Fixed Size Queue With Array

MediumPython

Problem

ExtraHop Networks telemetry components may need a bounded FIFO buffer for temporarily holding network events. Implement a fixed-size queue using an array and circular indexing so that insertions and removals remain efficient without shifting elements.

Create fixed_queue(capacity, operations). The function must process operations in order and return the result of each operation:

['enqueue', value]: Add value to the rear. Return True if successful, or False if the queue is full.
['dequeue']: Remove and return the oldest value, or return None if the queue is empty.
['front']: Return the oldest value without removing it, or None if empty.
['is_empty']: Return whether the queue contains no values.
['is_full']: Return whether the queue has reached capacity.

The queue must preserve FIFO order. Reusing positions freed by dequeue is required, and enqueue or dequeue must not shift existing elements.

Constraints

1 <= capacity <= 10^5
0 <= len(operations) <= 10^5
Each enqueued value is an integer
Queue storage must remain O(capacity)

Function Signature

def fixed_queue(capacity, operations):

Create fixed_queue(capacity, operations). The function must process operations in order and return the result of each operation:

['enqueue', value]: Add value to the rear. Return True if successful, or False if the queue is full.
['dequeue']: Remove and return the oldest value, or return None if the queue is empty.
['front']: Return the oldest value without removing it, or None if empty.
['is_empty']: Return whether the queue contains no values.
['is_full']: Return whether the queue has reached capacity.

The queue must preserve FIFO order. Reusing positions freed by dequeue is required, and enqueue or dequeue must not shift existing elements.