[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 1.24 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 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");
		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
33	# disable logging for package "AnyEvent" and all packages below it
34	AnyEvent->AnyEvent::Log::ctx->level (0);
35
36	# log everything below debug to a file, for the whole program
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		41
41	=head1 DESCRIPTION	42	=head1 DESCRIPTION
42		43
43	This module implements a relatively simple "logging framework". It doesn't	44	This module implements a relatively simple "logging framework". It doesn't
44	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
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	46	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	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
47	using it from other modules as well.	48	using it from other modules as well.
48		49
49	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
50	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
51	starting your program, or change the logging level at runtime with	52	before starting your program, or change the logging level at runtime with
52	something like:	53	something like:
53		54
54	use AnyEvent;	55	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	56	AnyEvent::Log::FILTER->level ("info");
56		57
57	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),
58	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
59	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
60	targets, or being able to log into a database.	61	targets, or being able to log into a database.
61		62
		63	The amount of documentation might indicate otherwise, but the module is
		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.
		97
62	=head1 LOGGING FUNCTIONS	98	=head1 LOGGING FUNCTIONS
63		99
64	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
65	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
66	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
67	loaded.	103	loaded.
68		104
69	=over 4	105	=over 4
70		106
…		…
75	use Carp ();	111	use Carp ();
76	use POSIX ();	112	use POSIX ();
77		113
78	use AnyEvent (); BEGIN { AnyEvent::common_sense }	114	use AnyEvent (); BEGIN { AnyEvent::common_sense }
79	use AnyEvent::Util ();	115	use AnyEvent::Util ();
		116
		117	our $VERSION = $AnyEvent::VERSION;
		118
		119	our ($COLLECT, $FILTER, $LOG);
80		120
81	our ($now_int, $now_str1, $now_str2);	121	our ($now_int, $now_str1, $now_str2);
82		122
83	# Format Time, not public - yet?	123	# Format Time, not public - yet?
84	sub ft($) {	124	sub ft($) {
…		…
89	if $now_int != $i;	129	if $now_int != $i;
90		130
91	"$now_str1$f$now_str2"	131	"$now_str1$f$now_str2"
92	}	132	}
93		133
94	our %CTX; # all logging contexts	134	our %CTX; # all package contexts
95		135
96	# creates a default package context object for the given package	136	# creates a default package context object for the given package
97	sub _pkg_ctx($) {	137	sub _pkg_ctx($) {
98	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	138	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
99		139
100	# link "parent" package	140	# link "parent" package
101	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	141	my $parent = $_[0] =~ /^(.+)::/
		142	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		143	: $COLLECT;
102		144
103	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
104	$ctx->[2]{$pkg+0} = $pkg;	145	$ctx->[2]{$parent+0} = $parent;
105		146
106	$ctx	147	$ctx
107	}	148	}
108		149
109	=item AnyEvent::Log::log $level, $msg[, @args]	150	=item AnyEvent::Log::log $level, $msg[, @args]
110		151
111	Requests logging of the given C<$msg> with the given log level (1..9).	152	Requests logging of the given C<$msg> with the given log level, and
112	You can also use the following strings as log level: C<fatal> (1),	153	returns true if the message was logged I<somewhere>.
113	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
114	C<info> (7), C<debug> (8), C<trace> (9).
115		154
116	For C<fatal> log levels, the program will abort.	155	For C<fatal> log levels, the program will abort.
117		156
118	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	157	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
119	C<$msg> is interpreted as an sprintf format string.	158	C<$msg> is interpreted as an sprintf format string.
…		…
125	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
126	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
127	message in the first place.	166	message in the first place.
128		167
129	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
130	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.
131		173
132	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
133	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
134	need any additional functionality), as those functions will load the	176	need any additional functionality), as those functions will load the
135	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.
…		…
152		194
153	=cut	195	=cut
154		196
155	# also allow syslog equivalent names	197	# also allow syslog equivalent names
156	our %STR2LEVEL = (	198	our %STR2LEVEL = (
157	fatal => 1, emerg => 1,	199	fatal => 1, emerg => 1, exit => 1,
158	alert => 2,	200	alert => 2,
159	critical => 3, crit => 3,	201	critical => 3, crit => 3,
160	error => 4, err => 4,	202	error => 4, err => 4, die => 4,
161	warn => 5, warning => 5,	203	warn => 5, warning => 5,
162	note => 6, notice => 6,	204	note => 6, notice => 6,
163	info => 7,	205	info => 7,
164	debug => 8,	206	debug => 8,
165	trace => 9,	207	trace => 9,
…		…
195	? $level+0	237	? $level+0
196	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	238	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
197		239
198	my $mask = 1 << $level;	240	my $mask = 1 << $level;
199		241
200	my (%seen, @ctx, $now, $fmt);	242	my ($success, %seen, @ctx, $now, $fmt);
201		243
202	do	244	do
203	{	245	{
204	# skip if masked	246	# skip if masked
205	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	247	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
…		…
215	};	257	};
216		258
217	# format msg	259	# format msg
218	my $str = $ctx->[4]	260	my $str = $ctx->[4]
219	? $ctx->[4]($now, $_[0], $level, $format)	261	? $ctx->[4]($now, $_[0], $level, $format)
220	: $fmt \|\|= _format $now, $_[0], $level, $format;	262	: ($fmt \|\|= _format $now, $_[0], $level, $format);
221		263
		264	$success = 1;
		265
222	$ctx->[3]($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
223	}	270	}
224
225	# not masked, not consumed - propagate to parent contexts
226	push @ctx, values %{ $ctx->[2] };
227	}	271	}
228	}	272	}
229	while $ctx = pop @ctx;	273	while $ctx = pop @ctx;
230		274
231	exit 1 if $level <= 1;	275	exit 1 if $level <= 1;
		276
		277	$success
232	}	278	}
233		279
234	sub log($$;@) {	280	sub log($$;@) {
235	_log	281	_log
236	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	282	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
240	AnyEvent::log = AE::log = \&log;	286	AnyEvent::log = AE::log = \&log;
241		287
242	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	288	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
243		289
244	Creates a code reference that, when called, acts as if the	290	Creates a code reference that, when called, acts as if the
245	C<AnyEvent::Log::log> function was called at this point with the givne	291	C<AnyEvent::Log::log> function was called at this point with the given
246	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	292	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
247	the C<AnyEvent::Log::log> function:	293	the C<AnyEvent::Log::log> function:
248		294
249	my $debug_log = AnyEvent::Log::logger "debug";	295	my $debug_log = AnyEvent::Log::logger "debug";
250		296
…		…
275	# and later in your program	321	# and later in your program
276	$debug_log->("yo, stuff here") if $debug;	322	$debug_log->("yo, stuff here") if $debug;
277		323
278	$debug and $debug_log->("123");	324	$debug and $debug_log->("123");
279		325
280	Note: currently the enabled var is always true - that will be fixed in a
281	future version :)
282
283	=cut	326	=cut
284		327
285	our %LOGGER;	328	our %LOGGER;
286		329
287	# re-assess logging status for all loggers	330	# re-assess logging status for all loggers
288	sub _reassess {	331	sub _reassess {
		332	local $SIG{__DIE__};
		333	my $die = sub { die };
		334
289	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	335	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
290	my ($ctx, $level, $renabled) = @$_;	336	my ($ctx, $level, $renabled) = @$_;
291		337
292	# to detect whether a message would be logged, we # actually	338	# 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	339	# try to log one and die. this isn't fast, but we can be
294	# sure that the logging decision is correct :)	340	# sure that the logging decision is correct :)
295		341
296	$$renabled = !eval {	342	$$renabled = !eval {
297	local $SIG{__DIE__};
298
299	_log $ctx, $level, sub { die };	343	_log $ctx, $level, $die;
300		344
301	1	345	1
302	};	346	};
303
304	$$renabled = 1; # TODO
305	}	347	}
306	}	348	}
307		349
308	sub _logger($;$) {	350	sub _logger {
309	my ($ctx, $level, $renabled) = @_;	351	my ($ctx, $level, $renabled) = @_;
310
311	$renabled \|\|= \my $enabled;
312		352
313	$$renabled = 1;	353	$$renabled = 1;
314		354
315	my $logger = [$ctx, $level, $renabled];	355	my $logger = [$ctx, $level, $renabled];
316		356
…		…
356	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
357	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
358	actually logging the formatted message and telling C<AnyEvent::Log>	398	actually logging the formatted message and telling C<AnyEvent::Log>
359	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).
360		400
361	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
362	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
363	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
364	contexts.	404	contexts.
365		405
366	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
367	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
368	message can arrive at the same context via multiple paths.	408	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	412	By default, all logging contexts have an full set of log levels ("all"), a
373	disabled logging callback and the default formatting callback.	413	disabled logging callback and the default formatting callback.
374		414
375	Package contexts have the package name as logging title by default.	415	Package contexts have the package name as logging title by default.
376		416
377	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
378	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
379	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	419	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
380	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	420	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	421	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	422	package name in Perl is C<main>, the default slave of any top-level
383	C<AnyEvent::Log::Top>.	423	package context is C<$AnyEvent::Log::COLLECT>.
384		424
385	Since perl packages form only an approximate hierarchy, this parent	425	Since perl packages form only an approximate hierarchy, this slave
386	context can of course be removed.	426	context can of course be removed.
387		427
388	All other (anonymous) contexts have no parents and an empty title by	428	All other (anonymous) contexts have no slaves and an empty title by
389	default.	429	default.
390		430
391	When the module is loaded it creates the default context called	431	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
392	C<AnyEvent::Log::Default>, which simply logs everything to STDERR and	432	context that simply logs everything via C<warn>, without propagating
393	doesn't propagate anything anywhere by default. The purpose of the default	433	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	434	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.	435	additional log targets. It's not meant for filtering.
396		436
397	It then creates the root context called C<AnyEvent::Log::Root> and	437	It then creates the C<$AnyEvent::Log::FILTER> context whose
398	sets its log level set to all levels up to the one specified by	438	purpose is to suppress all messages with priority higher
399	C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the default logging	439	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
400	context to it. The purpose of the root context is to simply provide	440	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
401	filtering according to some global log level.	441	is to simply provide filtering according to some global log level.
402		442
403	Finally it creates the toplevel package context called	443	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
404	C<AnyEvent::Log::Top> and attached the root context but otherwise leaves	444	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
405	it at default config. It's purpose is simply to collect all log messages	445	leaves it at default config. Its purpose is simply to collect all log
406	system-wide.	446	messages system-wide.
407		447
408	These three special contexts can also be referred to by the names	448	The hierarchy is then:
409	C<AE::Log::Default>, C<AE::Log::Root> and C<AE::Log::Top>.
410		449
		450	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		451
411	The effect of all this is that log messages, by default, wander up	452	The effect of all this is that log messages, by default, wander up to the
412	to the root context where log messages with lower priority then	453	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		454	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
413	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	455	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
414	AnyEvent::Log::Default context to be logged to STDERR.	456	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
415		457
416	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),
417	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
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	460	messages to the $LOG target despite the global logging level, or to attach
420	log targets that log messages, regardless of the global logging level.	461	additional log targets that log messages, regardless of the global logging
		462	level.
421		463
422	It also makes it easy to replace the default STDERR-logger by something	464	It also makes it easy to modify the default warn-logger ($LOG) to
423	that logs to a file, or to attach additional logging targets.	465	something that logs to a file, or to attach additional logging targets
		466	(such as loggign to a file) by attaching it to $FILTER.
424		467
425	=head2 CREATING/FINDING/DESTROYING CONTEXTS	468	=head2 CREATING/FINDING/DESTROYING CONTEXTS
426		469
427	=over 4	470	=over 4
428		471
…		…
450	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	493	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
451	}	494	}
452		495
453	=item AnyEvent::Log::reset	496	=item AnyEvent::Log::reset
454		497
455	Deletes all contexts and recreates the default hierarchy, i.e. resets the	498	Resets all package contexts and recreates the default hierarchy if
456	logging subsystem to defaults.	499	necessary, i.e. resets the logging subsystem to defaults, as much as
		500	possible. This process keeps references to contexts held by other parts of
		501	the program intact.
457		502
458	This can be used to implement config-file (re-)loading: before loading a	503	This can be used to implement config-file (re-)loading: before loading a
459	configuration, reset all contexts.	504	configuration, reset all contexts.
460		505
461	=cut	506	=cut
462		507
463	sub reset {	508	sub reset {
464	@$_ = () for values %CTX; # just to be sure - to kill circular logging dependencies	509	# hard to kill complex data structures
465	%CTX = ();	510	# we "recreate" all package loggers and reset the hierarchy
		511	while (my ($k, $v) = each %CTX) {
		512	@$v = ($k, (1 << 10) - 1 - 1, { });
466		513
467	my $default = ctx undef;	514	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
468	$default->title ("AnyEvent::Log::Default");	515	}
		516
		517	@$_ = ($_->[0], (1 << 10) - 1 - 1)
		518	for $LOG, $FILTER, $COLLECT;
		519
		520	$LOG->slaves;
		521	$LOG->title ('$AnyEvent::Log::LOG');
469	$default->log_cb (sub {	522	$LOG->log_cb (sub {
470	print STDERR shift;	523	warn shift;
471	0	524	0
472	});	525	});
473	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $default;
474		526
475	my $root = ctx undef;	527	$FILTER->slaves ($LOG);
476	$root->title ("AnyEvent::Log::Root");	528	$FILTER->title ('$AnyEvent::Log::FILTER');
477	$root->level ($AnyEvent::VERBOSE);	529	$FILTER->level ($AnyEvent::VERBOSE);
478	$root->attach ($default);
479	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $root;
480		530
481	my $top = ctx undef;	531	$COLLECT->slaves ($FILTER);
482	$top->title ("AnyEvent::Log::Top");	532	$COLLECT->title ('$AnyEvent::Log::COLLECT');
483	$top->attach ($root);	533
484	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $top;	534	_reassess;
485	}	535	}
		536
		537	# create the default logger contexts
		538	$LOG = ctx undef;
		539	$FILTER = ctx undef;
		540	$COLLECT = ctx undef;
486		541
487	AnyEvent::Log::reset;	542	AnyEvent::Log::reset;
488		543
		544	# hello, CPAN, please catch me
489	package AnyEvent::Log::Default;	545	package AnyEvent::Log::LOG;
490	package AE::Log::Default;	546	package AE::Log::LOG;
		547	package AnyEvent::Log::FILTER;
		548	package AE::Log::FILTER;
		549	package AnyEvent::Log::COLLECT;
		550	package AE::Log::COLLECT;
		551
491	package AnyEvent::Log::Root;	552	package AnyEvent::Log::Ctx;
492	package AE::Log::Root;	553
493	package AnyEvent::Log::Top;	554	# 0 1 2 3 4
494	package AE::Log::Top;	555	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
		556
		557	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
		558
		559	This is a convenience constructor that makes it simpler to construct
		560	anonymous logging contexts.
		561
		562	Each key-value pair results in an invocation of the method of the same
		563	name as the key with the value as parameter, unless the value is an
		564	arrayref, in which case it calls the method with the contents of the
		565	array. The methods are called in the same order as specified.
		566
		567	Example: create a new logging context and set both the default logging
		568	level, some slave contexts and a logging callback.
		569
		570	$ctx = new AnyEvent::Log::Ctx
		571	title => "dubious messages",
		572	level => "error",
		573	log_cb => sub { print STDOUT shift; 0 },
		574	slaves => [$ctx1, $ctx, $ctx2],
		575	;
495		576
496	=back	577	=back
497		578
498	=cut	579	=cut
499		580
500	package AnyEvent::Log::Ctx;	581	sub new {
		582	my $class = shift;
501		583
502	# 0 1 2 3 4	584	my $ctx = AnyEvent::Log::ctx undef;
503	# [$title, $level, %$parents, &$logcb, &$fmtcb]	585
		586	while (@_) {
		587	my ($k, $v) = splice @_, 0, 2;
		588	$ctx->$k (ref $v eq "ARRAY" ? @$v : $v);
		589	}
		590
		591	bless $ctx, $class # do we really support subclassing, hmm?
		592	}
		593
504		594
505	=head2 CONFIGURING A LOG CONTEXT	595	=head2 CONFIGURING A LOG CONTEXT
506		596
507	The following methods can be used to configure the logging context.	597	The following methods can be used to configure the logging context.
508		598
…		…
602	AnyEvent::Log::_reassess;	692	AnyEvent::Log::_reassess;
603	}	693	}
604		694
605	=back	695	=back
606		696
607	=head3 PARENT CONTEXTS	697	=head3 SLAVE CONTEXTS
608		698
609	The following methods attach and detach another logging context to a	699	The following methods attach and detach another logging context to a
610	logging context.	700	logging context.
611		701
612	Log messages are propagated to all parent contexts, unless the logging	702	Log messages are propagated to all slave contexts, unless the logging
613	callback consumes the message.	703	callback consumes the message.
614		704
615	=over 4	705	=over 4
616		706
617	=item $ctx->attach ($ctx2[, $ctx3...])	707	=item $ctx->attach ($ctx2[, $ctx3...])
618		708
619	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
620	to add a context twice (the second add will be ignored).	710	to add a context twice (the second add will be ignored).
621		711
622	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.
623		713
624	=item $ctx->detach ($ctx2[, $ctx3...])	714	=item $ctx->detach ($ctx2[, $ctx3...])
625		715
626	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
627	to remove a context that hasn't been added.	717	to remove a context that hasn't been added.
628		718
629	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.
630		720
631	=item $ctx->parents ($ctx2[, $ctx3...])	721	=item $ctx->slaves ($ctx2[, $ctx3...])
632		722
633	Replaces all parents attached to this context by the ones given.	723	Replaces all slaves attached to this context by the ones given.
634		724
635	=cut	725	=cut
636		726
637	sub attach {	727	sub attach {
638	my $ctx = shift;	728	my $ctx = shift;
…		…
646		736
647	delete $ctx->[2]{$_+0}	737	delete $ctx->[2]{$_+0}
648	for map { AnyEvent::Log::ctx $_ } @_;	738	for map { AnyEvent::Log::ctx $_ } @_;
649	}	739	}
650		740
651	sub parents {	741	sub slaves {
652	undef $_[0][2];	742	undef $_[0][2];
653	&attach;	743	&attach;
654	}	744	}
655		745
656	=back	746	=back
657		747
658	=head3 MESSAGE LOGGING	748	=head3 LOG TARGETS
659		749
660	The following methods configure how the logging context actually does	750	The following methods configure how the logging context actually does
661	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
662	whatever it wants to do with it) and also allows you to log messages	752	whatever it wants to do with it).
663	directly to a context, without going via your package context.
664		753
665	=over 4	754	=over 4
666		755
667	=item $ctx->log_cb ($cb->($str))	756	=item $ctx->log_cb ($cb->($str)
668		757
669	Replaces the logging callback on the context (C<undef> disables the	758	Replaces the logging callback on the context (C<undef> disables the
670	logging callback).	759	logging callback).
671		760
672	The logging callback is responsible for handling formatted log messages	761	The logging callback is responsible for handling formatted log messages
673	(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
674	newline (and are possibly multiline themselves).	763	newline (and are possibly multiline themselves).
675		764
676	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
677	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
678	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.
679		768
680	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
681	and do not consume it.	770	and do not consume it.
682		771
683	$ctx->log_cb (sub { print STDERR shift; 0 });	772	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
691	your program.	780	your program.
692		781
693	$ctx->levels ("debug", "trace");	782	$ctx->levels ("debug", "trace");
694	$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
695		784
696	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	785	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
697		786
698	Replaces the formatting callback on the context (C<undef> restores the	787	Replaces the formatting callback on the context (C<undef> restores the
699	default formatter).	788	default formatter).
700		789
701	The callback is passed the (possibly fractional) timestamp, the original	790	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	791	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	792	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.	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.
705		799
706	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
707	brackets.	801	brackets.
708		802
709	$ctx->fmt_cb (sub {	803	$ctx->fmt_cb (sub {
…		…
726	"$msg->[3]";	820	"$msg->[3]";
727		821
728	0	822	0
729	});	823	});
730		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, $str] as input.
		844
731	=cut	845	=cut
732		846
733	sub log_cb {	847	sub log_cb {
734	my ($ctx, $cb) = @_;	848	my ($ctx, $cb) = @_;
735		849
…		…
740	my ($ctx, $cb) = @_;	854	my ($ctx, $cb) = @_;
741		855
742	$ctx->[4] = $cb;	856	$ctx->[4] = $cb;
743	}	857	}
744		858
		859	sub log_to_file {
		860	my ($ctx, $path) = @_;
		861
		862	open my $fh, ">>", $path
		863	or die "$path: $!";
		864
		865	$ctx->log_cb (sub {
		866	syswrite $fh, shift;
		867	0
		868	});
		869	}
		870
		871	sub log_to_file {
		872	my ($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
745	=item $ctx->log ($level, $msg[, @params])	914	=item $ctx->log ($level, $msg[, @params])
746		915
747	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	916	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
748		917
749	=item $logger = $ctx->logger ($level[, \$enabled])	918	=item $logger = $ctx->logger ($level[, \$enabled])
…		…
758		927
759	1;	928	1;
760		929
761	=back	930	=back
762		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 {
		952
		953	=item Write all messages with priority C<error> and higher to a file.
		954
		955	This writes them only when the global logging level allows it, because
		956	it is attached to the default context which is invoked I<after> global
		957	filtering.
		958
		959	$AnyEvent::Log::FILTER->attach
		960	new AnyEvent::Log::Ctx log_to_file => $path);
		961
		962	This writes them regardless of the global logging level, because it is
		963	attached to the toplevel context, which receives all messages I<before>
		964	the global filtering.
		965
		966	$AnyEvent::Log::COLLECT->attach (
		967	new AnyEvent::Log::Ctx log_to_file => $path);
		968
		969	In both cases, messages are still written to STDERR.
		970
		971	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
		972
		973	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
		974	context - this simply circumvents the global filtering for trace messages.
		975
		976	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
		977	$debug->attach ($AnyEvent::Log::LOG);
		978
		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.
		982
		983	=back
		984
763	=head1 AUTHOR	985	=head1 AUTHOR
764		986
765	Marc Lehmann <schmorp@schmorp.de>	987	Marc Lehmann <schmorp@schmorp.de>
766	http://home.schmorp.de/	988	http://home.schmorp.de/
767		989

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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 1.24 by root, Sun Aug 21 03:24:59 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 1.24 by root, Sun Aug 21 03:24:59 2011 UTC