lru

Documentation

Overview

Package lru implements a Least Recently Used cache.

This implementation lets you set the limitations of the cache size based upon a number of entries.

The package also includes a utility called "tailor" for tailoring the cache to a specific key/value type instead of interface{}, allowing you to remove the overhead of runtime type inference.

Index

• type Cache
  • func New(options ...Option) (Cache, error)
• type Option
  • func NumberLimit(i int) Option
  • func PreSize(i uint64) Option

Types

type Cache

type Cache interface {
	// Get returns the value stored at key "k" and true if found. O(1) operation.
	Get(k interface{}) (interface{}, bool)

	// Set adds a value at key "k" of value "v". O(1) operation.
	Set(k interface{}, v interface{}) error

	// Remove removes a value at key "k". O(1) operation.
	Remove(k interface{})

	// RemoveOldest removes the oldest value in the cache. O(1) operation.
	RemoveOldest()

	// Len returns the current length of the cache.
	Len() int
}

Cache provides the LRU cache.

func New

func New(options ...Option) (Cache, error)

New is the constructor for Cache. Must pass either NumberLimit or MemoryLimit, but not both.

type Option

type Option func(c *cache)

Option is an optional argument for New().

func NumberLimit

func NumberLimit(i int) Option

NumberLimit sets a limit to the number of items that can be stored in the Cache before an insertion purges an existing item.

func PreSize

func PreSize(i uint64) Option

PreSize pre-sizes the internal data structures to hold "i" items. Similar to make(map[key]value, i).