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From Marshall Schor <...@schor.com>
Subject Re: How to use the new binary CAS (de)serialization?
Date Mon, 05 Aug 2013 15:40:20 GMT
I think if you "pre-read" some info from a stream, and then pass that stream to
the reinit (or other method of binary deserialization), it just continues
reading from wherever the stream was positioned, so I think your approach ought
to work...


On 8/2/2013 2:34 PM, Richard Eckart de Castilho wrote:
> Hm, I just notice that my problem analysis was not quite correct.
> BinaryCasSerDes6 indeed is able to handle the header… so my problem
> must be somewhere else.
> -- Richard 
> Am 02.08.2013 um 20:29 schrieb Richard Eckart de Castilho <richard.eckart@gmail.com>:
>> Hi,
>> I'm still trying to use the new serialization methods but continue
>> running into problems.
>> Last time we discussed that I need to know the original type system
>> when I want to deserialize a format 6 binary CAS into a CAS.
>> So when I serialize the CAS now, I first write a header, then I
>> dump the type system into my output stream, and then the binary CAS
>> using 
>> serializeWithCompression(cas, outputStream, cas.getTypeSystem());
>> When I read the data, I check for my header. If it is there, I
>> read the type system.
>> Now I wanted to call
>> deserializeCAS(cas, inputStream, typeSystem, null);
>> Unfortunately, that fails. The reason is, that this signature of
>> deserializeCAS immediately uses the BinaryCasSerDes6 to read
>> data from the input stream. However, serializeWithCompression
>> writes a header before the data that BinaryCasSerDes6. This
>> header is read by a deserializeCAS(cas, inputStream), but
>> in this signature, I have no way of specifying the original
>> type system.
>> Of course I can copy the whole header checking code from CASImpl,
>> but I don't think that is a good solution. I think the
>> deserializeCAS methods that UIMA provides should either all deal
>> with the header that the serializeWithCompression methods write,
>> or none should.
>> Maybe a solution for this dilemma is something that could also
>> go into a 2.4.2 release.
>> Cheers,
>> -- Richard

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