use AnyEvent;	53	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	54	AnyEvent::Log::FILTER->level ("info");
56		55
57	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),
58	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
59	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
60	targets, or being able to log into a database.	59	targets, or being able to log into a database.
61		60
		61	The amount of documentation might indicate otherwise, but the module is
		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.
		95
62	=head1 LOGGING FUNCTIONS	96	=head1 LOGGING FUNCTIONS
63		97
64	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
65	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
66	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
67	loaded.	101	loaded.
68		102
69	=over 4	103	=over 4
70		104
…		…
75	use Carp ();	109	use Carp ();
76	use POSIX ();	110	use POSIX ();
77		111
78	use AnyEvent (); BEGIN { AnyEvent::common_sense }	112	use AnyEvent (); BEGIN { AnyEvent::common_sense }
79	use AnyEvent::Util ();	113	use AnyEvent::Util ();
		114
		115	our $VERSION = $AnyEvent::VERSION;
		116
		117	our ($COLLECT, $FILTER, $LOG);
80		118
81	our ($now_int, $now_str1, $now_str2);	119	our ($now_int, $now_str1, $now_str2);
82		120
83	# Format Time, not public - yet?	121	# Format Time, not public - yet?
84	sub ft($) {	122	sub ft($) {
…		…
89	if $now_int != $i;	127	if $now_int != $i;
90		128
91	"$now_str1$f$now_str2"	129	"$now_str1$f$now_str2"
92	}	130	}
93		131
94	our %CTX; # all logging contexts	132	our %CTX; # all package contexts
95		133
96	# creates a default package context object for the given package	134	# creates a default package context object for the given package
97	sub _pkg_ctx($) {	135	sub _pkg_ctx($) {
98	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	136	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
99		137
100	# link "parent" package	138	# link "parent" package
101	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	139	my $parent = $_[0] =~ /^(.+)::/
		140	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		141	: $COLLECT;
102		142
103	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
104	$ctx->[2]{$pkg+0} = $pkg;	143	$ctx->[2]{$parent+0} = $parent;
105		144
106	$ctx	145	$ctx
107	}	146	}
108		147
109	=item AnyEvent::Log::log $level, $msg[, @args]	148	=item AnyEvent::Log::log $level, $msg[, @args]
110		149
111	Requests logging of the given C<$msg> with the given log level (1..9).	150	Requests logging of the given C<$msg> with the given log level, and
112	You can also use the following strings as log level: C<fatal> (1),	151	returns true if the message was logged I<somewhere>.
113	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
114	C<info> (7), C<debug> (8), C<trace> (9).
115		152
116	For C<fatal> log levels, the program will abort.	153	For C<fatal> log levels, the program will abort.
117		154
118	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	155	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
119	C<$msg> is interpreted as an sprintf format string.	156	C<$msg> is interpreted as an sprintf format string.
…		…
125	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
126	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
127	message in the first place.	164	message in the first place.
128		165
129	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
130	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.
131		171
132	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
133	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
134	need any additional functionality), as those functions will load the	174	need any additional functionality), as those functions will load the
135	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.
…		…
152		192
153	=cut	193	=cut
154		194
155	# also allow syslog equivalent names	195	# also allow syslog equivalent names
156	our %STR2LEVEL = (	196	our %STR2LEVEL = (
157	fatal => 1, emerg => 1,	197	fatal => 1, emerg => 1, exit => 1,
158	alert => 2,	198	alert => 2,
159	critical => 3, crit => 3,	199	critical => 3, crit => 3,
160	error => 4, err => 4,	200	error => 4, err => 4, die => 4,
161	warn => 5, warning => 5,	201	warn => 5, warning => 5,
162	note => 6, notice => 6,	202	note => 6, notice => 6,
163	info => 7,	203	info => 7,
164	debug => 8,	204	debug => 8,
165	trace => 9,	205	trace => 9,
…		…
195	? $level+0	235	? $level+0
196	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	236	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
197		237
198	my $mask = 1 << $level;	238	my $mask = 1 << $level;
199		239
200	my (%seen, @ctx, $now, $fmt);	240	my ($success, %seen, @ctx, $now, $fmt);
201		241
202	do	242	do
203	{	243	{
204	# skip if masked	244	# skip if masked
205	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	245	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
215	};	255	};
216		256
217	# format msg	257	# format msg
218	my $str = $ctx->[4]	258	my $str = $ctx->[4]
219	? $ctx->[4]($now, $_[0], $level, $format)	259	? $ctx->[4]($now, $_[0], $level, $format)
220	: $fmt \|\|= _format $now, $_[0], $level, $format;	260	: ($fmt \|\|= _format $now, $_[0], $level, $format);
221		261
		262	$success = 1;
		263
222	$ctx->[3]($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
223	}	268	}
224
225	# not masked, not consumed - propagate to parent contexts
226	push @ctx, values %{ $ctx->[2] };
227	}	269	}
228	}	270	}
229	while $ctx = pop @ctx;	271	while $ctx = pop @ctx;
230		272
231	exit 1 if $level <= 1;	273	exit 1 if $level <= 1;
		274
		275	$success
232	}	276	}
233		277
234	sub log($$;@) {	278	sub log($$;@) {
235	_log	279	_log
236	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	280	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
240	AnyEvent::log = AE::log = \&log;	284	AnyEvent::log = AE::log = \&log;
241		285
242	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	286	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
243		287
244	Creates a code reference that, when called, acts as if the	288	Creates a code reference that, when called, acts as if the
245	C<AnyEvent::Log::log> function was called at this point with the givne	289	C<AnyEvent::Log::log> function was called at this point with the given
246	level. C<$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
247	the C<AnyEvent::Log::log> function:	291	the C<AnyEvent::Log::log> function:
248		292
249	my $debug_log = AnyEvent::Log::logger "debug";	293	my $debug_log = AnyEvent::Log::logger "debug";
250		294
…		…
275	# and later in your program	319	# and later in your program
276	$debug_log->("yo, stuff here") if $debug;	320	$debug_log->("yo, stuff here") if $debug;
277		321
278	$debug and $debug_log->("123");	322	$debug and $debug_log->("123");
279		323
280	Note: currently the enabled var is always true - that will be fixed in a
281	future version :)
282
283	=cut	324	=cut
284		325
285	our %LOGGER;	326	our %LOGGER;
286		327
287	# re-assess logging status for all loggers	328	# re-assess logging status for all loggers
288	sub _reassess {	329	sub _reassess {
		330	local $SIG{__DIE__};
		331	my $die = sub { die };
		332
289	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	333	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
290	my ($ctx, $level, $renabled) = @$_;	334	my ($ctx, $level, $renabled) = @$_;
291		335
292	# to detect whether a message would be logged, we # actually	336	# to detect whether a message would be logged, we actually
293	# 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
294	# sure that the logging decision is correct :)	338	# sure that the logging decision is correct :)
295		339
296	$$renabled = !eval {	340	$$renabled = !eval {
297	local $SIG{__DIE__};
298
299	_log $ctx, $level, sub { die };	341	_log $ctx, $level, $die;
300		342
301	1	343	1
302	};	344	};
303
304	$$renabled = 1; # TODO
305	}	345	}
306	}	346	}
307		347
308	sub _logger($;$) {	348	sub _logger {
309	my ($ctx, $level, $renabled) = @_;	349	my ($ctx, $level, $renabled) = @_;
310
311	$renabled \|\|= \my $enabled;
312		350
313	$$renabled = 1;	351	$$renabled = 1;
314		352
315	my $logger = [$ctx, $level, $renabled];	353	my $logger = [$ctx, $level, $renabled];
316		354
…		…
356	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
357	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
358	actually logging the formatted message and telling C<AnyEvent::Log>	396	actually logging the formatted message and telling C<AnyEvent::Log>
359	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).
360		398
361	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
362	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
363	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
364	contexts.	402	contexts.
365		403
366	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
367	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
368	message can arrive at the same context via multiple paths.	406	message can arrive at the same context via multiple paths.
…		…
372	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
373	disabled logging callback and the default formatting callback.	411	disabled logging callback and the default formatting callback.
374		412
375	Package contexts have the package name as logging title by default.	413	Package contexts have the package name as logging title by default.
376		414
377	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
378	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
379	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	417	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
380	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	418	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
381	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
382	Perl is C<main>, the default parent of any toplevel package context is	420	package name in Perl is C<main>, the default slave of any top-level
383	C<AnyEvent::Log::Top>.	421	package context is C<$AnyEvent::Log::COLLECT>.
384		422
385	Since perl packages form only an approximate hierarchy, this parent	423	Since perl packages form only an approximate hierarchy, this slave
386	context can of course be removed.	424	context can of course be removed.
387		425
388	All other (anonymous) contexts have no parents and an empty title by	426	All other (anonymous) contexts have no slaves and an empty title by
389	default.	427	default.
390		428
391	When the module is loaded it creates the default context called	429	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
392	C<AnyEvent::Log::Default>, which simply logs everything to STDERR and	430	context that simply logs everything via C<warn>, without propagating
393	doesn't propagate anything anywhere by default. The purpose of the default	431	anything anywhere by default. The purpose of this context is to provide
394	context is to provide a convenient place to override the global logging	432	a convenient place to override the global logging target or to attach
395	target or to attach additional log targets. It's not meant for filtering.	433	additional log targets. It's not meant for filtering.
396		434
397	It then creates the root context called C<AnyEvent::Log::Root> and	435	It then creates the C<$AnyEvent::Log::FILTER> context whose
398	sets its log level set to all levels up to the one specified by	436	purpose is to suppress all messages with priority higher
399	C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the default logging	437	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
400	context to it. The purpose of the root context is to simply provide	438	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
401	filtering according to some global log level.	439	is to simply provide filtering according to some global log level.
402		440
403	Finally it creates the toplevel package context called	441	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
404	C<AnyEvent::Log::Top> and attached the root context but otherwise leaves	442	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
405	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
406	system-wide.	444	messages system-wide.
407		445
408	These three special contexts can also be referred to by the names	446	The hierarchy is then:
409	C<AE::Log::Default>, C<AE::Log::Root> and C<AE::Log::Top>.
410		447
		448	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		449
411	The effect of all this is that log messages, by default, wander up	450	The effect of all this is that log messages, by default, wander up to the
412	to the root context where log messages with lower priority then	451	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		452	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
413	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	453	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
414	AnyEvent::Log::Default context to be logged to STDERR.	454	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
415		455
416	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),
417	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
418	other contexts to log, for example, their debug and trace messages to the
419	default target despite the global logging level, or to attach additional	458	messages to the $LOG target despite the global logging level, or to attach
420	log targets that log messages, regardless of the global logging level.	459	additional log targets that log messages, regardless of the global logging
		460	level.
421		461
422	It also makes it easy to replace the default STDERR-logger by something	462	It also makes it easy to modify the default warn-logger ($LOG) to
423	that 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 $FILTER.
424		465
425	=head2 CREATING/FINDING/DESTROYING CONTEXTS	466	=head2 CREATING/FINDING/DESTROYING CONTEXTS
426		467
427	=over 4	468	=over 4
428		469
…		…
450	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	491	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
451	}	492	}
452		493
453	=item AnyEvent::Log::reset	494	=item AnyEvent::Log::reset
454		495
455	Deletes all contexts and recreates the default hierarchy, i.e. resets the	496	Resets all package contexts and recreates the default hierarchy if
456	logging subsystem to defaults.	497	necessary, i.e. resets the logging subsystem to defaults, as much as
		498	possible. This process keeps references to contexts held by other parts of
		499	the program intact.
457		500
458	This can be used to implement config-file (re-)loading: before loading a	501	This can be used to implement config-file (re-)loading: before loading a
459	configuration, reset all contexts.	502	configuration, reset all contexts.
460		503
461	=cut	504	=cut
462		505
463	sub reset {	506	sub reset {
464	@$_ = () for values %CTX; # just to be sure - to kill circular logging dependencies	507	# hard to kill complex data structures
465	%CTX = ();	508	# we "recreate" all package loggers and reset the hierarchy
		509	while (my ($k, $v) = each %CTX) {
		510	@$v = ($k, (1 << 10) - 1 - 1, { });
466		511
467	my $default = ctx undef;	512	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
468	$default->title ("AnyEvent::Log::Default");
469	$default->log_cb (sub {
470	print STDERR shift;
471	0
472	});	513	}
473	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $default;
474		514
475	my $root = ctx undef;	515	@$_ = ($_->[0], (1 << 10) - 1 - 1)
		516	for $LOG, $FILTER, $COLLECT;
		517
		518	$LOG->slaves;
476	$root->title ("AnyEvent::Log::Root");	519	$LOG->title ('$AnyEvent::Log::LOG');
		520	$LOG->log_to_warn;
		521
		522	$FILTER->slaves ($LOG);
		523	$FILTER->title ('$AnyEvent::Log::FILTER');
477	$root->level ($AnyEvent::VERBOSE);	524	$FILTER->level ($AnyEvent::VERBOSE);
478	$root->attach ($default);
479	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $root;
480		525
481	my $top = ctx undef;	526	$COLLECT->slaves ($FILTER);
482	$top->title ("AnyEvent::Log::Top");	527	$COLLECT->title ('$AnyEvent::Log::COLLECT');
483	$top->attach ($root);	528
484	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $top;	529	_reassess;
485	}	530	}
		531
		532	# create the default logger contexts
		533	$LOG = ctx undef;
		534	$FILTER = ctx undef;
		535	$COLLECT = ctx undef;
486		536
487	AnyEvent::Log::reset;	537	AnyEvent::Log::reset;
488		538
		539	# hello, CPAN, please catch me
489	package AnyEvent::Log::Default;	540	package AnyEvent::Log::LOG;
490	package AE::Log::Default;	541	package AE::Log::LOG;
		542	package AnyEvent::Log::FILTER;
		543	package AE::Log::FILTER;
		544	package AnyEvent::Log::COLLECT;
		545	package AE::Log::COLLECT;
		546
491	package AnyEvent::Log::Root;	547	package AnyEvent::Log::Ctx;
492	package AE::Log::Root;	548
493	package AnyEvent::Log::Top;	549	# 0 1 2 3 4
494	package AE::Log::Top;	550	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
		551
		552	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
		553
		554	This is a convenience constructor that makes it simpler to construct
		555	anonymous logging contexts.
		556
		557	Each key-value pair results in an invocation of the method of the same
		558	name as the key with the value as parameter, unless the value is an
		559	arrayref, in which case it calls the method with the contents of the
		560	array. The methods are called in the same order as specified.
		561
		562	Example: create a new logging context and set both the default logging
		563	level, some slave contexts and a logging callback.
		564
		565	$ctx = new AnyEvent::Log::Ctx
		566	title => "dubious messages",
		567	level => "error",
		568	log_cb => sub { print STDOUT shift; 0 },
		569	slaves => [$ctx1, $ctx, $ctx2],
		570	;
495		571
496	=back	572	=back
497		573
498	=cut	574	=cut
499		575
500	package AnyEvent::Log::Ctx;	576	sub new {
		577	my $class = shift;
501		578
502	# 0 1 2 3 4	579	my $ctx = AnyEvent::Log::ctx undef;
503	# [$title, $level, %$parents, &$logcb, &$fmtcb]	580
		581	while (@_) {
		582	my ($k, $v) = splice @_, 0, 2;
		583	$ctx->$k (ref $v eq "ARRAY" ? @$v : $v);
		584	}
		585
		586	bless $ctx, $class # do we really support subclassing, hmm?
		587	}
		588
504		589
505	=head2 CONFIGURING A LOG CONTEXT	590	=head2 CONFIGURING A LOG CONTEXT
506		591
507	The following methods can be used to configure the logging context.	592	The following methods can be used to configure the logging context.
508		593
…		…
602	AnyEvent::Log::_reassess;	687	AnyEvent::Log::_reassess;
603	}	688	}
604		689
605	=back	690	=back
606		691
607	=head3 PARENT CONTEXTS	692	=head3 SLAVE CONTEXTS
608		693
609	The following methods attach and detach another logging context to a	694	The following methods attach and detach another logging context to a
610	logging context.	695	logging context.
611		696
612	Log messages are propagated to all parent contexts, unless the logging	697	Log messages are propagated to all slave contexts, unless the logging
613	callback consumes the message.	698	callback consumes the message.
614		699
615	=over 4	700	=over 4
616		701
617	=item $ctx->attach ($ctx2[, $ctx3...])	702	=item $ctx->attach ($ctx2[, $ctx3...])
618		703
619	Attaches the given contexts as parents to this context. It is not an error	704	Attaches the given contexts as slaves to this context. It is not an error
620	to add a context twice (the second add will be ignored).	705	to add a context twice (the second add will be ignored).
621		706
622	A context can be specified either as package name or as a context object.	707	A context can be specified either as package name or as a context object.
623		708
624	=item $ctx->detach ($ctx2[, $ctx3...])	709	=item $ctx->detach ($ctx2[, $ctx3...])
625		710
626	Removes the given parents from this context - it's not an error to attempt	711	Removes the given slaves from this context - it's not an error to attempt
627	to remove a context that hasn't been added.	712	to remove a context that hasn't been added.
628		713
629	A context can be specified either as package name or as a context object.	714	A context can be specified either as package name or as a context object.
630		715
631	=item $ctx->parents ($ctx2[, $ctx3...])	716	=item $ctx->slaves ($ctx2[, $ctx3...])
632		717
633	Replaces all parents attached to this context by the ones given.	718	Replaces all slaves attached to this context by the ones given.
634		719
635	=cut	720	=cut
636		721
637	sub attach {	722	sub attach {
638	my $ctx = shift;	723	my $ctx = shift;
…		…
646		731
647	delete $ctx->[2]{$_+0}	732	delete $ctx->[2]{$_+0}
648	for map { AnyEvent::Log::ctx $_ } @_;	733	for map { AnyEvent::Log::ctx $_ } @_;
649	}	734	}
650		735
651	sub parents {	736	sub slaves {
652	undef $_[0][2];	737	undef $_[0][2];
653	&attach;	738	&attach;
654	}	739	}
655		740
656	=back	741	=back
657		742
658	=head3 MESSAGE LOGGING	743	=head3 LOG TARGETS
659		744
660	The following methods configure how the logging context actually does	745	The following methods configure how the logging context actually does
661	the logging (which consists of formatting the message and printing it or	746	the logging (which consists of formatting the message and printing it or
662	whatever it wants to do with it) and also allows you to log messages	747	whatever it wants to do with it).
663	directly to a context, without going via your package context.
664		748
665	=over 4	749	=over 4
666		750
667	=item $ctx->log_cb ($cb->($str))	751	=item $ctx->log_cb ($cb->($str)
668		752
669	Replaces the logging callback on the context (C<undef> disables the	753	Replaces the logging callback on the context (C<undef> disables the
670	logging callback).	754	logging callback).
671		755
672	The logging callback is responsible for handling formatted log messages	756	The logging callback is responsible for handling formatted log messages
673	(see C<fmt_cb> below) - normally simple text strings that end with a	757	(see C<fmt_cb> below) - normally simple text strings that end with a
674	newline (and are possibly multiline themselves).	758	newline (and are possibly multiline themselves).
675		759
676	It also has to return true iff it has consumed the log message, and false	760	It also has to return true iff it has consumed the log message, and false
677	if it hasn't. Consuming a message means that it will not be sent to any	761	if it hasn't. Consuming a message means that it will not be sent to any
678	parent context. When in doubt, return C<0> from your logging callback.	762	slave context. When in doubt, return C<0> from your logging callback.
679		763
680	Example: a very simple logging callback, simply dump the message to STDOUT	764	Example: a very simple logging callback, simply dump the message to STDOUT
681	and do not consume it.	765	and do not consume it.
682		766
683	$ctx->log_cb (sub { print STDERR shift; 0 });	767	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
691	your program.	775	your program.
692		776
693	$ctx->levels ("debug", "trace");	777	$ctx->levels ("debug", "trace");
694	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	778	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
695		779
696	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	780	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
697		781
698	Replaces the formatting callback on the context (C<undef> restores the	782	Replaces the formatting callback on the context (C<undef> restores the
699	default formatter).	783	default formatter).
700		784
701	The callback is passed the (possibly fractional) timestamp, the original	785	The callback is passed the (possibly fractional) timestamp, the original
702	logging context, the (numeric) logging level and the raw message string and needs to	786	logging context, the (numeric) logging level and the raw message string
703	return a formatted log message. In most cases this will be a string, but	787	and needs to return a formatted log message. In most cases this will be a
704	it could just as well be an array reference that just stores the values.	788	string, but it could just as well be an array reference that just stores
		789	the values.
		790
		791	If, for some reason, you want to use C<caller> to find out more baout the
		792	logger then you should walk up the call stack until you are no longer
		793	inside the C<AnyEvent::Log> package.
705		794
706	Example: format just the raw message, with numeric log level in angle	795	Example: format just the raw message, with numeric log level in angle
707	brackets.	796	brackets.
708		797
709	$ctx->fmt_cb (sub {	798	$ctx->fmt_cb (sub {
…		…
726	"$msg->[3]";	815	"$msg->[3]";
727		816
728	0	817	0
729	});	818	});
730		819
		820	=item $ctx->log_to_warn
		821
		822	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		823	(usually this logs to STDERR).
		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	Needless(?) to say, if you do not want to be bitten by some evil person
		836	calling C<chdir>, the path should be absolute. Doesn't help with
		837	C<chroot>, but hey...
		838
		839	=item $ctx->log_to_syslog ([$log_flags])
		840
		841	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		842	the others in the obvious way. If specified, then the C<$log_flags> are
		843	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		844	flags valid for Sys::Syslog::syslog, except for the priority levels.
		845
		846	Note that this function also sets a C<fmt_cb> - the logging part requires
		847	an array reference with [$level, $str] as input.
		848
731	=cut	849	=cut
732		850
733	sub log_cb {	851	sub log_cb {
734	my ($ctx, $cb) = @_;	852	my ($ctx, $cb) = @_;
735		853
…		…
740	my ($ctx, $cb) = @_;	858	my ($ctx, $cb) = @_;
741		859
742	$ctx->[4] = $cb;	860	$ctx->[4] = $cb;
743	}	861	}
744		862
		863	sub log_to_warn {
		864	my ($ctx, $path) = @_;
		865
		866	$ctx->log_cb (sub {
		867	warn shift;
		868	0
		869	});
		870	}
		871
		872	sub log_to_file {
		873	my ($ctx, $path) = @_;
		874
		875	open my $fh, ">>", $path
		876	or die "$path: $!";
		877
		878	$ctx->log_cb (sub {
		879	syswrite $fh, shift;
		880	0
		881	});
		882	}
		883
		884	sub log_to_path {
		885	my ($ctx, $path) = @_;
		886
		887	$ctx->log_cb (sub {
		888	open my $fh, ">>", $path
		889	or die "$path: $!";
		890
		891	syswrite $fh, shift;
		892	0
		893	});
		894	}
		895
		896	sub log_to_syslog {
		897	my ($ctx, $flags) = @_;
		898
		899	require Sys::Syslog;
		900
		901	$ctx->fmt_cb (sub {
		902	my $str = $_[3];
		903	$str =~ s/\n(?=.)/\n+ /g;
		904
		905	[$_[2], "($_[1][0]) $str"]
		906	});
		907
		908	$ctx->log_cb (sub {
		909	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		910
		911	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		912	for split /\n/, $_[0][1];
		913
		914	0
		915	});
		916	}
		917
		918	=back
		919
		920	=head3 MESSAGE LOGGING
		921
		922	These methods allow you to log messages directly to a context, without
		923	going via your package context.
		924
		925	=over 4
		926
745	=item $ctx->log ($level, $msg[, @params])	927	=item $ctx->log ($level, $msg[, @params])
746		928
747	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	929	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
748		930
749	=item $logger = $ctx->logger ($level[, \$enabled])	931	=item $logger = $ctx->logger ($level[, \$enabled])
…		…
754	=cut	936	=cut
755		937
756	*log = \&AnyEvent::Log::_log;	938	*log = \&AnyEvent::Log::_log;
757	*logger = \&AnyEvent::Log::_logger;	939	*logger = \&AnyEvent::Log::_logger;
758		940
		941	=back
		942
		943	=cut
		944
		945	package AnyEvent::Log;
		946
		947	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		948
		949	Logging can also be configured by setting the environment variable
		950	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		951
		952	The value consists of one or more logging context specifications separated
		953	by C<:> or whitespace. Each logging specification in turn starts with a
		954	context name, followed by C<=>, followed by zero or more comma-separated
		955	configuration directives, here are some examples:
		956
		957	# set default logging level
		958	filter=warn
		959
		960	# log to file instead of to stderr
		961	log=file=/tmp/mylog
		962
		963	# log to file in addition to stderr
		964	log=+%file:%file=file=/tmp/mylog
		965
		966	# enable debug log messages, log warnings and above to syslog
		967	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		968
		969	# log trace messages (only) from AnyEvent::Debug to file
		970	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		971
		972	A context name in the log specification can be any of the following:
		973
		974	=over 4
		975
		976	=item C<collect>, C<filter>, C<log>
		977
		978	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		979	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		980
		981	=item C<%name>
		982
		983	Context names starting with a C<%> are anonymous contexts created when the
		984	name is first mentioned. The difference to package contexts is that by
		985	default they have no attached slaves.
		986
		987	=item a perl package name
		988
		989	Any other string references the logging context associated with the given
		990	Perl C<package>. In the unlikely case where you want to specify a package
		991	context that matches on of the other context name forms, you can add a
		992	C<::> to the package name to force interpretation as a package.
		993
		994	=back
		995
		996	The configuration specifications can be any number of the following:
		997
		998	=over 4
		999
		1000	=item C<stderr>
		1001
		1002	Configures the context to use Perl's C<warn> function (which typically
		1003	logs to C<STDERR>). Works like C<log_to_warn>.
		1004
		1005	=item C<file=>I<path>
		1006
		1007	Configures the context to log to a file with the given path. Works like
		1008	C<log_to_file>.
		1009
		1010	=item C<path=>I<path>
		1011
		1012	Configures the context to log to a file with the given path. Works like
		1013	C<log_to_path>.
		1014
		1015	=item C<syslog> or C<syslog=>I<expr>
		1016
		1017	Configured the context to log to syslog. If I<expr> is given, then it is
		1018	evaluated in the L<Sys::Syslog> package, so you could use:
		1019
		1020	log=syslog=LOG_LOCAL0
		1021
		1022	=item C<nolog>
		1023
		1024	Configures the context to not log anything by itself, which is the
		1025	default. Same as C<< $ctx->log_cb (undef) >>.
		1026
		1027	=item C<0> or C<off>
		1028
		1029	Sets the logging level of the context ot C<0>, i.e. all messages will be
		1030	filtered out.
		1031
		1032	=item C<all>
		1033
		1034	Enables all logging levels, i.e. filtering will effectively be switched
		1035	off (the default).
		1036
		1037	=item C<only>
		1038
		1039	Disables all logging levels, and changes the interpretation of following
		1040	level specifications to enable the specified level only.
		1041
		1042	Example: only enable debug messages for a context.
		1043
		1044	context=only,debug
		1045
		1046	=item C<except>
		1047
		1048	Enables all logging levels, and changes the interpretation of following
		1049	level specifications to disable that level. Rarely used.
		1050
		1051	Example: enable all logging levels except fatal and trace (this is rather
		1052	nonsensical).
		1053
		1054	filter=exept,fatal,trace
		1055
		1056	=item C<level>
		1057
		1058	Enables all logging levels, and changes the interpretation of following
		1059	level specifications to be "that level or any higher priority
		1060	message". This is the default.
		1061
		1062	Example: log anything at or above warn level.
		1063
		1064	filter=warn
		1065
		1066	# or, more verbose
		1067	filter=only,level,warn
		1068
		1069	=item C<1>..C<9>, a logging level name (C<error>, C<debug> etc.)
		1070
		1071	A numeric loglevel or the name of a loglevel will be interpreted according
		1072	to the most recent C<only>, C<except> or C<level> directive. By default,
		1073	specifying a logging level enables that and any higher priority messages.
		1074
		1075	=item C<+>I<context>
		1076
		1077	Adds/attaches the named context as slave to the context.
		1078
		1079	=item C<+>
		1080
		1081	A line C<+> clears the slave list form the context. Anonymous (C<%name>)
		1082	contexts have no slaves by default, but package contexts have the parent
		1083	context as slave by default.
		1084
		1085	Example: log messages from My::Module to a file, do not send them to the
		1086	default log collector.
		1087
		1088	My::Module=+,file=/tmp/mymodulelog
		1089
		1090	=back
		1091
		1092	=cut
		1093
		1094	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1095	my %anon;
		1096
		1097	my $pkg = sub {
		1098	$_[0] eq "log" ? $LOG
		1099	: $_[0] eq "filter" ? $FILTER
		1100	: $_[0] eq "collect" ? $COLLECT
		1101	: $_[0] =~ /^%(.+)$/ && $anon{$1} \|\|= ctx undef
		1102	: $_[0] =~ /^(.*?)(?:::)?$/ && ctx "$1" # egad :/
		1103	};
		1104
		1105	while (/\G((?:[^:=]+\|::\|\\.)+)=/gc) {
		1106	my $ctx = $pkg->($1);
		1107	my $level = "level";
		1108
		1109	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1110	for ("$1") {
		1111	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1112	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1113	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1114	} elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog (eval "package Sys::Syslog; $1");
		1115	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1116	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1117	} elsif ($_ eq "+" ) { $ctx->slaves;
		1118	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1119	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1120	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1121	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1122	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1123	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1124	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1125	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1126	}
		1127	}
		1128
		1129	/\G,/gc or last;
		1130	}
		1131
		1132	/\G[:[:space:]]/gc or last;
		1133	}
		1134
		1135	if (/\G(.+)/g) {
		1136	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1137	}
		1138	}
		1139
759	1;	1140	1;
		1141
		1142	=head1 EXAMPLES
		1143
		1144	This section shows some common configurations, both as code, and as
		1145	C<PERL_ANYEVENT_LOG> string.
		1146
		1147	=over 4
		1148
		1149	=item Setting the global logging level.
		1150
		1151	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1152	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1153	the root context at runtime:
		1154
		1155	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1156
		1157	PERL_ANYEVENT_LOG=log=warn
		1158
		1159	$AnyEvent::Log::FILTER->level ("warn");
		1160
		1161	=item Append all messages to a file instead of sending them to STDERR.
		1162
		1163	This is affected by the global logging level.
		1164
		1165	$AnyEvent::Log::LOG->log_to_file ($path);
		1166
		1167	PERL_ANYEVENT_LOG=log=file=/some/path
		1168
		1169	=item Write all messages with priority C<error> and higher to a file.
		1170
		1171	This writes them only when the global logging level allows it, because
		1172	it is attached to the default context which is invoked I<after> global
		1173	filtering.
		1174
		1175	$AnyEvent::Log::FILTER->attach
		1176	new AnyEvent::Log::Ctx log_to_file => $path);
		1177
		1178	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
		1179
		1180	This writes them regardless of the global logging level, because it is
		1181	attached to the toplevel context, which receives all messages I<before>
		1182	the global filtering.
		1183
		1184	$AnyEvent::Log::COLLECT->attach (
		1185	new AnyEvent::Log::Ctx log_to_file => $path);
		1186
		1187	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1188
		1189	In both cases, messages are still written to STDERR.
		1190
		1191	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
		1192
		1193	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
		1194	context - this simply circumvents the global filtering for trace messages.
		1195
		1196	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
		1197	$debug->attach ($AnyEvent::Log::LOG);
		1198
		1199	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1200
		1201	This of course works for any package, not just L<AnyEvent::Debug>, but
		1202	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1203	default.
760		1204
761	=back	1205	=back
762		1206
763	=head1 AUTHOR	1207	=head1 AUTHOR
764		1208
765	Marc Lehmann <schmorp@schmorp.de>	1209	Marc Lehmann <schmorp@schmorp.de>
766	http://home.schmorp.de/	1210	http://home.schmorp.de/
767		1211
768	=cut	1212	=cut
		1213

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.11 by root, Sat Aug 20 01:03:09 2011 UTC vs. Revision 1.28 by root, Thu Aug 25 00:08:10 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.11 by root, Sat Aug 20 01:03:09 2011 UTC vs.
Revision 1.28 by root, Thu Aug 25 00:08:10 2011 UTC