[jdom-commits] CVS update: jdom/src/java/org/jdom/input

[cvs at jools.org]

Date:	Saturday March 2, 2002 @ 8:31
Author:	cvs

Update of /home/cvspublic/jdom/src/java/org/jdom/input
In directory jools.org:/tmp/cvs-serv32479

Modified Files:
	SAXHandler.java 
Log Message:
Changed some string comparators from != to !.equals().  The former works
so long as the parser interns strings, and although Xerces and Crimson do,
not all parsers do.  So using !.equals() is safer.  Brad Huffman ran some
tests to see if this had much of a performance impact, and surprisingly
it didn't and in fact sometimes ran *faster*.  Below is his table, for 
future reference.

This crosses off a long-standing TODO!

-jh-

Here's the minimum build times I got the other night comparing the interning
issue in SAXBuilder.

Running sosnoski's tests gave:

                      With Crimson
              current  intern  change  % of current
init.xml        158      161     +3        +2%
much_ado.xml    607      585    -22        -4%
periodic.xml    369      365     -4        -1%
soap1.xml       248      275    +27        +7%
soap2.xml       823      737    -86       -10%
test1.xml     18053    18548   +495        +3%
test2.xml     18056    17489   -567        -3%
test3.xml       633      628     -5        -0%

                      With Xerces-1.4.4
              current  intern  change  % of current
init.xml        165      167     +2        +1%
much_ado.xml    615      616     +1        +0%
periodic.xml    373      366     -7        -2%
soap1.xml       268      249    -19        -7%
soap2.xml       781      753    -28        -4%
test1.xml     18470    18232   -238        -1%
test2.xml     17666    17539   -127        -0%
test3.xml       641      642     +1        +0%


And wrapping CurrentTimeMillis around SAXBuilder.builder(filename) and
running it 10 times for each file gave:

                      With Crimson
              current  intern  change  % of current
init.xml         88       88      0         0%
much_ado.xml    599      608     +9        +1%
periodic.xml    361      361      0         0%
soap1.xml        18       19     +1        +5%
soap2.xml       749      787    +38        +5%
test1.xml     18254    19182   +928        +5%
test2.xml     17576    17819   +243        +2%
test3.xml       659      661     +2        +0%

The file I thought would do the worst is test2.xml, in it all prefix
are the as the local name except for the very last character.

===================================================================
File: no file SAXHandler.java		Status: Needs Checkout

   Working revision:	1.37	Sat Mar  2 13:31:53 2002
   Repository revision:	1.37	/home/cvspublic/jdom/src/java/org/jdom/input/SAXHandler.java,v

   Existing Tags:
	jdom_prefilter           	(revision: 1.27)
	jdom_1_0_b7              	(revision: 1.18)