Alfredo Braunstein wrote:
> A second option for LoaderQueue.
> I've left the previous interface untouched, but changed a little the
> implementation. Now touch() doesn't add directly the image pointer to the
> queue, but it adds it to an input bucket (implemented as a plain queue)
> without any checking and returns inmediately.
> Then on the 'threaded' method LoadNext we empty the input bucket into the
> queue, with all uniqueness and reprioritization checking.
> This implementation avoids completely having to lock the data, and so any
> posibility of losing time on the main thread.
> The startup time should be shorter also.
>
> I have to solve at least one problem: the graphics insets have
> startLoading called in document order, from first to last. Then they are
> added to the queue in inversed order, and start loading from last to
> first. Maybe we have to bypass this reprioritizing mechanism on startup
> somehow? Any clue on how to solve this please?
>
> (there are other remaining things if ever this gets incorporated: like to
> where the LoaderQueue class belongs (BufferView?).
It doesn't depend on BufferView. Why not make it a singleton class?
> Does it deserves its own file
Yes.
> PS: As before, please correct without mercy but being nice...
bucket1_ is filled with Cache::ItemPtrs to be dealt with by
LoaderQueue::touch.
The timer calls LoaderQueue::loadNext every 100 ms.
LoaderQueue::loadNext calls
emptyBucket(), which:
swap(bucket1_, bucket2_);
Why is bucket2_ a class member. It is used only in
LoaderQueue::emptyBucket() and is guaranteed to be empty on entry and on
exit to the method. In fact why not:
+void LoaderQueue::emptyBucket()
+{
+ cout << "emptying bucket" << endl;
+ while (! bucket1_.empty()) {
+ addToQueue(bucket1_.front());
+ bucket1_.pop();
+ }
+}
LoaderQueue::addToQueue takes this Cache::ItemPtr and adds it to the queue
of items to be processed, cache_queue_, if not already there.
Why not:
void LoaderQueue::addToQueue(Cache::ItemPtr & item)
(Ie, pass by reference). It isn't a simple pointer and so will add overhead
passing by value as you do now.
Once cache_queue_ is initialised, loadNext instigates the actual loading of
the Cache::ItemPtrs.
I'm a bit confused by cache_set_ and cache_queue_. Could you help me?
--
Angus
