/ 
Module-AnyEvent-Helper-v0.0.5
River stage one • 1 direct dependent • 1 total dependent
/ Module::AnyEvent::Helper

NAME

Module::AnyEvent::Helper - Helper module to make other modules AnyEvent-friendly

VERSION

version v0.0.5

SYNOPSIS

By using this module, ordinary (synchronous) method:

sub func {
  my $ret1 = func2();
  # ...1

  my $ret2 = func2();
  # ...2
}

can be mechanically translated into AnyEvent-friendly method as func_async:

use Module::AnyEvent::Helper qw(bind_scalar strip_async_all)

sub func_async {
  my $cv = AE::cv;

  bind_scalar($cv, func2_async(), sub {
    my $ret1 = shift->recv;
    # ...1
    bind_scalar($cv, func2_async(), sub {
      my $ret2 = shift->recv;
      # ...2
    });
  });

  return $cv;
}

At the module end, calling strip_async_all makes synchronous versions of _async methods in the calling package.

strip_async_all;

DESCRIPTION

AnyEvent-friendly versions of modules already exists for many modules. Most of them are intended to be drop-in-replacement of original module. In this case, return value should be the same as original. Therefore, at the last of the method in the module, blocking wait is made usually.

sub func {
  # some asynchronous works
  $cv->recv; # blocking wait
  return $ret;
}

However, this blocking wait almost prohibit to use the module with plain AnyEvent, because of recursive blocking wait error. Using Coro is one solution, and to make a variant of method to return condition variable is another. To employ the latter solution, semi-mechanical works are required. This module reduces the work bit.

FUNCTIONS

All functions can be exported but none is exported in default. They can be called as class methods, also.

strip_async(@names)

Make synchronous version for each specified method by @names. All method names MUST end with _async. If 'func_async' is passed, the following 'func' is made into the calling package.

sub func { shift->func_async(@_)->recv; }

Therefore, func_async MUST be callable as method.

strip_async_all

strip_async_all(-exclude => \@list)

strip_async is called for all methods end with _async in the calling package. NOTE that error occurs if function, that is not a method, having _async suffix exists.

You can specify excluding fuction name as @list. Function names SHOULD NOT include _async suffix.

bind_scalar($cv1, $cv2, \&successor)

$cv1 and $cv2 MUST be AnyEvent condition variables. \&successor MUST be code reference.

You can consider $cv2 is passed to \&successor, then return value of \&successor, forced in scalar-context, is sent by $cv1. Actually, there is some more treatment for nested call of bind_scalar/bind_array.

bind_array($cv1, $cv2, \&successor)

Similar as bind_scalar, but return value of successor is forced in array-context.

AUTHOR

Yasutaka ATARASHI <yakex@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2012 by Yasutaka ATARASHI.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.