public void LRUCacheTest()
{
// max cache size 1000 bytes
var cache = new LRUCache <int, Person>(1000);
Person p;
// create a new person object
int i = 1, firstValue = 1;
var p1 = new Person {
Id = i++, FirstName = "Hariom", LastName = "Kuntal"
};
var p2 = new Person {
Id = i++, FirstName = "Ruby", LastName = "Kuntal"
};
var p3 = new Person {
Id = i++, FirstName = "Dhruv", LastName = "Kuntal"
};
cache.Add(p1.Id, p1);
cache.Add(p2.Id, p2);
cache.Add(p3.Id, p3);
// Assert the size in the cache
var size = p1.GetSize() + p2.GetSize() + p3.GetSize();
Assert.AreEqual(size, cache.GetCurrentCacheSize());
// Add more data to cache so its size exceeds
while (size < 960)
{
p = GetNewObjectForCache(i++);
size += p.GetSize();
cache.Add(p.Id, p);
}
// get the size
var csize = cache.GetCurrentCacheSize();
// check the last entry in the cache
var lastKey = cache.GetTheLastKeyFromLinkedList();
Assert.AreEqual(lastKey, firstValue);
// Add another item. Last key item shoud be removed to make some space for this item
var k = i++;
var newP = GetNewObjectForCache(k);
cache.Add(newP.Id, newP);
lastKey = cache.GetTheLastKeyFromLinkedList();
Assert.AreNotEqual(lastKey, 1);
Assert.AreEqual(lastKey, 2);
// Add another item, last key should be removed again to make some space
p = GetNewObjectForCache(i++);
cache.Add(p.Id, p);
lastKey = cache.GetTheLastKeyFromLinkedList();
Assert.AreEqual(lastKey, 3);
// Add an item double the size, 2 elements be removed from the list and the 5th node should become the last node
p = GetNewObjectForCacheDoubleSize(i++);
cache.Add(p.Id, p);
lastKey = cache.GetTheLastKeyFromLinkedList();
Assert.AreEqual(lastKey, 5);
// Access a key. It should move to the new head
var count = cache.GetCacheItemsCount();
// take the middle element and access it
int el = count / 2;
cache.Get(el);
// this element should move to the start of the linked list
}
