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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.10 by root, Fri Aug 19 21:17:08 2011 UTC vs.
Revision 1.25 by root, Sun Aug 21 03:25:47 2011 UTC

…		…
2		2
3	AnyEvent::Log - simple logging "framework"	3	AnyEvent::Log - simple logging "framework"
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	# simple use	7	Simple uses:
		8
8	use AnyEvent;	9	use AnyEvent;
9		10
10	AE::log debug => "hit my knee";	11	AE::log debug => "hit my knee";
11	AE::log warn => "it's a bit too hot";	12	AE::log warn => "it's a bit too hot";
12	AE::log error => "the flag was false!";	13	AE::log error => "the flag was false!";
13	AE::log fatal => "the bit toggled! run!";	14	AE::log fatal => "the bit toggled! run!"; # never returns
14		15
15	# "complex" use	16	"Complex" uses (for speed sensitive code):
		17
16	use AnyEvent::Log;	18	use AnyEvent::Log;
17		19
18	my $tracer = AnyEvent::Log::logger trace => \$my $trace;	20	my $tracer = AnyEvent::Log::logger trace => \$my $trace;
19		21
20	$tracer->("i am here") if $trace;	22	$tracer->("i am here") if $trace;
21	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;	23	$tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
22		24
23	# configuration	25	Configuration (also look at the EXAMPLES section):
24		26
25	# set logging for this package to maximum	27	# set logging for the current package to errors and higher only
26	AnyEvent::Log::ctx->level ("all");	28	AnyEvent::Log::ctx->level ("error");
27		29
28	# set logging globally to anything below debug	30	# set logging level to suppress anything below "notice"
29	(AnyEvent::Log::ctx "")->level ("notice");	31	$AnyEvent::Log::FILTER->level ("notice");
30		32
31	# see also EXAMPLES, below	33	# send all critical and higher priority messages to syslog,
32		34	# regardless of (most) other settings
33	# disable logging for package "AnyEvent" and all packages below it	35	$AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
34	AnyEvent->AnyEvent::Log::ctx->level (0);	36	level => "critical",
35		37	log_to_syslog => 0,
36	# log everything below debug to a file, for the whole program	38	);
37	my $ctx = AnyEvent::Log::ctx;
38	$ctx->log_cb (sub { print FILE shift; 0 });
39	(AnyEvent::Log::ctx "")->add ($ctx);
40		39
41	=head1 DESCRIPTION	40	=head1 DESCRIPTION
42		41
43	This module implements a relatively simple "logging framework". It doesn't	42	This module implements a relatively simple "logging framework". It doesn't
44	attempt to be "the" logging solution or even "a" logging solution for	43	attempt to be "the" logging solution or even "a" logging solution for
45	AnyEvent - AnyEvent simply creates logging messages internally, and this	44	AnyEvent - AnyEvent simply creates logging messages internally, and this
46	module more or less exposes the mechanism, with some extra spiff to allow	45	module more or less exposes the mechanism, with some extra spiff to allow
47	using it from other modules as well.	46	using it from other modules as well.
48		47
49	Remember that the default verbosity level is C<0>, so nothing will be	48	Remember that the default verbosity level is C<0> (C<off>), so nothing
50	logged, 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
51	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
52	something like:	51	something like:
53		52
54	use AnyEvent;	53	use AnyEvent::Log;
55	(AnyEvent::Log::ctx "")->level ("info");	54	AnyEvent::Log::FILTER->level ("info");
56		55
57	The design goal behind this module was to keep it simple (and small),	56	The design goal behind this module was to keep it simple (and small),
58	but make it powerful enough to be potentially useful for any module, and	57	but make it powerful enough to be potentially useful for any module, and
59	extensive enough for the most common tasks, such as logging to multiple	58	extensive enough for the most common tasks, such as logging to multiple
60	targets, or being able to log into a database.	59	targets, or being able to log into a database.
61		60
		61	The amount of documentation might indicate otherwise, but the module is
		62	still just below 300 lines of code.
		63
		64	=head1 LOGGING LEVELS
		65
		66	Logging levels in this module range from C<1> (highest priority) to C<9>
		67	(lowest priority). Note that the lowest numerical value is the highest
		68	priority, so when this document says "higher priority" it means "lower
		69	numerical value".
		70
		71	Instead of specifying levels by name you can also specify them by aliases:
		72
		73	LVL NAME SYSLOG PERL NOTE
		74	1 fatal emerg exit aborts program!
		75	2 alert
		76	3 critical crit
		77	4 error err die
		78	5 warn warning
		79	6 note notice
		80	7 info
		81	8 debug
		82	9 trace
		83
		84	As you can see, some logging levels have multiple aliases - the first one
		85	is the "official" name, the second one the "syslog" name (if it differs)
		86	and the third one the "perl" name, suggesting that you log C<die> messages
		87	at C<error> priority.
		88
		89	You can normally only log a single message at highest priority level
		90	(C<1>, C<fatal>), because logging a fatal message will also quit the
		91	program - so use it sparingly :)
		92
		93	Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
		94	or C<all> - these are only valid in the methods they are documented for.
		95
62	=head1 LOGGING FUNCTIONS	96	=head1 LOGGING FUNCTIONS
63		97
64	These functions allow you to log messages. They always use the caller's	98	These functions allow you to log messages. They always use the caller's
65	package as a "logging module/source". Also, the main logging function is	99	package as a "logging context". Also, the main logging function C<log> is
66	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is	100	callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is
67	loaded.	101	loaded.
68		102
69	=over 4	103	=over 4
70		104
…		…
75	use Carp ();	109	use Carp ();
76	use POSIX ();	110	use POSIX ();
77		111
78	use AnyEvent (); BEGIN { AnyEvent::common_sense }	112	use AnyEvent (); BEGIN { AnyEvent::common_sense }
79	use AnyEvent::Util ();	113	use AnyEvent::Util ();
		114
		115	our $VERSION = $AnyEvent::VERSION;
		116
		117	our ($COLLECT, $FILTER, $LOG);
80		118
81	our ($now_int, $now_str1, $now_str2);	119	our ($now_int, $now_str1, $now_str2);
82		120
83	# Format Time, not public - yet?	121	# Format Time, not public - yet?
84	sub ft($) {	122	sub ft($) {
…		…
89	if $now_int != $i;	127	if $now_int != $i;
90		128
91	"$now_str1$f$now_str2"	129	"$now_str1$f$now_str2"
92	}	130	}
93		131
94	our %CTX; # all logging contexts	132	our %CTX; # all package contexts
95		133
96	# creates a default package context object for the given package	134	# creates a default package context object for the given package
97	sub _pkg_ctx($) {	135	sub _pkg_ctx($) {
98	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";	136	my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx";
99		137
100	# link "parent" package	138	# link "parent" package
101	my $pkg = $_[0] =~ /^(.+)::/ ? $1 : "";	139	my $parent = $_[0] =~ /^(.+)::/
		140	? $CTX{$1} \|\|= &_pkg_ctx ("$1")
		141	: $COLLECT;
102		142
103	$pkg = $CTX{$pkg} \|\|= &_pkg_ctx ($pkg);
104	$ctx->[2]{$pkg+0} = $pkg;	143	$ctx->[2]{$parent+0} = $parent;
105		144
106	$ctx	145	$ctx
107	}	146	}
108		147
109	=item AnyEvent::Log::log $level, $msg[, @args]	148	=item AnyEvent::Log::log $level, $msg[, @args]
110		149
111	Requests logging of the given C<$msg> with the given log level (1..9).	150	Requests logging of the given C<$msg> with the given log level, and
112	You can also use the following strings as log level: C<fatal> (1),	151	returns true if the message was logged I<somewhere>.
113	C<alert> (2), C<critical> (3), C<error> (4), C<warn> (5), C<note> (6),
114	C<info> (7), C<debug> (8), C<trace> (9).
115		152
116	For C<fatal> log levels, the program will abort.	153	For C<fatal> log levels, the program will abort.
117		154
118	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the	155	If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
119	C<$msg> is interpreted as an sprintf format string.	156	C<$msg> is interpreted as an sprintf format string.
…		…
125	supposed to return the message. It will be called only then the message	162	supposed to return the message. It will be called only then the message
126	actually gets logged, which is useful if it is costly to create the	163	actually gets logged, which is useful if it is costly to create the
127	message in the first place.	164	message in the first place.
128		165
129	Whether the given message will be logged depends on the maximum log level	166	Whether the given message will be logged depends on the maximum log level
130	and the caller's package.	167	and the caller's package. The return value can be used to ensure that
		168	messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
		169	runtime error it tries to log it at C<die> level, but if that message is
		170	lost it simply uses warn.
131		171
132	Note that you can (and should) call this function as C<AnyEvent::log> or	172	Note that you can (and should) call this function as C<AnyEvent::log> or
133	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't	173	C<AE::log>, without C<use>-ing this module if possible (i.e. you don't
134	need any additional functionality), as those functions will load the	174	need any additional functionality), as those functions will load the
135	logging module on demand only. They are also much shorter to write.	175	logging module on demand only. They are also much shorter to write.
136		176
137	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
138	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
139	boolean enabler (see C<logger>, below).	179	boolean enabler (see C<logger>, below).
140		180
141	Example: log something at error level.	181	Example: log something at error level.
142		182
…		…
152		192
153	=cut	193	=cut
154		194
155	# also allow syslog equivalent names	195	# also allow syslog equivalent names
156	our %STR2LEVEL = (	196	our %STR2LEVEL = (
157	fatal => 1, emerg => 1,	197	fatal => 1, emerg => 1, exit => 1,
158	alert => 2,	198	alert => 2,
159	critical => 3, crit => 3,	199	critical => 3, crit => 3,
160	error => 4, err => 4,	200	error => 4, err => 4, die => 4,
161	warn => 5, warning => 5,	201	warn => 5, warning => 5,
162	note => 6, notice => 6,	202	note => 6, notice => 6,
163	info => 7,	203	info => 7,
164	debug => 8,	204	debug => 8,
165	trace => 9,	205	trace => 9,
…		…
173		213
174	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);
175		215
176	# time, ctx, level, msg	216	# time, ctx, level, msg
177	sub _format($$$$) {	217	sub _format($$$$) {
178	my $pfx = ft $_[0];	218	my $ts = ft $_[0];
		219	my $ct = " ";
		220
179	my @res;	221	my @res;
180		222
181	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {	223	for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {
182	push @res, "$pfx $_\n";	224	push @res, "$ts$ct$_\n";
183	$pfx = "\t";	225	$ct = " + ";
184	}	226	}
185		227
186	join "", @res	228	join "", @res
187	}	229	}
188		230
189	sub _log {	231	sub _log {
190	my ($ctx, $level, $format, @args) = @_;	232	my ($ctx, $level, $format, @args) = @_;
191		233
		234	$level = $level > 0 && $level <= 9
		235	? $level+0
192	$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";
193		237
194	my $mask = 1 << $level;	238	my $mask = 1 << $level;
195		239
196	my (@ctx, $now, $fmt);	240	my ($success, %seen, @ctx, $now, $fmt);
197		241
198	do {	242	do
		243	{
199	# skip if masked	244	# skip if masked
200	next unless $ctx->[1] & $mask;	245	if ($ctx->[1] & $mask && !$seen{$ctx+0}++) {
201
202	if ($ctx->[3]) {	246	if ($ctx->[3]) {
203	# logging target found	247	# logging target found
204		248
205	# now get raw message, unless we have it already	249	# now get raw message, unless we have it already
206	unless ($now) {	250	unless ($now) {
207	$format = $format->() if ref $format;	251	$format = $format->() if ref $format;
208	$format = sprintf $format, @args if @args;	252	$format = sprintf $format, @args if @args;
209	$format =~ s/\n$//;	253	$format =~ s/\n$//;
210	$now = AE::now;	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	}
211	};	269	}
212
213	# format msg
214	my $str = $ctx->[4]
215	? $ctx->[4]($now, $_[0], $level, $format)
216	: $fmt \|\|= _format $now, $_[0], $level, $format;
217
218	$ctx->[3]($str)
219	and next;
220	}	270	}
221
222	# not masked, not consume - propagate to parent contexts
223	push @ctx, values %{ $ctx->[2] };
224	} while $ctx = pop @ctx;	271	while $ctx = pop @ctx;
225		272
226	exit 1 if $level <= 1;	273	exit 1 if $level <= 1;
		274
		275	$success
227	}	276	}
228		277
229	sub log($$;@) {	278	sub log($$;@) {
230	_log	279	_log
231	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],	280	$CTX{ (caller)[0] } \|\|= _pkg_ctx +(caller)[0],
…		…
235	AnyEvent::log = AE::log = \&log;	284	AnyEvent::log = AE::log = \&log;
236		285
237	=item $logger = AnyEvent::Log::logger $level[, \$enabled]	286	=item $logger = AnyEvent::Log::logger $level[, \$enabled]
238		287
239	Creates a code reference that, when called, acts as if the	288	Creates a code reference that, when called, acts as if the
240	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
241	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
242	the C<AnyEvent::Log::log> function:	291	the C<AnyEvent::Log::log> function:
243		292
244	my $debug_log = AnyEvent::Log::logger "debug";	293	my $debug_log = AnyEvent::Log::logger "debug";
245		294
…		…
270	# and later in your program	319	# and later in your program
271	$debug_log->("yo, stuff here") if $debug;	320	$debug_log->("yo, stuff here") if $debug;
272		321
273	$debug and $debug_log->("123");	322	$debug and $debug_log->("123");
274		323
275	Note: currently the enabled var is always true - that will be fixed in a
276	future version :)
277
278	=cut	324	=cut
279		325
280	our %LOGGER;	326	our %LOGGER;
281		327
282	# re-assess logging status for all loggers	328	# re-assess logging status for all loggers
283	sub _reassess {	329	sub _reassess {
		330	local $SIG{__DIE__};
		331	my $die = sub { die };
		332
284	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {	333	for (@_ ? $LOGGER{$_[0]} : values %LOGGER) {
285	my ($ctx, $level, $renabled) = @$_;	334	my ($ctx, $level, $renabled) = @$_;
286		335
287	# to detetc whether a message would be logged, we # actually	336	# to detect whether a message would be logged, we actually
288	# 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
289	# sure that the logging decision is correct :)	338	# sure that the logging decision is correct :)
290		339
291	$$renabled = !eval {	340	$$renabled = !eval {
292	local $SIG{__DIE__};
293
294	_log $ctx, $level, sub { die };	341	_log $ctx, $level, $die;
295		342
296	1	343	1
297	};	344	};
298
299	$$renabled = 1; # TODO
300	}	345	}
301	}	346	}
302		347
303	sub _logger($;$) {	348	sub _logger {
304	my ($ctx, $level, $renabled) = @_;	349	my ($ctx, $level, $renabled) = @_;
305
306	$renabled \|\|= \my $enabled;
307		350
308	$$renabled = 1;	351	$$renabled = 1;
309		352
310	my $logger = [$ctx, $level, $renabled];	353	my $logger = [$ctx, $level, $renabled];
311		354
…		…
351	timestamp, context, level and string message and formats it in the way	394	timestamp, context, level and string message and formats it in the way
352	it should be logged) and a logging callback (which is responsible for	395	it should be logged) and a logging callback (which is responsible for
353	actually logging the formatted message and telling C<AnyEvent::Log>	396	actually logging the formatted message and telling C<AnyEvent::Log>
354	whether it has consumed the message, or whether it should be propagated).	397	whether it has consumed the message, or whether it should be propagated).
355		398
356	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
357	contexts>. Any message that is neither masked by the logging mask nor	400	contexts>. Any message that is neither masked by the logging mask nor
358	masked by the logging callback returning true will be passed to all parent	401	masked by the logging callback returning true will be passed to all slave
359	contexts.	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.
360		407
361	=head2 DEFAULTS	408	=head2 DEFAULTS
362		409
363	By default, all logging contexts have an full set of log levels ("all"), a	410	By default, all logging contexts have an full set of log levels ("all"), a
364	disabled logging callback and the default formatting callback.	411	disabled logging callback and the default formatting callback.
365		412
366	Package contexts have the package name as logging title by default.	413	Package contexts have the package name as logging title by default.
367		414
368	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
369	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
370	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,	417	component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>,
371	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<$AnyEvent::Log::COLLECT>.
372		422
373	Since perl packages form only an approximate hierarchy, this parent	423	Since perl packages form only an approximate hierarchy, this slave
374	context can of course be removed.	424	context can of course be removed.
375		425
376	All other (anonymous) contexts have no parents and an empty title by	426	All other (anonymous) contexts have no slaves and an empty title by
377	default.	427	default.
378		428
379	When the module is first loaded, it configures the root context (the one	429	When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging
380	with the empty string) to simply dump all log messages to C<STDERR>,	430	context that simply logs everything via C<warn>, without propagating
381	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
382	C<$ENV{PERL_ANYEVENT_VERBOSE}>.	432	a convenient place to override the global logging target or to attach
		433	additional log targets. It's not meant for filtering.
		434
		435	It then creates the C<$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 -> $LOG
383		449
384	The effect of all this is that log messages, by default, wander up to the	450	The effect of all this is that log messages, by default, wander up to the
385	root context and will be logged to STDERR if their log level is less than	451	C<$AnyEvent::Log::COLLECT> context where all messages normally end up,
386	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>.
387		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
388	=head2 CREATING/FINDING A CONTEXT	466	=head2 CREATING/FINDING/DESTROYING CONTEXTS
389		467
390	=over 4	468	=over 4
391		469
392	=item $ctx = AnyEvent::Log::ctx [$pkg]	470	=item $ctx = AnyEvent::Log::ctx [$pkg]
393		471
…		…
411	: defined $pkg	489	: defined $pkg
412	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg	490	? $CTX{$pkg} \|\|= AnyEvent::Log::_pkg_ctx $pkg
413	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"	491	: bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx"
414	}	492	}
415		493
416	# create default root context	494	=item AnyEvent::Log::reset
417	{	495
418	my $root = ctx undef;	496	Resets all package contexts and recreates the default hierarchy if
419	$root->[0] = "";	497	necessary, i.e. resets the logging subsystem to defaults, as much as
420	$root->title ("default");	498	possible. This process keeps references to contexts held by other parts of
421	$root->level ($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');
422	$root->log_cb (sub {	520	$LOG->log_cb (sub {
423	print STDERR shift;	521	warn shift;
424	0	522	0
425	});	523	});
426	$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;
427	}	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	;
428		574
429	=back	575	=back
430		576
431	=cut	577	=cut
432		578
433	package AnyEvent::Log::Ctx;	579	sub new {
		580	my $class = shift;
434		581
435	# 0 1 2 3 4	582	my $ctx = AnyEvent::Log::ctx undef;
436	# [$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
437		592
438	=head2 CONFIGURING A LOG CONTEXT	593	=head2 CONFIGURING A LOG CONTEXT
439		594
440	The following methods can be used to configure the logging context.	595	The following methods can be used to configure the logging context.
441		596
…		…
535	AnyEvent::Log::_reassess;	690	AnyEvent::Log::_reassess;
536	}	691	}
537		692
538	=back	693	=back
539		694
540	=head3 PARENT CONTEXTS	695	=head3 SLAVE CONTEXTS
541		696
542	The following methods attach and detach another logging context to a	697	The following methods attach and detach another logging context to a
543	logging context.	698	logging context.
544		699
545	Log messages are propagated to all parent contexts, unless the logging	700	Log messages are propagated to all slave contexts, unless the logging
546	callback consumes the message.	701	callback consumes the message.
547		702
548	=over 4	703	=over 4
549		704
550	=item $ctx->attach ($ctx2[, $ctx3...])	705	=item $ctx->attach ($ctx2[, $ctx3...])
551		706
552	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
553	to add a context twice (the second add will be ignored).	708	to add a context twice (the second add will be ignored).
554		709
555	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.
556		711
557	=item $ctx->detach ($ctx2[, $ctx3...])	712	=item $ctx->detach ($ctx2[, $ctx3...])
558		713
559	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
560	to remove a context that hasn't been added.	715	to remove a context that hasn't been added.
561		716
562	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.
563		722
564	=cut	723	=cut
565		724
566	sub attach {	725	sub attach {
567	my $ctx = shift;	726	my $ctx = shift;
…		…
575		734
576	delete $ctx->[2]{$_+0}	735	delete $ctx->[2]{$_+0}
577	for map { AnyEvent::Log::ctx $_ } @_;	736	for map { AnyEvent::Log::ctx $_ } @_;
578	}	737	}
579		738
		739	sub slaves {
		740	undef $_[0][2];
		741	&attach;
		742	}
		743
580	=back	744	=back
581		745
582	=head3 MESSAGE LOGGING	746	=head3 LOG TARGETS
583		747
584	The following methods configure how the logging context actually does	748	The following methods configure how the logging context actually does
585	the logging (which consists of formatting the message and printing it or	749	the logging (which consists of formatting the message and printing it or
586	whatever it wants to do with it) and also allows you to log messages	750	whatever it wants to do with it).
587	directly to a context, without going via your package context.
588		751
589	=over 4	752	=over 4
590		753
591	=item $ctx->log_cb ($cb->($str))	754	=item $ctx->log_cb ($cb->($str)
592		755
593	Replaces the logging callback on the context (C<undef> disables the	756	Replaces the logging callback on the context (C<undef> disables the
594	logging callback).	757	logging callback).
595		758
596	The logging callback is responsible for handling formatted log messages	759	The logging callback is responsible for handling formatted log messages
597	(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
598	newline (and are possibly multiline themselves).	761	newline (and are possibly multiline themselves).
599		762
600	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
601	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
602	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.
603		766
604	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
605	and do not consume it.	768	and do not consume it.
606		769
607	$ctx->log_cb (sub { print STDERR shift; 0 });	770	$ctx->log_cb (sub { print STDERR shift; 0 });
…		…
615	your program.	778	your program.
616		779
617	$ctx->levels ("debug", "trace");	780	$ctx->levels ("debug", "trace");
618	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages	781	$ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages
619		782
620	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $ctx, $level, $message))	783	=item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message))
621		784
622	Replaces the formatting callback on the context (C<undef> restores the	785	Replaces the formatting callback on the context (C<undef> restores the
623	default formatter).	786	default formatter).
624		787
625	The callback is passed the (possibly fractional) timestamp, the original	788	The callback is passed the (possibly fractional) timestamp, the original
626	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
627	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
628	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 reaosn, 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.
629		797
630	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
631	brackets.	799	brackets.
632		800
633	$ctx->fmt_cb (sub {	801	$ctx->fmt_cb (sub {
…		…
650	"$msg->[3]";	818	"$msg->[3]";
651		819
652	0	820	0
653	});	821	});
654		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, $str] as input.
		842
655	=cut	843	=cut
656		844
657	sub log_cb {	845	sub log_cb {
658	my ($ctx, $cb) = @_;	846	my ($ctx, $cb) = @_;
659		847
…		…
664	my ($ctx, $cb) = @_;	852	my ($ctx, $cb) = @_;
665		853
666	$ctx->[4] = $cb;	854	$ctx->[4] = $cb;
667	}	855	}
668		856
		857	sub log_to_file {
		858	my ($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
669	=item $ctx->log ($level, $msg[, @params])	912	=item $ctx->log ($level, $msg[, @params])
670		913
671	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.
672		915
673	=item $logger = $ctx->logger ($level[, \$enabled])	916	=item $logger = $ctx->logger ($level[, \$enabled])
…		…
682		925
683	1;	926	1;
684		927
685	=back	928	=back
686		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
687	=head1 AUTHOR	983	=head1 AUTHOR
688		984
689	Marc Lehmann <schmorp@schmorp.de>	985	Marc Lehmann <schmorp@schmorp.de>
690	http://home.schmorp.de/	986	http://home.schmorp.de/
691		987

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.10 by root, Fri Aug 19 21:17:08 2011 UTC vs. Revision 1.25 by root, Sun Aug 21 03:25:47 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
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Revision 1.25 by root, Sun Aug 21 03:25:47 2011 UTC