"Dr. David Alan Gilbert" <dgilb...@redhat.com> wrote: > * Juan Quintela (quint...@redhat.com) wrote: >> "Dr. David Alan Gilbert" <dgilb...@redhat.com> wrote: >> > * Juan Quintela (quint...@redhat.com) wrote: >> >> We are divining by page_size to multiply again in the only use. >> > ^--- typo >> >> Once there, impreve the comments. >> > ^--- typo >> >> >> >> Signed-off-by: Juan Quintela <quint...@redhat.com> >> > >> > OK, with the typo's fixed: >> >> Thanks. >> >> > Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> >> > >> > but, could you also explain the x 2 (that's no worse than the current >> > code); is this defined somewhere in zlib? I thought there was a routine >> > that told you the worst case? >> >> Nowhere. >> >> There are pathological cases where it can be worse. Not clear at all >> how much (ok, for zlib it appears that it is on the order of dozen of >> bytes, because it marks it as uncompressed on the worst possible case), >> For zstd, there is not a clear/fast answer when you google. > > For zlib: > > ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); > /* > compressBound() returns an upper bound on the compressed size after > compress() or compress2() on sourceLen bytes. It would be used before a > compress() or compress2() call to allocate the destination buffer. > */
Aha, exaactly what I needed. thanks. zstd one is called: ZSTD_compressBound() Added to the series. Thanks, Juan.
