Mailing-List: contact dev-help@harmony.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@harmony.apache.org
Received-SPF: pass (nike.apache.org: domain of prashanth.jayashree@gmail.com
 designates 74.125.82.43 as permitted sender)
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type;
        b=NHht56aeXG+Es1JhNZjMi4NhnJkDm3iHwaRiT+vwPoMv8W0THEstoDXta51SnpZT/x
         1UogpQlaSzQnDPR557NCmakKletE81SLZF5VMjMJPN/7IJgl9vwSX59HlLyLmr1yPSTu
         pH5eHucRxEOjUmVsCJxDTaYWjsP/3NMVeIJoI=
MIME-Version: 1.0
In-Reply-To: <4C598D8D.4010404@googlemail.com>
References: <4C56E4F8.2040105@googlemail.com>
	<8652591182674059221@unknownmsgid>
	<AANLkTikT1+REkJr8H5nUK6E-UD-nHxh5WbwH2Gj3+MX5@mail.gmail.com>
	<201008041456.o74EuNhO004999@d12av03.megacenter.de.ibm.com>
	<4C598D8D.4010404@googlemail.com>
Date: Thu, 5 Aug 2010 12:55:11 +0530
Message-ID: <AANLkTi=R6ckyWV0631npToUh3=ZVSsfPy4CjY_VUQCvi@mail.gmail.com>
Subject: Re: [classlib][luni] Collections classes - code reviews and
	optimisations
From: Prashanth K S <prashanth.jayashree@gmail.com>
To: dev@harmony.apache.org
Content-Type: multipart/alternative; boundary=0016368332f460fe63048d0e73e6

--0016368332f460fe63048d0e73e6
Content-Type: text/plain; charset=UTF-8

I felt the same with the growth factor. We have a field called increment in
the grow methods which is set to 12 in most of the cases, attributing to the
excessive growth. Not sure how/why 12 was chosen.

-- 
Regards
Prashanth


On Wed, Aug 4, 2010 at 9:25 PM, Oliver Deakin
<oliver.deakin@googlemail.com>wrote:

>  On 04/08/2010 15:56, Mark Hindess wrote:
>
>> I've now refactored the exception code to the start of the methods and
>> shuffled some of the if else cases around a little.
>>
>> Next I plan to look at:
>>
>> 1) remove the following from addAll(...):
>>
>>          if (this == collection) {
>>              collection = (ArrayList)clone();
>>          }
>>
>>    since it is immediately followed by a call to collection.toArray() so
>>    it should be unnecessary.
>>
>> 2) Change the fields to firstIndex and size.
>>
>> In message<AANLkTikT1+REkJr8H5nUK6E-UD-nHxh5WbwH2Gj3+MX5@mail.gmail.com<AANLkTikT1%2BREkJr8H5nUK6E-UD-nHxh5WbwH2Gj3%2BMX5@mail.gmail.com>
>> >,
>> Catherine Hope writes:
>>
>>> I did some analysis on what API methods access others between the RI
>>> and Harmony (by subclassing ArrayList and adding some trace) to answer
>>> a couple of the review points.
>>>
>> Thanks Cath.  I wonder if we can use serialization/deserialization
>> to figure out how the RI grows the capacity of the ArrayList.  Our
>> implementation seems to grow it quite quickly.
>>
>>  The differences I found were:
>>>  - RI contains(Object) calls indexOf(Object), so we could also do this
>>> to reduce the code duplication
>>>
>> Sounds good.
>>
>
> +1
>
>
>   - RI add(Object), add(int, Object), addAll(Collection), addAll(int,
>>> Collection) use ensureCapacity(int)
>>>
>> Interesting.  Makes our three grow* methods seems a little excessive.
>>
>
> I was just thinking the same thing :)
>
> It occurs to me that the grow methods for the start and end of the list are
> just special cases of growForInsert(). I think we could probably roll them
> all into one neater method covering all three cases. This should remove the
> necessity to check if we are at the start/end of the array in the add
> methods too - when we return from growForInsert() we will know that there
> will be the required number of empty slots at location and that
> first/lastIndex have been updated, so we can then just write our data
> straight into that position.
>
>
>
>   - RI remove(Object) doesn't reference indexOf(Object) and remove(int) -
>>> though I don't think this would save anything if we changed it
>>>
>> Agreed.
>>
> +1
>
> Regards,
> Oliver
>
>  -Mark.
>>
>>
>>
>>
> --
> Oliver Deakin
> Unless stated otherwise above:
> IBM United Kingdom Limited - Registered in England and Wales with number
> 741598.
> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
>
>

--0016368332f460fe63048d0e73e6--