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From Matei Zaharia <matei.zaha...@gmail.com>
Subject Re: ClassTag in Serializer in 1.0.0 makes non-scala callers sad panda
Date Mon, 02 Jun 2014 00:10:16 GMT
Ah, got it. In general it will always be safe to pass the ClassTag for java.lang.Object here
— this is what our Java API does to say that type info is not known. So you can always pass
that. Look at the Java code for how to get this ClassTag.

Matei

On Jun 1, 2014, at 4:33 PM, Soren Macbeth <soren@yieldbot.com> wrote:

> I'm writing a Clojure DSL for Spark. I use kryo to serialize my clojure
> functions and for efficiency I hook into Spark's kryo serializer. In order
> to do that I get a SerializerInstance from SparkEnv and call the serialize
> and deserialize methods. I was able to workaround it by making ClassTag
> object in clojure, but it's less than ideal.
> 
> 
> On Sun, Jun 1, 2014 at 4:25 PM, Matei Zaharia <matei.zaharia@gmail.com>
> wrote:
> 
>> BTW passing a ClassTag tells the Serializer what the type of object being
>> serialized is when you compile your program, which will allow for more
>> efficient serializers (especially on streams).
>> 
>> Matei
>> 
>> On Jun 1, 2014, at 4:24 PM, Matei Zaharia <matei.zaharia@gmail.com> wrote:
>> 
>>> Why do you need to call Serializer from your own program? It’s an
>> internal developer API so ideally it would only be called to extend Spark.
>> Are you looking to implement a custom Serializer?
>>> 
>>> Matei
>>> 
>>> On Jun 1, 2014, at 3:40 PM, Soren Macbeth <soren@yieldbot.com> wrote:
>>> 
>>>> 
>> https://github.com/apache/spark/blob/v1.0.0/core/src/main/scala/org/apache/spark/serializer/Serializer.scala#L64-L66
>>>> 
>>>> These changes to the SerializerInstance make it really gross to call
>>>> serialize and deserialize from non-scala languages. I'm not sure what
>> the
>>>> purpose of a ClassTag is, but if we could get some other arities that
>> don't
>>>> require classtags that would help a ton.
>>> 
>> 
>> 


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