How did you implement pagination for data unloading?

Page-wise data unloading (pagination) is implemented to limit the amount of data transmitted in a single request, which is important for devices with limited resources.

Typically, one of the following approaches is used:

• Offset and limit:

  • The client sends the page number and page size.
  • The server returns data considering the offset: offset = (page - 1) * page_size.

• Cursor-based pagination:

  • Instead of a page number, a unique identifier of the last received element is used.
  • It allows more efficient handling of dynamic data.

Example implementation on an embedded device:

#define PAGE_SIZE 10

// Function to get a page of data
void get_page(int page_number, DataType* buffer) {
    int offset = (page_number - 1) * PAGE_SIZE;
    for (int i = 0; i < PAGE_SIZE; i++) {
        buffer[i] = read_data(offset + i); // reading data from memory or sensors
    }
}

This approach allows the client to sequentially request data in parts, reducing the load on the network and device memory.