[Exist-development] simple optimisation with org.exist.storage.btree.Value

[James F. <jam...@ex...>]

In org.exist.storage.btree.Value all occurrences of the following

-----------------------------------------------

if (b1 == b2){
  continue;
else {

-----------------------------------------------

with

-----------------------------------------------

if (b1 != b2){

-----------------------------------------------

e.g. I got rid of continue statement and changed operator == to !=

I have been using a simple but intensive query that walks the shakespeare data

declare function local:treewalker ($html) {
let $children := $html/* return
if(empty($children)) then () else for $c in $children return
( element {name($c)}{ $c/@*,
$c/text(),
local:treewalker($c)
})

};

<test>{local:treewalker(//PLAY)}</test>

which resulted in

------
local:treewalker	100 runs ~ 340s

w/ optimization
------
local:treewalker	100 ~234s

I have also done a number of other kinds of queries which confirms
between a 15 - 30% increase in query performance in certain scenarios
which makes me a bit dubious ... all the caveats apply when doing this
kind of adhoc benchmarking but was wondering if someone else wants to
check these things on their own trunk checkout.

James Fuller