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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.8 by root, Fri Aug 19 19:20:36 2011 UTC vs.
Revision 1.20 by root, Sat Aug 20 22:27:07 2011 UTC

…		…
10	AE::log debug => "hit my knee";	10	AE::log debug => "hit my knee";
11	AE::log warn => "it's a bit too hot";	11	AE::log warn => "it's a bit too hot";
12	AE::log error => "the flag was false!";	12	AE::log error => "the flag was false!";
13	AE::log fatal => "the bit toggled! run!";	13	AE::log fatal => "the bit toggled! run!";
14		14
15	# complex use	15	# "complex" use
16	use AnyEvent::Log;	16	use AnyEvent::Log;
17		17
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		19
20	$tracer->("i am here") if $trace;	20	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		22
23	#TODO: config	23	# configuration
24	#TODO: ctx () becomes caller[0]...	24
		25	# set logging for the current package to errors and higher only
		26	AnyEvent::Log::ctx->level ("error");
		27
		28	# set logging globally to anything below debug
		29	$AnyEvent::Log::FILTER->level ("notice");
		30
		31	# see also EXAMPLES, below
25		32
26	=head1 DESCRIPTION	33	=head1 DESCRIPTION
27		34
28	This module implements a relatively simple "logging framework". It doesn't	35	This module implements a relatively simple "logging framework". It doesn't
29	attempt to be "the" logging solution or even "a" logging solution for	36	attempt to be "the" logging solution or even "a" logging solution for
30	AnyEvent - AnyEvent simply creates logging messages internally, and this	37	AnyEvent - AnyEvent simply creates logging messages internally, and this
31	module more or less exposes the mechanism, with some extra spiff to allow	38	module more or less exposes the mechanism, with some extra spiff to allow
32	using it from other modules as well.	39	using it from other modules as well.
33		40
34	Remember that the default verbosity level is C<0>, so nothing will be	41	Remember that the default verbosity level is C<0> (C<off>), so nothing
35	logged, ever, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number	42	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
36	before starting your program.#TODO	43	before starting your program, or change the logging level at runtime with
		44	something like:
37		45
38	Possible future extensions are to allow custom log targets (where the	46	use AnyEvent::Log;
39	level is an object), log filtering based on package, formatting, aliasing	47	AnyEvent::Log::FILTER->level ("info");
40	or package groups.
41		48
		49	The design goal behind this module was to keep it simple (and small),
		50	but make it powerful enough to be potentially useful for any module, and
		51	extensive enough for the most common tasks, such as logging to multiple
		52	targets, or being able to log into a database.
		53
		54	The amount of documentation might indicate otherwise, but the module is
		55	still just below 300 lines of code.
		56
		57	=head1 LOGGING LEVELS
		58
		59	Logging levels in this module range from C<1> (highest priority) to C<9>
		60	(lowest priority). Note that the lowest numerical value is the highest
		61	priority, so when this document says "higher priority" it means "lower
		62	numerical value".
		63
		64	Instead of specifying levels by name you can also specify them by aliases:
		65
		66	LVL NAME SYSLOG PERL NOTE
		67	1 fatal emerg exit aborts program!
		68	2 alert
		69	3 critical crit
		70	4 error err die
		71	5 warn warning
		72	6 note notice
		73	7 info
		74	8 debug
		75	9 trace
		76
		77	As you can see, some logging levels have multiple aliases - the first one
		78	is the "official" name, the second one the "syslog" name (if it differs)
		79	and the third one the "perl" name, suggesting that you log C<die> messages
		80	at C<error> priority.
		81
		82	You can normally only log a single message at highest priority level
		83	(C<1>, C<fatal>), because logging a fatal message will also quit the
		84	program - so use it sparingly :)
		85
		86	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		87	or C<all> - these are only valid in the methods they are documented for.
		88
42	=head1 LOG FUNCTIONS	89	=head1 LOGGING FUNCTIONS
43		90
44	These functions allow you to log messages. They always use the caller's	91	These functions allow you to log messages. They always use the caller's
45	package as a "logging module/source". Also, the main logging function is	92	package as a "logging context". Also, the main logging function C<log> is
46	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	93	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
47	loaded.	94	loaded.
48		95
49	=over 4	96	=over 4
50		97
…		…
55	use Carp ();	102	use Carp ();
56	use POSIX ();	103	use POSIX ();
57		104
58	use AnyEvent (); BEGIN { AnyEvent::common_sense }	105	use AnyEvent (); BEGIN { AnyEvent::common_sense }
59	use AnyEvent::Util ();	106	use AnyEvent::Util ();
		107
		108	our $VERSION = $AnyEvent::VERSION;
		109
		110	our ($COLLECT, $FILTER, $LOG);
60		111
61	our ($now_int, $now_str1, $now_str2);	112	our ($now_int, $now_str1, $now_str2);
62		113
63	# Format Time, not public - yet?	114	# Format Time, not public - yet?
64	sub ft($) {	115	sub ft($) {
…		…
69	if $now_int != $i;	120	if $now_int != $i;
70		121
71	"$now_str1$f$now_str2"	122	"$now_str1$f$now_str2"
72	}	123	}
73		124
74	our %CTX; # all logging contexts	125	our %CTX; # all package contexts
75
76	my $default_log_cb = sub { 0 };
77		126
78	# creates a default package context object for the given package	127	# creates a default package context object for the given package
79	sub _pkg_ctx($) {	128	sub _pkg_ctx($) {
80	my $ctx = bless [$_[0], 0, {}, $default_log_cb], "AnyEvent::Log::Ctx";	129	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
81		130
82	# link "parent" package	131	# link "parent" package
83	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "";	132	my $parent = $_[0] =~ /^(.+)::/
		133	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		134	: $COLLECT;
84		135
85	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
86	$ctx->[2]{$pkg+0} = $pkg;	136	$ctx->[2]{$parent+0} = $parent;
87		137
88	$ctx	138	$ctx
89	}	139	}
90		140
91	=item AnyEvent::Log::log $level, $msg[, @args]	141	=item AnyEvent::Log::log $level, $msg[, @args]
92		142
93	Requests logging of the given C<$msg> with the given log level (1..9).	143	Requests logging of the given C<$msg> with the given log level.
94	You can also use the following strings as log level: C<fatal> (1),
95	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
96	C<info> (7), C<debug> (8), C<trace> (9).
97		144
98	For C<fatal> log levels, the program will abort.	145	For C<fatal> log levels, the program will abort.
99		146
100	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	147	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
101	C<$msg> is interpreted as an sprintf format string.	148	C<$msg> is interpreted as an sprintf format string.
…		…
114	Note that you can (and should) call this function as C<AnyEvent::log> or	161	Note that you can (and should) call this function as C<AnyEvent::log> or
115	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	162	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
116	need any additional functionality), as those functions will load the	163	need any additional functionality), as those functions will load the
117	logging module on demand only. They are also much shorter to write.	164	logging module on demand only. They are also much shorter to write.
118		165
119	Also, if you otpionally generate a lot of debug messages (such as when	166	Also, if you optionally generate a lot of debug messages (such as when
120	tracing some code), you should look into using a logger callback and a	167	tracing some code), you should look into using a logger callback and a
121	boolean enabler (see C<logger>, below).	168	boolean enabler (see C<logger>, below).
122		169
123	Example: log something at error level.	170	Example: log something at error level.
124		171
…		…
134		181
135	=cut	182	=cut
136		183
137	# also allow syslog equivalent names	184	# also allow syslog equivalent names
138	our %STR2LEVEL = (	185	our %STR2LEVEL = (
139	fatal => 1, emerg => 1,	186	fatal => 1, emerg => 1, exit => 1,
140	alert => 2,	187	alert => 2,
141	critical => 3, crit => 3,	188	critical => 3, crit => 3,
142	error => 4, err => 4,	189	error => 4, err => 4, die => 4,
143	warn => 5, warning => 5,	190	warn => 5, warning => 5,
144	note => 6, notice => 6,	191	note => 6, notice => 6,
145	info => 7,	192	info => 7,
146	debug => 8,	193	debug => 8,
147	trace => 9,	194	trace => 9,
148	);	195	);
149		196
150	sub now () { time }	197	sub now () { time }
		198
151	AnyEvent::post_detect {	199	AnyEvent::post_detect {
152	*now = \&AE::now;	200	*now = \&AE::now;
153	};	201	};
154		202
155	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	203	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
156		204
157	# time, ctx, level, msg	205	# time, ctx, level, msg
158	sub _format($$$$) {	206	sub _format($$$$) {
159	my $pfx = ft $_[0];	207	my $ts = ft $_[0];
		208	my $ct = " ";
160		209
161	join "",	210	my @res;
162	map "$pfx $_\n",	211
163	split /\n/,
164	sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]	212	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {
		213	push @res, "$ts$ct$_\n";
		214	$ct = " + ";
		215	}
		216
		217	join "", @res
165	}	218	}
166		219
167	sub _log {	220	sub _log {
168	my ($ctx, $level, $format, @args) = @_;	221	my ($ctx, $level, $format, @args) = @_;
169		222
		223	$level = $level > 0 && $level <= 9
		224	? $level+0
170	$level = $level > 0 && $level <= 9 ? $level+0 : $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	225	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
171		226
172	my $mask = 1 << $level;	227	my $mask = 1 << $level;
173	my $now = AE::now;
174		228
175	my (@ctx, $did_format, $fmt);	229	my (%seen, @ctx, $now, $fmt);
176		230
177	do {	231	do
178	if ($ctx->[1] & $mask) {	232	{
		233	# skip if masked
		234	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
		235	if ($ctx->[3]) {
179	# logging target found	236	# logging target found
180		237
181	# get raw message	238	# now get raw message, unless we have it already
182	unless ($did_format) {	239	unless ($now) {
183	$format = $format->() if ref $format;	240	$format = $format->() if ref $format;
184	$format = sprintf $format, @args if @args;	241	$format = sprintf $format, @args if @args;
185	$format =~ s/\n$//;	242	$format =~ s/\n$//;
186	$did_format = 1;	243	$now = AE::now;
		244	};
		245
		246	# format msg
		247	my $str = $ctx->[4]
		248	? $ctx->[4]($now, $_[0], $level, $format)
		249	: ($fmt \|\|= _format $now, $_[0], $level, $format);
		250
		251	$ctx->[3]($str, $_[0], $level)
		252	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		253	} else {
		254	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
		255	}
187	};	256	}
188
189	# format msg
190	my $str = $ctx->[4]
191	? $ctx->[4]($now, $_[0], $level, $format)
192	: $fmt \|\|= _format $now, $_[0], $level, $format;
193
194	$ctx->[3]($str)
195	and next;
196	}	257	}
197
198	# not consume - push parent contexts
199	push @ctx, values %{ $ctx->[2] };
200	} while $ctx = pop @ctx;	258	while $ctx = pop @ctx;
201		259
202	exit 1 if $level <= 1;	260	exit 1 if $level <= 1;
203	}	261	}
204		262
205	sub log($$;@) {	263	sub log($$;@) {
…		…
246	# and later in your program	304	# and later in your program
247	$debug_log->("yo, stuff here") if $debug;	305	$debug_log->("yo, stuff here") if $debug;
248		306
249	$debug and $debug_log->("123");	307	$debug and $debug_log->("123");
250		308
251	Note: currently the enabled var is always true - that will be fixed in a
252	future version :)
253
254	=cut	309	=cut
255		310
256	our %LOGGER;	311	our %LOGGER;
257		312
258	# re-assess logging status for all loggers	313	# re-assess logging status for all loggers
259	sub _reassess {	314	sub _reassess {
		315	local $SIG{__DIE__};
		316	my $die = sub { die };
		317
260	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	318	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
261	my ($ctx, $level, $renabled) = @$_;	319	my ($ctx, $level, $renabled) = @$_;
262		320
263	# to detetc whether a message would be logged, we # actually	321	# to detect whether a message would be logged, we actually
264	# try to log one and die. this isn't # fast, but we can be	322	# try to log one and die. this isn't fast, but we can be
265	# sure that the logging decision is correct :)	323	# sure that the logging decision is correct :)
266		324
267	$$renabled = !eval {	325	$$renabled = !eval {
268	local $SIG{__DIE__};
269
270	_log $ctx, $level, sub { die };	326	_log $ctx, $level, $die;
271		327
272	1	328	1
273	};	329	};
274
275	$$renabled = 1; # TODO
276	}	330	}
277	}	331	}
278		332
279	sub _logger($;$) {	333	sub _logger {
280	my ($ctx, $level, $renabled) = @_;	334	my ($ctx, $level, $renabled) = @_;
281
282	$renabled \|\|= \my $enabled;
283		335
284	$$renabled = 1;	336	$$renabled = 1;
285		337
286	my $logger = [$ctx, $level, $renabled];	338	my $logger = [$ctx, $level, $renabled];
287		339
…		…
306	_logger	358	_logger
307	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	359	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
308	@_	360	@_
309	}	361	}
310		362
311	#TODO
312
313	=back	363	=back
314		364
315	=head1 CONFIGURATION FUNCTIONALITY	365	=head1 LOGGING CONTEXTS
316		366
317	None, yet, except for C<PERL_ANYEVENT_VERBOSE>, described in the L<AnyEvent> manpage.	367	This module associates every log message with a so-called I<logging
		368	context>, based on the package of the caller. Every perl package has its
		369	own logging context.
318		370
319	#TODO: wahst a context	371	A logging context has three major responsibilities: filtering, logging and
320	#TODO	372	propagating the message.
		373
		374	For the first purpose, filtering, each context has a set of logging
		375	levels, called the log level mask. Messages not in the set will be ignored
		376	by this context (masked).
		377
		378	For logging, the context stores a formatting callback (which takes the
		379	timestamp, context, level and string message and formats it in the way
		380	it should be logged) and a logging callback (which is responsible for
		381	actually logging the formatted message and telling C<AnyEvent::Log>
		382	whether it has consumed the message, or whether it should be propagated).
		383
		384	For propagation, a context can have any number of attached I<slave
		385	contexts>. Any message that is neither masked by the logging mask nor
		386	masked by the logging callback returning true will be passed to all slave
		387	contexts.
		388
		389	Each call to a logging function will log the message at most once per
		390	context, so it does not matter (much) if there are cycles or if the
		391	message can arrive at the same context via multiple paths.
		392
		393	=head2 DEFAULTS
		394
		395	By default, all logging contexts have an full set of log levels ("all"), a
		396	disabled logging callback and the default formatting callback.
		397
		398	Package contexts have the package name as logging title by default.
		399
		400	They have exactly one slave - the context of the "parent" package. The
		401	parent package is simply defined to be the package name without the last
		402	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
		403	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
		404	exception of the rule - just like the "parent" of any single-component
		405	package name in Perl is C<main>, the default slave of any top-level
		406	package context is C<$AnyEvent::Log::COLLECT>.
		407
		408	Since perl packages form only an approximate hierarchy, this slave
		409	context can of course be removed.
		410
		411	All other (anonymous) contexts have no slaves and an empty title by
		412	default.
		413
		414	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
		415	context that simply logs everything via C<warn>, without propagating
		416	anything anywhere by default. The purpose of this context is to provide
		417	a convenient place to override the global logging target or to attach
		418	additional log targets. It's not meant for filtering.
		419
		420	It then creates the C<$AnyEvent::Log::FILTER> context whose
		421	purpose is to suppress all messages with priority higher
		422	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
		423	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
		424	is to simply provide filtering according to some global log level.
		425
		426	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
		427	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
		428	leaves it at default config. Its purpose is simply to collect all log
		429	messages system-wide.
		430
		431	The hierarchy is then:
		432
		433	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		434
		435	The effect of all this is that log messages, by default, wander up to the
		436	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
		437	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
		438	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
		439	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
		440
		441	This makes it easy to set a global logging level (by modifying $FILTER),
		442	but still allow other contexts to send, for example, their debug and trace
		443	messages to the $LOG target despite the global logging level, or to attach
		444	additional log targets that log messages, regardless of the global logging
		445	level.
		446
		447	It also makes it easy to modify the default warn-logger ($LOG) to
		448	something that logs to a file, or to attach additional logging targets
		449	(such as loggign to a file) by attaching it to $FILTER.
		450
		451	=head2 CREATING/FINDING/DESTROYING CONTEXTS
321		452
322	=over 4	453	=over 4
323		454
324	=item $ctx = AnyEvent::Log::ctx [$pkg]	455	=item $ctx = AnyEvent::Log::ctx [$pkg]
325		456
326	Returns a I<config> object for the given package name.	457	This function creates or returns a logging context (which is an object).
327		458
328	If no package name is given, returns the context for the current perl	459	If a package name is given, then the context for that packlage is
		460	returned. If it is called without any arguments, then the context for the
329	package (i.e. the same context as a C<AE::log> call would use).	461	callers package is returned (i.e. the same context as a C<AE::log> call
		462	would use).
330		463
331	If C<undef> is given, then it creates a new anonymous context that is not	464	If C<undef> is given, then it creates a new anonymous context that is not
332	tied to any package and is destroyed when no longer referenced.	465	tied to any package and is destroyed when no longer referenced.
333		466
334	=cut	467	=cut
…		…
338		471
339	ref $pkg	472	ref $pkg
340	? $pkg	473	? $pkg
341	: defined $pkg	474	: defined $pkg
342	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg	475	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg
343	: bless [undef, 0, undef, $default_log_cb], "AnyEvent::Log::Ctx"	476	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
344	}	477	}
345		478
346	# create default root context	479	=item AnyEvent::Log::reset
347	{	480
348	my $root = ctx undef;	481	Resets all package contexts and recreates the default hierarchy if
349	$root->[0] = "";	482	necessary, i.e. resets the logging subsystem to defaults, as much as
350	$root->title ("default");	483	possible. This process keeps references to contexts held by other parts of
351	$root->level ($AnyEvent::VERBOSE);	484	the program intact.
		485
		486	This can be used to implement config-file (re-)loading: before loading a
		487	configuration, reset all contexts.
		488
		489	=cut
		490
		491	sub reset {
		492	# hard to kill complex data structures
		493	# we "recreate" all package loggers and reset the hierarchy
		494	while (my ($k, $v) = each %CTX) {
		495	@$v = ($k, (1 << 10) - 1 - 1, { });
		496
		497	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
		498	}
		499
		500	@$_ = ($_->[0], (1 << 10) - 1 - 1)
		501	for $LOG, $FILTER, $COLLECT;
		502
		503	$LOG->slaves;
		504	$LOG->title ('$AnyEvent::Log::LOG');
352	$root->log_cb (sub {	505	$LOG->log_cb (sub {
353	print STDERR shift;	506	warn shift;
354	0	507	0
355	});	508	});
356	$CTX{""} = $root;	509
		510	$FILTER->slaves ($LOG);
		511	$FILTER->title ('$AnyEvent::Log::FILTER');
		512	$FILTER->level ($AnyEvent::VERBOSE);
		513
		514	$COLLECT->slaves ($FILTER);
		515	$COLLECT->title ('$AnyEvent::Log::COLLECT');
		516
		517	_reassess;
357	}	518	}
		519
		520	# create the default logger contexts
		521	$LOG = ctx undef;
		522	$FILTER = ctx undef;
		523	$COLLECT = ctx undef;
		524
		525	AnyEvent::Log::reset;
		526
		527	# hello, CPAN, please catch me
		528	package AnyEvent::Log::LOG;
		529	package AE::Log::LOG;
		530	package AnyEvent::Log::FILTER;
		531	package AE::Log::FILTER;
		532	package AnyEvent::Log::COLLECT;
		533	package AE::Log::COLLECT;
358		534
359	package AnyEvent::Log::Ctx;	535	package AnyEvent::Log::Ctx;
360		536
361	# 0 1 2 3 4	537	# 0 1 2 3 4
362	# [$title, $level, %$parents, &$logcb, &$fmtcb]	538	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
		539
		540	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
		541
		542	This is a convenience constructor that makes it simpler to construct
		543	anonymous logging contexts.
		544
		545	Each key-value pair results in an invocation of the method of the same
		546	name as the key with the value as parameter, unless the value is an
		547	arrayref, in which case it calls the method with the contents of the
		548	array. The methods are called in the same order as specified.
		549
		550	Example: create a new logging context and set both the default logging
		551	level, some slave contexts and a logging callback.
		552
		553	$ctx = new AnyEvent::Log::Ctx
		554	title => "dubious messages",
		555	level => "error",
		556	log_cb => sub { print STDOUT shift; 0 },
		557	slaves => [$ctx1, $ctx, $ctx2],
		558	;
		559
		560	=back
		561
		562	=cut
		563
		564	sub new {
		565	my $class = shift;
		566
		567	my $ctx = AnyEvent::Log::ctx undef;
		568
		569	while (@_) {
		570	my ($k, $v) = splice @_, 0, 2;
		571	$ctx->$k (ref $v eq "ARRAY" ? @$v : $v);
		572	}
		573
		574	bless $ctx, $class # do we really support subclassing, hmm?
		575	}
		576
		577
		578	=head2 CONFIGURING A LOG CONTEXT
		579
		580	The following methods can be used to configure the logging context.
		581
		582	=over 4
363		583
364	=item $ctx->title ([$new_title])	584	=item $ctx->title ([$new_title])
365		585
366	Returns the title of the logging context - this is the package name, for	586	Returns the title of the logging context - this is the package name, for
367	package contexts, and a user defined string for all others.	587	package contexts, and a user defined string for all others.
…		…
373	sub title {	593	sub title {
374	$_[0][0] = $_[1] if @_ > 1;	594	$_[0][0] = $_[1] if @_ > 1;
375	$_[0][0]	595	$_[0][0]
376	}	596	}
377		597
		598	=back
		599
		600	=head3 LOGGING LEVELS
		601
		602	The following methods deal with the logging level set associated with the
		603	log context.
		604
		605	The most common method to use is probably C<< $ctx->level ($level) >>,
		606	which configures the specified and any higher priority levels.
		607
		608	All functions which accept a list of levels also accept the special string
		609	C<all> which expands to all logging levels.
		610
		611	=over 4
		612
378	=item $ctx->levels ($level[, $level...)	613	=item $ctx->levels ($level[, $level...)
379		614
380	Enables logging fot the given levels and disables it for all others.	615	Enables logging for the given levels and disables it for all others.
381		616
382	=item $ctx->level ($level)	617	=item $ctx->level ($level)
383		618
384	Enables logging for the given level and all lower level (higher priority)	619	Enables logging for the given level and all lower level (higher priority)
385	ones. Specifying a level of C<0> or C<off> disables all logging for this	620	ones. In addition to normal logging levels, specifying a level of C<0> or
386	level.	621	C<off> disables all logging for this level.
387		622
388	Example: log warnings, errors and higher priority messages.	623	Example: log warnings, errors and higher priority messages.
389		624
390	$ctx->level ("warn");	625	$ctx->level ("warn");
391	$ctx->level (5); # same thing, just numeric	626	$ctx->level (5); # same thing, just numeric
…		…
399	Disables logging for the given levels, leaving all others unchanged.	634	Disables logging for the given levels, leaving all others unchanged.
400		635
401	=cut	636	=cut
402		637
403	sub _lvl_lst {	638	sub _lvl_lst {
		639	map {
		640	$_ > 0 && $_ <= 9 ? $_+0
		641	: $_ eq "all" ? (1 .. 9)
404	map { $_ > 0 && $_ <= 9 ? $_+0 : $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught" }	642	: $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught"
405	@_	643	} @_
406	}	644	}
407		645
408	our $NOP_CB = sub { 0 };	646	our $NOP_CB = sub { 0 };
409		647
410	sub levels {	648	sub levels {
…		…
415	AnyEvent::Log::_reassess;	653	AnyEvent::Log::_reassess;
416	}	654	}
417		655
418	sub level {	656	sub level {
419	my $ctx = shift;	657	my $ctx = shift;
420	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[0];	658	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[-1];
		659
421	$ctx->[1] = ((1 << $lvl) - 1) << 1;	660	$ctx->[1] = ((1 << $lvl) - 1) << 1;
422	AnyEvent::Log::_reassess;	661	AnyEvent::Log::_reassess;
423	}	662	}
424		663
425	sub enable {	664	sub enable {
…		…
434	$ctx->[1] &= ~(1 << $_)	673	$ctx->[1] &= ~(1 << $_)
435	for &_lvl_lst;	674	for &_lvl_lst;
436	AnyEvent::Log::_reassess;	675	AnyEvent::Log::_reassess;
437	}	676	}
438		677
		678	=back
		679
		680	=head3 SLAVE CONTEXTS
		681
		682	The following methods attach and detach another logging context to a
		683	logging context.
		684
		685	Log messages are propagated to all slave contexts, unless the logging
		686	callback consumes the message.
		687
		688	=over 4
		689
439	=item $ctx->attach ($ctx2[, $ctx3...])	690	=item $ctx->attach ($ctx2[, $ctx3...])
440		691
441	Attaches the given contexts as parents to this context. It is not an error	692	Attaches the given contexts as slaves to this context. It is not an error
442	to add a context twice (the second add will be ignored).	693	to add a context twice (the second add will be ignored).
443		694
444	A context can be specified either as package name or as a context object.	695	A context can be specified either as package name or as a context object.
445		696
446	=item $ctx->detach ($ctx2[, $ctx3...])	697	=item $ctx->detach ($ctx2[, $ctx3...])
447		698
448	Removes the given parents from this context - it's not an error to attempt	699	Removes the given slaves from this context - it's not an error to attempt
449	to remove a context that hasn't been added.	700	to remove a context that hasn't been added.
450		701
451	A context can be specified either as package name or as a context object.	702	A context can be specified either as package name or as a context object.
		703
		704	=item $ctx->slaves ($ctx2[, $ctx3...])
		705
		706	Replaces all slaves attached to this context by the ones given.
452		707
453	=cut	708	=cut
454		709
455	sub attach {	710	sub attach {
456	my $ctx = shift;	711	my $ctx = shift;
…		…
464		719
465	delete $ctx->[2]{$_+0}	720	delete $ctx->[2]{$_+0}
466	for map { AnyEvent::Log::ctx $_ } @_;	721	for map { AnyEvent::Log::ctx $_ } @_;
467	}	722	}
468		723
		724	sub slaves {
		725	undef $_[0][2];
		726	&attach;
		727	}
		728
		729	=back
		730
		731	=head3 LOG TARGETS
		732
		733	The following methods configure how the logging context actually does
		734	the logging (which consists of formatting the message and printing it or
		735	whatever it wants to do with it).
		736
		737	=over 4
		738
469	=item $ctx->log_cb ($cb->($str))	739	=item $ctx->log_cb ($cb->($str, $orig_ctx, $level))
470		740
471	Replaces the logging callback on the context (C<undef> disables the	741	Replaces the logging callback on the context (C<undef> disables the
472	logging callback).	742	logging callback).
473		743
474	The logging callback is responsible for handling formatted log messages	744	The logging callback is responsible for handling formatted log messages
475	(see C<fmt_cb> below) - normally simple text strings that end with a	745	(see C<fmt_cb> below) - normally simple text strings that end with a
476	newline (and are possibly multiline themselves).	746	newline (and are possibly multiline themselves). In addition to the
		747	message, which is often the only argument you need to look at, it is
		748	passed the numeric log level and originating context.
477		749
478	It also has to return true iff it has consumed the log message, and false	750	It also has to return true iff it has consumed the log message, and false
479	if it hasn't. Consuming a message means that it will not be sent to any	751	if it hasn't. Consuming a message means that it will not be sent to any
480	parent context. When in doubt, return C<0> from your logging callback.	752	slave context. When in doubt, return C<0> from your logging callback.
481		753
482	Example: a very simple logging callback, simply dump the message to STDOUT	754	Example: a very simple logging callback, simply dump the message to STDOUT
483	and do not consume it.	755	and do not consume it.
484		756
485	$ctx->log_cb (sub { print STDERR shift; 0 });	757	$ctx->log_cb (sub { print STDERR shift; 0 });
486		758
		759	You can filter messages by having a log callback that simply returns C<1>
		760	and does not do anything with the message, but this counts as "message
		761	being logged" and might not be very efficient.
		762
		763	Example: propagate all messages except for log levels "debug" and
		764	"trace". The messages will still be generated, though, which can slow down
		765	your program.
		766
		767	$ctx->levels ("debug", "trace");
		768	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
		769
		770	=item $ctx->log_to_file ($path)
		771
		772	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		773
		774	=item $ctx->log_to_path ($path)
		775
		776	Same as C<< ->log_to_file >>, but opens the file for each message. This
		777	is much slower, but allows you to change/move/rename/delete the file at
		778	basically any time.
		779
		780	=item $ctx->log_to_syslog ([$log_flags])
		781
		782	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		783	the others in the obvious way. If specified, then the C<$log_flags> are
		784	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		785	flags valid for Sys::Syslog::syslog, except for the priority levels.
		786
		787	Note that the default logging format includes a verbose timestamp, which
		788	is not so suited for syslog, so a simpler C<fmt_cb> might be useful:
		789
		790	$ctx->log_to_syslog;
		791	$ctx->fmt_cb (sub { "($_[1][0]) $_[3]" });
		792
487	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	793	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
488		794
489	Replaces the fornatting callback on the cobntext (C<undef> restores the	795	Replaces the formatting callback on the context (C<undef> restores the
490	default formatter).	796	default formatter).
491		797
492	The callback is passed the (possibly fractional) timestamp, the original	798	The callback is passed the (possibly fractional) timestamp, the original
493	logging context, the (numeric) logging level and the raw message string and needs to	799	logging context, the (numeric) logging level and the raw message string
494	return a formatted log message. In most cases this will be a string, but	800	and needs to return a formatted log message. In most cases this will be a
495	it could just as well be an array reference that just stores the values.	801	string, but it could just as well be an array reference that just stores
		802	the values.
		803
		804	If, for some reaosn, you want to use C<caller> to find out more baout the
		805	logger then you should walk up the call stack until you are no longer
		806	inside the C<AnyEvent::Log> package.
496		807
497	Example: format just the raw message, with numeric log level in angle	808	Example: format just the raw message, with numeric log level in angle
498	brackets.	809	brackets.
499		810
500	$ctx->fmt_cb (sub {	811	$ctx->fmt_cb (sub {
…		…
522	=cut	833	=cut
523		834
524	sub log_cb {	835	sub log_cb {
525	my ($ctx, $cb) = @_;	836	my ($ctx, $cb) = @_;
526		837
527	$ctx->[3] = $cb \|\| $default_log_cb;	838	$ctx->[3] = $cb;
528	}	839	}
529		840
530	sub fmt_cb {	841	sub fmt_cb {
531	my ($ctx, $cb) = @_;	842	my ($ctx, $cb) = @_;
532		843
533	$ctx->[4] = $cb;	844	$ctx->[4] = $cb;
534	}	845	}
535		846
		847	sub log_to_file {
		848	my ($ctx, $path) = @_;
		849
		850	open my $fh, ">>", $path
		851	or die "$path: $!";
		852
		853	$ctx->log_cb (sub {
		854	syswrite $fh, shift;
		855	0
		856	});
		857	}
		858
		859	sub log_to_file {
		860	my ($ctx, $path) = @_;
		861
		862	$ctx->log_cb (sub {
		863	open my $fh, ">>", $path
		864	or die "$path: $!";
		865
		866	syswrite $fh, shift;
		867	0
		868	});
		869	}
		870
		871	sub log_to_syslog {
		872	my ($ctx, $flags) = @_;
		873
		874	require Sys::Syslog;
		875
		876	$ctx->log_cb (sub {
		877	my $lvl = $_[2] < 9 ? $_[2] : 8;
		878
		879	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		880	for split /\n/, shift;
		881
		882	0
		883	});
		884	}
		885
		886	=back
		887
		888	=head3 MESSAGE LOGGING
		889
		890	These methods allow you to log messages directly to a context, without
		891	going via your package context.
		892
		893	=over 4
		894
536	=item $ctx->log ($level, $msg[, @params])	895	=item $ctx->log ($level, $msg[, @params])
537		896
538	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	897	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
539		898
540	=item $logger = $ctx->logger ($level[, \$enabled])	899	=item $logger = $ctx->logger ($level[, \$enabled])
…		…
549		908
550	1;	909	1;
551		910
552	=back	911	=back
553		912
		913	=head1 EXAMPLES
		914
		915	This section shows some common configurations.
		916
		917	=over 4
		918
		919	=item Setting the global logging level.
		920
		921	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
		922	running your program, or modify the log level of the root context:
		923
		924	PERL_ANYEVENT_VERBOSE=5 ./myprog
		925
		926	$AnyEvent::Log::FILTER->level ("warn");
		927
		928	=item Append all messages to a file instead of sending them to STDERR.
		929
		930	This is affected by the global logging level.
		931
		932	$AnyEvent::Log::LOG->log_to_file ($path); (sub {
		933
		934	=item Write all messages with priority C<error> and higher to a file.
		935
		936	This writes them only when the global logging level allows it, because
		937	it is attached to the default context which is invoked I<after> global
		938	filtering.
		939
		940	$AnyEvent::Log::FILTER->attach
		941	new AnyEvent::Log::Ctx log_to_file => $path);
		942
		943	This writes them regardless of the global logging level, because it is
		944	attached to the toplevel context, which receives all messages I<before>
		945	the global filtering.
		946
		947	$AnyEvent::Log::COLLECT->attach (
		948	new AnyEvent::Log::Ctx log_to_file => $path);
		949
		950	In both cases, messages are still written to STDERR.
		951
		952	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
		953
		954	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
		955	context - this simply circumvents the global filtering for trace messages.
		956
		957	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
		958	$debug->attach ($AnyEvent::Log::LOG);
		959
		960	This of course works for any package, not just L<AnyEvent::Debug>, but
		961	assumes the log level for AnyEvent::Debug hasn't been changed from the
		962	default.
		963
		964	=back
		965
554	=head1 AUTHOR	966	=head1 AUTHOR
555		967
556	Marc Lehmann <schmorp@schmorp.de>	968	Marc Lehmann <schmorp@schmorp.de>
557	http://home.schmorp.de/	969	http://home.schmorp.de/
558		970

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.8 by root, Fri Aug 19 19:20:36 2011 UTC vs. Revision 1.20 by root, Sat Aug 20 22:27:07 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.8 by root, Fri Aug 19 19:20:36 2011 UTC vs.
Revision 1.20 by root, Sat Aug 20 22:27:07 2011 UTC