lru

README

Lru

Package lru implements an LRU cache.

Documentation

Overview

Package lru implements an LRU cache.

Index

• type Elem
• type List
  • func (l *List[K, V]) Init() *List[K, V]
  • func (l *List[K, V]) Insert(e *Elem[K, V]) *Elem[K, V]
  • func (l *List[K, V]) Remove(e *Elem[K, V])
  • func (l *List[K, V]) Update(e *Elem[K, V])
• type Lru
  • func New[K comparable, V any](size int) *Lru[K, V]
  • func (l *Lru[K, V]) Del(k K)
  • func (l *Lru[K, V]) Get(k K) (v V)
  • func (l *Lru[K, V]) GetExists(k K) (v V, ok bool)
  • func (l *Lru[K, V]) Has(k K) bool
  • func (l *Lru[K, V]) Len() int
  • func (l *Lru[K, V]) Set(k K, v V)

Types

type Elem

type Elem[K comparable, V any] struct {
	Next, Prev *Elem[K, V]
	K          K
	V          V
}

Elem is an element of a linked list.

type List

type List[K comparable, V any] struct {
	Root *Elem[K, V]
	Size int
}

List represents a doubly linked list.

func (*List[K, V]) Init

func (l *List[K, V]) Init() *List[K, V]

Init initializes or clears list l.

func (*List[K, V]) Insert

func (l *List[K, V]) Insert(e *Elem[K, V]) *Elem[K, V]

Insert inserts e after root, increments l's size, and returns e.

func (*List[K, V]) Remove

func (l *List[K, V]) Remove(e *Elem[K, V])

Remove removes e from its list, decrements l's size.

func (*List[K, V]) Update

func (l *List[K, V]) Update(e *Elem[K, V])

Update e to next to root.

type Lru

type Lru[K comparable, V any] struct {
	// Drop is called automatically when an elem is deleted.
	Drop func(k K, v V)
	// Size is the maximum number of cache entries before an item is evicted. Zero means no limit.
	Size int
	List *List[K, V]
	C    map[K]*Elem[K, V]
	M    *sync.Mutex
}

Lru cache. It is safe for concurrent access.

func New

func New[K comparable, V any](size int) *Lru[K, V]

New returns a new LRU cache. If size is zero, the cache has no limit.

func (*Lru[K, V]) Del

func (l *Lru[K, V]) Del(k K)

Del removes the provided key from the cache.

func (*Lru[K, V]) Get

func (l *Lru[K, V]) Get(k K) (v V)

Get looks up a key's value from the cache.

func (*Lru[K, V]) GetExists

func (l *Lru[K, V]) GetExists(k K) (v V, ok bool)

Get looks up a key's value from the cache.

func (*Lru[K, V]) Has

func (l *Lru[K, V]) Has(k K) bool

Has returns true if a key exists.

func (*Lru[K, V]) Len

func (l *Lru[K, V]) Len() int

Len returns the number of items in the cache.

func (*Lru[K, V]) Set

func (l *Lru[K, V]) Set(k K, v V)

Set adds a value to the cache.