How to transmit Data

I want to implement a technique where i want to transmit all the data of a structure. The structure as per the requirement it may change as it is used for testing purpose. For example today i may want to transmit data1, data2 to external interface

Code:

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struct data_tag
{
double data1;
double data2;
}data;

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tomorrow someone else wants to transmit some other test data he can add another variable where i am not aware of which data type he will use. Another limitation is he can transmit only 8 bytes at a time, next call he has to start from where he stopped. Is it possible to do this? He will use an interface function to transmit data with a pointer to the structure. I am free in choosing the type of structure. please suggest.

If your users are responsible for serialising and deserialising their own data, then it's easy for you.

Whether they output
"data1=1.234, data2=4.567"
or
<element name="data1" type="double" value="1.234"/>
<element name="data2" type="double" value="4.567"/>
is not your concern.

All you have to do is achieve a reliable transport.


> Another limitation is he can transmit only 8 bytes at a time, next call he has to start from where he stopped. Is it possible to do this?
Yes, it's a loop.

Code:

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void sendData ( void *addr, size_t len ) {
  // split len up into 8-byte blocks and send them one at a time over your
  // restricted interface.
}

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