
=head1 NAME

OpenTracing::WrapScope - Automatically add spans to selected subroutines



=head1 SYNOPSIS

    use OpenTracing::WrapScope qw/foo Foo::bar/;
    use Foo;
      
    sub foo { ... }
   
    package Foo {
        sub bar { ... }
    }

Roughly equivalent to:

    use OpenTracing::AutoScope;
    
    sub foo {
        OpenTracing::AutoScope->start_guarded_span();
        ...
    }
    
    package Foo {
        sub bar {
            OpenTracing::AutoScope->start_guarded_span();
            ...
        }
    }



=head1 IMPORT ARGUMENTS

import takes subroutine names as arguments, these need to be fully qualified 
if they are not in the current package. All specified subroutines will have
spans attached to them. Context and caller frames will be preserved.
Additionally, if a wrapped subroutine dies, an additional C<error> tag will
be added to the span.



=head1 CAVEATS

=head2 C<caller>

Because this module overrides caller, it's best to use it as soon as possible,
before caller-using code is compiled. It likely won't work well with other
modules which override caller themselves.

=head2 C<Exporter>

Subroutines exported using L<Exporter> or a similar module could split into
two versions. If the export happens before the span handling is applied to
a subroutine, only the original version will have a span, the exported
version will be unmodified.

In order to wrap subroutines in modules utilising L<Exporter>,
use L<OpenTracing::WrapScope> directly in those modules.




=head1 AUTHOR

Szymon Nieznanski <snieznanski@perceptyx.com>



=head1 COPYRIGHT AND LICENSE

'OpenTracing::WrapScope'
is Copyright (C) 2020, Perceptyx Inc

This library is free software; you can redistribute it and/or modify it under
the terms of the Artistic License 2.0.

This package is distributed in the hope that it will be useful, but it is
provided "as is" and without any express or implied warranties.

For details, see the full text of the license in the file LICENSE.


=cut
