p6.p6

use MONKEY;
augment class IO::Path {
    method slurp3(IO::Path:D:) {
        # We have two paths:
        # 1) No args given; we open and slurp with just nqp ops. We also
        #   use a `try` on nqp::open to fail in the fast path if open fails.
        #   In that specific case we'll read the slow path and obtain proper
        #   Failure that we'll return
        # 2) In slow path, just pop open IO::Handle and then have two branches:
        #   if we have file size, steal handle's $!PIO attr and read from it
        #   with nqp ops; otherwise, forward to IO::Handle.slurp
        my $PIO;
        nqp::if(
          nqp::iseq_i(nqp::elems(nqp::getattr(%_,Map,'$!storage')),0)
            && ($PIO := try nqp::open(self.absolute,"r")),
          nqp::stmts(
            ($_ := nqp::p6box_s(nqp::readallfh($PIO))),
            nqp::closefh($PIO),
            $_), # <-- we've succeeed in fast-path; that's the data
          nqp::if(
            nqp::istype(
              (my $handle := IO::Handle.new(:path(self)).open(
                :enc(%_<enc>), :bin(%_<bin>), :mode<ro>)),
              Failure,),
            $handle, # our open failed; return the Failure object here,
            nqp::stmts(
              ($PIO := nqp::getattr($handle, IO::Handle, '$!PIO')),
              nqp::if( %_<bin>,
                nqp::if(
                  (my int $size = Rakudo::Internals.FILETEST-S(self.absolute)),
                  ($_ := nqp::readfh($PIO, buf8.new, $size)),
                  nqp::stmts(
                    ($_ := buf8.new),
                    nqp::while(
                      nqp::elems(
                        my $buf := nqp::readfh($PIO, buf8.new, 0x100000)),
                      .append($buf),
                    ))),
                ($_ := nqp::p6box_s(nqp::readallfh($PIO)))),
              nqp::closefh($PIO),
              $_))) # <-- we've succeeded in slow-path; that's the data
    }
}

'/tmp/meow'.IO.spurt: 'bar';
$ = '/tmp/meow'.IO.slurp3: :bin for ^3000;
say "no crash";