lru

Documentation

Index

• type Cache
  • func NewCache[K comparable, V any](opts ...Option) *Cache[K, V]
  • func (c *Cache[K, V]) Delete(key K)
  • func (c *Cache[K, V]) Get(key K) (zero V, _ bool)
  • func (c *Cache[K, V]) Keys() []K
  • func (c *Cache[K, V]) Len() int
  • func (c *Cache[K, V]) Set(key K, val V)
• type Option
  • func WithCapacity(cap int) Option

Examples

• Cache.Keys
• NewCache

Types

type Cache

type Cache[K comparable, V any] struct {
	// contains filtered or unexported fields
}

Cache is used a LRU (Least recently used) cache replacement policy.

Discards the least recently used items first. This algorithm requires keeping track of what was used when, which is expensive if one wants to make sure the algorithm always discards the least recently used item.

func NewCache

func NewCache[K comparable, V any](opts ...Option) *Cache[K, V]

NewCache creates a new non-thread safe LRU cache whose capacity is the default size (128).

Example

package main

import (
	"fmt"

	"github.com/Code-Hex/go-generics-cache/policy/lru"
)

func main() {
	c := lru.NewCache[string, int]()
	c.Set("a", 1)
	c.Set("b", 2)
	av, aok := c.Get("a")
	bv, bok := c.Get("b")
	cv, cok := c.Get("c")
	fmt.Println(av, aok)
	fmt.Println(bv, bok)
	fmt.Println(cv, cok)
}

Output:

1 true
2 true
0 false

func (*Cache[K, V]) Delete

func (c *Cache[K, V]) Delete(key K)

Delete deletes the item with provided key from the cache.

func (*Cache[K, V]) Get

func (c *Cache[K, V]) Get(key K) (zero V, _ bool)

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

func (*Cache[K, V]) Keys

func (c *Cache[K, V]) Keys() []K

Keys returns the keys of the cache. the order is from oldest to newest.

Example

package main

import (
	"fmt"

	"github.com/Code-Hex/go-generics-cache/policy/lru"
)

func main() {
	c := lru.NewCache[string, int]()
	c.Set("a", 1)
	c.Set("b", 2)
	c.Set("c", 3)
	keys := c.Keys()
	for _, key := range keys {
		fmt.Println(key)
	}
}

Output:

a
b
c

func (*Cache[K, V]) Len

func (c *Cache[K, V]) Len() int

Len returns the number of items in the cache.

func (*Cache[K, V]) Set

func (c *Cache[K, V]) Set(key K, val V)

Set sets a value to the cache with key. replacing any existing value.

type Option

type Option func(*options)

Option is an option for LRU cache.

func WithCapacity

func WithCapacity(cap int) Option

WithCapacity is an option to set cache capacity.