cache

Documentation

Index

• type Cache
  • func NewOtterCache[K KeyString, V any](config *Config) (Cache[K, V], error)
  • func NewOtterCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)
  • func NewRistrettoCache[K KeyString, V any](config *Config) (Cache[K, V], error)
  • func NewRistrettoCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)
  • func NewStandardCache[K KeyString, V any](config *Config) (Cache[K, V], error)
  • func NewStandardCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)
  • func NewTheineCache[K KeyString, V any](config *Config) (Cache[K, V], error)
  • func NewTheineCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)
  • func NoopCache[K KeyString, V any]() Cache[K, V]
• type Config
  • func (c *Config) MarshalZerologObject(e *zerolog.Event)
• type KeyString
• type Metrics
• type StringKey
  • func (sk StringKey) KeyString() string

Types

type Cache

type Cache[K KeyString, V any] interface {
	// Get returns the value for the given key in the cache, if it exists.
	Get(key K) (V, bool)

	// Set sets a value for the key in the cache, with the given cost.
	Set(key K, entry V, cost int64) bool

	// Wait waits for the cache to process and apply updates.
	Wait()

	// Close closes the cache's background workers (if any).
	Close()

	// GetMetrics returns the metrics block for the cache.
	GetMetrics() Metrics

	zerolog.LogObjectMarshaler
}

Cache defines an interface for a generic cache.

func NewOtterCache

func NewOtterCache[K KeyString, V any](config *Config) (Cache[K, V], error)

func NewOtterCacheWithMetrics

func NewOtterCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)

func NewRistrettoCache

func NewRistrettoCache[K KeyString, V any](config *Config) (Cache[K, V], error)

NewRistrettoCache creates a new ristretto cache from the given config.

func NewRistrettoCacheWithMetrics

func NewRistrettoCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)

NewRistrettoCacheWithMetrics creates a new ristretto cache from the given config that also reports metrics to the default Prometheus registry.

func NewStandardCache

func NewStandardCache[K KeyString, V any](config *Config) (Cache[K, V], error)

NewStandardCache creates a new cache with the given configuration.

func NewStandardCacheWithMetrics

func NewStandardCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)

func NewTheineCache

func NewTheineCache[K KeyString, V any](config *Config) (Cache[K, V], error)

func NewTheineCacheWithMetrics

func NewTheineCacheWithMetrics[K KeyString, V any](name string, config *Config) (Cache[K, V], error)

func NoopCache

func NoopCache[K KeyString, V any]() Cache[K, V]

NoopCache returns a cache that does nothing.

type Config

type Config struct {
	// NumCounters determines the number of counters (keys) to keep that hold
	// access frequency information. It's generally a good idea to have more
	// counters than the max cache capacity, as this will improve eviction
	// accuracy and subsequent hit ratios.
	//
	// For example, if you expect your cache to hold 1,000,000 items when full,
	// NumCounters should be 10,000,000 (10x). Each counter takes up roughly
	// 3 bytes (4 bits for each counter * 4 copies plus about a byte per
	// counter for the bloom filter). Note that the number of counters is
	// internally rounded up to the nearest power of 2, so the space usage
	// may be a little larger than 3 bytes * NumCounters.
	NumCounters int64

	// MaxCost can be considered as the cache capacity, in whatever units you
	// choose to use.
	//
	// For example, if you want the cache to have a max capacity of 100MB, you
	// would set MaxCost to 100,000,000 and pass an item's number of bytes as
	// the `cost` parameter for calls to Set. If new items are accepted, the
	// eviction process will take care of making room for the new item and not
	// overflowing the MaxCost value.
	MaxCost int64

	// DefaultTTL configures a default deadline on the lifetime of any keys set
	// to the cache.
	DefaultTTL time.Duration
}

Config for caching. See: https://github.com/outcaste-io/ristretto#Config

func (*Config) MarshalZerologObject

func (c *Config) MarshalZerologObject(e *zerolog.Event)

type KeyString

type KeyString interface {
	comparable
	KeyString() string
}

KeyString is an interface for keys that can be converted to strings.

type Metrics

type Metrics interface {
	// Hits is the number of cache hits.
	Hits() uint64

	// Misses is the number of cache misses.
	Misses() uint64

	// CostAdded returns the total cost of added items.
	CostAdded() uint64

	// CostEvicted returns the total cost of evicted items.
	CostEvicted() uint64
}

Metrics defines metrics exported by the cache.

type StringKey

type StringKey string

StringKey is a simple string key.

func (StringKey) KeyString

func (sk StringKey) KeyString() string