my @data = ();
my @final = ();
while (!$client->timeout()) {
  my $stream = $client->get_data();
  push(@data,$stream);
}

foreach (@data) {
  push(@final,munge($_)); #<-- push hash ref onto @final
}

sub munge {
  my %hash = ();
  #...create hash
  return \%hash;  #<-- hash ref
}