zlib.flush([kind, ]callback)

• kind 默认值：zlib.constants.Z_FULL_FLUSH 用于基于 zlib 的流，zlib.constants.BROTLI_OPERATION_FLUSH 用于基于 Brotli 的流。

  ¥kind Default: zlib.constants.Z_FULL_FLUSH for zlib-based streams, zlib.constants.BROTLI_OPERATION_FLUSH for Brotli-based streams.

• callback <Function>

刷新挂起的数据。不要轻率地称之为，过早刷新会对压缩算法的有效性产生负面影响。

¥Flush pending data. Don't call this frivolously, premature flushes negatively impact the effectiveness of the compression algorithm.

调用它只会从内部 zlib 状态刷新数据，并且不会在流级别执行任何类型的刷新。相反，它的行为类似于对 .write() 的正常调用，即它将排队等待其他未决写入，并且仅在从流中读取数据时才产生输出。

¥Calling this only flushes data from the internal zlib state, and does not perform flushing of any kind on the streams level. Rather, it behaves like a normal call to .write(), i.e. it will be queued up behind other pending writes and will only produce output when data is being read from the stream.