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lib/AnyEvent/KVStore/Etcd.pm  view on Meta::CPAN

=head2 exists

Checks to see if a key exists.  Here this is no less costly than read.

=cut

sub exists($$) {
    my ($self, $key) = @_;
    my $value =  $self->cnx->range({key => $key })->{response}->{content};
    $value = decode_json($value)->{kvs}->[0]->{value};
    return defined $value;;
}

=head2 list($pfx)

Returns a list of keys

=cut

# adds one to the binary representation of the string for prefix searches
sub _add_one($){
    my ($str) = @_;
    if ($str =~ /^\xff*$/){ # for empty string too
        return "\x00";
    }
    my $inc = $str;
    $inc =~ s/([^\xff])\xff*\z/ $1 =~ tr||\x01-\xff|cr /e;
    return $inc;
}

sub list($$) {
    my ($self, $pfx) = @_;
    my $value =  $self->cnx->range({key => $pfx, range_end => _add_one($pfx)})->{response}->{content};
    return  map { decode_base64($_->{key} ) }  @{decode_json($value)->{kvs}};
}


=head2 write($key, $value)

Writes the key to the database and returns 1 if successful, 0 if not.

=cut

sub write($$$) {
    my ($self, $key, $value)  = @_;
    return $self->cnx->put({ key => $key, value => $value })->is_success;
}

=head2 watch($pfx, $callback)

This sets up a "watch" where notifications of changed keys are passed to the
script.  This can only really be handled inside an AnyEvent loop because the
changes can come from outside the program.

The callback takes the arguments of C<($key, $value)> of the new values.

=cut

sub _portability_wrapper {
    my ($sub, $result) = @_;
    use Data::Dumper;
    for my $e (@{decode_json($result)->{result}->{events}}){
        $e = $e->{kv};
        &$sub(decode_base64($e->{key}), decode_base64($e->{value}));
   }
}

sub watch($$$) {
    my ($self, $pfx, $subroutine ) = @_;
    return $self->cnx->watch({key => $pfx, range_end => _add_one($pfx)},
        sub { my ($result)  = @_; _portability_wrapper($subroutine, $result) })->create;
}


=head1 AUTHOR

Chris Travers, C<< <chris.travers at gmail.com> >>

=head1 BUGS

Please report any bugs or feature requests to C<bug-anyevent-kvstore-etcd at rt.cpan.org>, or through
the web interface at L<https://rt.cpan.org/NoAuth/ReportBug.html?Queue=AnyEvent-KVStore-Etcd>.  I will be notified, and then you'll
automatically be notified of progress on your bug as I make changes.




=head1 SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc AnyEvent::KVStore::Etcd


You can also look for information at:

=over 4

=item * RT: CPAN's request tracker (report bugs here)

L<https://rt.cpan.org/NoAuth/Bugs.html?Dist=AnyEvent-KVStore-Etcd>

=item * CPAN Ratings

L<https://cpanratings.perl.org/d/AnyEvent-KVStore-Etcd>

=item * Search CPAN

L<https://metacpan.org/release/AnyEvent-KVStore-Etcd>

=back


=head1 ACKNOWLEDGEMENTS


=head1 LICENSE AND COPYRIGHT

This software is Copyright (c) 2023 by Chris Travers.

This is free software, licensed under: