How to serialize/Deserialize a String value?

[Sedrati Foued]

hello, 

I want to send a string value in the packet header, I added the variable but I don't know how to serialize and desirialize a string  : for Integer we use the methodes (i.WriteU8(variable) and i.WriteU16(variable) ect.. ).

what are the functions used for a string variable?

Thank you.

[Tom Henderson]

You probably want this method:

/**
* \param buffer a byte buffer to copy in the internal buffer.
* \param size number of bytes to copy.
*
* Write the data in buffer and advance the iterator position
* by size bytes.
*/
void Write (uint8_t const*buffer, uint32_t size);


If you have

std::string m_string;

as a member of your header class (MyHeader), when you are in Serialize()
method you should be able to do something like:

virtual void Serialize (Buffer::Iterator iter) const {
...
iter.Write (m_string.c_str(), m_string.length ());
...
}

You can do something similar using the matching Read() method. You
will need to pay attention to the size-- you need to read out the same
number of bytes that you wrote in (but you won't necessarily know the
size of the string at Read () time). So, you probably will want to pad
your string out to a well-defined fixed size and use that size value on
the Read () method.

- Tom

MyHeader hdr;
hdr.Write (m_str.c_str (), m_str.length ());

>
> Thank you.
>
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[Sedrati Foued]

thank you for the reply,

I tried what you have mentioned and this error came out 

[Tom Henderson]

On 7/31/22 00:00, Sedrati Foued wrote:
> thank you for the reply,
>
> I tried what you have mentioned and this error came out

Sorry, you need an additional cast, as described here:
https://stackoverflow.com/a/7664596

- Tom

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[Sedrati Foued]

thank you

[pdbarnes]

Another common technique for variable-sized objects is to serialize the size, then the data.  In this case

virtual void Serialize (Buffer::Iterator iter) const

{ 
  ... 
  iter.WriteHtolsbU64 ((uint64_t)m_string.size())

  iter.Write(m_string.c_str(), m_string.length ()); 

  ... 
}