Jay, My understanding is that java linked lists (even though they are backed by a doubly linked list) support O(1) deletion only if you have the index of the object. If you do a remove(object) it becomes O(n). As for scala lists - the scaladocs seem to indicate that the doubly linked lists are deprecated as of 2.11
Joel On Wednesday, February 4, 2015, Jay Kreps <jay.kr...@gmail.com> wrote: > Hey Jiangjie, > > Both the scala and java doubly linked lists allow O(1) deletion--it isn't > obvious because the api is slightly different from the CS101 linked list > but they do. Are you sure those wouldn't work? Can we remove this class and > use those? > > Also the convention for unit tests is if we have a class Foo.scala then we > would have a test FooTest.scala. So you can definitely write a unit test > for classes used by MM without adding it to kafka.utils. The > UtilsTest.scala is really for Utils.scala we shouldn't be adding other > tests there. > > -Jay > > On Tue, Feb 3, 2015 at 11:46 PM, Jiangjie Qin <j...@linkedin.com.invalid> > wrote: > > > We added this because in redesigned mirror maker we need a raw linked > list > > so we can removed an acked offset from a linked list in O(1). Java and > > Scala linked list won¹t work in that case. It was initially put in side > > mirror maker as a private class, but later on we also want to have unit > > test for it, that¹s why it becomes a separate util class and we have unit > > test in UtilsTest.scala. > > > > -Jiangjie (Becket) Qin > > > > On 2/3/15, 9:15 PM, "Jay Kreps" <jay.kr...@gmail.com <javascript:;>> > wrote: > > > > >How come we added this? Is it better than the linked list in java and > > >scala? Also it was added with only one test which is actually put inside > > >UtilsTest.scala which is meant to house tests for Utils.scala. > > > > > >-Jay > > > > > -- Sent from Gmail Mobile
