Problem with Serialize/Deserialize of Double

[Konstantinos]

Hey all,

I want to include a "double" value in a hello message that I send. Basically it is the velocity that I include. Since velocity is a 3D Vector, I have to serialize 3 double values.

This is how it I do it...

  i.WriteHtonU64  ((uint64_t)this->velocity.x);
  i.WriteHtonU64  ((uint64_t)this->velocity.y);
  i.WriteHtonU64  ((uint64_t)this->velocity.z);

After a lot of tries and debug messages, I realized that my problem was the fact that velocity can get also negative values but I serialize it as UINT64_T and thus I get values like this 1.84467e+19 which is the max value for a UINT64_T variable. Is there another way to implement this ??

From the ns3::Buffer::Iterator Class Reference I couldn't find something. Perhaps I should serialize only the magnitude of the velocity and include the heading as a second value as well.

Regards,
Konstantinos

[Mohammad]

Hello Konstantinos,

I have the same problem to serialize a negative value!!

Have you solve the problem? if so, please write ti down here so other also can use it,

Thanks

[Konstantinos]

I just serialize the abstract value (always positive) and have another variable to serialize the sign (if you need the value) or the heading (if you just need the velocity)

[Jordan Mihaylov]

Hi,

You have the Buffer::Iterator i ...
so try the following:

// for Serialization
i.Write((uint8_t*) &velocity, sizeof(velocity));

// for Deserialization
i.Read((uint8_t*) &velocity, sizeof(velocity));

I'm not sure if std::vector has some storage overhead, e.g. if it's size > 3x sizeof(double), so let's suppose that "velocity" in my example represents a simple struct like:

struct vel3d{
    double x;
    double y;
    double z;
} velocity;