Packet Reordering

Algorithm Streaming Buffer

You are tasked with implementing a system that processes a stream of data packets arriving out of order. Each packet is represented as an object with at least the following two properties:

  • sequence: an integer representing the packet's sequence number (sequence numbers are positive and ideally start at 1).
  • data: the payload of the packet (its content can be assumed to be a simple string).

The system should work as follows:

  1. Buffering Out-of-Order Packets: When a packet is received, if its sequence number is exactly one higher than the last processed packet, it should be immediately processed (e.g., output or stored in order). If the packet is out-of-order (i.e., its sequence is greater than the next expected number), it should be stored in a buffer.

  2. Processing When Possible: After processing any packet, the system should check the buffer to see if the next expected packet is present. If so, process it and repeat this step until the next expected packet is missing.

  3. Duplicate Handling: If a packet with a sequence number that has already been processed or buffered is received again, the system should discard the duplicate without affecting the order.

  4. Missing Packets: The system does not need to wait for indefinitely missing packets; it simply processes packets as they arrive and maintains the order based on the available packets.

Your goal is to design and implement this packet reordering system. Clearly define any assumptions you make, and ensure that your solution can handle packets arriving in any order with possible duplicates.

Write a function or a class in the programming language of your choice that handles these requirements. The input can be simulated by calling a method that receives a packet, and output can be achieved by printing or storing the in-order packets.

Demonstrate your solution with a simple simulation or test cases that showcase the functionality of your system.