[REBOL] Re: Profiling Rebol API to DyBASE
From: knizhnik:garret:ru at: 19-Dec-2003 18:26
Hello Romano,
Friday, December 19, 2003, 2:51:19 PM, you wrote:
RPT> Hi,
RPT> Just seem that clear waste hash table, perhaps this is a bug in clear.
Yes, I already noticed it.
So it is much cheaper to create new object than clean existed.
RPT> These are my tests:
>>> i: 100000 loop 5 [recycle s: now/precise h: make hash! i * 2 + 2 repeat n i
RPT> [find h n insert insert tail h n
RPT> make object! [a: 1] if 99 = (n // 100)[clear h]] print [i difference
RPT> now/precise s] i: i + 25000]
RPT> 100000 0:00:12.97
RPT> 125000 0:00:19.28
RPT> 150000 0:00:26.86
RPT> 175000 0:00:35.37
RPT> 200000 0:00:47.01
>>> i: 100000 loop 5 [recycle s: now/precise h: make hash! i * 2 + 2 repeat n i
RPT> [find h n insert insert tail h n
RPT> make object! [a: 1]] print [i difference now/precise s] i: i + 25000]
RPT> 100000 0:00:03.96
RPT> 125000 0:00:05.33
RPT> 150000 0:00:06.98
RPT> 175000 0:00:09.06
RPT> 200000 0:00:09.83
RPT> ---
RPT> Ciao
RPT> Romano
RPT> ----- Original Message -----
RPT> From: "Romano Paolo Tenca" <[rotenca--telvia--it]>
RPT> To: <[rebol-list--rebol--com]>
RPT> Sent: Friday, December 19, 2003 4:49 AM
RPT> Subject: [REBOL] Re: Profiling Rebol API to DyBASE
>>
>> Hi,
>>
>> > I was able to isolate the problem.
>> > The following script shows almost the same time as testindex.r
>> > searching for 200000 objects.
>> >
>> >
>> > n: 200000
>> > h: make hash! n
>> > start: now/time/precise
>> > repeat i n [
>> > oid: random n
>> > obj: select h oid
>> > if none? obj [
>> > obj: make object! [__oid__: oid]
>> > insert insert tail h oid obj
>> > ]
>> > if (i // 100) = 0 [clear h]
>> > ]
>> >
>> > print ["Elapsed time for adding" n "records" (now/time/precise - start)]
>>
>> 1) For what i understand, you allocate a 200.000 slot hash, then clear the
>> cache every 100 item. Why?
>>
>> 2) The last thing: time consuming task here is clear.
>>
>> 3) Another thing: if you make hash! n then you should insert n item not n *
RPT> 2
>> (with insert insert)
>>
>> Remember that Rebol uses internal and hidden keys to hash. Your oid value is
>> internally hashed like any other value.
>>
>> ---
>> Ciao
>> Romano
>>
>> --
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>>
--
Best regards,
Konstantin mailto:[knizhnik--garret--ru]
