IceStorm: Publishing my own class

[ShaChris23]

Hi,

Does IceStorm support publishing my own class?

For example, I want to pubishing a topic called "BigInteger" as described here:

C++ Big Integer Library - Matt McCutchen's Web Site

I have an application that I want to publish a number that keeps growing forever (i.e. never overflows or wraps around).

[bernard]

Hi Sivesh,

IceStorm allows you to publish any message, as long as this message is defined in Slice.

For example, you could associate an IceStorm topic with the following interface:

// Slice

sequence<long> BigIntegerData;

interface MyEvent
{
    void sentData(BigIntegerData bigIntData);
};

Your publisher would transform its BigInteger objects into BigIntegerData before calling sendData, and your subscribers would transform the received BigIntegerData into BigIntegers.

Best regards,
Bernard

[ShaChris23]

Hi Bernard,

So essentially, I would have to:

1) convert from an Object to a sequence of bytes (serializing it)
2) publish the serialized data (as specified in the Slice file)
3) have a subscriber that receives the serialized data
4) subscriber will convert from sequence of bytes to Object (de-serializing it)
5) and now it's ready to be used!

I just want to confirm this is along the line of what you said.

Note: Since I convert into sequence of bytes myself, this means I probably have to also take care of byte-endianness myself, or not?

Thanks!

S.

[bernard]

Hi Shivesh,

If you want to use bytes, you could, yes. In my example above, I used a sequence<long>: in that case, Ice would take care of reordering bytes as needed when your publisher and subscriber have different endianess.

In Java and C#, you can pass serializable objects directly as Ice operation parameters (the Ice runtime sees just a sequence<byte>): see
http://www.zeroc.com/doc/Ice-3.3.1/m...lice.5.18.html

However, we don't have anything equivalent for C++.

Cheers,
Bernard