private void optimizeUpdates()

in hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendMutation.java [83:147]
64 lines of code
19 McCabe index (conditional complexity)

    private void optimizeUpdates(BackendEntry entry, Action action) {
        final Id id = entry.id();
        assert id != null;
        final List<BackendAction> items = this.updates.get(entry.type(), id);
        assert items != null;
        boolean ignoreCurrent = false;
        for (Iterator<BackendAction> iter = items.iterator(); iter.hasNext(); ) {
            BackendAction originItem = iter.next();
            Action originAction = originItem.action();
            switch (action) {
                case INSERT:
                    iter.remove();
                    break;
                case DELETE:
                    if (originAction == Action.INSERT) {
                        throw incompatibleActionException(action, originAction);
                    } else if (originAction == Action.DELETE) {
                        ignoreCurrent = true;
                    } else {
                        iter.remove();
                    }
                    break;
                case APPEND:
                    if (entry.type().isUniqueIndex() &&
                        originAction == Action.APPEND) {
                        throw new IllegalArgumentException(String.format(
                                "Unique constraint conflict is found in" +
                                " transaction between %s and %s",
                                entry, originItem.entry()));
                    }

                    if (originAction == Action.INSERT ||
                        originAction == Action.DELETE) {
                        throw incompatibleActionException(action, originAction);
                    } else {
                        Id subId = entry.subId();
                        Id originSubId = originItem.entry().subId();
                        assert subId != null;
                        if (subId == originSubId || subId.equals(originSubId)) {
                            iter.remove();
                        }
                    }
                    break;
                case ELIMINATE:
                    if (originAction == Action.INSERT ||
                        originAction == Action.DELETE) {
                        throw incompatibleActionException(action, originAction);
                    } else {
                        Id subId = entry.subId();
                        Id originSubId = originItem.entry().subId();
                        assert subId != null;
                        if (subId == originSubId || subId.equals(originSubId)) {
                            iter.remove();
                        }
                    }
                    break;
                default:
                    throw new AssertionError(String.format(
                            "Unknown mutate action: %s", action));
            }
        }
        if (!ignoreCurrent) {
            items.add(BackendAction.of(action, entry));
        }
    }