34 lines
1.7 KiB
Go
34 lines
1.7 KiB
Go
package gocache
|
|
|
|
// EvictionPolicy is what dictates how evictions are handled
|
|
type EvictionPolicy string
|
|
|
|
var (
|
|
// LeastRecentlyUsed is an eviction policy that causes the most recently accessed cache entry to be moved to the
|
|
// head of the cache. Effectively, this causes the cache entries that have not been accessed for some time to
|
|
// gradually move closer and closer to the tail, and since the tail is the entry that gets deleted when an eviction
|
|
// is required, it allows less used cache entries to be evicted while keeping recently accessed entries at or close
|
|
// to the head.
|
|
//
|
|
// For instance, creating a Cache with a Cache.MaxSize of 3 and creating the entries 1, 2 and 3 in that order would
|
|
// put 3 at the head and 1 at the tail:
|
|
// 3 (head) -> 2 -> 1 (tail)
|
|
// If the cache entry 1 was then accessed, 1 would become the head and 2 the tail:
|
|
// 1 (head) -> 3 -> 2 (tail)
|
|
// If a cache entry 4 was then created, because the Cache.MaxSize is 3, the tail (2) would then be evicted:
|
|
// 4 (head) -> 1 -> 3 (tail)
|
|
LeastRecentlyUsed EvictionPolicy = "LeastRecentlyUsed"
|
|
|
|
// FirstInFirstOut is an eviction policy that causes cache entries to be evicted in the same order that they are
|
|
// created.
|
|
//
|
|
// For instance, creating a Cache with a Cache.MaxSize of 3 and creating the entries 1, 2 and 3 in that order would
|
|
// put 3 at the head and 1 at the tail:
|
|
// 3 (head) -> 2 -> 1 (tail)
|
|
// If the cache entry 1 was then accessed, unlike with LeastRecentlyUsed, nothing would change:
|
|
// 3 (head) -> 2 -> 1 (tail)
|
|
// If a cache entry 4 was then created, because the Cache.MaxSize is 3, the tail (1) would then be evicted:
|
|
// 4 (head) -> 3 -> 2 (tail)
|
|
FirstInFirstOut EvictionPolicy = "FirstInFirstOut"
|
|
)
|