lru

README

golang-lru

This provides the lru package which implements a fixed-size thread safe LRU cache. It is based on the cache in Groupcache.

Documentation

Full docs are available on Godoc

Example

Using the LRU is very simple:

l, _ := New(128)
for i := 0; i < 256; i++ {
    l.Add(i, nil)
}
if l.Len() != 128 {
    panic(fmt.Sprintf("bad len: %v", l.Len()))
}

Documentation

Overview

This package provides a simple LRU cache. It is based on the LRU implementation in groupcache: https://github.com/golang/groupcache/tree/master/lru

Index

• type Cache
  • func New(size int) (*Cache, error)
  • func NewWithEvict(size int, onEvicted func(key int64, value simplelru.VersionedValue)) (*Cache, error)
  • func (c *Cache) Add(key int64, value simplelru.VersionedValue) simplelru.VersionedValue
  • func (c *Cache) Contains(key int64) bool
  • func (c *Cache) Get(key int64) (simplelru.VersionedValue, bool)
  • func (c *Cache) Keys() []int64
  • func (c *Cache) Len() int
  • func (c *Cache) Peek(key int64) (simplelru.VersionedValue, bool)
  • func (c *Cache) Purge()
  • func (c *Cache) Remove(key int64)
  • func (c *Cache) RemoveOldest()

Types

type Cache

type Cache struct {
	// contains filtered or unexported fields
}

Cache is a thread-safe fixed size LRU cache.

func New

func New(size int) (*Cache, error)

New creates an LRU of the given size

func NewWithEvict

func NewWithEvict(size int, onEvicted func(key int64, value simplelru.VersionedValue)) (*Cache, error)

NewWithEvict constructs a fixed size cache with the given eviction callback.

func (*Cache) Add

func (c *Cache) Add(key int64, value simplelru.VersionedValue) simplelru.VersionedValue

Add adds a value to the cache. Returns true if an eviction occurred.

func (*Cache) Contains

func (c *Cache) Contains(key int64) bool

Check if a key is in the cache, without updating the recent-ness or deleting it for being stale.

func (*Cache) Get

func (c *Cache) Get(key int64) (simplelru.VersionedValue, bool)

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

func (*Cache) Keys

func (c *Cache) Keys() []int64

Keys returns a slice of the keys in the cache, from oldest to newest.

func (*Cache) Len

func (c *Cache) Len() int

Len returns the number of items in the cache.

func (*Cache) Peek

func (c *Cache) Peek(key int64) (simplelru.VersionedValue, bool)

Returns the key value (or undefined if not found) without updating the "recently used"-ness of the key.

func (*Cache) Purge

func (c *Cache) Purge()

Purge is used to completely clear the cache

func (*Cache) Remove

func (c *Cache) Remove(key int64)

Remove removes the provided key from the cache.

func (*Cache) RemoveOldest

func (c *Cache) RemoveOldest()

RemoveOldest removes the oldest item from the cache.