cache

Documentation

Index

• func HashKey(key string) string
• type BackgroundConfig
  • func (cfg *BackgroundConfig) RegisterFlagsWithPrefix(prefix string, description string, f *flag.FlagSet)
• type Cache
  • func Instrument(name string, cache Cache) Cache
  • func New(cfg Config) (Cache, error)
  • func NewBackground(name string, cfg BackgroundConfig, cache Cache) Cache
  • func NewMockCache() Cache
  • func NewSnappy(next Cache) Cache
  • func NewTiered(caches []Cache) Cache
  • func StopOnce(cache Cache) Cache
• type Config
  • func (cfg *Config) RegisterFlagsWithPrefix(prefix string, description string, f *flag.FlagSet)
• type FifoCache
  • func NewFifoCache(name string, cfg FifoCacheConfig) *FifoCache
  • func (c *FifoCache) Fetch(ctx context.Context, keys []string) (found []string, bufs [][]byte, missing []string)
  • func (c *FifoCache) Get(ctx context.Context, key string) (interface{}, bool)
  • func (c *FifoCache) Put(ctx context.Context, keys []string, values []interface{})
  • func (c *FifoCache) Stop() error
  • func (c *FifoCache) Store(ctx context.Context, keys []string, bufs [][]byte)
• type FifoCacheConfig
  • func (cfg *FifoCacheConfig) RegisterFlagsWithPrefix(prefix, description string, f *flag.FlagSet)
• type Memcached
  • func NewMemcached(cfg MemcachedConfig, client MemcachedClient, name string) *Memcached
  • func (c *Memcached) Fetch(ctx context.Context, keys []string) (found []string, bufs [][]byte, missed []string)
  • func (c *Memcached) Stop() error
  • func (c *Memcached) Store(ctx context.Context, keys []string, bufs [][]byte)
• type MemcachedClient
  • func NewMemcachedClient(cfg MemcachedClientConfig) MemcachedClient
• type MemcachedClientConfig
  • func (cfg *MemcachedClientConfig) RegisterFlagsWithPrefix(prefix, description string, f *flag.FlagSet)
• type MemcachedConfig
  • func (cfg *MemcachedConfig) RegisterFlagsWithPrefix(prefix, description string, f *flag.FlagSet)

Functions

func HashKey

func HashKey(key string) string

HashKey hashes key into something you can store in memcached.

Types

type BackgroundConfig

type BackgroundConfig struct {
	WriteBackGoroutines int `yaml:"writeback_goroutines,omitempty"`
	WriteBackBuffer     int `yaml:"writeback_buffer,omitempty"`
}

BackgroundConfig is config for a Background Cache.

func (*BackgroundConfig) RegisterFlagsWithPrefix

func (cfg *BackgroundConfig) RegisterFlagsWithPrefix(prefix string, description string, f *flag.FlagSet)

RegisterFlagsWithPrefix adds the flags required to config this to the given FlagSet

type Cache

type Cache interface {
	Store(ctx context.Context, key []string, buf [][]byte)
	Fetch(ctx context.Context, keys []string) (found []string, bufs [][]byte, missing []string)
	Stop() error
}

Cache byte arrays by key.

func Instrument

func Instrument(name string, cache Cache) Cache

Instrument returns an instrumented cache.

func New

func New(cfg Config) (Cache, error)

New creates a new Cache using Config.

func NewBackground

func NewBackground(name string, cfg BackgroundConfig, cache Cache) Cache

NewBackground returns a new Cache that does stores on background goroutines.

func NewMockCache

func NewMockCache() Cache

NewMockCache makes a new MockCache

func NewSnappy

func NewSnappy(next Cache) Cache

NewSnappy makes a new snappy encoding cache wrapper.

func NewTiered

func NewTiered(caches []Cache) Cache

NewTiered makes a new tiered cache.

func StopOnce

func StopOnce(cache Cache) Cache

StopOnce wraps a Cache and ensures its only stopped once.

type Config

type Config struct {
	EnableFifoCache bool `yaml:"enable_fifocache,omitempty"`

	DefaultValidity time.Duration `yaml:"defaul_validity,omitempty"`

	Background     BackgroundConfig      `yaml:"background,omitempty"`
	Memcache       MemcachedConfig       `yaml:"memcached,omitempty"`
	MemcacheClient MemcachedClientConfig `yaml:"memcached_client,omitempty"`
	Fifocache      FifoCacheConfig       `yaml:"fifocache,omitempty"`

	// This is to name the cache metrics properly.
	Prefix string `yaml:"prefix,omitempty"`

	// For tests to inject specific implementations.
	Cache Cache
}

Config for building Caches.

func (*Config) RegisterFlagsWithPrefix

func (cfg *Config) RegisterFlagsWithPrefix(prefix string, description string, f *flag.FlagSet)

RegisterFlagsWithPrefix adds the flags required to config this to the given FlagSet

type FifoCache

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

FifoCache is a simple string -> interface{} cache which uses a fifo slide to manage evictions. O(1) inserts and updates, O(1) gets.

func NewFifoCache

func NewFifoCache(name string, cfg FifoCacheConfig) *FifoCache

NewFifoCache returns a new initialised FifoCache of size.

func (*FifoCache) Fetch

func (c *FifoCache) Fetch(ctx context.Context, keys []string) (found []string, bufs [][]byte, missing []string)

Fetch implements Cache.

func (*FifoCache) Get

func (c *FifoCache) Get(ctx context.Context, key string) (interface{}, bool)

Get returns the stored value against the key and when the key was last updated.

func (*FifoCache) Put

func (c *FifoCache) Put(ctx context.Context, keys []string, values []interface{})

Put stores the value against the key.

func (*FifoCache) Stop

func (c *FifoCache) Stop() error

Stop implements Cache.

func (*FifoCache) Store

func (c *FifoCache) Store(ctx context.Context, keys []string, bufs [][]byte)

Store implements Cache.

type FifoCacheConfig

type FifoCacheConfig struct {
	Size     int           `yaml:"size,omitempty"`
	Validity time.Duration `yaml:"validity,omitempty"`
}

FifoCacheConfig holds config for the FifoCache.

func (*FifoCacheConfig) RegisterFlagsWithPrefix

func (cfg *FifoCacheConfig) RegisterFlagsWithPrefix(prefix, description string, f *flag.FlagSet)

RegisterFlagsWithPrefix adds the flags required to config this to the given FlagSet

type Memcached

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

Memcached type caches chunks in memcached

func NewMemcached

func NewMemcached(cfg MemcachedConfig, client MemcachedClient, name string) *Memcached

NewMemcached makes a new Memcache

func (*Memcached) Fetch

func (c *Memcached) Fetch(ctx context.Context, keys []string) (found []string, bufs [][]byte, missed []string)

Fetch gets keys from the cache. The keys that are found must be in the order of the keys requested.

func (*Memcached) Stop

func (c *Memcached) Stop() error

Stop does nothing.

func (*Memcached) Store

func (c *Memcached) Store(ctx context.Context, keys []string, bufs [][]byte)

Store stores the key in the cache.

type MemcachedClient

type MemcachedClient interface {
	GetMulti(keys []string) (map[string]*memcache.Item, error)
	Set(item *memcache.Item) error
}

MemcachedClient interface exists for mocking memcacheClient.

func NewMemcachedClient

func NewMemcachedClient(cfg MemcachedClientConfig) MemcachedClient

NewMemcachedClient creates a new MemcacheClient that gets its server list from SRV and updates the server list on a regular basis.

type MemcachedClientConfig

type MemcachedClientConfig struct {
	Host           string        `yaml:"host,omitempty"`
	Service        string        `yaml:"service,omitempty"`
	Timeout        time.Duration `yaml:"timeout,omitempty"`
	MaxIdleConns   int           `yaml:"max_idle_conns,omitempty"`
	UpdateInterval time.Duration `yaml:"update_interval,omitempty"`
}

MemcachedClientConfig defines how a MemcachedClient should be constructed.

func (*MemcachedClientConfig) RegisterFlagsWithPrefix

func (cfg *MemcachedClientConfig) RegisterFlagsWithPrefix(prefix, description string, f *flag.FlagSet)

RegisterFlagsWithPrefix adds the flags required to config this to the given FlagSet

type MemcachedConfig

type MemcachedConfig struct {
	Expiration time.Duration `yaml:"expiration,omitempty"`

	BatchSize   int `yaml:"batch_size,omitempty"`
	Parallelism int `yaml:"parallelism,omitempty"`
}

MemcachedConfig is config to make a Memcached

func (*MemcachedConfig) RegisterFlagsWithPrefix

func (cfg *MemcachedConfig) RegisterFlagsWithPrefix(prefix, description string, f *flag.FlagSet)

RegisterFlagsWithPrefix adds the flags required to config this to the given FlagSet