void drain()

in benchmarks/src/jmh/java/benchmarks/flow/scrabble/optimizations/FlowableSplit.java [187:321]
113 lines of code
29 McCabe index (conditional complexity)

        void drain() {
            if (getAndIncrement() != 0) {
                return;
            }

            SimplePlainQueue<String[]> q = queue;

            int missed = 1;
            int consumed = produced;
            String[] array = current;
            int idx = index;
            int emptyCount = empty;

            Subscriber<? super String> a = downstream;

            for (;;) {
                long r = requested.get();
                long e = 0;

                while (e != r) {
                    if (cancelled) {
                        current = null;
                        q.clear();
                        return;
                    }

                    boolean d = done;

                    if (array == null) {
                        array = q.poll();
                        if (array != null) {
                            current = array;
                            if (++consumed == limit) {
                                consumed = 0;
                                upstream.request(limit);
                            }
                        }
                    }

                    boolean empty = array == null;

                    if (d && empty) {
                        current = null;
                        Throwable ex = error;
                        if (ex != null) {
                            a.onError(ex);
                        } else {
                            a.onComplete();
                        }
                        return;
                    }

                    if (empty) {
                        break;
                    }

                    if (array.length == idx + 1) {
                        array = null;
                        current = null;
                        idx = 0;
                        continue;
                    }

                    String v = array[idx];

                    if (v.isEmpty()) {
                        emptyCount++;
                        idx++;
                    } else {
                        while (emptyCount != 0 && e != r) {
                            if (cancelled) {
                                current = null;
                                q.clear();
                                return;
                            }
                            a.onNext("");
                            e++;
                            emptyCount--;
                        }

                        if (e != r && emptyCount == 0) {
                            a.onNext(v);

                            e++;
                            idx++;
                        }
                    }
                }

                if (e == r) {
                    if (cancelled) {
                        current = null;
                        q.clear();
                        return;
                    }

                    boolean d = done;

                    if (array == null) {
                        array = q.poll();
                        if (array != null) {
                            current = array;
                            if (++consumed == limit) {
                                consumed = 0;
                                upstream.request(limit);
                            }
                        }
                    }

                    boolean empty = array == null;

                    if (d && empty) {
                        current = null;
                        Throwable ex = error;
                        if (ex != null) {
                            a.onError(ex);
                        } else {
                            a.onComplete();
                        }
                        return;
                    }
                }

                if (e != 0L) {
                    BackpressureHelper.produced(requested, e);
                }

                empty = emptyCount;
                produced = consumed;
                missed = addAndGet(-missed);
                if (missed == 0) {
                    break;
                }
            }
        }