view release on metacpan or  search on metacpan

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

has cnx => (is => 'ro', builder => '_etcd_connect', lazy => 1);

=head1 METHODS

=head2 read

Reads a value from a key and returns a JSON document payload.

=cut

sub read($$) {
    my ($self, $key) = @_;
    my $value =  $self->cnx->range({key => $key })->{response}->{content};
    $value = decode_json($value)->{kvs}->[0]->{value};
    return decode_base64($value);
}



=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.

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

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> >>