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https://issues.apache.org/jira/browse/BOOKKEEPER-964?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15770028#comment-15770028
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Hudson commented on BOOKKEEPER-964:
-----------------------------------

SUCCESS: Integrated in Jenkins build bookkeeper-master #1604 (See 
[https://builds.apache.org/job/bookkeeper-master/1604/])
BOOKKEEPER-964: Ignore findbugs warnings (sijie: rev 
f53cbf82758af7f620ecd1506c76801bd0e75c86)
* (edit) bookkeeper-server/src/main/resources/findbugsExclude.xml
* (edit) 
bookkeeper-server/src/main/java/org/apache/bookkeeper/proto/BookieServer.java


> Add concurrent maps and sets for primitive types
> ------------------------------------------------
>
>                 Key: BOOKKEEPER-964
>                 URL: https://issues.apache.org/jira/browse/BOOKKEEPER-964
>             Project: Bookkeeper
>          Issue Type: Improvement
>            Reporter: Matteo Merli
>            Assignee: Matteo Merli
>             Fix For: 4.5.0
>
>
> In BookKeeper there are many instances of maps and sets that use ledger id
> and entry ids as keys or values. JDK concurrent collections have the overhead
> of boxing all the primitive values into objects (eg: long --> Long) that would
> need to be allocated from the heap. In addition to that, JDK map 
> implementations
> are closed hash tables and they will require at least one more allocation to 
> hold
> the linked-list/tree node.
> There are already available libraries that offer primitive collections with
> zero-allocation, but none of these support concurrent maps/sets.
> We have added a handful of specializations, all based on the same 
> implementation
> idea. We have a hash table which is broken down into multiple sections. Each
> sections, on its own, is an open hash table with linear probing, protected by
> a stamped lock.
> All insertions, lookups and iterations on these collections are allocation 
> free.
> {noformat}
> ConcurrentLongHashMap: Map<long, Object>
> ConcurrentLongHashSet: Set<long>
> ConcurrentLongLongHashMap: Map<long, long>
> ConcurrentLongLongPairHashMap: Map< Pair<long, long>, Pair<long, long> >
> ConcurrentOpenHashMap: Map<Object, Object>
> ConcurrentOpenHashSet: Set<Object>
> {noformat}



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