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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.15 by root, Sat Aug 20 02:16:59 2011 UTC vs.
Revision 1.45 by root, Sun Oct 2 00:42:04 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 trace => "going to call function abc";
11	AE::log warn => "it's a bit too hot";	12	AE::log debug => "the function returned 3";
12	AE::log error => "the flag was false!";	13	AE::log info => "file soandso successfully deleted";
13	AE::log fatal => "the bit toggled! run!";	14	AE::log note => "wanted to create config, but config was alraedy created";
		15	AE::log warn => "couldn't delete the file";
		16	AE::log error => "failed to retrieve data";
		17	AE::log crit => "the battery temperature is too hot";
		18	AE::log alert => "the battery died";
		19	AE::log fatal => "no config found, cannot continue"; # never returns
14		20
15	# "complex" use	21	Log level overview:
		22
		23	LVL NAME SYSLOG PERL NOTE
		24	1 fatal emerg exit system unusable, aborts program!
		25	2 alert failure in primary system
		26	3 critical crit failure in backup system
		27	4 error err die non-urgent program errors, a bug
		28	5 warn warning possible problem, not necessarily error
		29	6 note notice unusual conditions
		30	7 info normal messages, no action required
		31	8 debug debugging messages for development
		32	9 trace copious tracing output
		33
		34	"Complex" uses (for speed sensitive code, e.g. trace/debug messages):
		35
16	use AnyEvent::Log;	36	use AnyEvent::Log;
17		37
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	38	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		39
20	$tracer->("i am here") if $trace;	40	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	41	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		42
23	# configuration	43	Configuration (also look at the EXAMPLES section):
24		44
25	# set logging for this package to maximum	45	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("all");	46	AnyEvent::Log::ctx->level ("error");
27		47
28	# set logging globally to anything below debug	48	# set logging level to suppress anything below "notice"
29	(AnyEvent::Log::ctx "")->level ("notice");	49	$AnyEvent::Log::FILTER->level ("notice");
30		50
31	# see also EXAMPLES, below	51	# send all critical and higher priority messages to syslog,
32		52	# regardless of (most) other settings
33	# disable logging for package "AnyEvent" and all packages below it	53	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
34	AnyEvent->AnyEvent::Log::ctx->level (0);	54	level => "critical",
35		55	log_to_syslog => "user",
36	# log everything below debug to a file, for the whole program	56	);
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		57
41	=head1 DESCRIPTION	58	=head1 DESCRIPTION
42		59
43	This module implements a relatively simple "logging framework". It doesn't	60	This module implements a relatively simple "logging framework". It doesn't
44	attempt to be "the" logging solution or even "a" logging solution for	61	attempt to be "the" logging solution or even "a" logging solution for
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	62	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	module more or less exposes the mechanism, with some extra spiff to allow	63	module more or less exposes the mechanism, with some extra spiff to allow
47	using it from other modules as well.	64	using it from other modules as well.
48		65
49	Remember that the default verbosity level is C<0>, so nothing will be	66	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	67	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	68	before starting your program, or change the logging level at runtime with
52	something like:	69	something like:
53		70
54	use AnyEvent;	71	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	72	$AnyEvent::Log::FILTER->level ("info");
56		73
57	The design goal behind this module was to keep it simple (and small),	74	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	75	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	76	extensive enough for the most common tasks, such as logging to multiple
60	targets, or being able to log into a database.	77	targets, or being able to log into a database.
61		78
		79	The module is also usable before AnyEvent itself is initialised, in which
		80	case some of the functionality might be reduced.
		81
62	The amount of documentation might indicate otherwise, but the module is	82	The amount of documentation might indicate otherwise, but the runtime part
63	still just 240 lines or so.	83	of the module is still just below 300 lines of code.
		84
		85	=head1 LOGGING LEVELS
		86
		87	Logging levels in this module range from C<1> (highest priority) to C<9>
		88	(lowest priority). Note that the lowest numerical value is the highest
		89	priority, so when this document says "higher priority" it means "lower
		90	numerical value".
		91
		92	Instead of specifying levels by name you can also specify them by aliases:
		93
		94	LVL NAME SYSLOG PERL NOTE
		95	1 fatal emerg exit system unusable, aborts program!
		96	2 alert failure in primary system
		97	3 critical crit failure in backup system
		98	4 error err die non-urgent program errors, a bug
		99	5 warn warning possible problem, not necessarily error
		100	6 note notice unusual conditions
		101	7 info normal messages, no action required
		102	8 debug debugging messages for development
		103	9 trace copious tracing output
		104
		105	As you can see, some logging levels have multiple aliases - the first one
		106	is the "official" name, the second one the "syslog" name (if it differs)
		107	and the third one the "perl" name, suggesting (only!) that you log C<die>
		108	messages at C<error> priority. The NOTE column tries to provide some
		109	rationale on how to chose a logging level.
		110
		111	As a rough guideline, levels 1..3 are primarily meant for users of
		112	the program (admins, staff), and are the only logged to STDERR by
		113	default. Levels 4..6 are meant for users and developers alike, while
		114	levels 7..9 are usually meant for developers.
		115
		116	You can normally only log a single message at highest priority level
		117	(C<1>, C<fatal>), because logging a fatal message will also quit the
		118	program - so use it sparingly :)
		119
		120	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		121	or C<all> - these are only valid in the methods they are documented for.
64		122
65	=head1 LOGGING FUNCTIONS	123	=head1 LOGGING FUNCTIONS
66		124
67	These functions allow you to log messages. They always use the caller's	125	These functions allow you to log messages. They always use the caller's
68	package as a "logging module/source". Also, the main logging function is	126	package as a "logging context". Also, the main logging function C<log> is
69	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	127	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
70	loaded.	128	loaded.
71		129
72	=over 4	130	=over 4
73		131
…		…
76	package AnyEvent::Log;	134	package AnyEvent::Log;
77		135
78	use Carp ();	136	use Carp ();
79	use POSIX ();	137	use POSIX ();
80		138
		139	# layout of a context
		140	# 0 1 2 3 4, 5
		141	# [$title, $level, %$slaves, &$logcb, &$fmtcb, $cap]
		142
81	use AnyEvent (); BEGIN { AnyEvent::common_sense }	143	use AnyEvent (); BEGIN { AnyEvent::common_sense }
82	use AnyEvent::Util ();	144	#use AnyEvent::Util (); need to load this in a delayed fashion, as it uses AE::log
83		145
84	our $VERSION = $AnyEvent::VERSION;	146	our $VERSION = $AnyEvent::VERSION;
		147
		148	our ($COLLECT, $FILTER, $LOG);
85		149
86	our ($now_int, $now_str1, $now_str2);	150	our ($now_int, $now_str1, $now_str2);
87		151
88	# Format Time, not public - yet?	152	# Format Time, not public - yet?
89	sub ft($) {	153	sub ft($) {
…		…
94	if $now_int != $i;	158	if $now_int != $i;
95		159
96	"$now_str1$f$now_str2"	160	"$now_str1$f$now_str2"
97	}	161	}
98		162
99	our %CTX; # all logging contexts	163	our %CTX; # all package contexts
100		164
101	# creates a default package context object for the given package	165	# creates a default package context object for the given package
102	sub _pkg_ctx($) {	166	sub _pkg_ctx($) {
103	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	167	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
104		168
105	# link "parent" package	169	# link "parent" package
106	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "AE::Log::Top";	170	my $parent = $_[0] =~ /^(.+)::/
		171	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		172	: $COLLECT;
107		173
108	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
109	$ctx->[2]{$pkg+0} = $pkg;	174	$ctx->[2]{$parent+0} = $parent;
110		175
111	$ctx	176	$ctx
112	}	177	}
113		178
114	=item AnyEvent::Log::log $level, $msg[, @args]	179	=item AnyEvent::Log::log $level, $msg[, @args]
115		180
116	Requests logging of the given C<$msg> with the given log level (1..9).	181	Requests logging of the given C<$msg> with the given log level, and
117	You can also use the following strings as log level: C<fatal> (1),	182	returns true if the message was logged I<somewhere>.
118	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
119	C<info> (7), C<debug> (8), C<trace> (9).
120		183
121	For C<fatal> log levels, the program will abort.	184	For loglevel C<fatal>, the program will abort.
122		185
123	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	186	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
124	C<$msg> is interpreted as an sprintf format string.	187	C<$msg> is interpreted as an sprintf format string.
125		188
126	The C<$msg> should not end with C<\n>, but may if that is convenient for	189	The C<$msg> should not end with C<\n>, but may if that is convenient for
…		…
130	supposed to return the message. It will be called only then the message	193	supposed to return the message. It will be called only then the message
131	actually gets logged, which is useful if it is costly to create the	194	actually gets logged, which is useful if it is costly to create the
132	message in the first place.	195	message in the first place.
133		196
134	Whether the given message will be logged depends on the maximum log level	197	Whether the given message will be logged depends on the maximum log level
135	and the caller's package.	198	and the caller's package. The return value can be used to ensure that
		199	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		200	runtime error it tries to log it at C<die> level, but if that message is
		201	lost it simply uses warn.
136		202
137	Note that you can (and should) call this function as C<AnyEvent::log> or	203	Note that you can (and should) call this function as C<AnyEvent::log> or
138	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	204	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
139	need any additional functionality), as those functions will load the	205	need any additional functionality), as those functions will load the
140	logging module on demand only. They are also much shorter to write.	206	logging module on demand only. They are also much shorter to write.
…		…
157		223
158	=cut	224	=cut
159		225
160	# also allow syslog equivalent names	226	# also allow syslog equivalent names
161	our %STR2LEVEL = (	227	our %STR2LEVEL = (
162	fatal => 1, emerg => 1,	228	fatal => 1, emerg => 1, exit => 1,
163	alert => 2,	229	alert => 2,
164	critical => 3, crit => 3,	230	critical => 3, crit => 3,
165	error => 4, err => 4,	231	error => 4, err => 4, die => 4,
166	warn => 5, warning => 5,	232	warn => 5, warning => 5,
167	note => 6, notice => 6,	233	note => 6, notice => 6,
168	info => 7,	234	info => 7,
169	debug => 8,	235	debug => 8,
170	trace => 9,	236	trace => 9,
171	);	237	);
172		238
173	sub now () { time }	239	our $TIME_EXACT;
		240
		241	sub exact_time($) {
		242	$TIME_EXACT = shift;
		243	*_ts = $AnyEvent::MODEL
		244	? $TIME_EXACT ? \&AE::now : \&AE::time
		245	: sub () { $TIME_EXACT ? do { require Time::HiRes; Time::HiRes::time () } : time };
		246	}
		247
		248	BEGIN {
		249	exact_time 0;
		250	}
174		251
175	AnyEvent::post_detect {	252	AnyEvent::post_detect {
176	*now = \&AE::now;	253	exact_time $TIME_EXACT;
177	};	254	};
178		255
179	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	256	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
180		257
181	# time, ctx, level, msg	258	# time, ctx, level, msg
…		…
191	}	268	}
192		269
193	join "", @res	270	join "", @res
194	}	271	}
195		272
		273	sub fatal_exit() {
		274	exit 1;
		275	}
		276
196	sub _log {	277	sub _log {
197	my ($ctx, $level, $format, @args) = @_;	278	my ($ctx, $level, $format, @args) = @_;
198		279
199	$level = $level > 0 && $level <= 9	280	$level = $level > 0 && $level <= 9
200	? $level+0	281	? $level+0
201	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	282	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
202		283
203	my $mask = 1 << $level;	284	my $mask = 1 << $level;
204		285
205	my (%seen, @ctx, $now, $fmt);	286	my ($success, %seen, @ctx, $now, @fmt);
206		287
207	do	288	do
208	{	289	{
209	# skip if masked	290	# if !ref, then it's a level number
		291	if (!ref $ctx) {
		292	$level = $ctx;
210	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {	293	} elsif ($ctx->[1] & $mask and !$seen{$ctx+0}++) {
		294	# logging/recursing into this context
		295
		296	# level cap
		297	if ($ctx->[5] > $level) {
		298	push @ctx, $level; # restore level when going up in tree
		299	$level = $ctx->[5];
		300	}
		301
		302	# log if log cb
211	if ($ctx->[3]) {	303	if ($ctx->[3]) {
212	# logging target found	304	# logging target found
213		305
214	# now get raw message, unless we have it already	306	# now get raw message, unless we have it already
215	unless ($now) {	307	unless ($now) {
216	$format = $format->() if ref $format;	308	$format = $format->() if ref $format;
217	$format = sprintf $format, @args if @args;	309	$format = sprintf $format, @args if @args;
218	$format =~ s/\n$//;	310	$format =~ s/\n$//;
219	$now = AE::now;	311	$now = _ts;
220	};	312	};
221		313
222	# format msg	314	# format msg
223	my $str = $ctx->[4]	315	my $str = $ctx->[4]
224	? $ctx->[4]($now, $_[0], $level, $format)	316	? $ctx->[4]($now, $_[0], $level, $format)
225	: $fmt \|\|= _format $now, $_[0], $level, $format;	317	: ($fmt[$level] \|\|= _format $now, $_[0], $level, $format);
226		318
		319	$success = 1;
		320
227	$ctx->[3]($str);	321	$ctx->[3]($str)
		322	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		323	} else {
		324	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
228	}	325	}
229
230	# not masked, not consumed - propagate to parent contexts
231	push @ctx, values %{ $ctx->[2] };
232	}	326	}
233	}	327	}
234	while $ctx = pop @ctx;	328	while $ctx = pop @ctx;
235		329
236	exit 1 if $level <= 1;	330	fatal_exit if $level <= 1;
		331
		332	$success
237	}	333	}
238		334
239	sub log($$;@) {	335	sub log($$;@) {
240	_log	336	_log
241	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	337	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
242	@_;	338	@_;
243	}	339	}
244		340
245	AnyEvent::log = AE::log = \&log;
246
247	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	341	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
248		342
249	Creates a code reference that, when called, acts as if the	343	Creates a code reference that, when called, acts as if the
250	C<AnyEvent::Log::log> function was called at this point with the givne	344	C<AnyEvent::Log::log> function was called at this point with the given
251	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	345	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
252	the C<AnyEvent::Log::log> function:	346	the C<AnyEvent::Log::log> function:
253		347
254	my $debug_log = AnyEvent::Log::logger "debug";	348	my $debug_log = AnyEvent::Log::logger "debug";
255		349
…		…
280	# and later in your program	374	# and later in your program
281	$debug_log->("yo, stuff here") if $debug;	375	$debug_log->("yo, stuff here") if $debug;
282		376
283	$debug and $debug_log->("123");	377	$debug and $debug_log->("123");
284		378
285	Note: currently the enabled var is always true - that will be fixed in a
286	future version :)
287
288	=cut	379	=cut
289		380
290	our %LOGGER;	381	our %LOGGER;
291		382
292	# re-assess logging status for all loggers	383	# re-assess logging status for all loggers
293	sub _reassess {	384	sub _reassess {
		385	local $SIG{__DIE__};
		386	my $die = sub { die };
		387
294	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	388	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
295	my ($ctx, $level, $renabled) = @$_;	389	my ($ctx, $level, $renabled) = @$_;
296		390
297	# to detect whether a message would be logged, we # actually	391	# to detect whether a message would be logged, we actually
298	# try to log one and die. this isn't fast, but we can be	392	# try to log one and die. this isn't fast, but we can be
299	# sure that the logging decision is correct :)	393	# sure that the logging decision is correct :)
300		394
301	$$renabled = !eval {	395	$$renabled = !eval {
302	local $SIG{__DIE__};
303
304	_log $ctx, $level, sub { die };	396	_log $ctx, $level, $die;
305		397
306	1	398	1
307	};	399	};
308
309	$$renabled = 1; # TODO
310	}	400	}
311	}	401	}
312		402
313	sub _logger {	403	sub _logger {
314	my ($ctx, $level, $renabled) = @_;	404	my ($ctx, $level, $renabled) = @_;
…		…
319		409
320	$LOGGER{$logger+0} = $logger;	410	$LOGGER{$logger+0} = $logger;
321		411
322	_reassess $logger+0;	412	_reassess $logger+0;
323		413
		414	require AnyEvent::Util unless $AnyEvent::Util::VERSION;
324	my $guard = AnyEvent::Util::guard {	415	my $guard = AnyEvent::Util::guard (sub {
325	# "clean up"	416	# "clean up"
326	delete $LOGGER{$logger+0};	417	delete $LOGGER{$logger+0};
327	};	418	});
328		419
329	sub {	420	sub {
330	$guard if 0; # keep guard alive, but don't cause runtime overhead	421	$guard if 0; # keep guard alive, but don't cause runtime overhead
331		422
332	_log $ctx, $level, @_	423	_log $ctx, $level, @_
…		…
337	sub logger($;$) {	428	sub logger($;$) {
338	_logger	429	_logger
339	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	430	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
340	@_	431	@_
341	}	432	}
		433
		434	=item AnyEvent::Log::exact_time $on
		435
		436	By default, C<AnyEvent::Log> will use C<AE::now>, i.e. the cached
		437	eventloop time, for the log timestamps. After calling this function with a
		438	true value it will instead resort to C<AE::time>, i.e. fetch the current
		439	time on each log message. This only makes a difference for event loops
		440	that actually cache the time (such as L<EV> or L<AnyEvent::Loop>).
		441
		442	This setting can be changed at any time by calling this function.
		443
		444	Since C<AnyEvent::Log> has to work even before the L<AnyEvent> has been
		445	initialised, this switch will also decide whether to use C<CORE::time> or
		446	C<Time::HiRes::time> when logging a message before L<AnyEvent> becomes
		447	available.
342		448
343	=back	449	=back
344		450
345	=head1 LOGGING CONTEXTS	451	=head1 LOGGING CONTEXTS
346		452
…		…
359	timestamp, context, level and string message and formats it in the way	465	timestamp, context, level and string message and formats it in the way
360	it should be logged) and a logging callback (which is responsible for	466	it should be logged) and a logging callback (which is responsible for
361	actually logging the formatted message and telling C<AnyEvent::Log>	467	actually logging the formatted message and telling C<AnyEvent::Log>
362	whether it has consumed the message, or whether it should be propagated).	468	whether it has consumed the message, or whether it should be propagated).
363		469
364	For propagation, a context can have any number of attached I<parent	470	For propagation, a context can have any number of attached I<slave
365	contexts>. Any message that is neither masked by the logging mask nor	471	contexts>. Any message that is neither masked by the logging mask nor
366	masked by the logging callback returning true will be passed to all parent	472	masked by the logging callback returning true will be passed to all slave
367	contexts.	473	contexts.
368		474
369	Each call to a logging function will log the message at most once per	475	Each call to a logging function will log the message at most once per
370	context, so it does not matter (much) if there are cycles or if the	476	context, so it does not matter (much) if there are cycles or if the
371	message can arrive at the same context via multiple paths.	477	message can arrive at the same context via multiple paths.
…		…
375	By default, all logging contexts have an full set of log levels ("all"), a	481	By default, all logging contexts have an full set of log levels ("all"), a
376	disabled logging callback and the default formatting callback.	482	disabled logging callback and the default formatting callback.
377		483
378	Package contexts have the package name as logging title by default.	484	Package contexts have the package name as logging title by default.
379		485
380	They have exactly one parent - the context of the "parent" package. The	486	They have exactly one slave - the context of the "parent" package. The
381	parent package is simply defined to be the package name without the last	487	parent package is simply defined to be the package name without the last
382	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	488	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
383	and C<AnyEvent> becomes ... C<AnyEvent::Log::Top> which is the	489	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
384	exception of the rule - just like the parent of any package name in	490	exception of the rule - just like the "parent" of any single-component
385	Perl is C<main>, the default parent of any top-level package context is	491	package name in Perl is C<main>, the default slave of any top-level
386	C<AnyEvent::Log::Top>.	492	package context is C<$AnyEvent::Log::COLLECT>.
387		493
388	Since perl packages form only an approximate hierarchy, this parent	494	Since perl packages form only an approximate hierarchy, this slave
389	context can of course be removed.	495	context can of course be removed.
390		496
391	All other (anonymous) contexts have no parents and an empty title by	497	All other (anonymous) contexts have no slaves and an empty title by
392	default.	498	default.
393		499
394	When the module is loaded it creates the default context called	500	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
395	C<AnyEvent::Log::Default> (also stored in C<$AnyEvent::Log::Default>),	501	context that simply logs everything via C<warn>, without propagating
396	which simply logs everything via C<warn> and doesn't propagate anything
397	anywhere by default. The purpose of the default context is to provide	502	anything anywhere by default. The purpose of this context is to provide
398	a convenient place to override the global logging target or to attach	503	a convenient place to override the global logging target or to attach
399	additional log targets. It's not meant for filtering.	504	additional log targets. It's not meant for filtering.
400		505
401	It then creates the root context called C<AnyEvent::Log::Root> (also	506	It then creates the C<$AnyEvent::Log::FILTER> context whose
402	stored in C<$AnyEvent::Log::Root>) and sets its log level set to all	507	purpose is to suppress all messages with priority higher
403	levels up to the one specified by C<$ENV{PERL_ANYEVENT_VERBOSE}>. It	508	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
404	then attached the default logging context to it. The purpose of the root	509	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
405	context is to simply provide filtering according to some global log level.	510	is to simply provide filtering according to some global log level.
406		511
407	Finally it creates the top-level package context called	512	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
408	C<AnyEvent::Log::Top> (also stored in, you might have guessed,	513	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
409	C<$AnyEvent::Log::Top>) and attached the root context but otherwise leaves
410	it at default config. It's purpose is simply to collect all log messages	514	leaves it at default config. Its purpose is simply to collect all log
411	system-wide.	515	messages system-wide.
412		516
413	These three special contexts can also be referred to by the	517	The hierarchy is then:
414	package/context names C<AE::Log::Default>, C<AE::Log::Root> and
415	C<AE::Log::Top>.
416		518
		519	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		520
417	The effect of all this is that log messages, by default, wander up	521	The effect of all this is that log messages, by default, wander up to the
418	to the root context where log messages with lower priority then	522	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		523	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
419	C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered away and then to the	524	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
420	AnyEvent::Log::Default context to be passed to C<warn>.	525	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
421		526
422	Splitting the top level context into three contexts makes it easy to set	527	This makes it easy to set a global logging level (by modifying $FILTER),
423	a global logging level (by modifying the root context), but still allow	528	but still allow other contexts to send, for example, their debug and trace
424	other contexts to log, for example, their debug and trace messages to the
425	default target despite the global logging level, or to attach additional	529	messages to the $LOG target despite the global logging level, or to attach
426	log targets that log messages, regardless of the global logging level.	530	additional log targets that log messages, regardless of the global logging
		531	level.
427		532
428	It also makes it easy to replace the default warn-logger by something that	533	It also makes it easy to modify the default warn-logger ($LOG) to
429	logs to a file, or to attach additional logging targets.	534	something that logs to a file, or to attach additional logging targets
		535	(such as loggign to a file) by attaching it to $FILTER.
430		536
431	=head2 CREATING/FINDING/DESTROYING CONTEXTS	537	=head2 CREATING/FINDING/DESTROYING CONTEXTS
432		538
433	=over 4	539	=over 4
434		540
…		…
456	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	562	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
457	}	563	}
458		564
459	=item AnyEvent::Log::reset	565	=item AnyEvent::Log::reset
460		566
461	Resets all package contexts contexts and recreates the default hierarchy	567	Resets all package contexts and recreates the default hierarchy if
462	if necessary, i.e. resets the logging subsystem to defaults.	568	necessary, i.e. resets the logging subsystem to defaults, as much as
		569	possible. This process keeps references to contexts held by other parts of
		570	the program intact.
463		571
464	This can be used to implement config-file (re-)loading: before loading a	572	This can be used to implement config-file (re-)loading: before loading a
465	configuration, reset all contexts.	573	configuration, reset all contexts.
466		574
467	Note that this currently destroys all logger callbacks - bug me if you
468	need this fixed :)
469
470	=cut	575	=cut
		576
		577	our $ORIG_VERBOSE = $AnyEvent::VERBOSE;
		578	$AnyEvent::VERBOSE = 9;
471		579
472	sub reset {	580	sub reset {
473	# hard to kill complex data structures	581	# hard to kill complex data structures
474	# we recreate all package loggers and reset the hierarchy	582	# we "recreate" all package loggers and reset the hierarchy
475	while (my ($k, $v) = each %CTX) {	583	while (my ($k, $v) = each %CTX) {
476	@$v = ($k, (1 << 10) - 1 - 1, { });	584	@$v = ($k, (1 << 10) - 1 - 1, { });
477		585
478	my $pkg = $k =~ /^(.+)::/ ? $1 : "AE::Log::Top";	586	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
479	$v->attach ($CTX{$pkg});
480	}	587	}
481		588
482	$AnyEvent::Log::Default->parents;	589	@$_ = ($_->[0], (1 << 10) - 1 - 1)
483	$AnyEvent::Log::Default->title ("AnyEvent::Log::Default");	590	for $LOG, $FILTER, $COLLECT;
484	$AnyEvent::Log::Default->log_cb (sub {
485	warn shift;
486	0
487	});
488	$CTX{"AnyEvent::Log::Default"} = $CTX{"AE::Log::Default"} = $AnyEvent::Log::Default;
489		591
490	$AnyEvent::Log::Root->parents ($AnyEvent::Log::Default);	592	#$LOG->slaves;
491	$AnyEvent::Log::Root->title ("AnyEvent::Log::Root");	593	$LOG->title ('$AnyEvent::Log::LOG');
492	$AnyEvent::Log::Root->level ($AnyEvent::VERBOSE);	594	$LOG->log_to_warn;
493	$CTX{"AnyEvent::Log::Root"} = $CTX{"AE::Log::Root"} = $AnyEvent::Log::Root;
494		595
495	$AnyEvent::Log::Top->parents ($AnyEvent::Log::Root);	596	$FILTER->slaves ($LOG);
496	$AnyEvent::Log::Top->title ("AnyEvent::Log::Top");	597	$FILTER->title ('$AnyEvent::Log::FILTER');
497	$CTX{"AnyEvent::Log::Top"} = $CTX{"AE::Log::Top"} = $AnyEvent::Log::Top;	598	$FILTER->level ($ORIG_VERBOSE);
		599
		600	$COLLECT->slaves ($FILTER);
		601	$COLLECT->title ('$AnyEvent::Log::COLLECT');
498		602
499	_reassess;	603	_reassess;
500	}	604	}
501		605
		606	# override AE::log/logger
		607	AnyEvent::log = AE::log = \&log;
		608	AnyEvent::logger = AE::logger = \&logger;
		609
		610	# convert AnyEvent loggers to AnyEvent::Log loggers
		611	$_->[0] = ctx $_->[0] # convert "pkg" to "ctx"
		612	for values %LOGGER;
		613
502	# create the default logger contexts	614	# create the default logger contexts
503	$AnyEvent::Log::Default = ctx undef;	615	$LOG = ctx undef;
504	$AnyEvent::Log::Root = ctx undef;	616	$FILTER = ctx undef;
505	$AnyEvent::Log::Top = ctx undef;	617	$COLLECT = ctx undef;
506		618
507	AnyEvent::Log::reset;	619	AnyEvent::Log::reset;
508		620
509	# hello, CPAN, please catch me	621	# hello, CPAN, please catch me
510	package AnyEvent::Log::Default;
511	package AE::Log::Default;
512	package AnyEvent::Log::Root;
513	package AE::Log::Root;
514	package AnyEvent::Log::Top;	622	package AnyEvent::Log::LOG;
515	package AE::Log::Top;	623	package AE::Log::LOG;
		624	package AnyEvent::Log::FILTER;
		625	package AE::Log::FILTER;
		626	package AnyEvent::Log::COLLECT;
		627	package AE::Log::COLLECT;
516		628
517	package AnyEvent::Log::Ctx;	629	package AnyEvent::Log::Ctx;
518
519	# 0 1 2 3 4
520	# [$title, $level, %$parents, &$logcb, &$fmtcb]
521		630
522	=item $ctx = new AnyEvent::Log::Ctx methodname => param...	631	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
523		632
524	This is a convenience constructor that makes it simpler to construct	633	This is a convenience constructor that makes it simpler to construct
525	anonymous logging contexts.	634	anonymous logging contexts.
…		…
528	name as the key with the value as parameter, unless the value is an	637	name as the key with the value as parameter, unless the value is an
529	arrayref, in which case it calls the method with the contents of the	638	arrayref, in which case it calls the method with the contents of the
530	array. The methods are called in the same order as specified.	639	array. The methods are called in the same order as specified.
531		640
532	Example: create a new logging context and set both the default logging	641	Example: create a new logging context and set both the default logging
533	level, some parent contexts and a logging callback.	642	level, some slave contexts and a logging callback.
534		643
535	$ctx = new AnyEvent::Log::Ctx	644	$ctx = new AnyEvent::Log::Ctx
536	title => "dubious messages",	645	title => "dubious messages",
537	level => "error",	646	level => "error",
538	log_cb => sub { print STDOUT shift; 0 },	647	log_cb => sub { print STDOUT shift; 0 },
539	parents => [$ctx1, $ctx, $ctx2],	648	slaves => [$ctx1, $ctx, $ctx2],
540	;	649	;
541		650
542	=back	651	=back
543		652
544	=cut	653	=cut
…		…
612	Enables logging for the given levels, leaving all others unchanged.	721	Enables logging for the given levels, leaving all others unchanged.
613		722
614	=item $ctx->disable ($level[, $level...])	723	=item $ctx->disable ($level[, $level...])
615		724
616	Disables logging for the given levels, leaving all others unchanged.	725	Disables logging for the given levels, leaving all others unchanged.
		726
		727	=item $ctx->cap ($level)
		728
		729	Caps the maximum priority to the given level, for all messages logged
		730	to, or passing through, this context. That is, while this doesn't affect
		731	whether a message is logged or passed on, the maximum priority of messages
		732	will be limited to the specified level - messages with a higher priority
		733	will be set to the specified priority.
		734
		735	Another way to view this is that C<< ->level >> filters out messages with
		736	a too low priority, while C<< ->cap >> modifies messages with a too high
		737	priority.
		738
		739	This is useful when different log targets have different interpretations
		740	of priority. For example, for a specific command line program, a wrong
		741	command line switch might well result in a C<fatal> log message, while the
		742	same message, logged to syslog, is likely I<not> fatal to the system or
		743	syslog facility as a whole, but more likely a mere C<error>.
		744
		745	This can be modeled by having a stderr logger that logs messages "as-is"
		746	and a syslog logger that logs messages with a level cap of, say, C<error>,
		747	or, for truly system-critical components, actually C<critical>.
617		748
618	=cut	749	=cut
619		750
620	sub _lvl_lst {	751	sub _lvl_lst {
621	map {	752	map {
…		…
623	: $_ eq "all" ? (1 .. 9)	754	: $_ eq "all" ? (1 .. 9)
624	: $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught"	755	: $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught"
625	} @_	756	} @_
626	}	757	}
627		758
		759	sub _lvl {
		760	$_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[-1]
		761	}
		762
628	our $NOP_CB = sub { 0 };	763	our $NOP_CB = sub { 0 };
629		764
630	sub levels {	765	sub levels {
631	my $ctx = shift;	766	my $ctx = shift;
632	$ctx->[1] = 0;	767	$ctx->[1] = 0;
…		…
635	AnyEvent::Log::_reassess;	770	AnyEvent::Log::_reassess;
636	}	771	}
637		772
638	sub level {	773	sub level {
639	my $ctx = shift;	774	my $ctx = shift;
640	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[-1];
641
642	$ctx->[1] = ((1 << $lvl) - 1) << 1;	775	$ctx->[1] = ((1 << &_lvl) - 1) << 1;
643	AnyEvent::Log::_reassess;	776	AnyEvent::Log::_reassess;
644	}	777	}
645		778
646	sub enable {	779	sub enable {
647	my $ctx = shift;	780	my $ctx = shift;
…		…
655	$ctx->[1] &= ~(1 << $_)	788	$ctx->[1] &= ~(1 << $_)
656	for &_lvl_lst;	789	for &_lvl_lst;
657	AnyEvent::Log::_reassess;	790	AnyEvent::Log::_reassess;
658	}	791	}
659		792
		793	sub cap {
		794	my $ctx = shift;
		795	$ctx->[5] = &_lvl;
		796	}
		797
660	=back	798	=back
661		799
662	=head3 PARENT CONTEXTS	800	=head3 SLAVE CONTEXTS
663		801
664	The following methods attach and detach another logging context to a	802	The following methods attach and detach another logging context to a
665	logging context.	803	logging context.
666		804
667	Log messages are propagated to all parent contexts, unless the logging	805	Log messages are propagated to all slave contexts, unless the logging
668	callback consumes the message.	806	callback consumes the message.
669		807
670	=over 4	808	=over 4
671		809
672	=item $ctx->attach ($ctx2[, $ctx3...])	810	=item $ctx->attach ($ctx2[, $ctx3...])
673		811
674	Attaches the given contexts as parents to this context. It is not an error	812	Attaches the given contexts as slaves to this context. It is not an error
675	to add a context twice (the second add will be ignored).	813	to add a context twice (the second add will be ignored).
676		814
677	A context can be specified either as package name or as a context object.	815	A context can be specified either as package name or as a context object.
678		816
679	=item $ctx->detach ($ctx2[, $ctx3...])	817	=item $ctx->detach ($ctx2[, $ctx3...])
680		818
681	Removes the given parents from this context - it's not an error to attempt	819	Removes the given slaves from this context - it's not an error to attempt
682	to remove a context that hasn't been added.	820	to remove a context that hasn't been added.
683		821
684	A context can be specified either as package name or as a context object.	822	A context can be specified either as package name or as a context object.
685		823
686	=item $ctx->parents ($ctx2[, $ctx3...])	824	=item $ctx->slaves ($ctx2[, $ctx3...])
687		825
688	Replaces all parents attached to this context by the ones given.	826	Replaces all slaves attached to this context by the ones given.
689		827
690	=cut	828	=cut
691		829
692	sub attach {	830	sub attach {
693	my $ctx = shift;	831	my $ctx = shift;
…		…
701		839
702	delete $ctx->[2]{$_+0}	840	delete $ctx->[2]{$_+0}
703	for map { AnyEvent::Log::ctx $_ } @_;	841	for map { AnyEvent::Log::ctx $_ } @_;
704	}	842	}
705		843
706	sub parents {	844	sub slaves {
707	undef $_[0][2];	845	undef $_[0][2];
708	&attach;	846	&attach;
709	}	847	}
710		848
711	=back	849	=back
712		850
713	=head3 MESSAGE LOGGING	851	=head3 LOG TARGETS
714		852
715	The following methods configure how the logging context actually does	853	The following methods configure how the logging context actually does
716	the logging (which consists of formatting the message and printing it or	854	the logging (which consists of formatting the message and printing it or
717	whatever it wants to do with it) and also allows you to log messages	855	whatever it wants to do with it).
718	directly to a context, without going via your package context.
719		856
720	=over 4	857	=over 4
721		858
722	=item $ctx->log_cb ($cb->($str))	859	=item $ctx->log_cb ($cb->($str)
723		860
724	Replaces the logging callback on the context (C<undef> disables the	861	Replaces the logging callback on the context (C<undef> disables the
725	logging callback).	862	logging callback).
726		863
727	The logging callback is responsible for handling formatted log messages	864	The logging callback is responsible for handling formatted log messages
728	(see C<fmt_cb> below) - normally simple text strings that end with a	865	(see C<fmt_cb> below) - normally simple text strings that end with a
729	newline (and are possibly multiline themselves).	866	newline (and are possibly multiline themselves).
730		867
731	It also has to return true iff it has consumed the log message, and false	868	It also has to return true iff it has consumed the log message, and false
732	if it hasn't. Consuming a message means that it will not be sent to any	869	if it hasn't. Consuming a message means that it will not be sent to any
733	parent context. When in doubt, return C<0> from your logging callback.	870	slave context. When in doubt, return C<0> from your logging callback.
734		871
735	Example: a very simple logging callback, simply dump the message to STDOUT	872	Example: a very simple logging callback, simply dump the message to STDOUT
736	and do not consume it.	873	and do not consume it.
737		874
738	$ctx->log_cb (sub { print STDERR shift; 0 });	875	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
746	your program.	883	your program.
747		884
748	$ctx->levels ("debug", "trace");	885	$ctx->levels ("debug", "trace");
749	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	886	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
750		887
751	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	888	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
752		889
753	Replaces the formatting callback on the context (C<undef> restores the	890	Replaces the formatting callback on the context (C<undef> restores the
754	default formatter).	891	default formatter).
755		892
756	The callback is passed the (possibly fractional) timestamp, the original	893	The callback is passed the (possibly fractional) timestamp, the original
757	logging context, the (numeric) logging level and the raw message string and needs to	894	logging context, the (numeric) logging level and the raw message string
758	return a formatted log message. In most cases this will be a string, but	895	and needs to return a formatted log message. In most cases this will be a
759	it could just as well be an array reference that just stores the values.	896	string, but it could just as well be an array reference that just stores
		897	the values.
		898
		899	If, for some reason, you want to use C<caller> to find out more baout the
		900	logger then you should walk up the call stack until you are no longer
		901	inside the C<AnyEvent::Log> package.
760		902
761	Example: format just the raw message, with numeric log level in angle	903	Example: format just the raw message, with numeric log level in angle
762	brackets.	904	brackets.
763		905
764	$ctx->fmt_cb (sub {	906	$ctx->fmt_cb (sub {
…		…
781	"$msg->[3]";	923	"$msg->[3]";
782		924
783	0	925	0
784	});	926	});
785		927
		928	=item $ctx->log_to_warn
		929
		930	Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
		931	(usually this logs to STDERR).
		932
		933	=item $ctx->log_to_file ($path)
		934
		935	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		936
		937	=item $ctx->log_to_path ($path)
		938
		939	Same as C<< ->log_to_file >>, but opens the file for each message. This
		940	is much slower, but allows you to change/move/rename/delete the file at
		941	basically any time.
		942
		943	Needless(?) to say, if you do not want to be bitten by some evil person
		944	calling C<chdir>, the path should be absolute. Doesn't help with
		945	C<chroot>, but hey...
		946
		947	=item $ctx->log_to_syslog ([$facility])
		948
		949	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and
		950	all the others in the obvious way. If specified, then the C<$facility> is
		951	used as the facility (C<user>, C<auth>, C<local0> and so on). The default
		952	facility is C<user>.
		953
		954	Note that this function also sets a C<fmt_cb> - the logging part requires
		955	an array reference with [$level, $str] as input.
		956
786	=cut	957	=cut
787		958
788	sub log_cb {	959	sub log_cb {
789	my ($ctx, $cb) = @_;	960	my ($ctx, $cb) = @_;
790		961
…		…
795	my ($ctx, $cb) = @_;	966	my ($ctx, $cb) = @_;
796		967
797	$ctx->[4] = $cb;	968	$ctx->[4] = $cb;
798	}	969	}
799		970
800	=item $ctx->log ($level, $msg[, @params])	971	sub log_to_warn {
		972	my ($ctx, $path) = @_;
801		973
802	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	974	$ctx->log_cb (sub {
		975	warn shift;
		976	0
		977	});
		978	}
803		979
804	=item $logger = $ctx->logger ($level[, \$enabled])	980	sub log_to_file {
805		981	my ($ctx, $path) = @_;
806	Same as C<AnyEvent::Log::logger>, but uses the given context as log
807	context.
808
809	=cut
810
811	*log = \&AnyEvent::Log::_log;
812	*logger = \&AnyEvent::Log::_logger;
813
814	1;
815
816	=back
817
818	=head1 EXAMPLES
819
820	This section shows some common configurations.
821
822	=over 4
823
824	=item Setting the global logging level.
825
826	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
827	running your program, or modify the log level of the root context:
828
829	PERL_ANYEVENT_VERBOSE=5 ./myprog
830
831	$AnyEvent::Log::Root->level ("warn");
832
833	=item Append all messages to a file instead of sending them to STDERR.
834
835	This is affected by the global logging level.
836		982
837	open my $fh, ">>", $path	983	open my $fh, ">>", $path
838	or die "$path: $!";	984	or die "$path: $!";
839		985
840	$AnyEvent::Log::Default->log_cb (sub {	986	$ctx->log_cb (sub {
841	syswrite $fh, shift;	987	syswrite $fh, shift;
842	0	988	0
843	});	989	});
		990	}
		991
		992	sub log_to_path {
		993	my ($ctx, $path) = @_;
		994
		995	$ctx->log_cb (sub {
		996	open my $fh, ">>", $path
		997	or die "$path: $!";
		998
		999	syswrite $fh, shift;
		1000	0
		1001	});
		1002	}
		1003
		1004	sub log_to_syslog {
		1005	my ($ctx, $facility) = @_;
		1006
		1007	require Sys::Syslog;
		1008
		1009	$ctx->fmt_cb (sub {
		1010	my $str = $_[3];
		1011	$str =~ s/\n(?=.)/\n+ /g;
		1012
		1013	[$_[2], "($_[1][0]) $str"]
		1014	});
		1015
		1016	$facility \|\|= "user";
		1017
		1018	$ctx->log_cb (sub {
		1019	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		1020
		1021	Sys::Syslog::syslog ("$facility\|" . ($lvl - 1), $_)
		1022	for split /\n/, $_[0][1];
		1023
		1024	0
		1025	});
		1026	}
		1027
		1028	=back
		1029
		1030	=head3 MESSAGE LOGGING
		1031
		1032	These methods allow you to log messages directly to a context, without
		1033	going via your package context.
		1034
		1035	=over 4
		1036
		1037	=item $ctx->log ($level, $msg[, @params])
		1038
		1039	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
		1040
		1041	=item $logger = $ctx->logger ($level[, \$enabled])
		1042
		1043	Same as C<AnyEvent::Log::logger>, but uses the given context as log
		1044	context.
		1045
		1046	=cut
		1047
		1048	*log = \&AnyEvent::Log::_log;
		1049	*logger = \&AnyEvent::Log::_logger;
		1050
		1051	=back
		1052
		1053	=cut
		1054
		1055	package AnyEvent::Log;
		1056
		1057	=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
		1058
		1059	Logging can also be configured by setting the environment variable
		1060	C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
		1061
		1062	The value consists of one or more logging context specifications separated
		1063	by C<:> or whitespace. Each logging specification in turn starts with a
		1064	context name, followed by C<=>, followed by zero or more comma-separated
		1065	configuration directives, here are some examples:
		1066
		1067	# set default logging level
		1068	filter=warn
		1069
		1070	# log to file instead of to stderr
		1071	log=file=/tmp/mylog
		1072
		1073	# log to file in addition to stderr
		1074	log=+%file:%file=file=/tmp/mylog
		1075
		1076	# enable debug log messages, log warnings and above to syslog
		1077	filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
		1078
		1079	# log trace messages (only) from AnyEvent::Debug to file
		1080	AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
		1081
		1082	A context name in the log specification can be any of the following:
		1083
		1084	=over 4
		1085
		1086	=item C<collect>, C<filter>, C<log>
		1087
		1088	Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
		1089	C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
		1090
		1091	=item C<%name>
		1092
		1093	Context names starting with a C<%> are anonymous contexts created when the
		1094	name is first mentioned. The difference to package contexts is that by
		1095	default they have no attached slaves.
		1096
		1097	=item a perl package name
		1098
		1099	Any other string references the logging context associated with the given
		1100	Perl C<package>. In the unlikely case where you want to specify a package
		1101	context that matches on of the other context name forms, you can add a
		1102	C<::> to the package name to force interpretation as a package.
		1103
		1104	=back
		1105
		1106	The configuration specifications can be any number of the following:
		1107
		1108	=over 4
		1109
		1110	=item C<stderr>
		1111
		1112	Configures the context to use Perl's C<warn> function (which typically
		1113	logs to C<STDERR>). Works like C<log_to_warn>.
		1114
		1115	=item C<file=>I<path>
		1116
		1117	Configures the context to log to a file with the given path. Works like
		1118	C<log_to_file>.
		1119
		1120	=item C<path=>I<path>
		1121
		1122	Configures the context to log to a file with the given path. Works like
		1123	C<log_to_path>.
		1124
		1125	=item C<syslog> or C<syslog=>I<expr>
		1126
		1127	Configures the context to log to syslog. If I<expr> is given, then it is
		1128	evaluated in the L<Sys::Syslog> package, so you could use:
		1129
		1130	log=syslog=LOG_LOCAL0
		1131
		1132	=item C<nolog>
		1133
		1134	Configures the context to not log anything by itself, which is the
		1135	default. Same as C<< $ctx->log_cb (undef) >>.
		1136
		1137	=item C<cap=>I<level>
		1138
		1139	Caps logging messages entering this context at the given level, i.e.
		1140	reduces the priority of messages with higher priority than this level. The
		1141	default is C<0> (or C<off>), meaning the priority will not be touched.
		1142
		1143	=item C<0> or C<off>
		1144
		1145	Sets the logging level of the context to C<0>, i.e. all messages will be
		1146	filtered out.
		1147
		1148	=item C<all>
		1149
		1150	Enables all logging levels, i.e. filtering will effectively be switched
		1151	off (the default).
		1152
		1153	=item C<only>
		1154
		1155	Disables all logging levels, and changes the interpretation of following
		1156	level specifications to enable the specified level only.
		1157
		1158	Example: only enable debug messages for a context.
		1159
		1160	context=only,debug
		1161
		1162	=item C<except>
		1163
		1164	Enables all logging levels, and changes the interpretation of following
		1165	level specifications to disable that level. Rarely used.
		1166
		1167	Example: enable all logging levels except fatal and trace (this is rather
		1168	nonsensical).
		1169
		1170	filter=exept,fatal,trace
		1171
		1172	=item C<level>
		1173
		1174	Enables all logging levels, and changes the interpretation of following
		1175	level specifications to be "that level or any higher priority
		1176	message". This is the default.
		1177
		1178	Example: log anything at or above warn level.
		1179
		1180	filter=warn
		1181
		1182	# or, more verbose
		1183	filter=only,level,warn
		1184
		1185	=item C<1>..C<9> or a logging level name (C<error>, C<debug> etc.)
		1186
		1187	A numeric loglevel or the name of a loglevel will be interpreted according
		1188	to the most recent C<only>, C<except> or C<level> directive. By default,
		1189	specifying a logging level enables that and any higher priority messages.
		1190
		1191	=item C<+>I<context>
		1192
		1193	Attaches the named context as slave to the context.
		1194
		1195	=item C<+>
		1196
		1197	A line C<+> detaches all contexts, i.e. clears the slave list from the
		1198	context. Anonymous (C<%name>) contexts have no attached slaves by default,
		1199	but package contexts have the parent context as slave by default.
		1200
		1201	Example: log messages from My::Module to a file, do not send them to the
		1202	default log collector.
		1203
		1204	My::Module=+,file=/tmp/mymodulelog
		1205
		1206	=back
		1207
		1208	Any character can be escaped by prefixing it with a C<\> (backslash), as
		1209	usual, so to log to a file containing a comma, colon, backslash and some
		1210	spaces in the filename, you would do this:
		1211
		1212	PERL_ANYEVENT_LOG='log=file=/some\ \:file\ with\,\ \\-escapes'
		1213
		1214	Since whitespace (which includes newlines) is allowed, it is fine to
		1215	specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
		1216
		1217	PERL_ANYEVENT_LOG="
		1218	filter=warn
		1219	AnyEvent::Debug=+%trace
		1220	%trace=only,trace,+log
		1221	" myprog
		1222
		1223	Also, in the unlikely case when you want to concatenate specifications,
		1224	use whitespace as separator, as C<::> will be interpreted as part of a
		1225	module name, an empty spec with two separators:
		1226
		1227	PERL_ANYEVENT_LOG="$PERL_ANYEVENT_LOG MyMod=debug"
		1228
		1229	=cut
		1230
		1231	for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
		1232	my %anon;
		1233
		1234	my $pkg = sub {
		1235	$_[0] eq "log" ? $LOG
		1236	: $_[0] eq "filter" ? $FILTER
		1237	: $_[0] eq "collect" ? $COLLECT
		1238	: $_[0] =~ /^%(.+)$/ ? ($anon{$1} \|\|= do { my $ctx = ctx undef; $ctx->[0] = $_[0]; $ctx })
		1239	: $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
		1240	: die # never reached?
		1241	};
		1242
		1243	/\G[[:space:]]+/gc; # skip initial whitespace
		1244
		1245	while (/\G((?:[^:=[:space:]]+\|::\|\\.)+)=/gc) {
		1246	my $ctx = $pkg->($1);
		1247	my $level = "level";
		1248
		1249	while (/\G((?:[^,:[:space:]]+\|::\|\\.)+)/gc) {
		1250	for ("$1") {
		1251	if ($_ eq "stderr" ) { $ctx->log_to_warn;
		1252	} elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
		1253	} elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
		1254	} elsif (/^syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog ("$1");
		1255	} elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
		1256	} elsif (/^cap=(.+)/ ) { $ctx->cap ("$1");
		1257	} elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
		1258	} elsif ($_ eq "+" ) { $ctx->slaves;
		1259	} elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
		1260	} elsif ($_ eq "all" ) { $ctx->level ("all");
		1261	} elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
		1262	} elsif ($_ eq "only" ) { $ctx->level ("off"); $level = "enable";
		1263	} elsif ($_ eq "except" ) { $ctx->level ("all"); $level = "disable";
		1264	} elsif (/^\d$/ ) { $ctx->$level ($_);
		1265	} elsif (exists $STR2LEVEL{$_} ) { $ctx->$level ($_);
		1266	} else { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
		1267	}
		1268	}
		1269
		1270	/\G,/gc or last;
		1271	}
		1272
		1273	/\G[:[:space:]]+/gc or last;
		1274	}
		1275
		1276	/\G[[:space:]]+/gc; # skip trailing whitespace
		1277
		1278	if (/\G(.+)/g) {
		1279	die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
		1280	}
		1281	}
		1282
		1283	1;
		1284
		1285	=head1 EXAMPLES
		1286
		1287	This section shows some common configurations, both as code, and as
		1288	C<PERL_ANYEVENT_LOG> string.
		1289
		1290	=over 4
		1291
		1292	=item Setting the global logging level.
		1293
		1294	Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
		1295	running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
		1296	the root context at runtime:
		1297
		1298	PERL_ANYEVENT_VERBOSE=5 ./myprog
		1299
		1300	PERL_ANYEVENT_LOG=log=warn
		1301
		1302	$AnyEvent::Log::FILTER->level ("warn");
		1303
		1304	=item Append all messages to a file instead of sending them to STDERR.
		1305
		1306	This is affected by the global logging level.
		1307
		1308	$AnyEvent::Log::LOG->log_to_file ($path);
		1309
		1310	PERL_ANYEVENT_LOG=log=file=/some/path
844		1311
845	=item Write all messages with priority C<error> and higher to a file.	1312	=item Write all messages with priority C<error> and higher to a file.
846		1313
847	This writes them only when the global logging level allows it, because	1314	This writes them only when the global logging level allows it, because
848	it is attached to the default context which is invoked I<after> global	1315	it is attached to the default context which is invoked I<after> global
849	filtering.	1316	filtering.
850		1317
851	open my $fh, ">>", $path	1318	$AnyEvent::Log::FILTER->attach (
852	or die "$path: $!";	1319	new AnyEvent::Log::Ctx log_to_file => $path);
853		1320
854	$AnyEvent::Log::Default->attach (new AnyEvent::Log::Ctx	1321	PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
855	log_cb => sub { syswrite $fh, shift; 0 });
856		1322
857	This writes them regardless of the global logging level, because it is	1323	This writes them regardless of the global logging level, because it is
858	attached to the toplevel context, which receives all messages I<before>	1324	attached to the toplevel context, which receives all messages I<before>
859	the global filtering.	1325	the global filtering.
860		1326
861	$AnyEvent::Log::Top->attach (new AnyEvent::Log::Ctx	1327	$AnyEvent::Log::COLLECT->attach (
862	log_cb => sub { syswrite $fh, shift; 0 });	1328	new AnyEvent::Log::Ctx log_to_file => $path);
863		1329
		1330	PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
		1331
864	In both cases, messages are still written to STDOUT.	1332	In both cases, messages are still written to STDERR.
		1333
		1334	=item Additionally log all messages with C<warn> and higher priority to
		1335	C<syslog>, but cap at C<error>.
		1336
		1337	This logs all messages to the default log target, but also logs messages
		1338	with priority C<warn> or higher (and not filtered otherwise) to syslog
		1339	facility C<user>. Messages with priority higher than C<error> will be
		1340	logged with level C<error>.
		1341
		1342	$AnyEvent::Log::LOG->attach (
		1343	new AnyEvent::Log::Ctx
		1344	level => "warn",
		1345	cap => "error",
		1346	syslog => "user",
		1347	);
		1348
		1349	PERL_ANYEVENT_LOG=log=+%syslog:%syslog=warn,cap=error,syslog
865		1350
866	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).	1351	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
867		1352
868	Attach the CyAnyEvent::Log::Default> context to the C<AnyEvent::Debug>	1353	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
869	context and increase the C<AnyEvent::Debug> logging level - this simply
870	circumvents the global filtering for trace messages.	1354	context - this simply circumvents the global filtering for trace messages.
871		1355
872	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;	1356	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
873	$debug->attach ($AnyEvent::Log::Default);	1357	$debug->attach ($AnyEvent::Log::LOG);
874	$debug->levels ("trace"); # not "level"!
875		1358
876	This of course works for any package.	1359	PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
		1360
		1361	This of course works for any package, not just L<AnyEvent::Debug>, but
		1362	assumes the log level for AnyEvent::Debug hasn't been changed from the
		1363	default.
877		1364
878	=back	1365	=back
879		1366
880	=head1 AUTHOR	1367	=head1 AUTHOR
881		1368
882	Marc Lehmann <schmorp@schmorp.de>	1369	Marc Lehmann <schmorp@schmorp.de>
883	http://home.schmorp.de/	1370	http://home.schmorp.de/
884		1371
885	=cut	1372	=cut
		1373

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.15 by root, Sat Aug 20 02:16:59 2011 UTC vs. Revision 1.45 by root, Sun Oct 2 00:42:04 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.15 by root, Sat Aug 20 02:16:59 2011 UTC vs.
Revision 1.45 by root, Sun Oct 2 00:42:04 2011 UTC