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author | Pádraig Brady <P@draigBrady.com> | 2013-11-11 02:51:17 +0000 |
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committer | Pádraig Brady <P@draigBrady.com> | 2013-11-11 23:30:39 +0000 |
commit | 91208453756bf0e86e25c2db35e481ac178f1255 (patch) | |
tree | 9da172f4244cfbd84950cd05eb36aac24463281b /man/truncate.x | |
parent | 90181a5926e96f34b5ffff21b81a2874a846ff6f (diff) | |
download | coreutils-91208453756bf0e86e25c2db35e481ac178f1255.tar.xz |
base64: improve encoding I/O efficiency
Since the I/O overhead is significant to the relatively
simple processing done by this utility, use fputs() rather
than fputc() to output '\n'.
Time to process a 100MiB file was measured to
decrease from 0.417s to 0.383s, i.e. an 8% improvement.
Related to these changes, is a processing improvement in
gnulib, which increases throughput by 60% when processing
full buffers, which improves processing of a 100MiB file
with standard wrapped output, down to 0.256s.
http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=commit;h=43fd1e7b
Also increase the encoding buffer size from 3 to 30KiB.
This was seen to give a further 8% improvement, taking
processing time down to 0.235s in the wrapped output case.
The decoding size buffer is not adjusted,
due to the noted caveat with --ignore-garbage.
* src/base64.c (BLOCKSIZE): Split into ENC_ and DEC_ variants,
with the former increased from 3KiB to 30KiB.
(wrap_write): Use the simpler fputc() rather than fputs()
to output the '\n' character. Also check against EOF
rather than < 0 for errors.
(do_encode): Likewise.
* NEWS: Mention the large increase in performance, which
with the I/O improvements in coreutils and the processing
improvement in gnulib, amount to about a 60% throughput increase.
Diffstat (limited to 'man/truncate.x')
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