NAME

NAME
Apache::LogFormat::Compiler - Compile a log format string to perl-code

SYNOPSIS
use Apache::LogFormat::Compiler;

my $log_handler = Apache::LogFormat::Compiler->new("combined");
my $log = $log_handler->log_line(
$env,
$res,
$length,
$reqtime,
$time
);

DESCRIPTION
Compile a log format string to perl-code. For faster generating
access_log line.

METHOD
new($fmt:String)
Takes a format string (or a preset template "combined" or "custom")
to specify the log format. This middleware implements a subset of
Apache's LogFormat templates
<http://httpd.apache.org/docs/2.0/mod/mod_log_config.html>:

%% a percent sign
%h REMOTE_ADDR from the PSGI environment, or -
%l remote logname not implemented (currently always -)
%u REMOTE_USER from the PSGI environment, or -
%t [local timestamp, in default format]
%r REQUEST_METHOD, REQUEST_URI and SERVER_PROTOCOL from the PSGI environment
%s the HTTP status code of the response
%b content length of the response
%T custom field for handling times in subclasses
%D custom field for handling sub-second times in subclasses
%v SERVER_NAME from the PSGI environment, or -
%V HTTP_HOST or SERVER_NAME from the PSGI environment, or -
%p SERVER_PORT from the PSGI environment
%P the worker's process id
%m REQUEST_METHOD from the PSGI environment
%U PATH_INFO from the PSGI environment
%q QUERY_STRING from the PSGI environment
%H SERVER_PROTOCOL from the PSGI environment

In addition, custom values can be referenced, using "%{name}", with
one of the mandatory modifier flags "i", "o" or "t":

%{variable-name}i HTTP_VARIABLE_NAME value from the PSGI environment
%{header-name}o header-name header in the response
%{time-format]t localtime in the specified strftime format

log_line($env:HashRef,$res:ArrayRef,$length:Integer,$reqtime:Integer,$ti
me:Integer): $log:String
Generates log line.

$env PSGI env request HashRef
$res PSGI response ArrayRef
$length Content-Length
$reqtime The time taken to serve request in microseconds. optional
$time Time the request was received. optional. If $time is undefined. current timestamp is used.

Sample psgi

use Plack::Builder;
use Time::HiRes;
use Apache::LogFormat::Compiler;

my $log_handler = Apache::LogFormat::Compiler->new(
'%h %l %u %t "%r" %>s %b "%{Referer}i" "%{User-agent}i" %D'
);
my $compile_log_app = builder {
enable sub {
my $app = shift;
sub {
my $env = shift;
my $t0 = [gettimeofday];
my $res = $app->();
my $reqtime = int(Time::HiRes::tv_interval($t0) * 1_000_000);
$env->{psgi.error}->print($log_handler->log_line(
$env,$res,6,$reqtime, $t0->[0]));
}
};
$app
};

ADD CUSTOM FORMAT STRING
Apache::LogFormat::Compiler allows to add custom format string

my $log_handler = Apache::LogFormat::Compiler->new(
'%z %{HTTP_X_FORWARDED_FOR|REMOTE_ADDR}Z',
char_handlers => +{
'z' => sub {
my ($env,$req) = @_;
return $env->{HTTP_X_FORWARDED_FOR};
}
},
block_handlers => +{
'Z' => sub {
my ($block,$env,$req) = @_;
# block eq 'HTTP_X_FORWARDED_FOR|REMOTE_ADDR'
my ($main, $alt) = split('\|', $args);
return exists $env->{$main} ? $env->{$main} : $env->{$alt};
}
},
);

Any single letter can be used other than Apache::LogFormat::Compiler
used. Your sub is called with two or three arguments the content inside
the "{}" from the format (block_handlers only), PSGI environment ($env),
and ArrayRef of the response. It should return the string to be logged

AUTHOR
Masahiro Nagano <[email protected]>

SEE ALSO
Plack::Middleware::AccessLog,
<http://httpd.apache.org/docs/2.2/mod/mod_log_config.html>

LICENSE
Copyright (C) Masahiro Nagano

This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.