InputStream.cs

using System;
using System.Collections.Generic;
using UnityEngine;

public static class Utilities {
	// shifts all array elements to the right, inserting newValue at the beginning
	public static void ShiftInto<T>(T[] array, T newValue) {
		T carry = newValue;
		for (int i=0; i<array.Length; i++) {
			// this is basically swapping carry and the array index
			T current = array[i];
			array[i] = carry;
			carry = current;
		}
	}
}

// Input is a stream of values from some source device
public class InputStream<T> {
	const int sampleCount = 64;
	public T[]      values = new T[sampleCount];
	public double[] times = new double[sampleCount];

	// Some useful properties
	public T current => values[0];
	public T last => values[1];
	public double currentTime => times[0];
	public double lastTime => times[1];

	public void Next(T value, double time) {
		Utilities.ShiftInto(values, value);
		Utilities.ShiftInto(times, time);
	}
}
public static class InputStreamExtensions {
	public static bool IsIdle    (this InputStream<bool> input) => !input.current && !input.last;
	public static bool IsPressed (this InputStream<bool> input) =>  input.current && !input.last;
	public static bool IsHeld    (this InputStream<bool> input) =>  input.current &&  input.last;
	public static bool IsReleased(this InputStream<bool> input) => !input.current &&  input.last;

	public static Vector3 Average(this InputStream<Vector3> input, int samples) {
		Vector3 total = new Vector3(0f, 0f, 0f);
		int count = Mathf.Min(samples, input.values.Length);
		for (int i=0; i<count; i++)
			total += input.values[i];
		return total / count;
	}
}

InputStreamtesting.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class InputStreamTesting : MonoBehaviour {
	static InputStream<bool> jump = new InputStream<bool>();
	static InputStream<bool> pickup = new InputStream<bool>();
	static InputStream<Vector3> position = new InputStream<Vector3>();

	void Update() {
		// how you add input to these, do this when you poll the backend API's
		jump.Next(Input.GetKey(KeyCode.Space), Time.time);
		pickup.Next(Input.GetKey(KeyCode.F), Time.time);
		position.Next(transform.position, Time.time);

		// when you want to poll input:
		if (jump.IsPressed()) print("Jump!");
		if (pickup.IsPressed()) print("Pickup!");
	}
	void OnDrawGizmos() {
		// you can poll the data anywhere basically
		Gizmos.DrawWireSphere(position.Average(16), 0.1f);
	}
}