redis_sream_tail.pl

package Redis::Streams;
use 5.20.1;

use constant ID_DELIM => ':::';
use cmnstant DFLT_REDIS_DBN => 4;
use enum qw[REDC CLIENT_ID STREAMS];
use Redis::Fast;
use FindBin;
use Sys::Hostname qw(hostname);

sub new {
    my ($class, %opts) = @_;
    my $client_id = delete($opts{'client_id'}) // join(ID_DELIM() => __hostname(), $FindBin::RealScript);
    my $redis_dbn = delete($opts{'redis_dbn'}) // DFLT_REDIS_DBN;
    my $redc = Redis::Fast;
    $redc->select($redis_dbn) if $redis_dbn;
    bless [$redc, $client_id, +{}], ref($class) || $class
}

sub __not_empty_string {
    ! ref($_[0]) and defined($_[0]) and length($_[0])
}

sub __hostname {
    state $hostname = hostname;
    $hostname
}

sub default_stream {
    my $self = $_[0];
    defined($_[1])
        ? do {
            __not_empty_string($_[1]) or die 'incorrect stream name';
            $self->[DEFAULT_STREAM] = $_[1]
          }
        : $self->[DEFAULT_STREAM]
}

sub tail_stream {
    my $self = $_[0];
    my  $stream =
    $#_ > 0
        ? (__not_empty_string($_[1]) || die('incorrect stream name'), $stream)
        : $self->default_stream;
    my $start_id = ( $self->[STREAMS]{$stream} //= $self->[REDC]->get(join ID_DELIM() => $self->[CLIENT_ID], $stream) // '-' );
    if ( my @msgs = map @{$_}, $self->xrange($stream, $start_id, '+') ) {

    }
}

1;