memory

Documentation

Overview

Package memory implements backend interface using a combination of Minheap (to store expiring items) and B-Tree for storing sorted dictionary of items. This package is used for caching layer

Index

• type Config
  • func (cfg *Config) CheckAndSetDefaults() error
• type Memory
  • func New(cfg Config) (*Memory, error)
  • func (m *Memory) Clock() clockwork.Clock
  • func (m *Memory) Close() error
  • func (m *Memory) CloseWatchers()
  • func (m *Memory) CompareAndSwap(ctx context.Context, expected backend.Item, replaceWith backend.Item) (*backend.Lease, error)
  • func (m *Memory) Create(ctx context.Context, i backend.Item) (*backend.Lease, error)
  • func (m *Memory) Delete(ctx context.Context, key []byte) error
  • func (m *Memory) DeleteRange(ctx context.Context, startKey, endKey []byte) error
  • func (m *Memory) Get(ctx context.Context, key []byte) (*backend.Item, error)
  • func (m *Memory) GetRange(ctx context.Context, startKey []byte, endKey []byte, limit int) (*backend.GetResult, error)
  • func (m *Memory) KeepAlive(ctx context.Context, lease backend.Lease, expires time.Time) error
  • func (m *Memory) NewWatcher(ctx context.Context, watch backend.Watch) (backend.Watcher, error)
  • func (m *Memory) Put(ctx context.Context, i backend.Item) (*backend.Lease, error)
  • func (m *Memory) PutRange(ctx context.Context, items []backend.Item) error
  • func (m *Memory) Update(ctx context.Context, i backend.Item) (*backend.Lease, error)

Types

type Config

type Config struct {
	// Context is a context for opening the
	// database
	Context context.Context
	// BTreeDegree is a degree of B-Tree, 2 for example, will create a
	// 2-3-4 tree (each node contains 1-3 items and 2-4 children).
	BTreeDegree int
	// Clock is a clock for time-related operations
	Clock clockwork.Clock
	// Component is a logging component
	Component string
	// EventsOff turns off events generation
	EventsOff bool
	// BufferSize sets up event buffer size
	BufferSize int
	// Mirror mode is used when the memory backend is used for caching. In mirror
	// mode, record IDs for Put and PutRange requests are re-used (instead of
	// generating fresh ones) and expiration is turned off.
	Mirror bool
}

Config holds configuration for the backend

func (*Config) CheckAndSetDefaults

func (cfg *Config) CheckAndSetDefaults() error

CheckAndSetDefaults checks and sets default values

type Memory

type Memory struct {
	*sync.Mutex
	*log.Entry
	Config
	// contains filtered or unexported fields
}

Memory is a memory B-Tree based backend

func New

func New(cfg Config) (*Memory, error)

New creates a new memory backend

func (*Memory) Clock

func (m *Memory) Clock() clockwork.Clock

Clock returns clock used by this backend

func (*Memory) Close

func (m *Memory) Close() error

Close closes memory backend

func (*Memory) CloseWatchers

func (m *Memory) CloseWatchers()

CloseWatchers closes all the watchers without closing the backend

func (*Memory) CompareAndSwap

func (m *Memory) CompareAndSwap(ctx context.Context, expected backend.Item, replaceWith backend.Item) (*backend.Lease, error)

CompareAndSwap compares item with existing item and replaces it with replaceWith item

func (*Memory) Create

func (m *Memory) Create(ctx context.Context, i backend.Item) (*backend.Lease, error)

Create creates item if it does not exist

func (*Memory) Delete

func (m *Memory) Delete(ctx context.Context, key []byte) error

Delete deletes item by key, returns NotFound error if item does not exist

func (*Memory) DeleteRange

func (m *Memory) DeleteRange(ctx context.Context, startKey, endKey []byte) error

DeleteRange deletes range of items with keys between startKey and endKey Note that elements deleted by range do not produce any events

func (*Memory) Get

func (m *Memory) Get(ctx context.Context, key []byte) (*backend.Item, error)

Get returns a single item or not found error

func (*Memory) GetRange

func (m *Memory) GetRange(ctx context.Context, startKey []byte, endKey []byte, limit int) (*backend.GetResult, error)

GetRange returns query range

func (*Memory) KeepAlive

func (m *Memory) KeepAlive(ctx context.Context, lease backend.Lease, expires time.Time) error

KeepAlive updates TTL on the lease

func (*Memory) NewWatcher

func (m *Memory) NewWatcher(ctx context.Context, watch backend.Watch) (backend.Watcher, error)

NewWatcher returns a new event watcher

func (*Memory) Put

func (m *Memory) Put(ctx context.Context, i backend.Item) (*backend.Lease, error)

Put puts value into backend (creates if it does not exists, updates it otherwise)

func (*Memory) PutRange

func (m *Memory) PutRange(ctx context.Context, items []backend.Item) error

PutRange puts range of items into backend (creates if items does not exists, updates it otherwise)

func (*Memory) Update

func (m *Memory) Update(ctx context.Context, i backend.Item) (*backend.Lease, error)

Update updates item if it exists, or returns NotFound error