小编Har*_*rry的帖子

我正在使用 Postgre SQL 来玩 R2DBC。我正在尝试的用例是通过 ID 以及语言、演员和类别获取电影。下面是架构

这是ServiceImpl中对应的一段代码

@Override
public Mono<FilmModel> getById(Long id) { 
    Mono<Film> filmMono = filmRepository.findById(id).switchIfEmpty(Mono.error(DataFormatException::new)).subscribeOn(Schedulers.boundedElastic());
    Flux<Actor> actorFlux = filmMono.flatMapMany(this::getByActorId).subscribeOn(Schedulers.boundedElastic());
    Mono<String> language = filmMono.flatMap(film -> languageRepository.findById(film.getLanguageId())).map(Language::getName).subscribeOn(Schedulers.boundedElastic());
    Mono<String> category = filmMono.flatMap(film -> filmCategoryRepository
                    .findFirstByFilmId(film.getFilmId()))
            .flatMap(filmCategory -> categoryRepository.findById(filmCategory.getCategoryId()))
            .map(Category::getName).subscribeOn(Schedulers.boundedElastic());

    return Mono.zip(filmMono, actorFlux.collectList(), language, category)
            .map(tuple -> {
                FilmModel filmModel = GenericMapper.INSTANCE.filmToFilmModel(tuple.getT1());
                List<ActorModel> actors = tuple
                        .getT2()
                        .stream()
                        .map(act -> GenericMapper.INSTANCE.actorToActorModel(act))
                        .collect(Collectors.toList());
                filmModel.setActorModelList(actors);
                filmModel.setLanguage(tuple.getT3());
                filmModel.setCategory(tuple.getT4());
                return filmModel;
            });
         }

日志显示 4 次调用拍摄

2021-12-16 21:21:20.026 DEBUG 32493 --- [ctor-tcp-nio-10] o.s.r2dbc.core.DefaultDatabaseClient     : Executing …

我想了解Netty的频道选项"WRITE_SPIN_COUNT"的用法.将此值设置为高于或低于默认值(16)的影响是什么.应该这样设置.？这是我从Netty文档中得到的,但不清楚为什么以及何时应该设置此值:http://netty.io/4.0/api/io/netty/channel/DefaultChannelConfig.html#getWriteSpinCount() 按照它说的文档:返回写操作的最大循环计数,直到WritableByteChannel.write(ByteBuffer)返回非零值.它类似于自旋锁用于并发编程的内容.它根据运行JVM的平台提高内存利用率和写入吞吐量.默认值为16.