memory leak or endless loop in v1.3.0

[rny]

after upgrade xpath v1.2.5 => v1.3.0 ( not change anything else)
our app memory keep increasing until OOM and CPU keeps 100%

I found a new loop was added in func (t *NodeIterator) MoveNext() bool
is it cause endless loop in some case?

[zhengchun]

v1.3.0 changes a lot of code. https://github.com/antchfx/xpath/commits/master/

The best way is give your xpath expression to cause CPU high, let me test it.

[zhengchun]

can you remove this code to disable caches and test again?

xpath/xpath.go

Line 96 in 4b4638b

id := getHashCode(n.Copy())

[rny]

I noticed 1.3.1 removed that loop. I have tested these upgrades

go: upgraded github.com/antchfx/xmlquery v1.3.18 => v1.4.1
go: upgraded github.com/antchfx/xpath v1.2.5 => v1.3.1

the v1.3.1 CPU and memory is ok

[zhengchun]

I guess the high CPU is caused by the thread deadlock when application run in the multiple goroutines that reused cached expr object. so I removed those loop code. antchfx/htmlquery#58

[rny]

agree. our app use xpath inside go { } a lot.