cache

Documentation

Index

• Variables
• type NoopLocker
  • func (*NoopLocker) Lock()
  • func (*NoopLocker) Unlock()
• type TokenCache
• type TokenCacheInMemoryProvider
  • func NewTokenCacheInMemoryProvider() *TokenCacheInMemoryProvider
  • func (t *TokenCacheInMemoryProvider) CondBroadcast()
  • func (t *TokenCacheInMemoryProvider) CondWait()
  • func (t *TokenCacheInMemoryProvider) GetToken() (*oauth2.Token, error)
  • func (t *TokenCacheInMemoryProvider) Lock()
  • func (t *TokenCacheInMemoryProvider) PurgeIfEquals(existing *oauth2.Token) (bool, error)
  • func (t *TokenCacheInMemoryProvider) SaveToken(token *oauth2.Token) error
  • func (t *TokenCacheInMemoryProvider) TryLock() bool
  • func (t *TokenCacheInMemoryProvider) Unlock()

Variables

var (
	ErrNotFound = fmt.Errorf("secret not found in keyring")
)

Types

type NoopLocker

type NoopLocker struct {
}

NoopLocker has empty implementation of Locker interface

func (*NoopLocker) Lock

func (*NoopLocker) Lock()

func (*NoopLocker) Unlock

func (*NoopLocker) Unlock()

type TokenCache

type TokenCache interface {
	// SaveToken saves the token securely to cache.
	SaveToken(token *oauth2.Token) error

	// GetToken retrieves the token from the cache.
	GetToken() (*oauth2.Token, error)

	// PurgeIfEquals purges the token from the cache.
	PurgeIfEquals(t *oauth2.Token) (bool, error)

	// Lock the cache.
	Lock()

	// TryLock tries to lock the cache.
	TryLock() bool

	// Unlock the cache.
	Unlock()

	// CondWait waits for the condition to be true.
	CondWait()

	// CondSignalCondBroadcast signals the condition.
	CondBroadcast()
}

TokenCache defines the interface needed to cache and retrieve oauth tokens.

type TokenCacheInMemoryProvider

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

func NewTokenCacheInMemoryProvider

func NewTokenCacheInMemoryProvider() *TokenCacheInMemoryProvider

func (*TokenCacheInMemoryProvider) CondBroadcast

func (t *TokenCacheInMemoryProvider) CondBroadcast()

CondBroadcast signals the condition.

func (*TokenCacheInMemoryProvider) CondWait

func (t *TokenCacheInMemoryProvider) CondWait()

CondWait adds the current go routine to the condition waitlist and waits for another go routine to notify using CondBroadcast The current usage is that one who was able to acquire the lock using TryLock is the one who gets a valid token and notifies all the waitlist requesters so that they can use the new valid token. It also locks the Locker in the condition variable as the semantics of Wait is that it unlocks the Locker after adding the consumer to the waitlist and before blocking on notification. We use the condLocker which is noOp locker to get added to waitlist for notifications. The underlying notifcationList doesn't need to be guarded as it implementation is atomic and is thread safe Refer https://go.dev/src/runtime/sema.go Following is the function and its comments notifyListAdd adds the caller to a notify list such that it can receive notifications. The caller must eventually call notifyListWait to wait for such a notification, passing the returned ticket number.

func notifyListAdd(l *notifyList) uint32 {
	// This may be called concurrently, for example, when called from
	// sync.Cond.Wait while holding a RWMutex in read mode.
	return l.wait.Add(1) - 1
}

func (*TokenCacheInMemoryProvider) GetToken

func (t *TokenCacheInMemoryProvider) GetToken() (*oauth2.Token, error)

func (*TokenCacheInMemoryProvider) Lock

func (t *TokenCacheInMemoryProvider) Lock()

func (*TokenCacheInMemoryProvider) PurgeIfEquals

func (t *TokenCacheInMemoryProvider) PurgeIfEquals(existing *oauth2.Token) (bool, error)

func (*TokenCacheInMemoryProvider) SaveToken

func (t *TokenCacheInMemoryProvider) SaveToken(token *oauth2.Token) error

func (*TokenCacheInMemoryProvider) TryLock

func (t *TokenCacheInMemoryProvider) TryLock() bool

func (*TokenCacheInMemoryProvider) Unlock

func (t *TokenCacheInMemoryProvider) Unlock()