Example for loading ObjectPool from Filesystem SPIFFS

[Oberchefe]

Is there an example for loading the iop with SPIFFS using register_object_pool_data_chunk_callback? I have no idea how to handle DataChunkCallback.

[ad3154]

There is sort of an example in the unit tests for the stack, but essentially it works like this:

First, you define a function that teaches the stack how to read bytes out of your object pool, like this:

bool MyVeryCoolDataChunkCallback(std::uint32_t,
                                         std::uint32_t bytesOffset,
                                         std::uint32_t numberOfBytesNeeded,
                                         std::uint8_t *chunkBuffer,
                                         void *)
{
    memcpy(chunkBuffer, &yourObjectPool[bytesOffset], numberOfBytesNeeded);
    return true;
}

The important part here is that when this function is called, you copy the number of bytes requested into the buffer provided by the stack at the memory offset it asks for. So, it will start at byte offset 0, and keep calling this function until you have copied over all bytes of your object pool.

Secondly, you call register_object_pool_data_chunk_callback on the VT client instead of set_object_pool. When you call that, the last parameter is the function you defined.

Like this:

client.register_object_pool_data_chunk_callback(0, yourPoolSize, MyVeryCoolDataChunkCallback);

That's about it!