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lib/Action/Retry.pm  view on Meta::CPAN

=head1 VERSION

version 0.24

=head1 SYNOPSIS

  # Simple usage, will attempt to run the code, retrying if it dies, retrying
  # 10 times max, sleeping 1 second between retries

  # functional interface
  use Action::Retry qw(retry);
  retry { do_stuff };
 
  # OO interface
  use Action::Retry;
  Action::Retry->new( attempt_code => sub { do_stuff; } )->run();



  # Same, but sleep time is doubling each time, and arguments passed to the
  # attempted code

  # OO interface
  my $action = Action::Retry->new(
    attempt_code => sub { my ($num, $str) = @_; ... },
    strategy => 'Linear',
  );
  my $result = $action->run(42, "foo");

  # functional interface
  retry { my ($num, $str) = @_;... } strategy => 'Linear';



  # Same, but sleep time is following the Fibonacci sequence

  # OO interface
  my $action = Action::Retry->new(
    attempt_code => sub { ... },
    strategy => 'Fibonacci',
  );
  $action->run();

  # functional interface
  retry { ... } strategy => 'Fibonacci';



  # The code to check if the attempt succeeded can be customized. Strategies
  # can take arguments. Code on failure can be specified.

  # OO way
  my $action = Action::Retry->new(
    attempt_code => sub { ... },
    retry_if_code => sub { $_[0] =~ /Connection lost/ || $_[1]->{attempt_result} > 20 },
    strategy => { Fibonacci => { multiplicator => 2000,
                                 initial_term_index => 3,
                                 max_retries_number => 5,
                               }
                },
    on_failure_code => sub { say "Given up retrying" },
  );
  $action->run();

  # functional way
  retry { ...}
    retry_if_code => sub { ... },
    strategy => { Fibonacci => { multiplicator => 2000,
                                 initial_term_index => 3,
                                 max_retries_number => 5,
                               }
                },
    on_failure_code => sub { ... };



  # Retry code in non-blocking way

  # OO way
  my $action = Action::Retry->new(
    attempt_code => sub { ...},
    non_blocking => 1,
  );
  while (1) {
    # if the action failed, it doesn't sleep
    # next time it's called, it won't do anything until it's time to retry
    $action->run();
    # do something else while time goes on
  }

=head1 ATTRIBUTES

=head2 attempt_code

  ro, CodeRef, required

The code to run to attempt doing the action. Will be evaluated taking care of
the caller's context. It will receive parameters that were passed to C<run()>

=head2 retry_if_code

  ro, CodeRef

The code to run to check if we need to retry the action. It defaults to:

  # Returns true if there were an exception evaluating to something true
  sub { $_[0] }

It will be given these arguments:

=over

=item * 

as first argument, a scalar which is the value of any exception that were
raised by the C<attempt_code>. Otherwise, undef.

=item *

as second argument, a HashRef, which contains these keys: