cache

Documentation

Index

• type Cache
  • func New(c Config) *Cache
  • func (cache *Cache) Delete(key string) error
  • func (cache *Cache) Discard(key string)
  • func (cache *Cache) DiscardPrefix(prefix string) error
  • func (cache *Cache) Evict(percent float64)
  • func (cache *Cache) Flush()
  • func (cache *Cache) GetOrCreate(key string) (interface{}, error)
  • func (cache *Cache) Lookup(key string) (interface{}, bool)
  • func (cache *Cache) Put(key string, val interface{})
  • func (cache *Cache) Size() uint64
  • func (cache *Cache) WriteBack()
• type Codec
• type Config
• type Metrics

Types

type Cache

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

func New

func New(c Config) *Cache

func (*Cache) Delete

func (cache *Cache) Delete(key string) error

func (*Cache) Discard

func (cache *Cache) Discard(key string)

func (*Cache) DiscardPrefix

func (cache *Cache) DiscardPrefix(prefix string) error

DiscardPrefix deletes all data that matches a certain prefix In both cache and database

func (*Cache) Evict

func (cache *Cache) Evict(percent float64)

Evict performs cache evictions. The difference between Evict and WriteBack is that evictions happen when cache grows above allowed threshold and write-back calls happen constantly, making pyroscope more crash-resilient. See https://github.com/pyroscope-io/pyroscope/issues/210 for more context

func (*Cache) Flush

func (cache *Cache) Flush()

func (*Cache) GetOrCreate

func (cache *Cache) GetOrCreate(key string) (interface{}, error)

func (*Cache) Lookup

func (cache *Cache) Lookup(key string) (interface{}, bool)

func (*Cache) Put

func (cache *Cache) Put(key string, val interface{})

func (*Cache) Size

func (cache *Cache) Size() uint64

func (*Cache) WriteBack

func (cache *Cache) WriteBack()

type Codec

type Codec interface {
	Serialize(w io.Writer, key string, value interface{}) error
	Deserialize(r io.Reader, key string) (interface{}, error)
	// New returns a new instance of the type. The method is
	// called by GetOrCreate when an item can not be found by
	// the given key.
	New(key string) interface{}
}

Codec is a shorthand of coder-decoder. A Codec implementation is responsible for type conversions and binary representation.

type Config

type Config struct {
	*badger.DB
	*Metrics
	Codec

	// Prefix for badger DB keys.
	Prefix string
	// TTL specifies number of seconds an item can reside in cache after
	// the last access. An obsolete item is evicted. Setting TTL to less
	// than a second disables time-based eviction.
	TTL time.Duration
}

type Metrics

type Metrics struct {
	MissesCounter     prometheus.Counter
	ReadsCounter      prometheus.Counter
	DBWrites          prometheus.Observer
	DBReads           prometheus.Observer
	WriteBackDuration prometheus.Observer
	EvictionsDuration prometheus.Observer
}