Future::Limiter - impose rate and resource limits
my $l = Future::Limiter->from_yaml(<<'YAML');
request:
# Make no more than 1 request per second
# have no more than 4 requests in flight at a time
# If there is a backlog, process them as quickly as possible
- burst : 3
rate : 60/60
- maximum: 4
namelookup:
- burst : 3
rate : 60/60
YAML
...
my ($host_token, $rate_token);
$limiter->limit( 'request', $hostname, $url )->then(sub {
my ($host_token, $url ) = @_;
request_url( $url )->on_ready( undef $host_token );
})->then(sub {
...
undef $host_token;
undef $rate_token;
});
This module provides an API to handle rate limits and resource limits in a unified API.
The usage with Future::AsyncAwait is much more elegant, as you only need to keep the token around and other parameters live implicitly in your scope:
my( $host_token ) = await $concurrency->limit( $hostname );
my( $rate_token ) = await $rate->limit( $hostname );
request_url( $url )
...
my ($token,@args) = await $limiter->limit('fetch',$url->hostname);
... do work
undef $token; # release token
$limiter->limit('fetch',$url->hostname,$url)->then(sub( $token, $url) {
return http_request($url)->on_ready(sub { undef $token });
};
The method to rate-limit an event from occurring, by key. The key can be
undef to mean a global limit on the event.
The method returns a future that will return a token to release the current limit and the arguments passed in.
Persistence of the rate limiter, or periodical writeback of the current limits to a shared file / scoreboard to allow for cross-process limiting
The public repository of this module is http://github.com/Corion/Future-Limiter.
The public support forum of this module is https://perlmonks.org/.
Please report bugs in this module via the RT CPAN bug queue at https://rt.cpan.org/Public/Dist/Display.html?Name=Future-Limiter or via mail to future-limiter-Bugs@rt.cpan.org.
Max Maischein corion@cpan.org
Copyright 2018-2019 by Max Maischein corion@cpan.org.
This module is released under the same terms as Perl itself.