Using ZSTD_compressBound for Streaming Input about zstd

[Cyan4973]

Yes, the guarantee would hold.

Such final flushes do not create intermediate small blocks. They just ensure that all buffers are completely emptied hence the operation is truly complete.

[Cyan4973]

It's guaranteed if you merely compressStream, but not if you also employ flush.

flush can be abused in creating a lot of tiny blocks which, in extreme cases, might cumulatively reach beyond ZSTD_compressBound().
This is really for extreme cases, a few parsimonious flushes here and there shouldn't change the picture here and there,
but the simple fact that it's possible to abuse flush() to create the above scenario makes it not possible to guarantee ZSTD_compressBound() when flush() is employed.

[Arjav-Patel]

@Cyan4973

If I use if in the following manner:

1. compressStream2 with continue
2. compressStream2 with continue
   ...
   N. compressStream2 with continue
   N + 1. compressStream2 with end
   N + 2. compressStream2 with flush

That is, call flush at most 1 time after N calls to compressStream2, does the guarantee still hold?

[Arjav-Patel]

Nice, thanks!