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https://issues.apache.org/jira/browse/OFBIZ-6298?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Nicolas Malin updated OFBIZ-6298:
---------------------------------
Description:
With the javolution collection cleaning (OFBIZ-5169,OFBIZ-5781) , we need to
realize a second pass to control what instantiation would be better.
For List between LinkedList, ArrayList
{quote}
Using ArrayList, rather than LinkedList, as a default is a good approach
because ArrayList will work better in most situations (in terms of algorithmic
runtimes and memory footprints).
However I think it is important to wisely choose ArrayList or LinkedList based
on the context, because sometimes a linked list may be a better choice: I am
not saying we should do it now and we can tackle this at a later moment,
possibly focusing only on list that can be very big and analyzing their usage
to see if array or linked list is better; it would be also nice, when we use
ArrayList, to see if we can predict the capacity of the list and allocate it at
creation: if we can do this we will have a more predictable memory usage and
less unpredictable peaks under heavy load (when the array capacity is reached
and the array is copied to a new one with double capacity).
{quote}
more documentation on :
* https://docs.oracle.com/javase/tutorial/collections/implementations/list.html
*
http://stackoverflow.com/questions/322715/when-to-use-linkedlist-over-arraylist
For Map between HashMap and LinkedHashMap :
{quote}
Javolution Map Iterators return items in insertion sequence (HashMap does not),
so any code relying on the original insertion order must use a LinkedHashMap.
{quote}
*
http://stackoverflow.com/questions/2889777/difference-between-hashmap-linkedhashmap-and-treemap
For Set beetwen HashSet and LinkedHashSet. (OFBIZ-6299)
If you detect an optimization, please comments this issues
was:
With the javolution collection cleaning (OFBIZ-5169,OFBIZ-5781) , we need to
realize a second pass to control what instantiation would be better.
For List between LinkedList, ArrayList
{quote}
Using ArrayList, rather than LinkedList, as a default is a good approach
because ArrayList will work better in most situations (in terms of algorithmic
runtimes and memory footprints).
However I think it is important to wisely choose ArrayList or LinkedList based
on the context, because sometimes a linked list may be a better choice: I am
not saying we should do it now and we can tackle this at a later moment,
possibly focusing only on list that can be very big and analyzing their usage
to see if array or linked list is better; it would be also nice, when we use
ArrayList, to see if we can predict the capacity of the list and allocate it at
creation: if we can do this we will have a more predictable memory usage and
less unpredictable peaks under heavy load (when the array capacity is reached
and the array is copied to a new one with double capacity).
{quote}
more documentation on :
* https://docs.oracle.com/javase/tutorial/collections/implementations/list.html
*
http://stackoverflow.com/questions/322715/when-to-use-linkedlist-over-arraylist
For Map between HashMap and LinkedHashMap :
{quote}
Javolution Map Iterators return items in insertion sequence (HashMap does not),
so any code relying on the original insertion order must use a LinkedHashMap.
{quote}
*
http://stackoverflow.com/questions/2889777/difference-between-hashmap-linkedhashmap-and-treemap
If you detect an optimization, please comments this issues
> Java collection use optimized
> -----------------------------
>
> Key: OFBIZ-6298
> URL: https://issues.apache.org/jira/browse/OFBIZ-6298
> Project: OFBiz
> Issue Type: Improvement
> Components: ALL COMPONENTS
> Affects Versions: Trunk
> Reporter: Nicolas Malin
> Assignee: Nicolas Malin
> Priority: Minor
> Labels: collection, performance
>
> With the javolution collection cleaning (OFBIZ-5169,OFBIZ-5781) , we need to
> realize a second pass to control what instantiation would be better.
> For List between LinkedList, ArrayList
> {quote}
> Using ArrayList, rather than LinkedList, as a default is a good approach
> because ArrayList will work better in most situations (in terms of
> algorithmic runtimes and memory footprints).
> However I think it is important to wisely choose ArrayList or LinkedList
> based on the context, because sometimes a linked list may be a better choice:
> I am not saying we should do it now and we can tackle this at a later moment,
> possibly focusing only on list that can be very big and analyzing their usage
> to see if array or linked list is better; it would be also nice, when we use
> ArrayList, to see if we can predict the capacity of the list and allocate it
> at creation: if we can do this we will have a more predictable memory usage
> and less unpredictable peaks under heavy load (when the array capacity is
> reached and the array is copied to a new one with double capacity).
> {quote}
> more documentation on :
> *
> https://docs.oracle.com/javase/tutorial/collections/implementations/list.html
> *
> http://stackoverflow.com/questions/322715/when-to-use-linkedlist-over-arraylist
> For Map between HashMap and LinkedHashMap :
> {quote}
> Javolution Map Iterators return items in insertion sequence (HashMap does
> not), so any code relying on the original insertion order must use a
> LinkedHashMap.
> {quote}
> *
> http://stackoverflow.com/questions/2889777/difference-between-hashmap-linkedhashmap-and-treemap
> For Set beetwen HashSet and LinkedHashSet. (OFBIZ-6299)
> If you detect an optimization, please comments this issues
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