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3 | AnyEvent::Log - simple logging "framework" |
3 | AnyEvent::Log - simple logging "framework" |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
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7 | Simple uses: |
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8 | |
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9 | use AnyEvent; |
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10 | |
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11 | AE::log debug => "hit my knee"; |
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12 | AE::log warn => "it's a bit too hot"; |
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13 | AE::log error => "the flag was false!"; |
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14 | AE::log fatal => "the bit toggled! run!"; # never returns |
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15 | |
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16 | "Complex" uses (for speed sensitive code): |
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17 | |
7 | use AnyEvent::Log; |
18 | use AnyEvent::Log; |
8 | |
19 | |
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20 | my $tracer = AnyEvent::Log::logger trace => \$my $trace; |
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21 | |
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22 | $tracer->("i am here") if $trace; |
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23 | $tracer->(sub { "lots of data: " . Dumper $self }) if $trace; |
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24 | |
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25 | Configuration (also look at the EXAMPLES section): |
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26 | |
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27 | # set logging for the current package to errors and higher only |
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28 | AnyEvent::Log::ctx->level ("error"); |
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29 | |
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30 | # set logging level to suppress anything below "notice" |
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31 | $AnyEvent::Log::FILTER->level ("notice"); |
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32 | |
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33 | # send all critical and higher priority messages to syslog, |
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34 | # regardless of (most) other settings |
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35 | $AnyEvent::Log::COLLECT->attach (new AnyEvent::Log::Ctx |
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36 | level => "critical", |
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37 | log_to_syslog => 0, |
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38 | ); |
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39 | |
9 | =head1 DESCRIPTION |
40 | =head1 DESCRIPTION |
10 | |
41 | |
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42 | This module implements a relatively simple "logging framework". It doesn't |
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43 | attempt to be "the" logging solution or even "a" logging solution for |
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44 | AnyEvent - AnyEvent simply creates logging messages internally, and this |
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45 | module more or less exposes the mechanism, with some extra spiff to allow |
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46 | using it from other modules as well. |
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47 | |
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48 | Remember that the default verbosity level is C<0> (C<off>), so nothing |
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49 | will be logged, unless you set C<PERL_ANYEVENT_VERBOSE> to a higher number |
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50 | before starting your program, or change the logging level at runtime with |
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51 | something like: |
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52 | |
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53 | use AnyEvent::Log; |
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54 | AnyEvent::Log::FILTER->level ("info"); |
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55 | |
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56 | The design goal behind this module was to keep it simple (and small), |
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57 | but make it powerful enough to be potentially useful for any module, and |
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58 | extensive enough for the most common tasks, such as logging to multiple |
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59 | targets, or being able to log into a database. |
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60 | |
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61 | The amount of documentation might indicate otherwise, but the module is |
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62 | still just below 300 lines of code. |
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63 | |
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64 | =head1 LOGGING LEVELS |
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65 | |
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66 | Logging levels in this module range from C<1> (highest priority) to C<9> |
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67 | (lowest priority). Note that the lowest numerical value is the highest |
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68 | priority, so when this document says "higher priority" it means "lower |
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69 | numerical value". |
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70 | |
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71 | Instead of specifying levels by name you can also specify them by aliases: |
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72 | |
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73 | LVL NAME SYSLOG PERL NOTE |
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74 | 1 fatal emerg exit aborts program! |
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75 | 2 alert |
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76 | 3 critical crit |
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77 | 4 error err die |
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78 | 5 warn warning |
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79 | 6 note notice |
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80 | 7 info |
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81 | 8 debug |
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82 | 9 trace |
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83 | |
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84 | As you can see, some logging levels have multiple aliases - the first one |
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85 | is the "official" name, the second one the "syslog" name (if it differs) |
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86 | and the third one the "perl" name, suggesting that you log C<die> messages |
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87 | at C<error> priority. |
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88 | |
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89 | You can normally only log a single message at highest priority level |
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90 | (C<1>, C<fatal>), because logging a fatal message will also quit the |
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91 | program - so use it sparingly :) |
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92 | |
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93 | Some methods also offer some extra levels, such as C<0>, C<off>, C<none> |
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94 | or C<all> - these are only valid in the methods they are documented for. |
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95 | |
11 | =head1 FUNCTIONS |
96 | =head1 LOGGING FUNCTIONS |
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97 | |
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98 | These functions allow you to log messages. They always use the caller's |
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99 | package as a "logging context". Also, the main logging function C<log> is |
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100 | callable as C<AnyEvent::log> or C<AE::log> when the C<AnyEvent> module is |
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101 | loaded. |
12 | |
102 | |
13 | =over 4 |
103 | =over 4 |
14 | |
104 | |
15 | =cut |
105 | =cut |
16 | |
106 | |
17 | package AnyEvent::Log; |
107 | package AnyEvent::Log; |
18 | |
108 | |
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109 | use Carp (); |
19 | use POSIX (); |
110 | use POSIX (); |
20 | |
111 | |
21 | use AnyEvent (); BEGIN { AnyEvent::common_sense } |
112 | use AnyEvent (); BEGIN { AnyEvent::common_sense } |
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113 | use AnyEvent::Util (); |
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114 | |
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115 | our $VERSION = $AnyEvent::VERSION; |
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116 | |
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117 | our ($COLLECT, $FILTER, $LOG); |
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118 | |
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119 | our ($now_int, $now_str1, $now_str2); |
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120 | |
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121 | # Format Time, not public - yet? |
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122 | sub ft($) { |
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123 | my $i = int $_[0]; |
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124 | my $f = sprintf "%06d", 1e6 * ($_[0] - $i); |
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125 | |
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126 | ($now_int, $now_str1, $now_str2) = ($i, split /\x01/, POSIX::strftime "%Y-%m-%d %H:%M:%S.\x01 %z", localtime $i) |
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127 | if $now_int != $i; |
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128 | |
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129 | "$now_str1$f$now_str2" |
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130 | } |
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131 | |
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132 | our %CTX; # all package contexts |
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133 | |
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134 | # creates a default package context object for the given package |
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135 | sub _pkg_ctx($) { |
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136 | my $ctx = bless [$_[0], (1 << 10) - 1 - 1, {}], "AnyEvent::Log::Ctx"; |
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137 | |
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138 | # link "parent" package |
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139 | my $parent = $_[0] =~ /^(.+)::/ |
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140 | ? $CTX{$1} ||= &_pkg_ctx ("$1") |
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141 | : $COLLECT; |
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142 | |
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143 | $ctx->[2]{$parent+0} = $parent; |
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144 | |
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145 | $ctx |
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146 | } |
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147 | |
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148 | =item AnyEvent::Log::log $level, $msg[, @args] |
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149 | |
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150 | Requests logging of the given C<$msg> with the given log level, and |
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151 | returns true if the message was logged I<somewhere>. |
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152 | |
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153 | For C<fatal> log levels, the program will abort. |
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154 | |
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155 | If only a C<$msg> is given, it is logged as-is. With extra C<@args>, the |
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156 | C<$msg> is interpreted as an sprintf format string. |
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157 | |
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158 | The C<$msg> should not end with C<\n>, but may if that is convenient for |
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159 | you. Also, multiline messages are handled properly. |
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160 | |
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161 | Last not least, C<$msg> might be a code reference, in which case it is |
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162 | supposed to return the message. It will be called only then the message |
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163 | actually gets logged, which is useful if it is costly to create the |
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164 | message in the first place. |
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165 | |
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166 | Whether the given message will be logged depends on the maximum log level |
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167 | and the caller's package. The return value can be used to ensure that |
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168 | messages or not "lost" - for example, when L<AnyEvent::Debug> detects a |
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169 | runtime error it tries to log it at C<die> level, but if that message is |
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170 | lost it simply uses warn. |
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171 | |
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172 | Note that you can (and should) call this function as C<AnyEvent::log> or |
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173 | C<AE::log>, without C<use>-ing this module if possible (i.e. you don't |
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174 | need any additional functionality), as those functions will load the |
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175 | logging module on demand only. They are also much shorter to write. |
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176 | |
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177 | Also, if you optionally generate a lot of debug messages (such as when |
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178 | tracing some code), you should look into using a logger callback and a |
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179 | boolean enabler (see C<logger>, below). |
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180 | |
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181 | Example: log something at error level. |
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182 | |
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183 | AE::log error => "something"; |
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184 | |
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185 | Example: use printf-formatting. |
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186 | |
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187 | AE::log info => "%5d %-10.10s %s", $index, $category, $msg; |
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188 | |
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189 | Example: only generate a costly dump when the message is actually being logged. |
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190 | |
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191 | AE::log debug => sub { require Data::Dump; Data::Dump::dump \%cache }; |
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192 | |
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193 | =cut |
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194 | |
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195 | # also allow syslog equivalent names |
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196 | our %STR2LEVEL = ( |
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197 | fatal => 1, emerg => 1, exit => 1, |
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198 | alert => 2, |
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199 | critical => 3, crit => 3, |
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200 | error => 4, err => 4, die => 4, |
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201 | warn => 5, warning => 5, |
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202 | note => 6, notice => 6, |
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203 | info => 7, |
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204 | debug => 8, |
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205 | trace => 9, |
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206 | ); |
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207 | |
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208 | sub now () { time } |
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209 | |
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210 | AnyEvent::post_detect { |
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211 | *now = \&AE::now; |
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212 | }; |
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213 | |
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214 | our @LEVEL2STR = qw(0 fatal alert crit error warn note info debug trace); |
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215 | |
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216 | # time, ctx, level, msg |
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217 | sub _format($$$$) { |
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218 | my $ts = ft $_[0]; |
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219 | my $ct = " "; |
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220 | |
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221 | my @res; |
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222 | |
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223 | for (split /\n/, sprintf "%-5s %s: %s", $LEVEL2STR[$_[2]], $_[1][0], $_[3]) { |
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224 | push @res, "$ts$ct$_\n"; |
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225 | $ct = " + "; |
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226 | } |
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227 | |
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228 | join "", @res |
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229 | } |
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230 | |
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231 | sub _log { |
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232 | my ($ctx, $level, $format, @args) = @_; |
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233 | |
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234 | $level = $level > 0 && $level <= 9 |
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235 | ? $level+0 |
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236 | : $STR2LEVEL{$level} || Carp::croak "$level: not a valid logging level, caught"; |
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237 | |
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238 | my $mask = 1 << $level; |
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239 | |
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240 | my ($success, %seen, @ctx, $now, $fmt); |
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241 | |
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242 | do |
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243 | { |
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244 | # skip if masked |
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245 | if ($ctx->[1] & $mask && !$seen{$ctx+0}++) { |
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246 | if ($ctx->[3]) { |
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247 | # logging target found |
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248 | |
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249 | # now get raw message, unless we have it already |
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250 | unless ($now) { |
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251 | $format = $format->() if ref $format; |
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252 | $format = sprintf $format, @args if @args; |
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253 | $format =~ s/\n$//; |
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254 | $now = AE::now; |
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255 | }; |
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256 | |
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257 | # format msg |
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258 | my $str = $ctx->[4] |
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259 | ? $ctx->[4]($now, $_[0], $level, $format) |
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260 | : ($fmt ||= _format $now, $_[0], $level, $format); |
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261 | |
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262 | $success = 1; |
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263 | |
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264 | $ctx->[3]($str) |
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265 | or push @ctx, values %{ $ctx->[2] }; # not consumed - propagate |
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266 | } else { |
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267 | push @ctx, values %{ $ctx->[2] }; # not masked - propagate |
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268 | } |
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269 | } |
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270 | } |
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271 | while $ctx = pop @ctx; |
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272 | |
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273 | exit 1 if $level <= 1; |
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274 | |
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275 | $success |
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276 | } |
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277 | |
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278 | sub log($$;@) { |
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279 | _log |
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280 | $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0], |
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281 | @_; |
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282 | } |
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283 | |
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284 | *AnyEvent::log = *AE::log = \&log; |
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285 | |
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286 | =item $logger = AnyEvent::Log::logger $level[, \$enabled] |
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287 | |
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288 | Creates a code reference that, when called, acts as if the |
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289 | C<AnyEvent::Log::log> function was called at this point with the given |
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290 | level. C<$logger> is passed a C<$msg> and optional C<@args>, just as with |
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291 | the C<AnyEvent::Log::log> function: |
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292 | |
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293 | my $debug_log = AnyEvent::Log::logger "debug"; |
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294 | |
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295 | $debug_log->("debug here"); |
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296 | $debug_log->("%06d emails processed", 12345); |
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297 | $debug_log->(sub { $obj->as_string }); |
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298 | |
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299 | The idea behind this function is to decide whether to log before actually |
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300 | logging - when the C<logger> function is called once, but the returned |
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301 | logger callback often, then this can be a tremendous speed win. |
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302 | |
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303 | Despite this speed advantage, changes in logging configuration will |
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304 | still be reflected by the logger callback, even if configuration changes |
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305 | I<after> it was created. |
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306 | |
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307 | To further speed up logging, you can bind a scalar variable to the logger, |
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308 | which contains true if the logger should be called or not - if it is |
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309 | false, calling the logger can be safely skipped. This variable will be |
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310 | updated as long as C<$logger> is alive. |
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311 | |
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312 | Full example: |
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313 | |
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314 | # near the init section |
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315 | use AnyEvent::Log; |
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316 | |
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317 | my $debug_log = AnyEvent:Log::logger debug => \my $debug; |
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318 | |
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319 | # and later in your program |
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320 | $debug_log->("yo, stuff here") if $debug; |
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321 | |
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322 | $debug and $debug_log->("123"); |
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323 | |
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324 | =cut |
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325 | |
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326 | our %LOGGER; |
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327 | |
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328 | # re-assess logging status for all loggers |
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329 | sub _reassess { |
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330 | local $SIG{__DIE__}; |
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331 | my $die = sub { die }; |
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332 | |
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333 | for (@_ ? $LOGGER{$_[0]} : values %LOGGER) { |
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334 | my ($ctx, $level, $renabled) = @$_; |
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335 | |
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336 | # to detect whether a message would be logged, we actually |
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337 | # try to log one and die. this isn't fast, but we can be |
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338 | # sure that the logging decision is correct :) |
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339 | |
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340 | $$renabled = !eval { |
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341 | _log $ctx, $level, $die; |
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342 | |
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343 | 1 |
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344 | }; |
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345 | } |
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346 | } |
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347 | |
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348 | sub _logger { |
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349 | my ($ctx, $level, $renabled) = @_; |
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350 | |
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351 | $$renabled = 1; |
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352 | |
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353 | my $logger = [$ctx, $level, $renabled]; |
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354 | |
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355 | $LOGGER{$logger+0} = $logger; |
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356 | |
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357 | _reassess $logger+0; |
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358 | |
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359 | my $guard = AnyEvent::Util::guard { |
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360 | # "clean up" |
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361 | delete $LOGGER{$logger+0}; |
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362 | }; |
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363 | |
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364 | sub { |
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365 | $guard if 0; # keep guard alive, but don't cause runtime overhead |
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366 | |
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367 | _log $ctx, $level, @_ |
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368 | if $$renabled; |
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369 | } |
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370 | } |
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371 | |
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372 | sub logger($;$) { |
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373 | _logger |
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374 | $CTX{ (caller)[0] } ||= _pkg_ctx +(caller)[0], |
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375 | @_ |
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376 | } |
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377 | |
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378 | =back |
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379 | |
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380 | =head1 LOGGING CONTEXTS |
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381 | |
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382 | This module associates every log message with a so-called I<logging |
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383 | context>, based on the package of the caller. Every perl package has its |
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384 | own logging context. |
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385 | |
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386 | A logging context has three major responsibilities: filtering, logging and |
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387 | propagating the message. |
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388 | |
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389 | For the first purpose, filtering, each context has a set of logging |
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390 | levels, called the log level mask. Messages not in the set will be ignored |
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391 | by this context (masked). |
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392 | |
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393 | For logging, the context stores a formatting callback (which takes the |
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394 | timestamp, context, level and string message and formats it in the way |
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395 | it should be logged) and a logging callback (which is responsible for |
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396 | actually logging the formatted message and telling C<AnyEvent::Log> |
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397 | whether it has consumed the message, or whether it should be propagated). |
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398 | |
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399 | For propagation, a context can have any number of attached I<slave |
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400 | contexts>. Any message that is neither masked by the logging mask nor |
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401 | masked by the logging callback returning true will be passed to all slave |
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402 | contexts. |
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403 | |
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404 | Each call to a logging function will log the message at most once per |
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405 | context, so it does not matter (much) if there are cycles or if the |
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406 | message can arrive at the same context via multiple paths. |
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407 | |
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408 | =head2 DEFAULTS |
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409 | |
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410 | By default, all logging contexts have an full set of log levels ("all"), a |
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411 | disabled logging callback and the default formatting callback. |
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412 | |
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413 | Package contexts have the package name as logging title by default. |
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414 | |
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415 | They have exactly one slave - the context of the "parent" package. The |
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416 | parent package is simply defined to be the package name without the last |
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417 | component, i.e. C<AnyEvent::Debug::Wrapped> becomes C<AnyEvent::Debug>, |
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418 | and C<AnyEvent> becomes ... C<$AnyEvent::Log::COLLECT> which is the |
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419 | exception of the rule - just like the "parent" of any single-component |
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420 | package name in Perl is C<main>, the default slave of any top-level |
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421 | package context is C<$AnyEvent::Log::COLLECT>. |
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422 | |
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423 | Since perl packages form only an approximate hierarchy, this slave |
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424 | context can of course be removed. |
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425 | |
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426 | All other (anonymous) contexts have no slaves and an empty title by |
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427 | default. |
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428 | |
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429 | When the module is loaded it creates the C<$AnyEvent::Log::LOG> logging |
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430 | context that simply logs everything via C<warn>, without propagating |
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431 | anything anywhere by default. The purpose of this context is to provide |
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432 | a convenient place to override the global logging target or to attach |
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433 | additional log targets. It's not meant for filtering. |
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434 | |
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435 | It then creates the C<$AnyEvent::Log::FILTER> context whose |
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436 | purpose is to suppress all messages with priority higher |
|
|
437 | than C<$ENV{PERL_ANYEVENT_VERBOSE}>. It then attached the |
|
|
438 | C<$AnyEvent::Log::LOG> context to it. The purpose of the filter context |
|
|
439 | is to simply provide filtering according to some global log level. |
|
|
440 | |
|
|
441 | Finally it creates the top-level package context C<$AnyEvent::Log::COLLECT> |
|
|
442 | and attaches the C<$AnyEvent::Log::FILTER> context to it, but otherwise |
|
|
443 | leaves it at default config. Its purpose is simply to collect all log |
|
|
444 | messages system-wide. |
|
|
445 | |
|
|
446 | The hierarchy is then: |
|
|
447 | |
|
|
448 | any package, eventually -> $COLLECT -> $FILTER -> $LOG |
|
|
449 | |
|
|
450 | The effect of all this is that log messages, by default, wander up to the |
|
|
451 | C<$AnyEvent::Log::COLLECT> context where all messages normally end up, |
|
|
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>. |
|
|
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 | |
|
|
466 | =head2 CREATING/FINDING/DESTROYING CONTEXTS |
|
|
467 | |
|
|
468 | =over 4 |
|
|
469 | |
|
|
470 | =item $ctx = AnyEvent::Log::ctx [$pkg] |
|
|
471 | |
|
|
472 | This function creates or returns a logging context (which is an object). |
|
|
473 | |
|
|
474 | If a package name is given, then the context for that packlage is |
|
|
475 | returned. If it is called without any arguments, then the context for the |
|
|
476 | callers package is returned (i.e. the same context as a C<AE::log> call |
|
|
477 | would use). |
|
|
478 | |
|
|
479 | If C<undef> is given, then it creates a new anonymous context that is not |
|
|
480 | tied to any package and is destroyed when no longer referenced. |
|
|
481 | |
|
|
482 | =cut |
|
|
483 | |
|
|
484 | sub ctx(;$) { |
|
|
485 | my $pkg = @_ ? shift : (caller)[0]; |
|
|
486 | |
|
|
487 | ref $pkg |
|
|
488 | ? $pkg |
|
|
489 | : defined $pkg |
|
|
490 | ? $CTX{$pkg} ||= AnyEvent::Log::_pkg_ctx $pkg |
|
|
491 | : bless [undef, (1 << 10) - 1 - 1], "AnyEvent::Log::Ctx" |
|
|
492 | } |
|
|
493 | |
|
|
494 | =item AnyEvent::Log::reset |
|
|
495 | |
|
|
496 | Resets all package contexts and recreates the default hierarchy if |
|
|
497 | necessary, i.e. resets the logging subsystem to defaults, as much as |
|
|
498 | possible. This process keeps references to contexts held by other parts of |
|
|
499 | the program intact. |
|
|
500 | |
|
|
501 | This can be used to implement config-file (re-)loading: before loading a |
|
|
502 | configuration, reset all contexts. |
|
|
503 | |
|
|
504 | =cut |
|
|
505 | |
|
|
506 | sub reset { |
|
|
507 | # hard to kill complex data structures |
|
|
508 | # we "recreate" all package loggers and reset the hierarchy |
|
|
509 | while (my ($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'); |
|
|
520 | $LOG->log_cb (sub { |
|
|
521 | warn shift; |
|
|
522 | 0 |
|
|
523 | }); |
|
|
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; |
|
|
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 | ; |
|
|
574 | |
|
|
575 | =back |
|
|
576 | |
|
|
577 | =cut |
|
|
578 | |
|
|
579 | sub new { |
|
|
580 | my $class = shift; |
|
|
581 | |
|
|
582 | my $ctx = AnyEvent::Log::ctx undef; |
|
|
583 | |
|
|
584 | while (@_) { |
|
|
585 | my ($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 | |
|
|
592 | |
|
|
593 | =head2 CONFIGURING A LOG CONTEXT |
|
|
594 | |
|
|
595 | The following methods can be used to configure the logging context. |
|
|
596 | |
|
|
597 | =over 4 |
|
|
598 | |
|
|
599 | =item $ctx->title ([$new_title]) |
|
|
600 | |
|
|
601 | Returns the title of the logging context - this is the package name, for |
|
|
602 | package contexts, and a user defined string for all others. |
|
|
603 | |
|
|
604 | If C<$new_title> is given, then it replaces the package name or title. |
|
|
605 | |
|
|
606 | =cut |
|
|
607 | |
|
|
608 | sub title { |
|
|
609 | $_[0][0] = $_[1] if @_ > 1; |
|
|
610 | $_[0][0] |
|
|
611 | } |
|
|
612 | |
|
|
613 | =back |
|
|
614 | |
|
|
615 | =head3 LOGGING LEVELS |
|
|
616 | |
|
|
617 | The following methods deal with the logging level set associated with the |
|
|
618 | log context. |
|
|
619 | |
|
|
620 | The most common method to use is probably C<< $ctx->level ($level) >>, |
|
|
621 | which configures the specified and any higher priority levels. |
|
|
622 | |
|
|
623 | All functions which accept a list of levels also accept the special string |
|
|
624 | C<all> which expands to all logging levels. |
|
|
625 | |
|
|
626 | =over 4 |
|
|
627 | |
|
|
628 | =item $ctx->levels ($level[, $level...) |
|
|
629 | |
|
|
630 | Enables logging for the given levels and disables it for all others. |
|
|
631 | |
|
|
632 | =item $ctx->level ($level) |
|
|
633 | |
|
|
634 | Enables logging for the given level and all lower level (higher priority) |
|
|
635 | ones. In addition to normal logging levels, specifying a level of C<0> or |
|
|
636 | C<off> disables all logging for this level. |
|
|
637 | |
|
|
638 | Example: log warnings, errors and higher priority messages. |
|
|
639 | |
|
|
640 | $ctx->level ("warn"); |
|
|
641 | $ctx->level (5); # same thing, just numeric |
|
|
642 | |
|
|
643 | =item $ctx->enable ($level[, $level...]) |
|
|
644 | |
|
|
645 | Enables logging for the given levels, leaving all others unchanged. |
|
|
646 | |
|
|
647 | =item $ctx->disable ($level[, $level...]) |
|
|
648 | |
|
|
649 | Disables logging for the given levels, leaving all others unchanged. |
|
|
650 | |
|
|
651 | =cut |
|
|
652 | |
|
|
653 | sub _lvl_lst { |
|
|
654 | map { |
|
|
655 | $_ > 0 && $_ <= 9 ? $_+0 |
|
|
656 | : $_ eq "all" ? (1 .. 9) |
|
|
657 | : $STR2LEVEL{$_} || Carp::croak "$_: not a valid logging level, caught" |
|
|
658 | } @_ |
|
|
659 | } |
|
|
660 | |
|
|
661 | our $NOP_CB = sub { 0 }; |
|
|
662 | |
|
|
663 | sub levels { |
|
|
664 | my $ctx = shift; |
|
|
665 | $ctx->[1] = 0; |
|
|
666 | $ctx->[1] |= 1 << $_ |
|
|
667 | for &_lvl_lst; |
|
|
668 | AnyEvent::Log::_reassess; |
|
|
669 | } |
|
|
670 | |
|
|
671 | sub level { |
|
|
672 | my $ctx = shift; |
|
|
673 | my $lvl = $_[0] =~ /^(?:0|off|none)$/ ? 0 : (_lvl_lst $_[0])[-1]; |
|
|
674 | |
|
|
675 | $ctx->[1] = ((1 << $lvl) - 1) << 1; |
|
|
676 | AnyEvent::Log::_reassess; |
|
|
677 | } |
|
|
678 | |
|
|
679 | sub enable { |
|
|
680 | my $ctx = shift; |
|
|
681 | $ctx->[1] |= 1 << $_ |
|
|
682 | for &_lvl_lst; |
|
|
683 | AnyEvent::Log::_reassess; |
|
|
684 | } |
|
|
685 | |
|
|
686 | sub disable { |
|
|
687 | my $ctx = shift; |
|
|
688 | $ctx->[1] &= ~(1 << $_) |
|
|
689 | for &_lvl_lst; |
|
|
690 | AnyEvent::Log::_reassess; |
|
|
691 | } |
|
|
692 | |
|
|
693 | =back |
|
|
694 | |
|
|
695 | =head3 SLAVE CONTEXTS |
|
|
696 | |
|
|
697 | The following methods attach and detach another logging context to a |
|
|
698 | logging context. |
|
|
699 | |
|
|
700 | Log messages are propagated to all slave contexts, unless the logging |
|
|
701 | callback consumes the message. |
|
|
702 | |
|
|
703 | =over 4 |
|
|
704 | |
|
|
705 | =item $ctx->attach ($ctx2[, $ctx3...]) |
|
|
706 | |
|
|
707 | Attaches the given contexts as slaves to this context. It is not an error |
|
|
708 | to add a context twice (the second add will be ignored). |
|
|
709 | |
|
|
710 | A context can be specified either as package name or as a context object. |
|
|
711 | |
|
|
712 | =item $ctx->detach ($ctx2[, $ctx3...]) |
|
|
713 | |
|
|
714 | Removes the given slaves from this context - it's not an error to attempt |
|
|
715 | to remove a context that hasn't been added. |
|
|
716 | |
|
|
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. |
|
|
722 | |
|
|
723 | =cut |
|
|
724 | |
|
|
725 | sub attach { |
|
|
726 | my $ctx = shift; |
|
|
727 | |
|
|
728 | $ctx->[2]{$_+0} = $_ |
|
|
729 | for map { AnyEvent::Log::ctx $_ } @_; |
|
|
730 | } |
|
|
731 | |
|
|
732 | sub detach { |
|
|
733 | my $ctx = shift; |
|
|
734 | |
|
|
735 | delete $ctx->[2]{$_+0} |
|
|
736 | for map { AnyEvent::Log::ctx $_ } @_; |
|
|
737 | } |
|
|
738 | |
|
|
739 | sub slaves { |
|
|
740 | undef $_[0][2]; |
|
|
741 | &attach; |
|
|
742 | } |
|
|
743 | |
|
|
744 | =back |
|
|
745 | |
|
|
746 | =head3 LOG TARGETS |
|
|
747 | |
|
|
748 | The following methods configure how the logging context actually does |
|
|
749 | the logging (which consists of formatting the message and printing it or |
|
|
750 | whatever it wants to do with it). |
|
|
751 | |
|
|
752 | =over 4 |
|
|
753 | |
|
|
754 | =item $ctx->log_cb ($cb->($str) |
|
|
755 | |
|
|
756 | Replaces the logging callback on the context (C<undef> disables the |
|
|
757 | logging callback). |
|
|
758 | |
|
|
759 | The logging callback is responsible for handling formatted log messages |
|
|
760 | (see C<fmt_cb> below) - normally simple text strings that end with a |
|
|
761 | newline (and are possibly multiline themselves). |
|
|
762 | |
|
|
763 | It also has to return true iff it has consumed the log message, and false |
|
|
764 | if it hasn't. Consuming a message means that it will not be sent to any |
|
|
765 | slave context. When in doubt, return C<0> from your logging callback. |
|
|
766 | |
|
|
767 | Example: a very simple logging callback, simply dump the message to STDOUT |
|
|
768 | and do not consume it. |
|
|
769 | |
|
|
770 | $ctx->log_cb (sub { print STDERR shift; 0 }); |
|
|
771 | |
|
|
772 | You can filter messages by having a log callback that simply returns C<1> |
|
|
773 | and does not do anything with the message, but this counts as "message |
|
|
774 | being logged" and might not be very efficient. |
|
|
775 | |
|
|
776 | Example: propagate all messages except for log levels "debug" and |
|
|
777 | "trace". The messages will still be generated, though, which can slow down |
|
|
778 | your program. |
|
|
779 | |
|
|
780 | $ctx->levels ("debug", "trace"); |
|
|
781 | $ctx->log_cb (sub { 1 }); # do not log, but eat debug and trace messages |
|
|
782 | |
|
|
783 | =item $ctx->fmt_cb ($fmt_cb->($timestamp, $orig_ctx, $level, $message)) |
|
|
784 | |
|
|
785 | Replaces the formatting callback on the context (C<undef> restores the |
|
|
786 | default formatter). |
|
|
787 | |
|
|
788 | The callback is passed the (possibly fractional) timestamp, the original |
|
|
789 | logging context, the (numeric) logging level and the raw message string |
|
|
790 | and needs to return a formatted log message. In most cases this will be a |
|
|
791 | string, but it could just as well be an array reference that just stores |
|
|
792 | the values. |
|
|
793 | |
|
|
794 | If, for some reason, you want to use C<caller> to find out more baout the |
|
|
795 | logger then you should walk up the call stack until you are no longer |
|
|
796 | inside the C<AnyEvent::Log> package. |
|
|
797 | |
|
|
798 | Example: format just the raw message, with numeric log level in angle |
|
|
799 | brackets. |
|
|
800 | |
|
|
801 | $ctx->fmt_cb (sub { |
|
|
802 | my ($time, $ctx, $lvl, $msg) = @_; |
|
|
803 | |
|
|
804 | "<$lvl>$msg\n" |
|
|
805 | }); |
|
|
806 | |
|
|
807 | Example: return an array reference with just the log values, and use |
|
|
808 | C<PApp::SQL::sql_exec> to store the emssage in a database. |
|
|
809 | |
|
|
810 | $ctx->fmt_cb (sub { \@_ }); |
|
|
811 | $ctx->log_cb (sub { |
|
|
812 | my ($msg) = @_; |
|
|
813 | |
|
|
814 | sql_exec "insert into log (when, subsys, prio, msg) values (?, ?, ?, ?)", |
|
|
815 | $msg->[0] + 0, |
|
|
816 | "$msg->[1]", |
|
|
817 | $msg->[2] + 0, |
|
|
818 | "$msg->[3]"; |
|
|
819 | |
|
|
820 | 0 |
|
|
821 | }); |
|
|
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, $str] as input. |
|
|
842 | |
|
|
843 | =cut |
|
|
844 | |
|
|
845 | sub log_cb { |
|
|
846 | my ($ctx, $cb) = @_; |
|
|
847 | |
|
|
848 | $ctx->[3] = $cb; |
|
|
849 | } |
|
|
850 | |
|
|
851 | sub fmt_cb { |
|
|
852 | my ($ctx, $cb) = @_; |
|
|
853 | |
|
|
854 | $ctx->[4] = $cb; |
|
|
855 | } |
|
|
856 | |
|
|
857 | sub log_to_file { |
|
|
858 | my ($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 | |
|
|
912 | =item $ctx->log ($level, $msg[, @params]) |
|
|
913 | |
|
|
914 | Same as C<AnyEvent::Log::log>, but uses the given context as log context. |
|
|
915 | |
|
|
916 | =item $logger = $ctx->logger ($level[, \$enabled]) |
|
|
917 | |
|
|
918 | Same as C<AnyEvent::Log::logger>, but uses the given context as log |
|
|
919 | context. |
|
|
920 | |
|
|
921 | =cut |
|
|
922 | |
|
|
923 | *log = \&AnyEvent::Log::_log; |
|
|
924 | *logger = \&AnyEvent::Log::_logger; |
22 | |
925 | |
23 | 1; |
926 | 1; |
|
|
927 | |
|
|
928 | =back |
|
|
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. |
24 | |
980 | |
25 | =back |
981 | =back |
26 | |
982 | |
27 | =head1 AUTHOR |
983 | =head1 AUTHOR |
28 | |
984 | |