NAME

AnyEvent::Handle::Throttle - AnyEvent::Handle subclass with user-defined up/down bandwidth cap

Synopsis

use AnyEvent;
use AnyEvent::Handle::Throttle;
my $condvar = AnyEvent->condvar;
my $handle;
$handle = AnyEvent::Handle::Throttle->new(
    upload_limit   => 2,  # Very...
    download_limit => 50, # ...slow
    connect  => ['google.com', 'http'],
    on_error => sub {
        warn "error $_[2]\n";
        $_[0]->destroy;
        $condvar->send;
    },
    on_eof => sub {
        $handle->destroy;
        warn "done.\n";
        $condvar->send;
    }
);
$handle->push_write("GET / HTTP/1.0\015\012\015\012");
$handle->push_read(
    line => "\015\012\015\012",
    sub {
        my ($handle, $line) = @_;
        print "HEADER\n$line\n\nBODY\n";
        $handle->on_read(sub { print $_[0]->rbuf; $_[0]->rbuf = ''; });
    }
);
$condvar->recv;

Description

This class adds a (nearly too) simple throughput limiter to AnyEvent::Handle.

Methods

In addition to AnyEvent::Handle's base methods, this subclass supports the following...

$handle = AnyEvent::Handle::Throttle->new( key => value, ... )

In addition to the arguments handled by AnyEvent::Handle->new( ... ), this constructor supports these arguments (all as key => value pairs).

upload_limit => <bytes>

This is the maximum amount of data (in bytes) written to the filehandle per period. If upload_limit is not specified, the upload rate is not limited.

Note that this value can/will override read_size.

download_limit => <bytes>

This is the maximum amount of data (in bytes) read from the filehandle per period. If download_limit is not specified, the upload rate is not limited.

$handle->upload_limit( $bytes )

Sets/returns the current upload rate in bytes per period.

$handle->download_limit( $bytes )

Sets/returns the current download rate in bytes per period.

$bytes = $handle->upload_speed( )

Returns the amount of data written during the previous period.

$bytes = $handle->download_speed( )

Returns the amount of data read during the previous period.

If you're using AnyEvent::Handle::Throttle to limit bandwidth and realize you'd rather set flat limits on the total bandwidth instead of per-handle, try these methods:

AnyEvent::Handle::Throttle->global_upload_limit( $bytes )

Sets/returns the current global upload rate in bytes per period.

AnyEvent::Handle::Throttle->global_download_limit( $bytes )

Sets/returns the current global download rate in bytes per period.

$bytes = $handle->global_upload_speed( )

Returns the amount of data written through all AnyEvent::Handle::Throttle objects during the previous period.

$bytes = $handle->global_download_speed( )

Returns the amount of data read through all AnyEvent::Handle::Throttle objects during the previous period.

$bytes = $handle->download_total( )

Returns the total amount of data read through the AnyEvent::Handle::Throttle object.

$bytes = $handle->upload_total( )

Returns the total amount of data written through the AnyEvent::Handle::Throttle object.

$bytes = $handle->global_download_total( )

Returns the total amount of data read through all AnyEvent::Handle::Throttle objects so far.

$bytes = $handle->global_upload_total( )

Returns the total amount of data sent through all AnyEvent::Handle::Throttle objects so far.

Notes

• The current default period is 1 second.

• On destruction, all remaining data is sent ASAP, ignoring the user defined upload limit. This may change in the future.

Bugs

I'm sure this module is just burting with 'em. When you stumble upon one, please report it via the Issue Tracker.

Author

Sanko Robinson <sanko@cpan.org> - http://sankorobinson.com/

CPAN ID: SANKO

License and Legal

Copyright (C) 2010 by Sanko Robinson <sanko@cpan.org>

This program is free software; you can redistribute it and/or modify it under the terms of The Artistic License 2.0. See the LICENSE file included with this distribution or notes on the Artistic License 2.0 for clarification.

When separated from the distribution, all original POD documentation is covered by the Creative Commons Attribution-Share Alike 3.0 License. See the clarification of the CCA-SA3.0.