Re: Review/comment needed for the new public java.util.Base64 class

[Xueming Shen]

On 10/13/12 10:21 AM, Xueming Shen wrote:

With moving some code piece around (moved those lookup table into En/Decoder) and some array access code tuning (with the hope of eliminating the array boundary access) in encode0(), it appears the hotspot now can better optimize the decoder loop for the -server mode for encoding. decode0 also get 10% +boost with simply

moving in the lookup table.

The latest version is at (decode0() vs decode1())

--> encode0() vs encode1())

encode0 is the latest/faster one. encode1 is the one in webrev.

-Sherman

http://cr.openjdk.java.net/~sherman/4235519/Base64.java

The latest scores is at

http://cr.openjdk.java.net/~sherman/4235519/score2

(compared to http://cr.openjdk.java.net/~sherman/4235519/score1)

-Sherman


On 10/11/12 11:38 PM, Xueming Shen wrote:

On 10/11/2012 02:43 AM, Stephen Colebourne wrote:

There are lots of other public base 64 implementations to test/check against. http://commons.apache.org/net/api-3.1/org/apache/commons/net/util/Base64.html http://www.cs.berkeley.edu/~jonah/bc/org/bouncycastle/util/encoders/Base64.html

http://migbase64.sourceforge.net/  (claims to be fast)

I did a quick performance check against migbase64 with the basic base64 de/encoding

using this non-scientific benchmark.
http://cr.openjdk.java.net/~sherman/4235519/PermBase64.java

Here is the scores
http://cr.openjdk.java.net/~sherman/4235519/scores

It's a tie, j.u.Base64 wins the decoding, but needs some work on encoding side.

java -server PermBase64 200000 50
 j.u.Base64.encode() : 1390212
  migBase64.encode() : 720517
 j.u.Base64.decode() : 1200642
  migBase64.decode() : 2070015

java -server PermBase64 200000 100
 j.u.Base64.encode() : 1239407
  migBase64.encode() : 740404
 j.u.Base64.decode() : 1257092
  migBase64.decode() : 2012910

java -server PermBase64 200000 1000
 j.u.Base64.encode() : 1062212
  migBase64.encode() : 657342
 j.u.Base64.decode() : 1133740
  migBase64.decode() : 1930612

java -client PermBase64 200000 50
 j.u.Base64.encode() : 961331
  migBase64.encode() : 875635
 j.u.Base64.decode() : 1528790
  migBase64.decode() : 2188473

java -client PermBase64 200000 100
 j.u.Base64.encode() : 966453
  migBase64.encode() : 858082
 j.u.Base64.decode() : 1459159
  migBase64.decode() : 2115045

java -client PermBase64 200000 1000
 j.u.Base64.encode() : 954401
  migBase64.encode() : 854903
 j.u.Base64.decode() : 1444603
  migBase64.decode() : 2038865