[Kmymoney-devel] Is there a cache for accounts balance?

[Alvaro Soliverez]

On Sun, Aug 29, 2010 at 5:09 PM, Fernando Vilas <fvilas at iname.com> wrote:
> On Sunday, August 29, 2010 11:10:46 Thomas Baumgart wrote:
>> Hi,
>>
>> on Sunday 29 August 2010 16:24:30 Alvaro Soliverez wrote:
>> > Hello all,
>> > I've been doing some callgrind tests to check the startup performance.
>> > One thing I noticed is that almost a 10% of the time is spent
>> > calculating balances.
>> > For a normal start, balances are needed by forecast, reports and the home
>> >
>> >  view.
>> >
>> > Do you think it would be worth to cache the balance data on MyMoneyFile?
>>
>> That's already done. Once the XML file is loaded, the method
>> MyMoneySeqAccessMgr::rebuildAccountBalances() is called which caches the
>> balance with each MyMoneyAccount object.
>>
>> Also, MyMoneySeqAccessMgr::balance() maintains a cache.
>>
>> The problem is, that you cannot cache 'the' balance of an account, as it
>> may be different for each date.
>
> There was something similar in the DB backend, but I removed it some time ago
> when trying to debug account balance inconsistencies.
>
> I think we should move the balance cache from the backends into the MMFile
> object, so we have a common cache. As Thomas says, it also needs to handle
> multiple dates.
>

The cache of course should be per account, per date. As there is not a
single balance per account.
On a similar note, forecast performance might be improved if I change
it from requesting a balance in the past and calculating the balance
forward, to requesting the current balance, and calculate the past
balances backward. At least for the historic method, I think that
might result in a performance improvement.