> On July 25, 2014, 12:51 a.m., Ben Mahler wrote:
> > 3rdparty/libprocess/3rdparty/stout/include/stout/multihashmap.hpp, line 42
> > <https://reviews.apache.org/r/23911/diff/1/?file=641620#file641620line42>
> >
> >     Aren't there potentially multiple keys for a particular value?
> >     
> >     i.e. Option<hashset<K> > getKeys(const V& value) const;
> >     
> >     Or should the calling code just iterate through the map for now to find 
> > the first key?
> 
> Ben Mahler wrote:
>     Sorry, the Option was unnecessary. :)
> 
> Bernd Mathiske wrote:
>     I could add the method that returns all keys for a given value, but I do 
> not have a use case for it.

My concern is that it seems to be tailored to your particular use-case, where 
you happen to have unique values per key. But this is not an inherent property 
of multimap.

For your use-case getKeys() is equivalent:

getKey     getKeys
  None <-> Empty set
Some K <-> Non-empty set (use *iterator.begin() to obtain the only key)

Or you could just iterate the map since there only appears to be one use case 
so far?


- Ben


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On July 25, 2014, 12:40 a.m., Bernd Mathiske wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/23911/
> -----------------------------------------------------------
> 
> (Updated July 25, 2014, 12:40 a.m.)
> 
> 
> Review request for mesos.
> 
> 
> Bugs: MESOS-947
>     https://issues.apache.org/jira/browse/MESOS-947
> 
> 
> Repository: mesos-git
> 
> 
> Description
> -------
> 
> Small extension of stout that is useful for fixing MESOS-947, but also in 
> general. adding a getKey() method to multihashmap, which finds a key given a 
> value in the map.
> 
> A dependent Mesos patch fixing MESOS-947 will follow promptly.
> 
> 
> Diffs
> -----
> 
>   3rdparty/libprocess/3rdparty/stout/include/stout/multihashmap.hpp ecda6a9 
> 
> Diff: https://reviews.apache.org/r/23911/diff/
> 
> 
> Testing
> -------
> 
> The method behaves as expected in the unit test for MESOS-947. I did not 
> create stout unit tests for it. (There is no precedence for testing 
> multihashmap and this particular piece of code is very straightforward.)
> 
> 
> Thanks,
> 
> Bernd Mathiske
> 
>

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