Comments on: Hash this http://tech.puredanger.com/2007/07/25/hash/ Alex Miller's technical blog Thu, 28 Aug 2008 14:20:44 +0000 http://wordpress.org/?v=2.0.2 by: Alex Popescu http://tech.puredanger.com/2007/07/25/hash/#comment-5499 Fri, 27 Jul 2007 10:59:22 +0000 http://tech.puredanger.com/2007/07/25/hash/#comment-5499 Thanks for the OpenCourseWare hint. It is just great (I just wish I'll have the time to see the CS courses). bests, ./alex -- .w( the_mindstorm )p. Thanks for the OpenCourseWare hint. It is just great (I just wish I’ll have the time to see the CS courses).

bests,
./alex
–
.w( the_mindstorm )p.

]]> by: Tim http://tech.puredanger.com/2007/07/25/hash/#comment-5479 Thu, 26 Jul 2007 17:58:36 +0000 http://tech.puredanger.com/2007/07/25/hash/#comment-5479 This exact topic captured my attention several JDKs ago. Additionally, I had learned to make hash tables prime length so it surprise me to find HashMap was deliberately using powers of two. Since it has been a long time I don't remember the details, but I vaguely recall seeing Josh Bloch's name attached to this code. More importantly, I recall there used to be comment in the source code saying that the shift values were: ``precomputed/selected from a four? dimensional search space" I don't remember the exact phrasing of the comment and it was beyond me. Nevertheless, I thought it was really cool. Regards. This exact topic captured my attention several JDKs ago. Additionally, I had learned to make hash tables prime length so it surprise me to find HashMap was deliberately using powers of two.

Since it has been a long time I don’t remember the details, but I vaguely recall seeing Josh Bloch’s name attached to this code. More importantly, I recall there used to be comment in the source code saying that the shift values were:
“precomputed/selected from a four? dimensional search space”
I don’t remember the exact phrasing of the comment and it was beyond me. Nevertheless, I thought it was really cool.
Regards.

]]>