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

Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.25 by root, Sun Aug 21 03:25:47 2011 UTC vs.
Revision 1.44 by root, Mon Sep 26 11:32:19 2011 UTC

 Simple uses:
    use AnyEvent;
-   AE::log debug => "hit my knee";
+   AE::log trace => "going to call function abc";
-   AE::log warn  => "it's a bit too hot";
+   AE::log debug => "the function returned 3";
-   AE::log error => "the flag was false!";
+   AE::log info  => "file soandso successfully deleted";
-   AE::log fatal => "the bit toggled! run!"; # never returns
+   AE::log note  => "wanted to create config, but config was alraedy created";
+   AE::log warn  => "couldn't delete the file";
+   AE::log error => "failed to retrieve data";
+   AE::log crit  => "the battery temperature is too hot";
+   AE::log alert => "the battery died";
+   AE::log fatal => "no config found, cannot continue"; # never returns
+Log level overview:
+   LVL NAME      SYSLOG   PERL  NOTE
+    1  fatal     emerg    exit  system unusable, aborts program!
+    2  alert                    failure in primary system
+    3  critical  crit           failure in backup system
+    4  error     err      die   non-urgent program errors, a bug
+    5  warn      warning        possible problem, not necessarily error
+    6  note      notice         unusual conditions
+    7  info                     normal messages, no action required
+    8  debug                    debugging messages for development
+    9  trace                    copious tracing output
-"Complex" uses (for speed sensitive code):
+"Complex" uses (for speed sensitive code, e.g. trace/debug messages):
    use AnyEvent::Log;
    my $tracer = AnyEvent::Log::logger trace => \$my $trace;
    # send all critical and higher priority messages to syslog,
    # regardless of (most) other settings
    $AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx
       level         => "critical",
-      log_to_syslog => 0,
+      log_to_syslog => "user",
    );
 =head1 DESCRIPTION
 This module implements a relatively simple "logging framework". It doesn't
 will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number
 before starting your program, or change the logging level at runtime with
 something like:
    use AnyEvent::Log;
-   AnyEvent::Log::FILTER->level ("info");
+   $AnyEvent::Log::FILTER->level ("info");
 The design goal behind this module was to keep it simple (and small),
 but make it powerful enough to be potentially useful for any module, and
 extensive enough for the most common tasks, such as logging to multiple
 targets, or being able to log into a database.
+The module is also usable before AnyEvent itself is initialised, in which
+case some of the functionality might be reduced.
-The amount of documentation might indicate otherwise, but the module is
+The amount of documentation might indicate otherwise, but the runtime part
-still just below 300 lines of code.
+of the module is still just below 300 lines of code.
 =head1 LOGGING LEVELS
 Logging levels in this module range from C<1> (highest priority) to C<9>
 (lowest priority). Note that the lowest numerical value is the highest
 numerical value".
 Instead of specifying levels by name you can also specify them by aliases:
    LVL NAME      SYSLOG   PERL  NOTE
-   1   fatal     emerg    exit  aborts program!
+    1  fatal     emerg    exit  system unusable, aborts program!
-   2   alert
+    2  alert                    failure in primary system
-   3   critical  crit
+    3  critical  crit           failure in backup system
-   4   error     err      die
+    4  error     err      die   non-urgent program errors, a bug
-   5   warn      warning
+    5  warn      warning        possible problem, not necessarily error
-   6   note      notice
+    6  note      notice         unusual conditions
-   7   info
+    7  info                     normal messages, no action required
-   8   debug
+    8  debug                    debugging messages for development
-   9   trace
+    9  trace                    copious tracing output
 As you can see, some logging levels have multiple aliases - the first one
 is the "official" name, the second one the "syslog" name (if it differs)
-and the third one the "perl" name, suggesting that you log C<die> messages
+and the third one the "perl" name, suggesting (only!) that you log C<die>
-at C<error> priority.
+messages at C<error> priority. The NOTE column tries to provide some
+rationale on how to chose a logging level.
+As a rough guideline, levels 1..3 are primarily meant for users of
+the program (admins, staff), and are the only logged to STDERR by
+default. Levels 4..6 are meant for users and developers alike, while
+levels 7..9 are usually meant for developers.
 You can normally only log a single message at highest priority level
 (C<1>, C<fatal>), because logging a fatal message will also quit the
 program - so use it sparingly :)
 use Carp ();
 use POSIX ();
 use AnyEvent (); BEGIN { AnyEvent::common_sense }
-use AnyEvent::Util ();
+#use AnyEvent::Util (); need to load this in a delayed fashion, as it uses AE::log
 our $VERSION = $AnyEvent::VERSION;
 our ($COLLECT, $FILTER, $LOG);
 =item AnyEvent::Log::log $level, $msg[, @args]
 Requests logging of the given C<$msg> with the given log level, and
 returns true if the message was logged I<somewhere>.
-For C<fatal> log levels, the program will abort.
+For loglevel C<fatal>, the program will abort.
 If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the
 C<$msg> is interpreted as an sprintf format string.
 The C<$msg> should not end with C<\n>, but may if that is convenient for
    info     => 7,
    debug    => 8,
    trace    => 9,
 );
-sub now () { time }
+our $TIME_EXACT;
+sub exact_time($) {
+   $TIME_EXACT = shift;
+   *_ts = $AnyEvent::MODEL
+      ? $TIME_EXACT ? \&AE::now : \&AE::time
+      : sub () { $TIME_EXACT ? do { require Time::HiRes; Time::HiRes::time () } : time };
+}
+BEGIN {
+   exact_time 0;
+}
 AnyEvent::post_detect {
-   *now = \&AE::now;
+   exact_time $TIME_EXACT;
 };
 our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace);
 # time, ctx, level, msg
       push @res, "$ts$ct$_\n";
       $ct = " + ";
    }
    join "", @res
+}
+sub fatal_exit() {
+   exit 1;
 }
 sub _log {
    my ($ctx, $level, $format, @args) = @_;
                # now get raw message, unless we have it already
                unless ($now) {
                   $format = $format->() if ref $format;
                   $format = sprintf $format, @args if @args;
                   $format =~ s/\n$//;
-                  $now = AE::now;
+                  $now = _ts;
                };
                # format msg
                my $str = $ctx->[4]
                   ? $ctx->[4]($now, $_[0], $level, $format)
             }
          }
       }
    while $ctx = pop @ctx;
-   exit 1 if $level <= 1;
+   fatal_exit if $level <= 1;
    $success
 }
 sub log($$;@) {
    _log
       $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0],
       @_;
 }
-*AnyEvent::log = *AE::log = \&log;
 =item $logger = AnyEvent::Log::logger $level[, \$enabled]
 Creates a code reference that, when called, acts as if the
 C<AnyEvent::Log::log> function was called at this point with the given
 level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with
    $LOGGER{$logger+0} = $logger;
    _reassess $logger+0;
+   require AnyEvent::Util unless $AnyEvent::Util::VERSION;
-   my $guard = AnyEvent::Util::guard {
+   my $guard = AnyEvent::Util::guard (sub {
       # "clean up"
       delete $LOGGER{$logger+0};
-   };
+   });
    sub {
       $guard if 0; # keep guard alive, but don't cause runtime overhead
       _log $ctx, $level, @_
 sub logger($;$) {
    _logger
       $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0],
       @_
 }
+=item AnyEvent::Log::exact_time $on
+By default, C<AnyEvent::Log> will use C<AE::now>, i.e. the cached
+eventloop time, for the log timestamps. After calling this function with a
+true value it will instead resort to C<AE::time>, i.e. fetch the current
+time on each log message. This only makes a difference for event loops
+that actually cache the time (such as L<EV> or L<AnyEvent::Loop>).
+This setting can be changed at any time by calling this function.
+Since C<AnyEvent::Log> has to work even before the L<AnyEvent> has been
+initialised, this switch will also decide whether to use C<CORE::time> or
+C<Time::HiRes::time> when logging a message before L<AnyEvent> becomes
+available.
 =back
 =head1 LOGGING CONTEXTS
 This can be used to implement config-file (re-)loading: before loading a
 configuration, reset all contexts.
 =cut
+our $ORIG_VERBOSE = $AnyEvent::VERBOSE;
+$AnyEvent::VERBOSE = 9;
 sub reset {
    # hard to kill complex data structures
    # we "recreate" all package loggers and reset the hierarchy
    while (my ($k, $v) = each %CTX) {
       @$v = ($k, (1 << 10) - 1 - 1, { });
    }
    @$_ = ($_->[0], (1 << 10) - 1 - 1)
       for $LOG, $FILTER, $COLLECT;
-   $LOG->slaves;
+   #$LOG->slaves;
    $LOG->title ('$AnyEvent::Log::LOG');
-   $LOG->log_cb (sub {
+   $LOG->log_to_warn;
-      warn shift;
-      0
-   });
    $FILTER->slaves ($LOG);
    $FILTER->title ('$AnyEvent::Log::FILTER');
-   $FILTER->level ($AnyEvent::VERBOSE);
+   $FILTER->level ($ORIG_VERBOSE);
    $COLLECT->slaves ($FILTER);
    $COLLECT->title ('$AnyEvent::Log::COLLECT');
    _reassess;
 }
+# override AE::log/logger
+*AnyEvent::log    = *AE::log    = \&log;
+*AnyEvent::logger = *AE::logger = \&logger;
+# convert AnyEvent loggers to AnyEvent::Log loggers
+$_->[0] = ctx $_->[0] # convert "pkg" to "ctx"
+   for values %LOGGER;
 # create the default logger contexts
 $LOG     = ctx undef;
 $FILTER  = ctx undef;
 $COLLECT = ctx undef;
 logging context, the (numeric) logging level and the raw message string
 and needs to return a formatted log message. In most cases this will be a
 string, but it could just as well be an array reference that just stores
 the values.
-If, for some reaosn, you want to use C<caller> to find out more baout the
+If, for some reason, you want to use C<caller> to find out more baout the
 logger then you should walk up the call stack until you are no longer
 inside the C<AnyEvent::Log> package.
 Example: format just the raw message, with numeric log level in angle
 brackets.
                "$msg->[3]";
       0
    });
+=item $ctx->log_to_warn
+Sets the C<log_cb> to simply use C<CORE::warn> to report any messages
+(usually this logs to STDERR).
 =item $ctx->log_to_file ($path)
 Sets the C<log_cb> to log to a file (by appending), unbuffered.
 =item $ctx->log_to_path ($path)
 Same as C<< ->log_to_file >>, but opens the file for each message. This
 is much slower, but allows you to change/move/rename/delete the file at
 basically any time.
+Needless(?) to say, if you do not want to be bitten by some evil person
+calling C<chdir>, the path should be absolute. Doesn't help with
+C<chroot>, but hey...
-=item $ctx->log_to_syslog ([$log_flags])
+=item $ctx->log_to_syslog ([$facility])
-Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and all
+Logs all messages via L<Sys::Syslog>, mapping C<trace> to C<debug> and
-the others in the obvious way. If specified, then the C<$log_flags> are
+all the others in the obvious way. If specified, then the C<$facility> is
-simply or'ed onto the priority argument and can contain any C<LOG_xxx>
+used as the facility (C<user>, C<auth>, C<local0> and so on). The default
-flags valid for Sys::Syslog::syslog, except for the priority levels.
+facility is C<user>.
 Note that this function also sets a C<fmt_cb> - the logging part requires
 an array reference with [$level, $str] as input.
 =cut
 sub fmt_cb {
    my ($ctx, $cb) = @_;
    $ctx->[4] = $cb;
+}
+sub log_to_warn {
+   my ($ctx, $path) = @_;
+   $ctx->log_cb (sub {
+      warn shift;
+      0
+   });
 }
 sub log_to_file {
    my ($ctx, $path) = @_;
       syswrite $fh, shift;
       0
    });
 }
-sub log_to_file {
+sub log_to_path {
    my ($ctx, $path) = @_;
    $ctx->log_cb (sub {
       open my $fh, ">>", $path
          or die "$path: $!";
       0
    });
 }
 sub log_to_syslog {
-   my ($ctx, $flags) = @_;
+   my ($ctx, $facility) = @_;
    require Sys::Syslog;
    $ctx->fmt_cb (sub {
       my $str = $_[3];
       $str =~ s/\n(?=.)/\n+ /g;
       [$_[2], "($_[1][0]) $str"]
    });
+   $facility ||= "user";
    $ctx->log_cb (sub {
       my $lvl = $_[0][0] < 9 ? $_[0][0] : 8;
-      Sys::Syslog::syslog ($flags | ($lvl - 1), $_)
+      Sys::Syslog::syslog ("$facility|" . ($lvl - 1), $_)
          for split /\n/, $_[0][1];
       0
    });
 }
 =cut
 *log    = \&AnyEvent::Log::_log;
 *logger = \&AnyEvent::Log::_logger;
+=back
+=cut
+package AnyEvent::Log;
+=head1 CONFIGURATION VIA $ENV{PERL_ANYEVENT_LOG}
+Logging can also be configured by setting the environment variable
+C<PERL_ANYEVENT_LOG> (or C<AE_LOG>).
+The value consists of one or more logging context specifications separated
+by C<:> or whitespace. Each logging specification in turn starts with a
+context name, followed by C<=>, followed by zero or more comma-separated
+configuration directives, here are some examples:
+   # set default logging level
+   filter=warn
+   # log to file instead of to stderr
+   log=file=/tmp/mylog
+   # log to file in addition to stderr
+   log=+%file:%file=file=/tmp/mylog
+   # enable debug log messages, log warnings and above to syslog
+   filter=debug:log=+%warnings:%warnings=warn,syslog=LOG_LOCAL0
+   # log trace messages (only) from AnyEvent::Debug to file
+   AnyEvent::Debug=+%trace:%trace=only,trace,file=/tmp/tracelog
+A context name in the log specification can be any of the following:
+=over 4
+=item C<collect>, C<filter>, C<log>
+Correspond to the three predefined C<$AnyEvent::Log::COLLECT>,
+C<AnyEvent::Log::FILTER> and C<$AnyEvent::Log::LOG> contexts.
+=item C<%name>
+Context names starting with a C<%> are anonymous contexts created when the
+name is first mentioned. The difference to package contexts is that by
+default they have no attached slaves.
+=item a perl package name
+Any other string references the logging context associated with the given
+Perl C<package>. In the unlikely case where you want to specify a package
+context that matches on of the other context name forms, you can add a
+C<::> to the package name to force interpretation as a package.
+=back
+The configuration specifications can be any number of the following:
+=over 4
+=item C<stderr>
+Configures the context to use Perl's C<warn> function (which typically
+logs to C<STDERR>). Works like C<log_to_warn>.
+=item C<file=>I<path>
+Configures the context to log to a file with the given path. Works like
+C<log_to_file>.
+=item C<path=>I<path>
+Configures the context to log to a file with the given path. Works like
+C<log_to_path>.
+=item C<syslog> or C<syslog=>I<expr>
+Configures the context to log to syslog. If I<expr> is given, then it is
+evaluated in the L<Sys::Syslog> package, so you could use:
+   log=syslog=LOG_LOCAL0
+=item C<nolog>
+Configures the context to not log anything by itself, which is the
+default. Same as C<< $ctx->log_cb (undef) >>.
+=item C<0> or C<off>
+Sets the logging level of the context ot C<0>, i.e. all messages will be
+filtered out.
+=item C<all>
+Enables all logging levels, i.e. filtering will effectively be switched
+off (the default).
+=item C<only>
+Disables all logging levels, and changes the interpretation of following
+level specifications to enable the specified level only.
+Example: only enable debug messages for a context.
+   context=only,debug
+=item C<except>
+Enables all logging levels, and changes the interpretation of following
+level specifications to disable that level. Rarely used.
+Example: enable all logging levels except fatal and trace (this is rather
+nonsensical).
+   filter=exept,fatal,trace
+=item C<level>
+Enables all logging levels, and changes the interpretation of following
+level specifications to be "that level or any higher priority
+message". This is the default.
+Example: log anything at or above warn level.
+   filter=warn
+   # or, more verbose
+   filter=only,level,warn
+=item C<1>..C<9> or a logging level name (C<error>, C<debug> etc.)
+A numeric loglevel or the name of a loglevel will be interpreted according
+to the most recent C<only>, C<except> or C<level> directive. By default,
+specifying a logging level enables that and any higher priority messages.
+=item C<+>I<context>
+Attaches the named context as slave to the context.
+=item C<+>
+A line C<+> detaches all contexts, i.e. clears the slave list from the
+context. Anonymous (C<%name>) contexts have no attached slaves by default,
+but package contexts have the parent context as slave by default.
+Example: log messages from My::Module to a file, do not send them to the
+default log collector.
+   My::Module=+,file=/tmp/mymodulelog
+=back
+Any character can be escaped by prefixing it with a C<\> (backslash), as
+usual, so to log to a file containing a comma, colon, backslash and some
+spaces in the filename, you would do this:
+   PERL_ANYEVENT_LOG='log=file=/some\ \:file\ with\,\ \\-escapes'
+Since whitespace (which includes newlines) is allowed, it is fine to
+specify multiple lines in C<PERL_ANYEVENT_LOG>, e.g.:
+   PERL_ANYEVENT_LOG="
+      filter=warn
+      AnyEvent::Debug=+%trace
+      %trace=only,trace,+log
+   " myprog
+Also, in the unlikely case when you want to concatenate specifications,
+use whitespace as separator, as C<::> will be interpreted as part of a
+module name, an empty spec with two separators:
+   PERL_ANYEVENT_LOG="$PERL_ANYEVENT_LOG MyMod=debug"
+=cut
+for (my $spec = $ENV{PERL_ANYEVENT_LOG}) {
+   my %anon;
+   my $pkg = sub {
+      $_[0] eq "log"              ? $LOG
+      : $_[0] eq "filter"         ? $FILTER
+      : $_[0] eq "collect"        ? $COLLECT
+      : $_[0] =~ /^%(.+)$/        ? ($anon{$1} ||= ctx undef)
+      : $_[0] =~ /^(.*?)(?:::)?$/ ? ctx "$1" # egad :/
+      : die # never reached?
+   };
+   /\G[[:space:]]+/gc; # skip initial whitespace
+   while (/\G((?:[^:=[:space:]]+|::|\\.)+)=/gc) {
+      my $ctx = $pkg->($1);
+      my $level = "level";
+      while (/\G((?:[^,:[:space:]]+|::|\\.)+)/gc) {
+         for ("$1") {
+            if ($_ eq "stderr"               ) { $ctx->log_to_warn;
+            } elsif (/^file=(.+)/            ) { $ctx->log_to_file ("$1");
+            } elsif (/^path=(.+)/            ) { $ctx->log_to_path ("$1");
+            } elsif (/syslog(?:=(.*))?/      ) { require Sys::Syslog; $ctx->log_to_syslog ($1);
+            } elsif ($_ eq "nolog"           ) { $ctx->log_cb (undef);
+            } elsif (/^\+(.+)$/              ) { $ctx->attach ($pkg->("$1"));
+            } elsif ($_ eq "+"               ) { $ctx->slaves;
+            } elsif ($_ eq "off" or $_ eq "0") { $ctx->level (0);
+            } elsif ($_ eq "all"             ) { $ctx->level ("all");
+            } elsif ($_ eq "level"           ) { $ctx->level ("all"); $level = "level";
+            } elsif ($_ eq "only"            ) { $ctx->level ("off"); $level = "enable";
+            } elsif ($_ eq "except"          ) { $ctx->level ("all"); $level = "disable";
+            } elsif (/^\d$/                  ) { $ctx->$level ($_);
+            } elsif (exists $STR2LEVEL{$_}   ) { $ctx->$level ($_);
+            } else                             { die "PERL_ANYEVENT_LOG ($spec): parse error at '$_'\n";
+            }
+         }
+         /\G,/gc or last;
+      }
+      /\G[:[:space:]]+/gc or last;
+   }
+   /\G[[:space:]]+/gc; # skip trailing whitespace
+   if (/\G(.+)/g) {
+      die "PERL_ANYEVENT_LOG ($spec): parse error at '$1'\n";
+   }
+}
 1;
-=back
 =head1 EXAMPLES
-This section shows some common configurations.
+This section shows some common configurations, both as code, and as
+C<PERL_ANYEVENT_LOG> string.
 =over 4
 =item Setting the global logging level.
-Either put PERL_ANYEVENT_VERBOSE=<number> into your environment before
+Either put C<PERL_ANYEVENT_VERBOSE=><number> into your environment before
-running your program, or modify the log level of the root context:
+running your program, use C<PERL_ANYEVENT_LOG> or modify the log level of
+the root context at runtime:
    PERL_ANYEVENT_VERBOSE=5 ./myprog
+   PERL_ANYEVENT_LOG=log=warn
    $AnyEvent::Log::FILTER->level ("warn");
 =item Append all messages to a file instead of sending them to STDERR.
 This is affected by the global logging level.
-   $AnyEvent::Log::LOG->log_to_file ($path); (sub {
+   $AnyEvent::Log::LOG->log_to_file ($path);
+   PERL_ANYEVENT_LOG=log=file=/some/path
 =item Write all messages with priority C<error> and higher to a file.
 This writes them only when the global logging level allows it, because
 it is attached to the default context which is invoked I<after> global
 filtering.
-   $AnyEvent::Log::FILTER->attach
+   $AnyEvent::Log::FILTER->attach (
       new AnyEvent::Log::Ctx log_to_file => $path);
+   PERL_ANYEVENT_LOG=filter=+%filelogger:%filelogger=file=/some/path
 This writes them regardless of the global logging level, because it is
 attached to the toplevel context, which receives all messages I<before>
 the global filtering.
    $AnyEvent::Log::COLLECT->attach (
       new AnyEvent::Log::Ctx log_to_file => $path);
+   PERL_ANYEVENT_LOG=%filelogger=file=/some/path:collect=+%filelogger
 In both cases, messages are still written to STDERR.
 =item Write trace messages (only) from L<AnyEvent::Debug> to the default logging target(s).
 Attach the C<$AnyEvent::Log::LOG> context to the C<AnyEvent::Debug>
 context - this simply circumvents the global filtering for trace messages.
    my $debug = AnyEvent::Debug->AnyEvent::Log::ctx;
    $debug->attach ($AnyEvent::Log::LOG);
+   PERL_ANYEVENT_LOG=AnyEvent::Debug=+log
 This of course works for any package, not just L<AnyEvent::Debug>, but
 assumes the log level for AnyEvent::Debug hasn't been changed from the
 default.
  Marc Lehmann <schmorp@schmorp.de>
  http://home.schmorp.de/
 =cut

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents): Revision 1.25 by root, Sun Aug 21 03:25:47 2011 UTC vs. Revision 1.44 by root, Mon Sep 26 11:32:19 2011 UTC

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Comparing AnyEvent/lib/AnyEvent/Log.pm (file contents):
Revision 1.25 by root, Sun Aug 21 03:25:47 2011 UTC vs.
Revision 1.44 by root, Mon Sep 26 11:32:19 2011 UTC