Re: Binary serialization

Jacques wrote:

Thanks for the prompt response.

From what I can deduce from your answer below, the answer to my
question is yes? I.e. every unique managed object I create needs its
own streamwriter (and thus streamreader) routine if the desired
result is to store its DATA MEMBERS ONLY! Sorry for my pessimism
about the error prone-ness of the above, but this new (for me)
approach involves significantly more work for me!

Yes then you need your own streamwriter/reader combo. It will be
significantly faster than the binary formatter, so I think it's worth
the try.

FB


Thanks for clearing things up though!
Jacques

"Frans Bouma [C# MVP]" wrote:

Jacques wrote:

Hi

You are correct in assuming that I don't want do save files of 8
bytes! I am writing a realtime data capture app and need to
minimise disk space. Previously I would use a file write routine
that worked similarly to memcpy, ie
"File.Write(&MyClass,sizeof(MyClass))".

My question is this: Is the only way in which I can extract ONLY
the DATA members from the class in question the method of writing
each individual data member to astream/file.. MYSELF? The problem
I have with this is twofold: 1. every custom object needs its
own custom streamwriter routine 2. point nr (1) is quite error
prone for a clumsy programmer like myself!

You can somewhat solve it quite elegantly with the strategy pattern
through some base class/subclass construction: in the base class you
create the stream writer code, in the subclass you override a
method of the base class where you collect the data in to a byte
array which is then written to the stream by the base class. I dont
see how that can go wrong :)

FB


Kind regards
Jacques

"Frans Bouma [C# MVP]" wrote:> Jacques wrote:

Hi
I am an dotNet newby, so pardon my ignorance.

I am looking for a method of saving/copying a managed class
to a stream/file WITHOUT saving the object's state, eg. if I
have a ref class with two int32's as its data members, the
binary file of that class must have a size of 8 bytes (i.e.
only contains class data members, not methods etc.).

Is serialization the answer to the above problem?

No.

Binary serialization is a mechanism which writes that data to
the output stream which is necessary to re-create the object
when reading that precise data. I.o.w.: you get the contents +
extra fluff. If you want to save 8 bytes, you should grab the 8
bytes and write them yourself. Though I fail to see the
necessity for files of 8 bytes. This thus leads to the
assumption that you want to save the data of a lot of objects
into one file. If you do that yourself, you can end up with a
compact file, but also with a lot of code, or better: more code
than you would end up with when you would just go for the
binary formatter approach.

--
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Lead developer of LLBLGen Pro, the productive O/R mapper for .NET
LLBLGen Pro website: http://www.llblgen.com
My .NET blog: http://weblogs.asp.net/fbouma
Microsoft MVP (C#)
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.

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