How to get the size of a JSON root

[Race]

Hi,

I need to get the size of a JSON root (here the root is 'response') and this is how I do it now:
  str = json_dumps(response, JSON_ENSURE_ASCII);
  if (str)
  {
    reponse_size = strlen(str);
    free(str);
  }
  return (response_size);
Is there a smarter way to get the size of that response ?

/Race

[Petri Lehtinen]

If you need to know the length of the serialized JSON text in bytes,
there's no other way. Why would you even need the length if you throw
the actual JSON text away?

Petri

[Max Shaffer]

I did come across this problem one time myself. For HTTP HEAD requests it is often useful to know the size of a JSON resource without needing the actual JSON data...

~Max

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[Graeme Smecher]

Hi all,

Assuming the buffer length is all you need, it's slightly more efficient
to use json_dump_callback() with a function that sums the length of each
callback buffer, instead of completely assembling the results in a
single linear buffer and using strlen(). You can avoid a number of
malloc() and memcpy() calls this way.

As has been suggested, though, it does seem strange to calculate the
length of a JSON object without keeping the serialized version for
later.

cheers,
Graeme

[Rasmus Fink]

You're right, it does seem a bit strange :-)

It is because I need to allocate memory for it in a different function,
but that construct might need some reviewing too.

I'll have a look at the json_dump_callback() construct.

Thanks for the pointers and quick reply's.

Cheers
Race