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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.9 by root, Fri Aug 19 19:59:53 2011 UTC vs.
Revision 1.26 by root, Sun Aug 21 03:29:19 2011 UTC

…		…
2		2
3	AnyEvent::Log - simple logging "framework"	3	AnyEvent::Log - simple logging "framework"
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	# simple use	7	Simple uses:
		8
8	use AnyEvent;	9	use AnyEvent;
9		10
10	AE::log debug => "hit my knee";	11	AE::log debug => "hit my knee";
11	AE::log warn => "it's a bit too hot";	12	AE::log warn => "it's a bit too hot";
12	AE::log error => "the flag was false!";	13	AE::log error => "the flag was false!";
13	AE::log fatal => "the bit toggled! run!";	14	AE::log fatal => "the bit toggled! run!"; # never returns
14		15
15	# complex use	16	"Complex" uses (for speed sensitive code):
		17
16	use AnyEvent::Log;	18	use AnyEvent::Log;
17		19
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	20	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		21
20	$tracer->("i am here") if $trace;	22	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	23	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		24
23	#TODO: config	25	Configuration (also look at the EXAMPLES section):
24	#TODO: ctx () becomes caller[0]...	26
		27	# set logging for the current package to errors and higher only
		28	AnyEvent::Log::ctx->level ("error");
		29
		30	# set logging level to suppress anything below "notice"
		31	$AnyEvent::Log::FILTER->level ("notice");
		32
		33	# send all critical and higher priority messages to syslog,
		34	# regardless of (most) other settings
		35	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
		36	level => "critical",
		37	log_to_syslog => 0,
		38	);
25		39
26	=head1 DESCRIPTION	40	=head1 DESCRIPTION
27		41
28	This module implements a relatively simple "logging framework". It doesn't	42	This module implements a relatively simple "logging framework". It doesn't
29	attempt to be "the" logging solution or even "a" logging solution for	43	attempt to be "the" logging solution or even "a" logging solution for
30	AnyEvent - AnyEvent simply creates logging messages internally, and this	44	AnyEvent - AnyEvent simply creates logging messages internally, and this
31	module more or less exposes the mechanism, with some extra spiff to allow	45	module more or less exposes the mechanism, with some extra spiff to allow
32	using it from other modules as well.	46	using it from other modules as well.
33		47
34	Remember that the default verbosity level is C<0>, so nothing will be	48	Remember that the default verbosity level is C<0> (C<off>), so nothing
35	logged, ever, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number	49	will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
36	before starting your program, or change the logging level at runtime wiht	50	before starting your program, or change the logging level at runtime with
37	something like:	51	something like:
38		52
39	use AnyEvent;	53	use AnyEvent::Log;
40	(AnyEvent::Log::ctx "")->level ("info");	54	AnyEvent::Log::FILTER->level ("info");
		55
		56	The design goal behind this module was to keep it simple (and small),
		57	but make it powerful enough to be potentially useful for any module, and
		58	extensive enough for the most common tasks, such as logging to multiple
		59	targets, or being able to log into a database.
		60
		61	The amount of documentation might indicate otherwise, but the module is
		62	still just below 300 lines of code.
		63
		64	=head1 LOGGING LEVELS
		65
		66	Logging levels in this module range from C<1> (highest priority) to C<9>
		67	(lowest priority). Note that the lowest numerical value is the highest
		68	priority, so when this document says "higher priority" it means "lower
		69	numerical value".
		70
		71	Instead of specifying levels by name you can also specify them by aliases:
		72
		73	LVL NAME SYSLOG PERL NOTE
		74	1 fatal emerg exit aborts program!
		75	2 alert
		76	3 critical crit
		77	4 error err die
		78	5 warn warning
		79	6 note notice
		80	7 info
		81	8 debug
		82	9 trace
		83
		84	As you can see, some logging levels have multiple aliases - the first one
		85	is the "official" name, the second one the "syslog" name (if it differs)
		86	and the third one the "perl" name, suggesting that you log C<die> messages
		87	at C<error> priority.
		88
		89	You can normally only log a single message at highest priority level
		90	(C<1>, C<fatal>), because logging a fatal message will also quit the
		91	program - so use it sparingly :)
		92
		93	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		94	or C<all> - these are only valid in the methods they are documented for.
41		95
42	=head1 LOGGING FUNCTIONS	96	=head1 LOGGING FUNCTIONS
43		97
44	These functions allow you to log messages. They always use the caller's	98	These functions allow you to log messages. They always use the caller's
45	package as a "logging module/source". Also, the main logging function is	99	package as a "logging context". Also, the main logging function C<log> is
46	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	100	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
47	loaded.	101	loaded.
48		102
49	=over 4	103	=over 4
50		104
…		…
55	use Carp ();	109	use Carp ();
56	use POSIX ();	110	use POSIX ();
57		111
58	use AnyEvent (); BEGIN { AnyEvent::common_sense }	112	use AnyEvent (); BEGIN { AnyEvent::common_sense }
59	use AnyEvent::Util ();	113	use AnyEvent::Util ();
		114
		115	our $VERSION = $AnyEvent::VERSION;
		116
		117	our ($COLLECT, $FILTER, $LOG);
60		118
61	our ($now_int, $now_str1, $now_str2);	119	our ($now_int, $now_str1, $now_str2);
62		120
63	# Format Time, not public - yet?	121	# Format Time, not public - yet?
64	sub ft($) {	122	sub ft($) {
…		…
69	if $now_int != $i;	127	if $now_int != $i;
70		128
71	"$now_str1$f$now_str2"	129	"$now_str1$f$now_str2"
72	}	130	}
73		131
74	our %CTX; # all logging contexts	132	our %CTX; # all package contexts
75
76	my $default_log_cb = sub { 0 };
77		133
78	# creates a default package context object for the given package	134	# creates a default package context object for the given package
79	sub _pkg_ctx($) {	135	sub _pkg_ctx($) {
80	my $ctx = bless [$_[0], 0, {}, $default_log_cb], "AnyEvent::Log::Ctx";	136	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
81		137
82	# link "parent" package	138	# link "parent" package
83	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "";	139	my $parent = $_[0] =~ /^(.+)::/
		140	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		141	: $COLLECT;
84		142
85	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
86	$ctx->[2]{$pkg+0} = $pkg;	143	$ctx->[2]{$parent+0} = $parent;
87		144
88	$ctx	145	$ctx
89	}	146	}
90		147
91	=item AnyEvent::Log::log $level, $msg[, @args]	148	=item AnyEvent::Log::log $level, $msg[, @args]
92		149
93	Requests logging of the given C<$msg> with the given log level (1..9).	150	Requests logging of the given C<$msg> with the given log level, and
94	You can also use the following strings as log level: C<fatal> (1),	151	returns true if the message was logged I<somewhere>.
95	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
96	C<info> (7), C<debug> (8), C<trace> (9).
97		152
98	For C<fatal> log levels, the program will abort.	153	For C<fatal> log levels, the program will abort.
99		154
100	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	155	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
101	C<$msg> is interpreted as an sprintf format string.	156	C<$msg> is interpreted as an sprintf format string.
…		…
107	supposed to return the message. It will be called only then the message	162	supposed to return the message. It will be called only then the message
108	actually gets logged, which is useful if it is costly to create the	163	actually gets logged, which is useful if it is costly to create the
109	message in the first place.	164	message in the first place.
110		165
111	Whether the given message will be logged depends on the maximum log level	166	Whether the given message will be logged depends on the maximum log level
112	and the caller's package.	167	and the caller's package. The return value can be used to ensure that
		168	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		169	runtime error it tries to log it at C<die> level, but if that message is
		170	lost it simply uses warn.
113		171
114	Note that you can (and should) call this function as C<AnyEvent::log> or	172	Note that you can (and should) call this function as C<AnyEvent::log> or
115	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	173	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
116	need any additional functionality), as those functions will load the	174	need any additional functionality), as those functions will load the
117	logging module on demand only. They are also much shorter to write.	175	logging module on demand only. They are also much shorter to write.
118		176
119	Also, if you otpionally generate a lot of debug messages (such as when	177	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	178	tracing some code), you should look into using a logger callback and a
121	boolean enabler (see C<logger>, below).	179	boolean enabler (see C<logger>, below).
122		180
123	Example: log something at error level.	181	Example: log something at error level.
124		182
…		…
134		192
135	=cut	193	=cut
136		194
137	# also allow syslog equivalent names	195	# also allow syslog equivalent names
138	our %STR2LEVEL = (	196	our %STR2LEVEL = (
139	fatal => 1, emerg => 1,	197	fatal => 1, emerg => 1, exit => 1,
140	alert => 2,	198	alert => 2,
141	critical => 3, crit => 3,	199	critical => 3, crit => 3,
142	error => 4, err => 4,	200	error => 4, err => 4, die => 4,
143	warn => 5, warning => 5,	201	warn => 5, warning => 5,
144	note => 6, notice => 6,	202	note => 6, notice => 6,
145	info => 7,	203	info => 7,
146	debug => 8,	204	debug => 8,
147	trace => 9,	205	trace => 9,
148	);	206	);
149		207
150	sub now () { time }	208	sub now () { time }
		209
151	AnyEvent::post_detect {	210	AnyEvent::post_detect {
152	*now = \&AE::now;	211	*now = \&AE::now;
153	};	212	};
154		213
155	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);	214	our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
156		215
157	# time, ctx, level, msg	216	# time, ctx, level, msg
158	sub _format($$$$) {	217	sub _format($$$$) {
159	my $pfx = ft $_[0];	218	my $ts = ft $_[0];
		219	my $ct = " ";
160		220
161	join "",	221	my @res;
162	map "$pfx $_\n",	222
163	split /\n/,
164	sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]	223	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {
		224	push @res, "$ts$ct$_\n";
		225	$ct = " + ";
		226	}
		227
		228	join "", @res
165	}	229	}
166		230
167	sub _log {	231	sub _log {
168	my ($ctx, $level, $format, @args) = @_;	232	my ($ctx, $level, $format, @args) = @_;
169		233
		234	$level = $level > 0 && $level <= 9
		235	? $level+0
170	$level = $level > 0 && $level <= 9 ? $level+0 : $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";	236	: $STR2LEVEL{$level} \|\| Carp::croak "$level: not a valid logging level, caught";
171		237
172	my $mask = 1 << $level;	238	my $mask = 1 << $level;
173	my $now = AE::now;
174		239
175	my (@ctx, $did_format, $fmt);	240	my ($success, %seen, @ctx, $now, $fmt);
176		241
177	do {	242	do
178	if ($ctx->[1] & $mask) {	243	{
		244	# skip if masked
		245	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
		246	if ($ctx->[3]) {
179	# logging target found	247	# logging target found
180		248
181	# get raw message	249	# now get raw message, unless we have it already
182	unless ($did_format) {	250	unless ($now) {
183	$format = $format->() if ref $format;	251	$format = $format->() if ref $format;
184	$format = sprintf $format, @args if @args;	252	$format = sprintf $format, @args if @args;
185	$format =~ s/\n$//;	253	$format =~ s/\n$//;
186	$did_format = 1;	254	$now = AE::now;
		255	};
		256
		257	# format msg
		258	my $str = $ctx->[4]
		259	? $ctx->[4]($now, $_[0], $level, $format)
		260	: ($fmt \|\|= _format $now, $_[0], $level, $format);
		261
		262	$success = 1;
		263
		264	$ctx->[3]($str)
		265	or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
		266	} else {
		267	push @ctx, values %{ $ctx->[2] }; # not masked - propagate
		268	}
187	};	269	}
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	}	270	}
197
198	# not consume - push parent contexts
199	push @ctx, values %{ $ctx->[2] };
200	} while $ctx = pop @ctx;	271	while $ctx = pop @ctx;
201		272
202	exit 1 if $level <= 1;	273	exit 1 if $level <= 1;
		274
		275	$success
203	}	276	}
204		277
205	sub log($$;@) {	278	sub log($$;@) {
206	_log	279	_log
207	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	280	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
211	AnyEvent::log = AE::log = \&log;	284	AnyEvent::log = AE::log = \&log;
212		285
213	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	286	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
214		287
215	Creates a code reference that, when called, acts as if the	288	Creates a code reference that, when called, acts as if the
216	C<AnyEvent::Log::log> function was called at this point with the givne	289	C<AnyEvent::Log::log> function was called at this point with the given
217	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with	290	level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
218	the C<AnyEvent::Log::log> function:	291	the C<AnyEvent::Log::log> function:
219		292
220	my $debug_log = AnyEvent::Log::logger "debug";	293	my $debug_log = AnyEvent::Log::logger "debug";
221		294
…		…
246	# and later in your program	319	# and later in your program
247	$debug_log->("yo, stuff here") if $debug;	320	$debug_log->("yo, stuff here") if $debug;
248		321
249	$debug and $debug_log->("123");	322	$debug and $debug_log->("123");
250		323
251	Note: currently the enabled var is always true - that will be fixed in a
252	future version :)
253
254	=cut	324	=cut
255		325
256	our %LOGGER;	326	our %LOGGER;
257		327
258	# re-assess logging status for all loggers	328	# re-assess logging status for all loggers
259	sub _reassess {	329	sub _reassess {
		330	local $SIG{__DIE__};
		331	my $die = sub { die };
		332
260	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	333	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
261	my ($ctx, $level, $renabled) = @$_;	334	my ($ctx, $level, $renabled) = @$_;
262		335
263	# to detetc whether a message would be logged, we # actually	336	# 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	337	# try to log one and die. this isn't fast, but we can be
265	# sure that the logging decision is correct :)	338	# sure that the logging decision is correct :)
266		339
267	$$renabled = !eval {	340	$$renabled = !eval {
268	local $SIG{__DIE__};
269
270	_log $ctx, $level, sub { die };	341	_log $ctx, $level, $die;
271		342
272	1	343	1
273	};	344	};
274
275	$$renabled = 1; # TODO
276	}	345	}
277	}	346	}
278		347
279	sub _logger($;$) {	348	sub _logger {
280	my ($ctx, $level, $renabled) = @_;	349	my ($ctx, $level, $renabled) = @_;
281
282	$renabled \|\|= \my $enabled;
283		350
284	$$renabled = 1;	351	$$renabled = 1;
285		352
286	my $logger = [$ctx, $level, $renabled];	353	my $logger = [$ctx, $level, $renabled];
287		354
…		…
306	_logger	373	_logger
307	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	374	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
308	@_	375	@_
309	}	376	}
310		377
311	#TODO
312
313	=back	378	=back
314		379
315	=head1 LOGGING CONTEXTS	380	=head1 LOGGING CONTEXTS
316		381
317	This module associates every log message with a so-called I<logging	382	This module associates every log message with a so-called I<logging
318	context>, based on the package of the caller. Every perl package has its	383	context>, based on the package of the caller. Every perl package has its
319	own logging context.	384	own logging context.
320		385
321	A logging context has two major responsibilities: logging the message and	386	A logging context has three major responsibilities: filtering, logging and
322	propagating the message to other contexts.	387	propagating the message.
323		388
324	For logging, the context stores a set of logging levels that it	389	For the first purpose, filtering, each context has a set of logging
325	potentially wishes to log, a formatting callback that takes the timestamp,	390	levels, called the log level mask. Messages not in the set will be ignored
		391	by this context (masked).
		392
		393	For logging, the context stores a formatting callback (which takes the
326	context, level and string emssage and formats it in the way it should be	394	timestamp, context, level and string message and formats it in the way
327	logged, and a logging callback, which is responsible for actually logging	395	it should be logged) and a logging callback (which is responsible for
328	the formatted message and telling C<AnyEvent::Log> whether it has consumed	396	actually logging the formatted message and telling C<AnyEvent::Log>
329	the message, or whether it should be propagated.	397	whether it has consumed the message, or whether it should be propagated).
330		398
331	For propagation, a context can have any number of attached I<parent	399	For propagation, a context can have any number of attached I<slave
332	contexts>. They will be ignored if the logging callback consumes the	400	contexts>. Any message that is neither masked by the logging mask nor
333	message, but in all other cases, the log message will be passed to all	401	masked by the logging callback returning true will be passed to all slave
334	parent contexts attached to a context.	402	contexts.
		403
		404	Each call to a logging function will log the message at most once per
		405	context, so it does not matter (much) if there are cycles or if the
		406	message can arrive at the same context via multiple paths.
335		407
336	=head2 DEFAULTS	408	=head2 DEFAULTS
337		409
338	By default, all logging contexts have an empty set of log levels, a	410	By default, all logging contexts have an full set of log levels ("all"), a
339	disabled logging callback and the default formatting callback.	411	disabled logging callback and the default formatting callback.
340		412
341	Package contexts have the package name as logging title by default.	413	Package contexts have the package name as logging title by default.
342		414
343	They have exactly one parent - the context of the "parent" package. The	415	They have exactly one slave - the context of the "parent" package. The
344	parent package is simply defined to be the package name without the last	416	parent package is simply defined to be the package name without the last
345	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	417	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
346	and C<AnyEvent> becomes the empty string.	418	and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the
		419	exception of the rule - just like the "parent" of any single-component
		420	package name in Perl is C<main>, the default slave of any top-level
		421	package context is C<$AnyEvent::Log::COLLECT>.
347		422
348	Since perl packages form only an approximate hierarchy, this parent	423	Since perl packages form only an approximate hierarchy, this slave
349	context can of course be removed.	424	context can of course be removed.
350		425
351	All other (anonymous) contexts have no parents and an empty title by	426	All other (anonymous) contexts have no slaves and an empty title by
352	default.	427	default.
353		428
354	When the module is first loaded, it configures the root context (the one	429	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
355	with the empty string) to simply dump all log messages to C<STDERR>,	430	context that simply logs everything via C<warn>, without propagating
356	and sets it's log level set to all levels up to the one specified by	431	anything anywhere by default. The purpose of this context is to provide
357	C<$ENV{PERL_ANYEVENT_VERBOSE}>.	432	a convenient place to override the global logging target or to attach
		433	additional log targets. It's not meant for filtering.
358		434
		435	It then creates the C<$AnyEvent::Log::FILTER> context whose
		436	purpose is to suppress all messages with priority higher
		437	than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the
		438	C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context
		439	is to simply provide filtering according to some global log level.
		440
		441	Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT>
		442	and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise
		443	leaves it at default config. Its purpose is simply to collect all log
		444	messages system-wide.
		445
		446	The hierarchy is then:
		447
		448	any package, eventually -> $COLLECT -> $FILTER -> $LOG
		449
359	The effetc of all this is that log messages, by default, wander up to the	450	The effect of all this is that log messages, by default, wander up to the
360	root context and will be logged to STDERR if their log level is less than	451	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
361	or equal to C<$ENV{PERL_ANYEVENT_VERBOSE}>.	452	from there to C<$AnyEvent::Log::FILTER> where log messages with lower
		453	priority then C<$ENV{PERL_ANYEVENT_VERBOSE}> will be filtered out and then
		454	to the C<$AnyEvent::Log::LOG> context to be passed to C<warn>.
362		455
		456	This makes it easy to set a global logging level (by modifying $FILTER),
		457	but still allow other contexts to send, for example, their debug and trace
		458	messages to the $LOG target despite the global logging level, or to attach
		459	additional log targets that log messages, regardless of the global logging
		460	level.
		461
		462	It also makes it easy to modify the default warn-logger ($LOG) to
		463	something that logs to a file, or to attach additional logging targets
		464	(such as loggign to a file) by attaching it to $FILTER.
		465
363	=head2 CREATING/FINDING A CONTEXT	466	=head2 CREATING/FINDING/DESTROYING CONTEXTS
364		467
365	=over 4	468	=over 4
366		469
367	=item $ctx = AnyEvent::Log::ctx [$pkg]	470	=item $ctx = AnyEvent::Log::ctx [$pkg]
368		471
…		…
383		486
384	ref $pkg	487	ref $pkg
385	? $pkg	488	? $pkg
386	: defined $pkg	489	: defined $pkg
387	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg	490	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg
388	: bless [undef, 0, undef, $default_log_cb], "AnyEvent::Log::Ctx"	491	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
389	}	492	}
390		493
391	# create default root context	494	=item AnyEvent::Log::reset
392	{	495
393	my $root = ctx undef;	496	Resets all package contexts and recreates the default hierarchy if
394	$root->[0] = "";	497	necessary, i.e. resets the logging subsystem to defaults, as much as
395	$root->title ("default");	498	possible. This process keeps references to contexts held by other parts of
396	$root->level ($AnyEvent::VERBOSE); undef $AnyEvent::VERBOSE;	499	the program intact.
		500
		501	This can be used to implement config-file (re-)loading: before loading a
		502	configuration, reset all contexts.
		503
		504	=cut
		505
		506	sub reset {
		507	# hard to kill complex data structures
		508	# we "recreate" all package loggers and reset the hierarchy
		509	while (my ($k, $v) = each %CTX) {
		510	@$v = ($k, (1 << 10) - 1 - 1, { });
		511
		512	$v->attach ($k =~ /^(.+)::/ ? $CTX{$1} : $AnyEvent::Log::COLLECT);
		513	}
		514
		515	@$_ = ($_->[0], (1 << 10) - 1 - 1)
		516	for $LOG, $FILTER, $COLLECT;
		517
		518	$LOG->slaves;
		519	$LOG->title ('$AnyEvent::Log::LOG');
397	$root->log_cb (sub {	520	$LOG->log_cb (sub {
398	print STDERR shift;	521	warn shift;
399	0	522	0
400	});	523	});
401	$CTX{""} = $root;	524
		525	$FILTER->slaves ($LOG);
		526	$FILTER->title ('$AnyEvent::Log::FILTER');
		527	$FILTER->level ($AnyEvent::VERBOSE);
		528
		529	$COLLECT->slaves ($FILTER);
		530	$COLLECT->title ('$AnyEvent::Log::COLLECT');
		531
		532	_reassess;
402	}	533	}
		534
		535	# create the default logger contexts
		536	$LOG = ctx undef;
		537	$FILTER = ctx undef;
		538	$COLLECT = ctx undef;
		539
		540	AnyEvent::Log::reset;
		541
		542	# hello, CPAN, please catch me
		543	package AnyEvent::Log::LOG;
		544	package AE::Log::LOG;
		545	package AnyEvent::Log::FILTER;
		546	package AE::Log::FILTER;
		547	package AnyEvent::Log::COLLECT;
		548	package AE::Log::COLLECT;
		549
		550	package AnyEvent::Log::Ctx;
		551
		552	# 0 1 2 3 4
		553	# [$title, $level, %$slaves, &$logcb, &$fmtcb]
		554
		555	=item $ctx = new AnyEvent::Log::Ctx methodname => param...
		556
		557	This is a convenience constructor that makes it simpler to construct
		558	anonymous logging contexts.
		559
		560	Each key-value pair results in an invocation of the method of the same
		561	name as the key with the value as parameter, unless the value is an
		562	arrayref, in which case it calls the method with the contents of the
		563	array. The methods are called in the same order as specified.
		564
		565	Example: create a new logging context and set both the default logging
		566	level, some slave contexts and a logging callback.
		567
		568	$ctx = new AnyEvent::Log::Ctx
		569	title => "dubious messages",
		570	level => "error",
		571	log_cb => sub { print STDOUT shift; 0 },
		572	slaves => [$ctx1, $ctx, $ctx2],
		573	;
403		574
404	=back	575	=back
405		576
406	=cut	577	=cut
407		578
408	package AnyEvent::Log::Ctx;	579	sub new {
		580	my $class = shift;
409		581
410	# 0 1 2 3 4	582	my $ctx = AnyEvent::Log::ctx undef;
411	# [$title, $level, %$parents, &$logcb, &$fmtcb]	583
		584	while (@_) {
		585	my ($k, $v) = splice @_, 0, 2;
		586	$ctx->$k (ref $v eq "ARRAY" ? @$v : $v);
		587	}
		588
		589	bless $ctx, $class # do we really support subclassing, hmm?
		590	}
		591
412		592
413	=head2 CONFIGURING A LOG CONTEXT	593	=head2 CONFIGURING A LOG CONTEXT
414		594
415	The following methods can be used to configure the logging context.	595	The following methods can be used to configure the logging context.
416		596
…		…
432		612
433	=back	613	=back
434		614
435	=head3 LOGGING LEVELS	615	=head3 LOGGING LEVELS
436		616
437	The following methods deal with the logging level set associated wiht the log context.	617	The following methods deal with the logging level set associated with the
		618	log context.
438		619
439	The most common method to use is probably C<< $ctx->level ($level) >>,	620	The most common method to use is probably C<< $ctx->level ($level) >>,
440	which configures the specified and any higher priority levels.	621	which configures the specified and any higher priority levels.
441		622
		623	All functions which accept a list of levels also accept the special string
		624	C<all> which expands to all logging levels.
		625
442	=over 4	626	=over 4
443		627
444	=item $ctx->levels ($level[, $level...)	628	=item $ctx->levels ($level[, $level...)
445		629
446	Enables logging fot the given levels and disables it for all others.	630	Enables logging for the given levels and disables it for all others.
447		631
448	=item $ctx->level ($level)	632	=item $ctx->level ($level)
449		633
450	Enables logging for the given level and all lower level (higher priority)	634	Enables logging for the given level and all lower level (higher priority)
451	ones. Specifying a level of C<0> or C<off> disables all logging for this	635	ones. In addition to normal logging levels, specifying a level of C<0> or
452	level.	636	C<off> disables all logging for this level.
453		637
454	Example: log warnings, errors and higher priority messages.	638	Example: log warnings, errors and higher priority messages.
455		639
456	$ctx->level ("warn");	640	$ctx->level ("warn");
457	$ctx->level (5); # same thing, just numeric	641	$ctx->level (5); # same thing, just numeric
…		…
465	Disables logging for the given levels, leaving all others unchanged.	649	Disables logging for the given levels, leaving all others unchanged.
466		650
467	=cut	651	=cut
468		652
469	sub _lvl_lst {	653	sub _lvl_lst {
		654	map {
		655	$_ > 0 && $_ <= 9 ? $_+0
		656	: $_ eq "all" ? (1 .. 9)
470	map { $_ > 0 && $_ <= 9 ? $_+0 : $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught" }	657	: $STR2LEVEL{$_} \|\| Carp::croak "$_: not a valid logging level, caught"
471	@_	658	} @_
472	}	659	}
473		660
474	our $NOP_CB = sub { 0 };	661	our $NOP_CB = sub { 0 };
475		662
476	sub levels {	663	sub levels {
…		…
481	AnyEvent::Log::_reassess;	668	AnyEvent::Log::_reassess;
482	}	669	}
483		670
484	sub level {	671	sub level {
485	my $ctx = shift;	672	my $ctx = shift;
486	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[0];	673	my $lvl = $_[0] =~ /^(?:0\|off\|none)$/ ? 0 : (_lvl_lst $_[0])[-1];
		674
487	$ctx->[1] = ((1 << $lvl) - 1) << 1;	675	$ctx->[1] = ((1 << $lvl) - 1) << 1;
488	AnyEvent::Log::_reassess;	676	AnyEvent::Log::_reassess;
489	}	677	}
490		678
491	sub enable {	679	sub enable {
…		…
502	AnyEvent::Log::_reassess;	690	AnyEvent::Log::_reassess;
503	}	691	}
504		692
505	=back	693	=back
506		694
507	=head3 PARENT CONTEXTS	695	=head3 SLAVE CONTEXTS
508		696
509	The following methods attach and detach another logging context to a	697	The following methods attach and detach another logging context to a
510	logging context.	698	logging context.
511		699
512	Log messages are propagated to all parent contexts, unless the logging	700	Log messages are propagated to all slave contexts, unless the logging
513	callback consumes the message.	701	callback consumes the message.
514		702
515	=over 4	703	=over 4
516		704
517	=item $ctx->attach ($ctx2[, $ctx3...])	705	=item $ctx->attach ($ctx2[, $ctx3...])
518		706
519	Attaches the given contexts as parents to this context. It is not an error	707	Attaches the given contexts as slaves to this context. It is not an error
520	to add a context twice (the second add will be ignored).	708	to add a context twice (the second add will be ignored).
521		709
522	A context can be specified either as package name or as a context object.	710	A context can be specified either as package name or as a context object.
523		711
524	=item $ctx->detach ($ctx2[, $ctx3...])	712	=item $ctx->detach ($ctx2[, $ctx3...])
525		713
526	Removes the given parents from this context - it's not an error to attempt	714	Removes the given slaves from this context - it's not an error to attempt
527	to remove a context that hasn't been added.	715	to remove a context that hasn't been added.
528		716
529	A context can be specified either as package name or as a context object.	717	A context can be specified either as package name or as a context object.
		718
		719	=item $ctx->slaves ($ctx2[, $ctx3...])
		720
		721	Replaces all slaves attached to this context by the ones given.
530		722
531	=cut	723	=cut
532		724
533	sub attach {	725	sub attach {
534	my $ctx = shift;	726	my $ctx = shift;
…		…
542		734
543	delete $ctx->[2]{$_+0}	735	delete $ctx->[2]{$_+0}
544	for map { AnyEvent::Log::ctx $_ } @_;	736	for map { AnyEvent::Log::ctx $_ } @_;
545	}	737	}
546		738
		739	sub slaves {
		740	undef $_[0][2];
		741	&attach;
		742	}
		743
547	=back	744	=back
548		745
549	=head3 MESSAGE LOGGING	746	=head3 LOG TARGETS
550		747
551	The following methods configure how the logging context actually does	748	The following methods configure how the logging context actually does
552	the logging (which consists of foratting the message and printing it or	749	the logging (which consists of formatting the message and printing it or
553	whatever it wants to do with it) and also allows you to log messages	750	whatever it wants to do with it).
554	directly to a context, without going via your package context.
555		751
556	=over 4	752	=over 4
557		753
558	=item $ctx->log_cb ($cb->($str))	754	=item $ctx->log_cb ($cb->($str)
559		755
560	Replaces the logging callback on the context (C<undef> disables the	756	Replaces the logging callback on the context (C<undef> disables the
561	logging callback).	757	logging callback).
562		758
563	The logging callback is responsible for handling formatted log messages	759	The logging callback is responsible for handling formatted log messages
564	(see C<fmt_cb> below) - normally simple text strings that end with a	760	(see C<fmt_cb> below) - normally simple text strings that end with a
565	newline (and are possibly multiline themselves).	761	newline (and are possibly multiline themselves).
566		762
567	It also has to return true iff it has consumed the log message, and false	763	It also has to return true iff it has consumed the log message, and false
568	if it hasn't. Consuming a message means that it will not be sent to any	764	if it hasn't. Consuming a message means that it will not be sent to any
569	parent context. When in doubt, return C<0> from your logging callback.	765	slave context. When in doubt, return C<0> from your logging callback.
570		766
571	Example: a very simple logging callback, simply dump the message to STDOUT	767	Example: a very simple logging callback, simply dump the message to STDOUT
572	and do not consume it.	768	and do not consume it.
573		769
574	$ctx->log_cb (sub { print STDERR shift; 0 });	770	$ctx->log_cb (sub { print STDERR shift; 0 });
575		771
		772	You can filter messages by having a log callback that simply returns C<1>
		773	and does not do anything with the message, but this counts as "message
		774	being logged" and might not be very efficient.
		775
		776	Example: propagate all messages except for log levels "debug" and
		777	"trace". The messages will still be generated, though, which can slow down
		778	your program.
		779
		780	$ctx->levels ("debug", "trace");
		781	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
		782
576	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	783	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
577		784
578	Replaces the fornatting callback on the cobntext (C<undef> restores the	785	Replaces the formatting callback on the context (C<undef> restores the
579	default formatter).	786	default formatter).
580		787
581	The callback is passed the (possibly fractional) timestamp, the original	788	The callback is passed the (possibly fractional) timestamp, the original
582	logging context, the (numeric) logging level and the raw message string and needs to	789	logging context, the (numeric) logging level and the raw message string
583	return a formatted log message. In most cases this will be a string, but	790	and needs to return a formatted log message. In most cases this will be a
584	it could just as well be an array reference that just stores the values.	791	string, but it could just as well be an array reference that just stores
		792	the values.
		793
		794	If, for some reason, you want to use C<caller> to find out more baout the
		795	logger then you should walk up the call stack until you are no longer
		796	inside the C<AnyEvent::Log> package.
585		797
586	Example: format just the raw message, with numeric log level in angle	798	Example: format just the raw message, with numeric log level in angle
587	brackets.	799	brackets.
588		800
589	$ctx->fmt_cb (sub {	801	$ctx->fmt_cb (sub {
…		…
606	"$msg->[3]";	818	"$msg->[3]";
607		819
608	0	820	0
609	});	821	});
610		822
		823	=item $ctx->log_to_file ($path)
		824
		825	Sets the C<log_cb> to log to a file (by appending), unbuffered.
		826
		827	=item $ctx->log_to_path ($path)
		828
		829	Same as C<< ->log_to_file >>, but opens the file for each message. This
		830	is much slower, but allows you to change/move/rename/delete the file at
		831	basically any time.
		832
		833	=item $ctx->log_to_syslog ([$log_flags])
		834
		835	Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
		836	the others in the obvious way. If specified, then the C<$log_flags> are
		837	simply or'ed onto the priority argument and can contain any C<LOG_xxx>
		838	flags valid for Sys::Syslog::syslog, except for the priority levels.
		839
		840	Note that this function also sets a C<fmt_cb> - the logging part requires
		841	an array reference with [$level, $str] as input.
		842
611	=cut	843	=cut
612		844
613	sub log_cb {	845	sub log_cb {
614	my ($ctx, $cb) = @_;	846	my ($ctx, $cb) = @_;
615		847
616	$ctx->[3] = $cb \|\| $default_log_cb;	848	$ctx->[3] = $cb;
617	}	849	}
618		850
619	sub fmt_cb {	851	sub fmt_cb {
620	my ($ctx, $cb) = @_;	852	my ($ctx, $cb) = @_;
621		853
622	$ctx->[4] = $cb;	854	$ctx->[4] = $cb;
623	}	855	}
624		856
		857	sub log_to_file {
		858	my ($ctx, $path) = @_;
		859
		860	open my $fh, ">>", $path
		861	or die "$path: $!";
		862
		863	$ctx->log_cb (sub {
		864	syswrite $fh, shift;
		865	0
		866	});
		867	}
		868
		869	sub log_to_file {
		870	my ($ctx, $path) = @_;
		871
		872	$ctx->log_cb (sub {
		873	open my $fh, ">>", $path
		874	or die "$path: $!";
		875
		876	syswrite $fh, shift;
		877	0
		878	});
		879	}
		880
		881	sub log_to_syslog {
		882	my ($ctx, $flags) = @_;
		883
		884	require Sys::Syslog;
		885
		886	$ctx->fmt_cb (sub {
		887	my $str = $_[3];
		888	$str =~ s/\n(?=.)/\n+ /g;
		889
		890	[$_[2], "($_[1][0]) $str"]
		891	});
		892
		893	$ctx->log_cb (sub {
		894	my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
		895
		896	Sys::Syslog::syslog ($flags \| ($lvl - 1), $_)
		897	for split /\n/, $_[0][1];
		898
		899	0
		900	});
		901	}
		902
		903	=back
		904
		905	=head3 MESSAGE LOGGING
		906
		907	These methods allow you to log messages directly to a context, without
		908	going via your package context.
		909
		910	=over 4
		911
625	=item $ctx->log ($level, $msg[, @params])	912	=item $ctx->log ($level, $msg[, @params])
626		913
627	Same as C<AnyEvent::Log::log>, but uses the given context as log context.	914	Same as C<AnyEvent::Log::log>, but uses the given context as log context.
628		915
629	=item $logger = $ctx->logger ($level[, \$enabled])	916	=item $logger = $ctx->logger ($level[, \$enabled])
…		…
638		925
639	1;	926	1;
640		927
641	=back	928	=back
642		929
		930	=head1 EXAMPLES
		931
		932	This section shows some common configurations.
		933
		934	=over 4
		935
		936	=item Setting the global logging level.
		937
		938	Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
		939	running your program, or modify the log level of the root context:
		940
		941	PERL_ANYEVENT_VERBOSE=5 ./myprog
		942
		943	$AnyEvent::Log::FILTER->level ("warn");
		944
		945	=item Append all messages to a file instead of sending them to STDERR.
		946
		947	This is affected by the global logging level.
		948
		949	$AnyEvent::Log::LOG->log_to_file ($path); (sub {
		950
		951	=item Write all messages with priority C<error> and higher to a file.
		952
		953	This writes them only when the global logging level allows it, because
		954	it is attached to the default context which is invoked I<after> global
		955	filtering.
		956
		957	$AnyEvent::Log::FILTER->attach
		958	new AnyEvent::Log::Ctx log_to_file => $path);
		959
		960	This writes them regardless of the global logging level, because it is
		961	attached to the toplevel context, which receives all messages I<before>
		962	the global filtering.
		963
		964	$AnyEvent::Log::COLLECT->attach (
		965	new AnyEvent::Log::Ctx log_to_file => $path);
		966
		967	In both cases, messages are still written to STDERR.
		968
		969	=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
		970
		971	Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
		972	context - this simply circumvents the global filtering for trace messages.
		973
		974	my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
		975	$debug->attach ($AnyEvent::Log::LOG);
		976
		977	This of course works for any package, not just L<AnyEvent::Debug>, but
		978	assumes the log level for AnyEvent::Debug hasn't been changed from the
		979	default.
		980
		981	=back
		982
643	=head1 AUTHOR	983	=head1 AUTHOR
644		984
645	Marc Lehmann <schmorp@schmorp.de>	985	Marc Lehmann <schmorp@schmorp.de>
646	http://home.schmorp.de/	986	http://home.schmorp.de/
647		987

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.9 by root, Fri Aug 19 19:59:53 2011 UTC vs. Revision 1.26 by root, Sun Aug 21 03:29:19 2011 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.9 by root, Fri Aug 19 19:59:53 2011 UTC vs.
Revision 1.26 by root, Sun Aug 21 03:29:19 2011 UTC