Binary Serialized file much larger than expected

  • Thread starter Thread starter Stewart
  • Start date Start date
S

Stewart

Hi,

I have a class which has 6 automatic properties (6 x 8 bytes). This
means the total size of the class is 48 bytes. I have 15000 of these
in a generic List. When I serialize these to disc using the
BinaryFormatter I get a file which is 970kb. I would have expected
closer to 48 * 15000 / 1000 = 720kb.

Thoughts?

Stewart
 
I have a class which has 6 automatic properties (6 x 8 bytes). This
means the total size of the class is 48 bytes. I have 15000 of these
in a generic List. When I serialize these to disc using the
BinaryFormatter I get a file which is 970kb. I would have expected
closer to 48 * 15000 / 1000 = 720kb.
Click to expand...

Did you open the output in a hex viewer to see what its contents looked
like?
 
I have a class which has 6 automatic properties (6 x 8 bytes). This
means the total size of the class is 48 bytes. I have 15000 of these
in a generic List. When I serialize these to disc using the
BinaryFormatter I get a file which is 970kb. I would have expected
closer to 48 * 15000 / 1000 = 720kb.
Click to expand...

[Sent my reply too soon]

1K = 1024, so divide by that, not 1000 (the difference would not turn 970
into 720, but it's still better to be correct).

Finally, how about serializing just one class and seeing how big that is,
then serializing 2 and seeing what the difference is. Exactly 2x? Something
else?
 
I have a class which has 6 automatic properties (6 x 8 bytes). This
means the total size of the class is 48 bytes. I have 15000 of these
in a generic List. When I serialize these to disc using the
BinaryFormatter I get a file which is 970kb. I would have expected
closer to 48 * 15000 / 1000 = 720kb.
Click to expand...

You forget that you need metadata in the serialized bytes to
describe what the data is.

Arne
 
Stewart said:
Hi,

I have a class which has 6 automatic properties (6 x 8 bytes). This
means the total size of the class is 48 bytes. I have 15000 of these
in a generic List. When I serialize these to disc using the
BinaryFormatter I get a file which is 970kb. I would have expected
closer to 48 * 15000 / 1000 = 720kb.

Thoughts?

Stewart
Click to expand...

"This means the total size of the class is 48 bytes." I think I would view it
as: "The minimum required storage for the fields of the class is 48 bytes."
They are not the same thing.

Did you expect it (binary serialization) to be completetely free of overhead?
Your numbers work out to only about 16 bytes of overhead per object. That seems
very modest to me, but of course your example is very simple.

-rick-
 
Back
Top