c# - What is the difference between BufferedStream and MemoryStream in terms of application?

Question

What is the difference between BufferedStream and MemoryStream in terms of application? Since MemoryStream can be flushed into a file at any time, couldn't it replace BufferedStream?

Answer 1

BufferedStream is just a buffer over an existing stream. MemoryStream is a buffer for the whole stream - it isn't chained to another one. You can ask it to write itself to another stream at any time, but that's not the same thing.

One of the principle reasons for buffering is to avoid frequent writes to expensive resources. However, that doesn't mean you want to buffer all the data in memory - just enough to avoid very small writes. For example, if FileStream didn't have its own buffering strategy, then wrapping it in BufferedStream could end up with a buffer of only 8K even if you write megabytes of data. As pointed out in the comments though, FileStream has enough buffering that using BufferedStream in conjunction with it is pointless.