cache

README

cache: Go LRU cache package

This package is based on https://github.com/hashicorp/golang-lru which is in turn based on the LRU implementation in Brad Fitz's Groupcache package.

Documentation

Index

• type Cache
  • func NOOPCache() Cache
  • func New(maxSize int) Cache
  • func WriteOnly(c Cache) Cache
• type LRUCache
  • func NewLRUCache(size int) (*LRUCache, error)
  • func (c *LRUCache) Add(key, value interface{})
  • func (c *LRUCache) Get(key interface{}) (value interface{}, ok bool)
  • func (c *LRUCache) Len() int
  • func (c *LRUCache) Purge()
  • func (c *LRUCache) Remove(key interface{})
  • func (c *LRUCache) RemoveOldest()
• type Result

Types

type Cache

type Cache interface {

	// Put an object into the cache and expire after the given ttl
	Put(key string, value interface{}, ttl time.Duration)

	// Get an object from the cache. Stale objects are returned, but marked as stale
	Get(key string) (value interface{}, status Result)

	// Size returns the max items that may be stored in the cache
	Size() int

	// Remove removes the provided key from the cache.
	Remove(key string)

	// method DOES NOT take into account TTL, so the result may include stale items.
	Len() int
}

Cache is the abstract interface for a cache that requires an TTL duration for objects

func NOOPCache

func NOOPCache() Cache

func New

func New(maxSize int) Cache

New constructs a new LRU/TTL cache with the given max size (num objects)

func WriteOnly

func WriteOnly(c Cache) Cache

WriteOnly wraps a cache in a write-only wrapper (Get() always returns null)

type LRUCache

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

Cache is a thread-safe fixed size LRU cache.

func NewLRUCache

func NewLRUCache(size int) (*LRUCache, error)

NewLRUCache creates an LRU of the given size

func (*LRUCache) Add

func (c *LRUCache) Add(key, value interface{})

Add adds a value to the cache.

func (*LRUCache) Get

func (c *LRUCache) Get(key interface{}) (value interface{}, ok bool)

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

func (*LRUCache) Len

func (c *LRUCache) Len() int

Len returns the number of items in the cache.

func (*LRUCache) Purge

func (c *LRUCache) Purge()

Purge is used to completely clear the cache

func (*LRUCache) Remove

func (c *LRUCache) Remove(key interface{})

Remove removes the provided key from the cache.

func (*LRUCache) RemoveOldest

func (c *LRUCache) RemoveOldest()

RemoveOldest removes the oldest item from the cache.

type Result

type Result string

Result is the code of a cache Get operation

const (
	// OK : object for key found and fresh
	OK Result = "ok"
	// NotFound : object for key not found
	NotFound Result = "not found"
	// Stale : object for key found, but stale
	Stale Result = "stale"
)