On 7 Jun 2011, at 15:29, Jacques wrote:
> Have you had any success with reading the server response?
Yes. Sorry I didn't post a reply.
It was trivial (but fraught, see below), I just used the OtpInputStream to
deserialize the byte array returned from pbc.MapReduceResponse.
Like:
ByteString bs = resp.getContent();
OtpInputStream is = new OtpInputStream(bs.toByteArray());
OtpErlangObject result = is.read_any();
// and then all sorts of looping, sniffing types, unpacking etc
Caveats:
You have a pain unpacking any reasonably complex result.
The ETF specification drops this doozy about "strings":
http://www.erlang.org/doc/apps/erts/erl_ext_dist.html#id85596. My first test
actually returned a list of [0,1,2,3...200] and Jinterface helpfully turned
that into a string for me.
That aside it is certainly feasible to use Jinterface to serialize/deserialize
Map/Reduce jobs/results.
Cheers
Russell
>
> Thanks,
> Jacques
>
> On Sat, Jun 4, 2011 at 1:19 PM, Russell Brown <[email protected]> wrote:
>
> On 4 Jun 2011, at 18:22, Jacques wrote:
>
>> I like the sound of option 3 also. I'll have a look at it this weekend and
>> get back to you.
>>
>> Awesome! Thanks. If you can give me a point in the right direction
>> regarding the correct typing approach and what not, I'm up for giving it a
>> shot as well.
>
> Ok, I have a half working hack. It isn't pretty 'cos the Jinterface API is
> verbose. I've hacked the pbc.MapReduceBuilder to encode the job as
> "application/x-erlang-binary" and submit that, but really this code should be
> in a separate class, maybe using the output from MapReduceBuilder.getJSON()
> as input. That way you can get the feature without patching the client.
>
> What I haven't done is decode the response from Riak yet. If you want a
> pointer here is a gist of the (unclean) hack. It could use a lot of work, but
> it proves the concept:
>
> https://gist.github.com/1008293
>
> The gist is just the diff so you can apply it as a patch to
> src/main/java/com/basho/riak/pbc/mapreduce/MapReduceBuilder.java if you want
> to play with it.
>
> You'll have to add Jinterface to your pom too.
>
> <!-- jinterface -->
> <dependency>
> <groupId>org.erlang.otp</groupId>
> <artifactId>jinterface</artifactId>
> <version>1.5.4</version>
> </dependency>
>
> I think it is best to put the result decoding outside the library too. I'm
> going to hack up a poc for that now, but I thought I'd post what I have thus
> far.
>
> Cheers
>
> Russell
>
>>
>> Thanks again,
>> Jacques
>
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