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package Plack::Middleware::Throttle;
use Moose;
use Carp;
use Scalar::Util;
use DateTime;
use Plack::Util;
our $VERSION = '0.01';
extends 'Plack::Middleware';
has code => ( is => 'rw', isa => 'Int', lazy => 1, default => '503' );
has message =>
( is => 'rw', isa => 'Str', lazy => 1, default => 'Over rate limit' );
has backend => ( is => 'rw', isa => 'Object', required => 1 );
has key_prefix =>
( is => 'rw', isa => 'Str', lazy => 1, default => 'throttle' );
has max => ( is => 'rw', isa => 'Int', lazy => 1, default => 100 );
sub prepare_app {
my $self = shift;
$self->backend( $self->_create_backend( $self->backend ) );
}
sub _create_backend {
my ( $self, $backend ) = @_;
if ( defined !$backend ) {
Plack::Util::load_class("Plack::Middleware::Throttle::Backend::Hash");
}
return $backend if defined $backend && Scalar::Util::blessed $backend;
die "backend must be a cache objectn";
}
sub call {
my ( $self, $env ) = @_;
my $res = $self->app->($env);
my $request_done = $self->request_done($env);
if ( $request_done > $self->max ) {
$self->over_rate_limit();
}
else {
$self->response_cb(
$res,
sub {
my $res = shift;
$self->add_headers( $res, $request_done );
}
);
}
}
sub request_done {
return 1;
}
sub over_rate_limit {
my $self = shift;
return [
$self->code,
[
'Content-Type' => 'text/plain',
'X-RateLimit-Reset' => $self->reset_time
],
[ $self->message ]
];
}
sub add_headers {
my ( $self, $res, $request_done ) = @_;
my $headers = $res->[1];
Plack::Util::header_set( $headers, 'X-RateLimit-Limit',
$self->max );
Plack::Util::header_set( $headers, 'X-RateLimit-Remaining',
( $self->max - $request_done ) );
Plack::Util::header_set( $headers, 'X-RateLimit-Reset',
$self->reset_time );
return $res;
}
sub client_identifier {
my ( $self, $env ) = @_;
if ( $env->{REMOTE_USER} ) {
return $self->key_prefix."_".$env->{REMOTE_USER};
}
else {
return $self->key_prefix."_".$env->{REMOTE_ADDR};
}
}
1;
__END__
=head1 NAME
Plack::Middleware::Throttle - A Plack Middleware for rate-limiting incoming HTTP requests.
=head1 SYNOPSIS
=head1 DESCRIPTION
Set a limit on how many requests per hour is allowed on your API. In of a authorized request, 3 headers are added:
=over 2
=item B<X-RateLimit-Limit>
How many requests are authorized by hours
=item B<X-RateLimit-Remaining>
How many remaining requests
=item B<X-RateLimit-Reset>
When will the counter be reseted (in epoch)
=back
=head2 VARIABLES
=over 4
=item B<backend>
Which backend to use. Currently only Hash and Redis are supported. If no
backend is specified, Hash is used by default. Backend must implement B<set>,
B<get> and B<incr>.
=item B<code>
HTTP code that will be returned when too many connections have been reached.
=item B<message>
HTTP message that will be returned when too many connections have been reached.
=back
=head1 AUTHOR
franck cuny E<lt>franck@lumberjaph.netE<gt>
=head1 SEE ALSO
=head1 LICENSE
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut
|
