Ruben Vorderman <r.h.p.vorder...@lumc.nl> added the comment:
I increased the performance of the patch. I added the file used for benchmarking. I also test the FHCRC changes now. The benchmark tests headers with different flags concatenated to a DEFLATE block with no data and a gzip trailer. The data is fed to gzip.decompress. Please note that this is the *worst-case* performance overhead. When there is actual data to decompress the overhead will get less. When GzipFile is used the overhead will get less as well. BEFORE (Current main branch): $ ./python benchmark_gzip_read_header.py with_fname average: 3.01, range: 2.9-4.79 stdev: 0.19 with_noflags average: 2.99, range: 2.93-3.04 stdev: 0.02 All flags (incl FHCRC) average: 3.13, range: 3.05-3.16 stdev: 0.02 After (bpo-45509 PR): with_fname average: 3.09, range: 3.01-4.63 stdev: 0.16 with_noflags average: 3.1, range: 3.03-3.38 stdev: 0.04 All flags (incl FHCRC) average: 4.09, range: 4.05-4.49 stdev: 0.04 An increase of .1 microsecond in the most common use cases. Roughly 3%. But now the FNAME field is correctly checked for truncation. With the FHCRC the overhead is increased by 33%. But this is worth it, because the header is now actually checked. As it should. ---------- Added file: https://bugs.python.org/file50458/benchmark_gzip_read_header.py _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45509> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
