Hi Deepak, I can answer one of two questions here...
On Fri, Sep 14, 2012 at 9:42 AM, Deepak Balasubramanyam <deepak.b...@gmail.com> wrote: > Thanks for the tip Russell. I managed to get this done. > > I have one more question and a suggestion. > > Is the name keyData a misnomer in the mapping function -> function(value, > keyData, arg) ? keyData is a String that carries the bucket name. The value > object carries more information. value[0].data represents the data itself > among other properties that represent user metadata; riak links; indexes; > key; etc etc. > If mapValuesJson: function(value, keyData, arg) can take an input argument > and use it to add a json property whose value is the riak key, a custom > function would not be necessary. It would be a neat little system feature > which I take would need amendments to mapred_builtins.js. > > Is riak_kv the repo to make contributions to system built functions ? There > are quite a few open pull requests on that repo, so I'm not sure where this > change should go. > The riak_kv repo is indeed the repo you want for this. Specifically, you'll want to start here: https://github.com/basho/riak_kv/blob/master/priv/mapred_builtins.js As far as the large queue of pull requests go, we're working on merging/addressing the backlog (for this and a few other repos). Send yours our way. It'll get some love when time allows. Thanks. Mark > > Thanks > Deepak Bala > > On Fri, Sep 14, 2012 at 7:16 PM, Russell Brown <russell.br...@me.com> wrote: >> >> >> On 14 Sep 2012, at 14:24, Deepak Balasubramanyam wrote: >> >> > Hi, >> > >> > I've written a map reduce query on the riak java client like so... >> > >> > client.mapReduce(BUCKET).addKeyFilter(keyFilter) >> > .addLinkPhase(BUCKET, "_", false) >> > .addMapPhase(new >> > NamedJSFunction("Riak.mapValuesJson"), false) >> > .addReducePhase(phaseFunction).execute(); >> > Collection<MyType> types = result.getResult(MyType.class); >> > >> > This is the class definition for MyType >> > >> > public class MyType >> > { >> > @RiakKey >> > private String myKey; >> > private String property1; >> > private String property2; >> > >> > /* Getters / Setters go here */ >> > } >> > >> > When the object mapper deserializes the results into Collection<MyType>, >> > none of the types have the myKey property populated in them. When I >> > debugged >> > the calls made by riak I realized that the result of the /mapred call does >> > not contain any key information in the body. It only contains the value >> > that >> > each key represents. So that explains why the keys are null in the result. >> >> The Java client doesn't add the value of the @RiakKey field to the value >> stored in riak. >> >> > >> > On the contrary, a link walk in riak returns the Location header for >> > each multipart form entry in the response (Location: /riak/bucket/key). So >> > I >> > guess there is at least some way to tweak a client to parse the location to >> > get the keys, but you lose out on the map-reduce goodness. >> > >> > Is there some way a map-reduce query can be formed to allow the >> > resulting type's RiakKey to be populated ? What are my options ? >> >> A custom Map function may do what you want. Get the Key from the Key Data >> passed to the Map function and add it to the JSON value returned. Jackson >> should then take care of de-serialising it into your values. >> >> Cheers >> >> Russell >> >> > >> > Thanks >> > Deepak Bala >> > _______________________________________________ >> > riak-users mailing list >> > riak-users@lists.basho.com >> > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >> > > > _______________________________________________ > riak-users mailing list > riak-users@lists.basho.com > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > _______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
