Mirror/zeek
1
0
Fork 0
mirror of https://github.com/zeek/zeek.git synced 2025-10-15 21:18:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Remove the siphash->hmac-md5 switch after 36 bytes.

Browse source 
Currently, siphash is used for strings up to 36 bytes. hmac-md5 is used
for longer strings.

This switch-over is a remnant of the previous hash-function that was
used, which apparently was slower with longer input strings.

This change serves no purpose anymore. I performed a few performance tests
on strings of varying sizes:

For a 40 byte string with 10 million iterations:

siphash: 0.31 seconds
hmac-md5: 3.8 seconds

For a 1080 byte string with 10 million iterations:

siphash: 4.2 seconds
hmac-md5: 17 seconds

For a 18360 byte string with 10 million iterations:

siphash: 69 seconds
hmac-md5: 240 seconds

Hence, this commit removes the use of hmac-md5.

This change causes reordering of lines in a few logs.

This commit also changes the datastructure for the seed in probabilistic/Hasher
to get rid of a type-punning warning.
This commit is contained in:
Johanna Amann 2020-04-24 13:12:01 -07:00
parent bb050910bb
commit 5e7915ae7a
13 changed files with 269 additions and 297 deletions
Download patch file Download diff file Expand all files Collapse all files

2
testing/btest/Baseline/language.table-pattern-index/out
View file

@ -13,7 +13,7 @@
/^?(one|foo|bar)$?/, 0
/^?(three|oob)$?/, 2
-----------------
/^?(two|oob)$?/, 3, 2
/^?(one|foo|bar)$?/, 2, 0
/^?(four)$?/, 5, 6
/^?(two|oob)$?/, 3, 2
/^?(three|oob)$?/, 4, 4