Re: [classlib][performance] Harmony's great performance of ArrayList.add(int index, Object element)

[Alexey Petrenko]

Nice to hear that :)

SY, Alexey

2007/4/20, Andrew Zhang <[EMAIL PROTECTED]>:

Hey guys,

I wrote a small performance benchmark for testing List.add(int index, Object
element). Beyond my expectation, Harmony's ArrayList is amazingly fast
compared with RI. The test scenario is very simple:

1. fill a list with 100,000 elements
       for (int i = 0; i < LIST_COUNT; ++i) {
           list.add(element);
       }
2. add another 100,000 elements into this list in the random index from 0 -
100,000.
      for (int i = 0; i < LIST_COUNT; ++i) {
           list.add(indexGenerator.nextInt(LIST_COUNT),element);
       }

For step2, Harmony's ArrayList  50% - 100% faster than RI!

Here's the result from my machine:
1st run:
Harmony ArrayList insert1: elapsed = 10ms
Harmony ArrayList insert2: elapsed = 14861ms
Harmony Vector insert1: elapsed = 70ms
Harmony Vector insert2: elapsed = 30333ms

RI ArrayList insert1: elapsed = 110ms
RI ArrayList insert2: elapsed = 29532ms
RI Vector insert1: elapsed = 70ms
RI Vector insert2: elapsed = 30384ms

2nd run:
Harmony ArrayList insert1: elapsed = 20ms
Harmony ArrayList insert2: elapsed = 14941ms
Harmony Vector insert1: elapsed = 70ms
Harmony Vector insert2: elapsed = 31345ms

RI ArrayList insert1: elapsed = 70ms
RI ArrayList insert2: elapsed = 31726ms
RI Vector insert1: elapsed = 60ms
RI Vector insert2: elapsed = 31095ms

Very good work!

--
Best regards,
Andrew Zhang