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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.36 by root, Thu Aug 25 05:39:47 2011 UTC vs.
Revision 1.66 by root, Mon Mar 11 20:48:19 2019 UTC

… …
6 6
7Simple uses: 7Simple uses:
8 8
9 use AnyEvent; 9 use AnyEvent;
10 10
11 AE::log debug => "hit my knee"; 11 AE::log fatal => "No config found, cannot continue!"; # never returns
12 AE::log warn => "it's a bit too hot"; 12 AE::log alert => "The battery died!";
13 AE::log error => "the flag was false!"; 13 AE::log crit => "The battery temperature is too hot!";
14 AE::log fatal => "the bit toggled! run!"; # never returns 14 AE::log error => "Division by zero attempted.";
15 AE::log warn => "Couldn't delete the file.";
16 AE::log note => "Wanted to create config, but config already exists.";
17 AE::log info => "File soandso successfully deleted.";
18 AE::log debug => "the function returned 3";
19 AE::log trace => "going to call function abc";
15 20
21Log level overview:
22
23 LVL NAME SYSLOG PERL NOTE
24 1 fatal emerg exit system unusable, aborts program!
25 2 alert failure in primary system
26 3 critical crit failure in backup system
27 4 error err die non-urgent program errors, a bug
28 5 warn warning possible problem, not necessarily error
29 6 note notice unusual conditions
30 7 info normal messages, no action required
31 8 debug debugging messages for development
32 9 trace copious tracing output
33
16"Complex" uses (for speed sensitive code): 34"Complex" uses (for speed sensitive code, e.g. trace/debug messages):
17 35
18 use AnyEvent::Log; 36 use AnyEvent::Log;
19 37
20 my $tracer = AnyEvent::Log::logger trace => \$my $trace; 38 my $tracer = AnyEvent::Log::logger trace => \my $trace;
21 39
22 $tracer->("i am here") if $trace; 40 $tracer->("i am here") if $trace;
23 $tracer->(sub { "lots of data: " . Dumper $self }) if $trace; 41 $tracer->(sub { "lots of data: " . Dumper $self }) if $trace;
24 42
25Configuration (also look at the EXAMPLES section): 43Configuration (also look at the EXAMPLES section):
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32 50
33 # send all critical and higher priority messages to syslog, 51 # send all critical and higher priority messages to syslog,
34 # regardless of (most) other settings 52 # regardless of (most) other settings
35 $AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx 53 $AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
36 level => "critical", 54 level => "critical",
37 log_to_syslog => 0, 55 log_to_syslog => "user",
38 ); 56 );
39 57
40=head1 DESCRIPTION 58=head1 DESCRIPTION
41 59
42This module implements a relatively simple "logging framework". It doesn't 60This module implements a relatively simple "logging framework". It doesn't
43attempt to be "the" logging solution or even "a" logging solution for 61attempt to be "the" logging solution or even "a" logging solution for
44AnyEvent - AnyEvent simply creates logging messages internally, and this 62AnyEvent - AnyEvent simply creates logging messages internally, and this
45module more or less exposes the mechanism, with some extra spiff to allow 63module more or less exposes the mechanism, with some extra spiff to allow
46using it from other modules as well. 64using it from other modules as well.
47 65
48Remember that the default verbosity level is C<0> (C<off>), so nothing 66Remember that the default verbosity level is C<4> (C<error>), so only
49will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number 67errors and more important messages will be logged, unless you set
50before starting your program, or change the logging level at runtime with 68C<PERL_ANYEVENT_VERBOSE> to a higher number before starting your program
51something like: 69(C<AE_VERBOSE=5> is recommended during development), or change the logging
70level at runtime with something like:
52 71
53 use AnyEvent::Log; 72 use AnyEvent::Log;
54 $AnyEvent::Log::FILTER->level ("info"); 73 $AnyEvent::Log::FILTER->level ("info");
55 74
56The design goal behind this module was to keep it simple (and small), 75The design goal behind this module was to keep it simple (and small),
57but make it powerful enough to be potentially useful for any module, and 76but make it powerful enough to be potentially useful for any module,
58extensive enough for the most common tasks, such as logging to multiple 77and extensive enough for the most common tasks, such as logging to
59targets, or being able to log into a database. 78multiple targets, or being able to log into a database.
60 79
61The module is also usable before AnyEvent itself is initialised, in which 80The module is also usable before AnyEvent itself is initialised, in which
62case some of the functionality might be reduced. 81case some of the functionality might be reduced.
63 82
64The amount of documentation might indicate otherwise, but the runtime part 83The amount of documentation might indicate otherwise, but the runtime part
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72numerical value". 91numerical value".
73 92
74Instead of specifying levels by name you can also specify them by aliases: 93Instead of specifying levels by name you can also specify them by aliases:
75 94
76 LVL NAME SYSLOG PERL NOTE 95 LVL NAME SYSLOG PERL NOTE
77 1 fatal emerg exit aborts program! 96 1 fatal emerg exit system unusable, aborts program!
78 2 alert 97 2 alert failure in primary system
79 3 critical crit 98 3 critical crit failure in backup system
80 4 error err die 99 4 error err die non-urgent program errors, a bug
81 5 warn warning 100 5 warn warning possible problem, not necessarily error
82 6 note notice 101 6 note notice unusual conditions
83 7 info 102 7 info normal messages, no action required
84 8 debug 103 8 debug debugging messages for development
85 9 trace 104 9 trace copious tracing output
86 105
87As you can see, some logging levels have multiple aliases - the first one 106As you can see, some logging levels have multiple aliases - the first one
88is the "official" name, the second one the "syslog" name (if it differs) 107is the "official" name, the second one the "syslog" name (if it differs)
89and the third one the "perl" name, suggesting that you log C<die> messages 108and the third one the "perl" name, suggesting (only!) that you log C<die>
90at C<error> priority. 109messages at C<error> priority. The NOTE column tries to provide some
110rationale on how to chose a logging level.
91 111
112As a rough guideline, levels 1..3 are primarily meant for users of the
113program (admins, staff), and are the only ones logged to STDERR by
114default. Levels 4..6 are meant for users and developers alike, while
115levels 7..9 are usually meant for developers.
116
92You can normally only log a single message at highest priority level 117You can normally only log a message once at highest priority level (C<1>,
93(C<1>, C<fatal>), because logging a fatal message will also quit the 118C<fatal>), because logging a fatal message will also quit the program - so
94program - so use it sparingly :) 119use it sparingly :)
120
121For example, a program that finds an unknown switch on the commandline
122might well use a fatal logging level to tell users about it - the "system"
123in this case would be the program, or module.
95 124
96Some methods also offer some extra levels, such as C<0>, C<off>, C<none> 125Some methods also offer some extra levels, such as C<0>, C<off>, C<none>
97or C<all> - these are only valid in the methods they are documented for. 126or C<all> - these are only valid for the methods that documented them.
98 127
99=head1 LOGGING FUNCTIONS 128=head1 LOGGING FUNCTIONS
100 129
101These functions allow you to log messages. They always use the caller's 130The following functions allow you to log messages. They always use the
102package as a "logging context". Also, the main logging function C<log> is 131caller's package as a "logging context". Also, the main logging function,
103callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is 132C<log>, is aliased to C<AnyEvent::log> and C<AE::log> when the C<AnyEvent>
104loaded. 133module is loaded.
105 134
106=over 4 135=over 4
107 136
108=cut 137=cut
109 138
110package AnyEvent::Log; 139package AnyEvent::Log;
111 140
112use Carp (); 141use Carp ();
113use POSIX (); 142use POSIX ();
114 143
144# layout of a context
145# 0 1 2 3 4, 5
146# [$title, $level, %$slaves, &$logcb, &$fmtcb, $cap]
147
115use AnyEvent (); BEGIN { AnyEvent::common_sense } 148use AnyEvent (); BEGIN { AnyEvent::common_sense }
116use AnyEvent::Util (); 149#use AnyEvent::Util (); need to load this in a delayed fashion, as it uses AE::log
117 150
118our $VERSION = $AnyEvent::VERSION; 151our $VERSION = $AnyEvent::VERSION;
119 152
120our ($COLLECT, $FILTER, $LOG); 153our ($COLLECT, $FILTER, $LOG);
121 154
122our ($now_int, $now_str1, $now_str2); 155our ($now_int, $now_str1, $now_str2);
123 156
124# Format Time, not public - yet? 157# Format Time, not public - yet?
125sub ft($) { 158sub format_time($) {
126 my $i = int $_[0]; 159 my $i = int $_[0];
127 my $f = sprintf "%06d", 1e6 * ($_[0] - $i); 160 my $f = sprintf "%06d", 1e6 * ($_[0] - $i);
128 161
129 ($now_int, $now_str1, $now_str2) = ($i, split /\x01/, POSIX::strftime "%Y-%m-%d %H:%M:%S.\x01 %z", localtime $i) 162 ($now_int, $now_str1, $now_str2) = ($i, split /\x01/, POSIX::strftime "%Y-%m-%d %H:%M:%S.\x01 %z", localtime $i)
130 if $now_int != $i; 163 if $now_int != $i;
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151=item AnyEvent::Log::log $level, $msg[, @args] 184=item AnyEvent::Log::log $level, $msg[, @args]
152 185
153Requests logging of the given C<$msg> with the given log level, and 186Requests logging of the given C<$msg> with the given log level, and
154returns true if the message was logged I<somewhere>. 187returns true if the message was logged I<somewhere>.
155 188
156For C<fatal> log levels, the program will abort. 189For loglevel C<fatal>, the program will abort.
157 190
158If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the 191If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
159C<$msg> is interpreted as an sprintf format string. 192C<$msg> is interpreted as an sprintf format string.
160 193
161The C<$msg> should not end with C<\n>, but may if that is convenient for 194The C<$msg> should not end with C<\n>, but may if that is convenient for
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163 196
164Last not least, C<$msg> might be a code reference, in which case it is 197Last not least, C<$msg> might be a code reference, in which case it is
165supposed to return the message. It will be called only then the message 198supposed to return the message. It will be called only then the message
166actually gets logged, which is useful if it is costly to create the 199actually gets logged, which is useful if it is costly to create the
167message in the first place. 200message in the first place.
201
202This function takes care of saving and restoring C<$!> and C<$@>, so you
203don't have to.
168 204
169Whether the given message will be logged depends on the maximum log level 205Whether the given message will be logged depends on the maximum log level
170and the caller's package. The return value can be used to ensure that 206and the caller's package. The return value can be used to ensure that
171messages or not "lost" - for example, when L<AnyEvent::Debug> detects a 207messages or not "lost" - for example, when L<AnyEvent::Debug> detects a
172runtime error it tries to log it at C<die> level, but if that message is 208runtime error it tries to log it at C<die> level, but if that message is
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206 info => 7, 242 info => 7,
207 debug => 8, 243 debug => 8,
208 trace => 9, 244 trace => 9,
209); 245);
210 246
211sub now () { time } 247our $TIME_EXACT;
248
249sub exact_time($) {
250 $TIME_EXACT = shift;
251 *_ts = $AnyEvent::MODEL
252 ? $TIME_EXACT ? \&AE::now : \&AE::time
253 : sub () { $TIME_EXACT ? do { require Time::HiRes; Time::HiRes::time () } : time };
254}
255
256BEGIN {
257 exact_time 0;
258}
212 259
213AnyEvent::post_detect { 260AnyEvent::post_detect {
214 *now = \&AE::now; 261 exact_time $TIME_EXACT;
215}; 262};
216 263
217our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace); 264our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
218 265
219# time, ctx, level, msg 266# time, ctx, level, msg
220sub _format($$$$) { 267sub default_format($$$$) {
221 my $ts = ft $_[0]; 268 my $ts = format_time $_[0];
222 my $ct = " "; 269 my $ct = " ";
223 270
224 my @res; 271 my @res;
225 272
226 for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) { 273 for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) {
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229 } 276 }
230 277
231 join "", @res 278 join "", @res
232} 279}
233 280
281sub fatal_exit() {
282 exit 1;
283}
284
234sub _log { 285sub _log {
235 my ($ctx, $level, $format, @args) = @_; 286 my ($ctx, $level, $format, @args) = @_;
236 287
237 $level = $level > 0 && $level <= 9 288 $level = $level > 0 && $level <= 9
238 ? $level+0 289 ? $level+0
239 : $STR2LEVEL{$level} || Carp::croak "$level: not a valid logging level, caught"; 290 : $STR2LEVEL{$level} || Carp::croak "$level: not a valid logging level, caught";
240 291
241 my $mask = 1 << $level; 292 my $mask = 1 << $level;
242 293
243 my ($success, %seen, @ctx, $now, $fmt); 294 my ($success, %seen, @ctx, $now, @fmt);
244 295
245 do 296 do
246 { 297 {
247 # skip if masked 298 # if !ref, then it's a level number
299 if (!ref $ctx) {
300 $level = $ctx;
248 if ($ctx->[1] & $mask && !$seen{$ctx+0}++) { 301 } elsif ($ctx->[1] & $mask and !$seen{$ctx+0}++) {
302 # logging/recursing into this context
303
304 # level cap
305 if ($ctx->[5] > $level) {
306 push @ctx, $level; # restore level when going up in tree
307 $level = $ctx->[5];
308 }
309
310 # log if log cb
249 if ($ctx->[3]) { 311 if ($ctx->[3]) {
250 # logging target found 312 # logging target found
313
314 local ($!, $@);
251 315
252 # now get raw message, unless we have it already 316 # now get raw message, unless we have it already
253 unless ($now) { 317 unless ($now) {
254 $format = $format->() if ref $format; 318 $format = $format->() if ref $format;
255 $format = sprintf $format, @args if @args; 319 $format = sprintf $format, @args if @args;
256 $format =~ s/\n$//; 320 $format =~ s/\n$//;
257 $now = now; 321 $now = _ts;
258 }; 322 };
259 323
260 # format msg 324 # format msg
261 my $str = $ctx->[4] 325 my $str = $ctx->[4]
262 ? $ctx->[4]($now, $_[0], $level, $format) 326 ? $ctx->[4]($now, $_[0], $level, $format)
263 : ($fmt ||= _format $now, $_[0], $level, $format); 327 : ($fmt[$level] ||= default_format $now, $_[0], $level, $format);
264 328
265 $success = 1; 329 $success = 1;
266 330
267 $ctx->[3]($str) 331 $ctx->[3]($str)
268 or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate 332 or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate
… …
271 } 335 }
272 } 336 }
273 } 337 }
274 while $ctx = pop @ctx; 338 while $ctx = pop @ctx;
275 339
276 exit 1 if $level <= 1; 340 fatal_exit if $level <= 1;
277 341
278 $success 342 $success
279} 343}
280 344
281sub log($$;@) { 345sub log($$;@) {
282 _log 346 _log
283 $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0], 347 $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0],
284 @_; 348 @_;
285} 349}
286 350
287*AnyEvent::log = *AE::log = \&log;
288
289=item $logger = AnyEvent::Log::logger $level[, \$enabled] 351=item $logger = AnyEvent::Log::logger $level[, \$enabled]
290 352
291Creates a code reference that, when called, acts as if the 353Creates a code reference that, when called, acts as if the
292C<AnyEvent::Log::log> function was called at this point with the given 354C<AnyEvent::Log::log> function was called at this point with the given
293level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with 355level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
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357 419
358 $LOGGER{$logger+0} = $logger; 420 $LOGGER{$logger+0} = $logger;
359 421
360 _reassess $logger+0; 422 _reassess $logger+0;
361 423
424 require AnyEvent::Util unless $AnyEvent::Util::VERSION;
362 my $guard = AnyEvent::Util::guard { 425 my $guard = AnyEvent::Util::guard (sub {
363 # "clean up" 426 # "clean up"
364 delete $LOGGER{$logger+0}; 427 delete $LOGGER{$logger+0};
365 }; 428 });
366 429
367 sub { 430 sub {
368 $guard if 0; # keep guard alive, but don't cause runtime overhead 431 $guard if 0; # keep guard alive, but don't cause runtime overhead
369 432
370 _log $ctx, $level, @_ 433 _log $ctx, $level, @_
… …
375sub logger($;$) { 438sub logger($;$) {
376 _logger 439 _logger
377 $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0], 440 $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0],
378 @_ 441 @_
379} 442}
443
444=item AnyEvent::Log::exact_time $on
445
446By default, C<AnyEvent::Log> will use C<AE::now>, i.e. the cached
447eventloop time, for the log timestamps. After calling this function with a
448true value it will instead resort to C<AE::time>, i.e. fetch the current
449time on each log message. This only makes a difference for event loops
450that actually cache the time (such as L<EV> or L<AnyEvent::Loop>).
451
452This setting can be changed at any time by calling this function.
453
454Since C<AnyEvent::Log> has to work even before the L<AnyEvent> has been
455initialised, this switch will also decide whether to use C<CORE::time> or
456C<Time::HiRes::time> when logging a message before L<AnyEvent> becomes
457available.
458
459=item AnyEvent::Log::format_time $timestamp
460
461Formats a timestamp as returned by C<< AnyEvent->now >> or C<<
462AnyEvent->time >> or many other functions in the same way as
463C<AnyEvent::Log> does.
464
465In your main program (as opposed to in your module) you can override
466the default timestamp display format by loading this module and then
467redefining this function.
468
469Most commonly, this function can be used in formatting callbacks.
470
471=item AnyEvent::Log::default_format $time, $ctx, $level, $msg
472
473Format a log message using the given timestamp, logging context, log level
474and log message.
475
476This is the formatting function used to format messages when no custom
477function is provided.
478
479In your main program (as opposed to in your module) you can override the
480default message format by loading this module and then redefining this
481function.
482
483=item AnyEvent::Log::fatal_exit()
484
485This is the function that is called after logging a C<fatal> log
486message. It must not return.
487
488The default implementation simply calls C<exit 1>.
489
490In your main program (as opposed to in your module) you can override
491the fatal exit function by loading this module and then redefining this
492function. Make sure you don't return.
380 493
381=back 494=back
382 495
383=head1 LOGGING CONTEXTS 496=head1 LOGGING CONTEXTS
384 497
… …
504This can be used to implement config-file (re-)loading: before loading a 617This can be used to implement config-file (re-)loading: before loading a
505configuration, reset all contexts. 618configuration, reset all contexts.
506 619
507=cut 620=cut
508 621
622our $ORIG_VERBOSE = $AnyEvent::VERBOSE;
623$AnyEvent::VERBOSE = 9;
624
509sub reset { 625sub reset {
510 # hard to kill complex data structures 626 # hard to kill complex data structures
511 # we "recreate" all package loggers and reset the hierarchy 627 # we "recreate" all package loggers and reset the hierarchy
512 while (my ($k, $v) = each %CTX) { 628 while (my ($k, $v) = each %CTX) {
513 @$v = ($k, (1 << 10) - 1 - 1, { }); 629 @$v = ($k, (1 << 10) - 1 - 1, { });
… …
522 $LOG->title ('$AnyEvent::Log::LOG'); 638 $LOG->title ('$AnyEvent::Log::LOG');
523 $LOG->log_to_warn; 639 $LOG->log_to_warn;
524 640
525 $FILTER->slaves ($LOG); 641 $FILTER->slaves ($LOG);
526 $FILTER->title ('$AnyEvent::Log::FILTER'); 642 $FILTER->title ('$AnyEvent::Log::FILTER');
527 $FILTER->level ($AnyEvent::VERBOSE); 643 $FILTER->level ($ORIG_VERBOSE);
528 644
529 $COLLECT->slaves ($FILTER); 645 $COLLECT->slaves ($FILTER);
530 $COLLECT->title ('$AnyEvent::Log::COLLECT'); 646 $COLLECT->title ('$AnyEvent::Log::COLLECT');
531 647
532 _reassess; 648 _reassess;
533} 649}
650
651# override AE::log/logger
652*AnyEvent::log = *AE::log = \&log;
653*AnyEvent::logger = *AE::logger = \&logger;
654
655# convert AnyEvent loggers to AnyEvent::Log loggers
656$_->[0] = ctx $_->[0] # convert "pkg" to "ctx"
657 for values %LOGGER;
534 658
535# create the default logger contexts 659# create the default logger contexts
536$LOG = ctx undef; 660$LOG = ctx undef;
537$FILTER = ctx undef; 661$FILTER = ctx undef;
538$COLLECT = ctx undef; 662$COLLECT = ctx undef;
… …
547package AnyEvent::Log::COLLECT; 671package AnyEvent::Log::COLLECT;
548package AE::Log::COLLECT; 672package AE::Log::COLLECT;
549 673
550package AnyEvent::Log::Ctx; 674package AnyEvent::Log::Ctx;
551 675
552# 0 1 2 3 4
553# [$title, $level, %$slaves, &$logcb, &$fmtcb]
554
555=item $ctx = new AnyEvent::Log::Ctx methodname => param... 676=item $ctx = new AnyEvent::Log::Ctx methodname => param...
556 677
557This is a convenience constructor that makes it simpler to construct 678This is a convenience constructor that makes it simpler to construct
558anonymous logging contexts. 679anonymous logging contexts.
559 680
… …
646 767
647=item $ctx->disable ($level[, $level...]) 768=item $ctx->disable ($level[, $level...])
648 769
649Disables logging for the given levels, leaving all others unchanged. 770Disables logging for the given levels, leaving all others unchanged.
650 771
772=item $ctx->cap ($level)
773
774Caps the maximum priority to the given level, for all messages logged
775to, or passing through, this context. That is, while this doesn't affect
776whether a message is logged or passed on, the maximum priority of messages
777will be limited to the specified level - messages with a higher priority
778will be set to the specified priority.
779
780Another way to view this is that C<< ->level >> filters out messages with
781a too low priority, while C<< ->cap >> modifies messages with a too high
782priority.
783
784This is useful when different log targets have different interpretations
785of priority. For example, for a specific command line program, a wrong
786command line switch might well result in a C<fatal> log message, while the
787same message, logged to syslog, is likely I<not> fatal to the system or
788syslog facility as a whole, but more likely a mere C<error>.
789
790This can be modeled by having a stderr logger that logs messages "as-is"
791and a syslog logger that logs messages with a level cap of, say, C<error>,
792or, for truly system-critical components, actually C<critical>.
793
651=cut 794=cut
652 795
653sub _lvl_lst { 796sub _lvl_lst {
654 map { 797 map {
655 $_ > 0 && $_ <= 9 ? $_+0 798 $_ > 0 && $_ <= 9 ? $_+0
656 : $_ eq "all" ? (1 .. 9) 799 : $_ eq "all" ? (1 .. 9)
657 : $STR2LEVEL{$_} || Carp::croak "$_: not a valid logging level, caught" 800 : $STR2LEVEL{$_} || Carp::croak "$_: not a valid logging level, caught"
658 } @_ 801 } @_
659} 802}
660 803
804sub _lvl {
805 $_[0] =~ /^(?:0|off|none)$/ ? 0 : (_lvl_lst $_[0])[-1]
806}
807
661our $NOP_CB = sub { 0 }; 808our $NOP_CB = sub { 0 };
662 809
663sub levels { 810sub levels {
664 my $ctx = shift; 811 my $ctx = shift;
665 $ctx->[1] = 0; 812 $ctx->[1] = 0;
… …
668 AnyEvent::Log::_reassess; 815 AnyEvent::Log::_reassess;
669} 816}
670 817
671sub level { 818sub level {
672 my $ctx = shift; 819 my $ctx = shift;
673 my $lvl = $_[0] =~ /^(?:0|off|none)$/ ? 0 : (_lvl_lst $_[0])[-1];
674
675 $ctx->[1] = ((1 << $lvl) - 1) << 1; 820 $ctx->[1] = ((1 << &_lvl) - 1) << 1;
676 AnyEvent::Log::_reassess; 821 AnyEvent::Log::_reassess;
677} 822}
678 823
679sub enable { 824sub enable {
680 my $ctx = shift; 825 my $ctx = shift;
… …
688 $ctx->[1] &= ~(1 << $_) 833 $ctx->[1] &= ~(1 << $_)
689 for &_lvl_lst; 834 for &_lvl_lst;
690 AnyEvent::Log::_reassess; 835 AnyEvent::Log::_reassess;
691} 836}
692 837
838sub cap {
839 my $ctx = shift;
840 $ctx->[5] = &_lvl;
841}
842
693=back 843=back
694 844
695=head3 SLAVE CONTEXTS 845=head3 SLAVE CONTEXTS
696 846
697The following methods attach and detach another logging context to a 847The following methods attach and detach another logging context to a
… …
749the logging (which consists of formatting the message and printing it or 899the logging (which consists of formatting the message and printing it or
750whatever it wants to do with it). 900whatever it wants to do with it).
751 901
752=over 4 902=over 4
753 903
754=item $ctx->log_cb ($cb->($str) 904=item $ctx->log_cb ($cb->($str))
755 905
756Replaces the logging callback on the context (C<undef> disables the 906Replaces the logging callback on the context (C<undef> disables the
757logging callback). 907logging callback).
758 908
759The logging callback is responsible for handling formatted log messages 909The logging callback is responsible for handling formatted log messages
… …
784 934
785Replaces the formatting callback on the context (C<undef> restores the 935Replaces the formatting callback on the context (C<undef> restores the
786default formatter). 936default formatter).
787 937
788The callback is passed the (possibly fractional) timestamp, the original 938The callback is passed the (possibly fractional) timestamp, the original
789logging context, the (numeric) logging level and the raw message string 939logging context (object, not title), the (numeric) logging level and
790and needs to return a formatted log message. In most cases this will be a 940the raw message string and needs to return a formatted log message. In
791string, but it could just as well be an array reference that just stores 941most cases this will be a string, but it could just as well be an array
792the values. 942reference that just stores the values.
793 943
794If, for some reason, you want to use C<caller> to find out more baout the 944If, for some reason, you want to use C<caller> to find out more about the
795logger then you should walk up the call stack until you are no longer 945logger then you should walk up the call stack until you are no longer
796inside the C<AnyEvent::Log> package. 946inside the C<AnyEvent::Log> package.
797 947
948To implement your own logging callback, you might find the
949C<AnyEvent::Log::format_time> and C<AnyEvent::Log::default_format>
950functions useful.
951
952Example: format the message just as AnyEvent::Log would, by letting
953AnyEvent::Log do the work. This is a good basis to design a formatting
954callback that only changes minor aspects of the formatting.
955
956 $ctx->fmt_cb (sub {
957 my ($time, $ctx, $lvl, $msg) = @_;
958
959 AnyEvent::Log::default_format $time, $ctx, $lvl, $msg
960 });
961
798Example: format just the raw message, with numeric log level in angle 962Example: format just the raw message, with numeric log level in angle
799brackets. 963brackets.
800 964
801 $ctx->fmt_cb (sub { 965 $ctx->fmt_cb (sub {
802 my ($time, $ctx, $lvl, $msg) = @_; 966 my ($time, $ctx, $lvl, $msg) = @_;
803 967
804 "<$lvl>$msg\n" 968 "<$lvl>$msg\n"
805 }); 969 });
806 970
807Example: return an array reference with just the log values, and use 971Example: return an array reference with just the log values, and use
808C<PApp::SQL::sql_exec> to store the emssage in a database. 972C<PApp::SQL::sql_exec> to store the message in a database.
809 973
810 $ctx->fmt_cb (sub { \@_ }); 974 $ctx->fmt_cb (sub { \@_ });
811 $ctx->log_cb (sub { 975 $ctx->log_cb (sub {
812 my ($msg) = @_; 976 my ($msg) = @_;
813 977
… …
825Sets the C<log_cb> to simply use C<CORE::warn> to report any messages 989Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
826(usually this logs to STDERR). 990(usually this logs to STDERR).
827 991
828=item $ctx->log_to_file ($path) 992=item $ctx->log_to_file ($path)
829 993
830Sets the C<log_cb> to log to a file (by appending), unbuffered. 994Sets the C<log_cb> to log to a file (by appending), unbuffered. The
995function might return before the log file has been opened or created.
831 996
832=item $ctx->log_to_path ($path) 997=item $ctx->log_to_path ($path)
833 998
834Same as C<< ->log_to_file >>, but opens the file for each message. This 999Same as C<< ->log_to_file >>, but opens the file for each message. This
835is much slower, but allows you to change/move/rename/delete the file at 1000is much slower, but allows you to change/move/rename/delete the file at
… …
837 1002
838Needless(?) to say, if you do not want to be bitten by some evil person 1003Needless(?) to say, if you do not want to be bitten by some evil person
839calling C<chdir>, the path should be absolute. Doesn't help with 1004calling C<chdir>, the path should be absolute. Doesn't help with
840C<chroot>, but hey... 1005C<chroot>, but hey...
841 1006
842=item $ctx->log_to_syslog ([$log_flags]) 1007=item $ctx->log_to_syslog ([$facility])
843 1008
844Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all 1009Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and
845the others in the obvious way. If specified, then the C<$log_flags> are 1010all the others in the obvious way. If specified, then the C<$facility> is
846simply or'ed onto the priority argument and can contain any C<LOG_xxx> 1011used as the facility (C<user>, C<auth>, C<local0> and so on). The default
847flags valid for Sys::Syslog::syslog, except for the priority levels. 1012facility is C<user>.
848 1013
849Note that this function also sets a C<fmt_cb> - the logging part requires 1014Note that this function also sets a C<fmt_cb> - the logging part requires
850an array reference with [$level, $str] as input. 1015an array reference with [$level, $str] as input.
851 1016
852=cut 1017=cut
… …
870 warn shift; 1035 warn shift;
871 0 1036 0
872 }); 1037 });
873} 1038}
874 1039
1040# this function is a good example of why threads are a must,
1041# simply for priority inversion.
1042sub _log_to_disk {
1043 # eval'uating this at runtime saves 220kb rss - perl has become
1044 # an insane memory waster.
1045 eval q{ # poor man's autoloading {}
1046 sub _log_to_disk {
1047 my ($ctx, $path, $keepopen) = @_;
1048
1049 my $fh;
1050 my @queue;
1051 my $delay;
1052 my $disable;
1053
1054 use AnyEvent::IO ();
1055
1056 my $kick = sub {
1057 undef $delay;
1058 return unless @queue;
1059 $delay = 1;
1060
1061 # we pass $kick to $kick, so $kick itself doesn't keep a reference to $kick.
1062 my $kick = shift;
1063
1064 # write one or more messages
1065 my $write = sub {
1066 # we write as many messages as have been queued
1067 my $data = join "", @queue;
1068 @queue = ();
1069
1070 AnyEvent::IO::aio_write $fh, $data, sub {
1071 $disable = 1;
1072 @_
1073 ? ($_[0] == length $data or AE::log 4 => "unable to write to logfile '$path': short write")
1074 : AE::log 4 => "unable to write to logfile '$path': $!";
1075 undef $disable;
1076
1077 if ($keepopen) {
1078 $kick->($kick);
1079 } else {
1080 AnyEvent::IO::aio_close ($fh, sub {
1081 undef $fh;
1082 $kick->($kick);
1083 });
1084 }
1085 };
1086 };
1087
1088 if ($fh) {
1089 $write->();
1090 } else {
1091 AnyEvent::IO::aio_open
1092 $path,
1093 AnyEvent::IO::O_CREAT | AnyEvent::IO::O_WRONLY | AnyEvent::IO::O_APPEND,
1094 0666,
1095 sub {
1096 $fh = shift
1097 or do {
1098 $disable = 1;
1099 AE::log 4 => "unable to open logfile '$path': $!";
1100 undef $disable;
1101 return;
1102 };
1103
1104 $write->();
1105 }
1106 ;
1107 }
1108 };
1109
1110 $ctx->log_cb (sub {
1111 return if $disable;
1112 push @queue, shift;
1113 $kick->($kick) unless $delay;
1114 0
1115 });
1116
1117 $kick->($kick) if $keepopen; # initial open
1118 };
1119 };
1120 die if $@;
1121 &_log_to_disk
1122}
1123
875sub log_to_file { 1124sub log_to_file {
876 my ($ctx, $path) = @_; 1125 my ($ctx, $path) = @_;
877 1126
878 open my $fh, ">>", $path 1127 _log_to_disk $ctx, $path, 1;
879 or die "$path: $!";
880
881 $ctx->log_cb (sub {
882 syswrite $fh, shift;
883 0
884 });
885} 1128}
886 1129
887sub log_to_path { 1130sub log_to_path {
888 my ($ctx, $path) = @_; 1131 my ($ctx, $path) = @_;
889 1132
890 $ctx->log_cb (sub { 1133 _log_to_disk $ctx, $path, 0;
891 open my $fh, ">>", $path
892 or die "$path: $!";
893
894 syswrite $fh, shift;
895 0
896 });
897} 1134}
898 1135
899sub log_to_syslog { 1136sub log_to_syslog {
900 my ($ctx, $flags) = @_; 1137 my ($ctx, $facility) = @_;
901 1138
902 require Sys::Syslog; 1139 require Sys::Syslog;
903 1140
904 $ctx->fmt_cb (sub { 1141 $ctx->fmt_cb (sub {
905 my $str = $_[3]; 1142 my $str = $_[3];
906 $str =~ s/\n(?=.)/\n+ /g; 1143 $str =~ s/\n(?=.)/\n+ /g;
907 1144
908 [$_[2], "($_[1][0]) $str"] 1145 [$_[2], "($_[1][0]) $str"]
909 }); 1146 });
910 1147
1148 $facility ||= "user";
1149
911 $ctx->log_cb (sub { 1150 $ctx->log_cb (sub {
912 my $lvl = $_[0][0] < 9 ? $_[0][0] : 8; 1151 my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
913 1152
914 Sys::Syslog::syslog ($flags | ($lvl - 1), $_) 1153 Sys::Syslog::syslog ("$facility|" . ($lvl - 1), $_)
915 for split /\n/, $_[0][1]; 1154 for split /\n/, $_[0][1];
916 1155
917 0 1156 0
918 }); 1157 });
919} 1158}
… …
928=over 4 1167=over 4
929 1168
930=item $ctx->log ($level, $msg[, @params]) 1169=item $ctx->log ($level, $msg[, @params])
931 1170
932Same as C<AnyEvent::Log::log>, but uses the given context as log context. 1171Same as C<AnyEvent::Log::log>, but uses the given context as log context.
1172
1173Example: log a message in the context of another package.
1174
1175 (AnyEvent::Log::ctx "Other::Package")->log (warn => "heely bo");
933 1176
934=item $logger = $ctx->logger ($level[, \$enabled]) 1177=item $logger = $ctx->logger ($level[, \$enabled])
935 1178
936Same as C<AnyEvent::Log::logger>, but uses the given context as log 1179Same as C<AnyEvent::Log::logger>, but uses the given context as log
937context. 1180context.
… …
985 1228
986Context names starting with a C<%> are anonymous contexts created when the 1229Context names starting with a C<%> are anonymous contexts created when the
987name is first mentioned. The difference to package contexts is that by 1230name is first mentioned. The difference to package contexts is that by
988default they have no attached slaves. 1231default they have no attached slaves.
989 1232
1233This makes it possible to create new log contexts that can be refered to
1234multiple times by name within the same log specification.
1235
990=item a perl package name 1236=item a perl package name
991 1237
992Any other string references the logging context associated with the given 1238Any other string references the logging context associated with the given
993Perl C<package>. In the unlikely case where you want to specify a package 1239Perl C<package>. In the unlikely case where you want to specify a package
994context that matches on of the other context name forms, you can add a 1240context that matches on of the other context name forms, you can add a
… …
1025=item C<nolog> 1271=item C<nolog>
1026 1272
1027Configures the context to not log anything by itself, which is the 1273Configures the context to not log anything by itself, which is the
1028default. Same as C<< $ctx->log_cb (undef) >>. 1274default. Same as C<< $ctx->log_cb (undef) >>.
1029 1275
1276=item C<cap=>I<level>
1277
1278Caps logging messages entering this context at the given level, i.e.
1279reduces the priority of messages with higher priority than this level. The
1280default is C<0> (or C<off>), meaning the priority will not be touched.
1281
1030=item C<0> or C<off> 1282=item C<0> or C<off>
1031 1283
1032Sets the logging level of the context ot C<0>, i.e. all messages will be 1284Sets the logging level of the context to C<0>, i.e. all messages will be
1033filtered out. 1285filtered out.
1034 1286
1035=item C<all> 1287=item C<all>
1036 1288
1037Enables all logging levels, i.e. filtering will effectively be switched 1289Enables all logging levels, i.e. filtering will effectively be switched
… …
1079 1331
1080Attaches the named context as slave to the context. 1332Attaches the named context as slave to the context.
1081 1333
1082=item C<+> 1334=item C<+>
1083 1335
1084A line C<+> detaches all contexts, i.e. clears the slave list from the 1336A lone C<+> detaches all contexts, i.e. clears the slave list from the
1085context. Anonymous (C<%name>) contexts have no attached slaves by default, 1337context. Anonymous (C<%name>) contexts have no attached slaves by default,
1086but package contexts have the parent context as slave by default. 1338but package contexts have the parent context as slave by default.
1087 1339
1088Example: log messages from My::Module to a file, do not send them to the 1340Example: log messages from My::Module to a file, do not send them to the
1089default log collector. 1341default log collector.
… …
1120 1372
1121 my $pkg = sub { 1373 my $pkg = sub {
1122 $_[0] eq "log" ? $LOG 1374 $_[0] eq "log" ? $LOG
1123 : $_[0] eq "filter" ? $FILTER 1375 : $_[0] eq "filter" ? $FILTER
1124 : $_[0] eq "collect" ? $COLLECT 1376 : $_[0] eq "collect" ? $COLLECT
1125 : $_[0] =~ /^%(.+)$/ ? ($anon{$1} ||= ctx undef) 1377 : $_[0] =~ /^%(.+)$/ ? ($anon{$1} ||= do { my $ctx = ctx undef; $ctx->[0] = $_[0]; $ctx })
1126 : $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/ 1378 : $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
1127 : die # never reached? 1379 : die # never reached?
1128 }; 1380 };
1129 1381
1130 /\G[[:space:]]+/gc; # skip initial whitespace 1382 /\G[[:space:]]+/gc; # skip initial whitespace
… …
1136 while (/\G((?:[^,:[:space:]]+|::|\\.)+)/gc) { 1388 while (/\G((?:[^,:[:space:]]+|::|\\.)+)/gc) {
1137 for ("$1") { 1389 for ("$1") {
1138 if ($_ eq "stderr" ) { $ctx->log_to_warn; 1390 if ($_ eq "stderr" ) { $ctx->log_to_warn;
1139 } elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1"); 1391 } elsif (/^file=(.+)/ ) { $ctx->log_to_file ("$1");
1140 } elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1"); 1392 } elsif (/^path=(.+)/ ) { $ctx->log_to_path ("$1");
1141 } elsif (/syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog (eval "package Sys::Syslog; $1"); 1393 } elsif (/^syslog(?:=(.*))?/ ) { require Sys::Syslog; $ctx->log_to_syslog ("$1");
1142 } elsif ($_ eq "nolog" ) { $ctx->log_cb (undef); 1394 } elsif ($_ eq "nolog" ) { $ctx->log_cb (undef);
1395 } elsif (/^cap=(.+)/ ) { $ctx->cap ("$1");
1143 } elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1")); 1396 } elsif (/^\+(.+)$/ ) { $ctx->attach ($pkg->("$1"));
1144 } elsif ($_ eq "+" ) { $ctx->slaves; 1397 } elsif ($_ eq "+" ) { $ctx->slaves;
1145 } elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0); 1398 } elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
1146 } elsif ($_ eq "all" ) { $ctx->level ("all"); 1399 } elsif ($_ eq "all" ) { $ctx->level ("all");
1147 } elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level"; 1400 } elsif ($_ eq "level" ) { $ctx->level ("all"); $level = "level";
… …
1164 if (/\G(.+)/g) { 1417 if (/\G(.+)/g) {
1165 die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n"; 1418 die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
1166 } 1419 }
1167} 1420}
1168 1421
11691;
1170
1171=head1 EXAMPLES 1422=head1 EXAMPLES
1172 1423
1173This section shows some common configurations, both as code, and as 1424This section shows some common configurations, both as code, and as
1174C<PERL_ANYEVENT_LOG> string. 1425C<PERL_ANYEVENT_LOG> string.
1175 1426
… …
1199 1450
1200This writes them only when the global logging level allows it, because 1451This writes them only when the global logging level allows it, because
1201it is attached to the default context which is invoked I<after> global 1452it is attached to the default context which is invoked I<after> global
1202filtering. 1453filtering.
1203 1454
1204 $AnyEvent::Log::FILTER->attach 1455 $AnyEvent::Log::FILTER->attach (
1205 new AnyEvent::Log::Ctx log_to_file => $path); 1456 new AnyEvent::Log::Ctx log_to_file => $path);
1206 1457
1207 PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path 1458 PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
1208 1459
1209This writes them regardless of the global logging level, because it is 1460This writes them regardless of the global logging level, because it is
… …
1215 1466
1216 PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger 1467 PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
1217 1468
1218In both cases, messages are still written to STDERR. 1469In both cases, messages are still written to STDERR.
1219 1470
1471=item Additionally log all messages with C<warn> and higher priority to
1472C<syslog>, but cap at C<error>.
1473
1474This logs all messages to the default log target, but also logs messages
1475with priority C<warn> or higher (and not filtered otherwise) to syslog
1476facility C<user>. Messages with priority higher than C<error> will be
1477logged with level C<error>.
1478
1479 $AnyEvent::Log::LOG->attach (
1480 new AnyEvent::Log::Ctx
1481 level => "warn",
1482 cap => "error",
1483 syslog => "user",
1484 );
1485
1486 PERL_ANYEVENT_LOG=log=+%syslog:%syslog=warn,cap=error,syslog
1487
1220=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s). 1488=item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
1221 1489
1222Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug> 1490Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
1223context - this simply circumvents the global filtering for trace messages. 1491context - this simply circumvents the global filtering for trace messages.
1224 1492
… …
1231assumes the log level for AnyEvent::Debug hasn't been changed from the 1499assumes the log level for AnyEvent::Debug hasn't been changed from the
1232default. 1500default.
1233 1501
1234=back 1502=back
1235 1503
1504=head1 ASYNCHRONOUS DISK I/O
1505
1506This module uses L<AnyEvent::IO> to actually write log messages (in
1507C<log_to_file> and C<log_to_path>), so it doesn't block your program when
1508the disk is busy and a non-blocking L<AnyEvent::IO> backend is available.
1509
1236=head1 AUTHOR 1510=head1 AUTHOR
1237 1511
1238 Marc Lehmann <schmorp@schmorp.de> 1512 Marc Lehmann <schmorp@schmorp.de>
1239 http://home.schmorp.de/ 1513 http://anyevent.schmorp.de
1240 1514
1241=cut 1515=cut
1242 1516
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