concurrencylimiter

Documentation

Index

• Constants
• type ConcurrencyLimiter
• type GlobalTokenCounter
  • func NewGlobalTokenCounter(dc *distcache.DistCache, name string, maxIdleDuration time.Duration, ...) (*GlobalTokenCounter, error)
  • func (gtc *GlobalTokenCounter) Close() error
  • func (gtc *GlobalTokenCounter) GetCapacity() float64
  • func (gtc *GlobalTokenCounter) GetPassThrough() bool
  • func (gtc *GlobalTokenCounter) Name() string
  • func (gtc *GlobalTokenCounter) Return(ctx context.Context, label string, count float64, reqID string) (ok bool, err error)
  • func (gtc *GlobalTokenCounter) SetCapacity(capacity float64)
  • func (gtc *GlobalTokenCounter) SetPassThrough(passthrough bool)
  • func (gtc *GlobalTokenCounter) Take(ctx context.Context, label string, count float64) (ok bool, _ time.Duration, remaining float64, current float64, reqID string)
  • func (gtc *GlobalTokenCounter) TakeIfAvailable(ctx context.Context, label string, n float64) (ok bool, waitTime time.Duration, remaining float64, current float64, ...)

Constants

const (
	// TakeNFunction is the name of the function used to take N tokens from the global counter.
	TakeNFunction = "TakeN"
	// ReturnFunction is the name of the function used to return N tokens to the global counter.
	ReturnFunction = "Return"
	// CancelQueuedFunction is the name of the function used to cancel a queued request.
	CancelQueuedFunction = "CancelQueued"
	// CancelInflightFunction is the name of the function used to cancel an inflight request.
	CancelInflightFunction = "CancelInflight"
	// MinimumWaitTime is the minimum wait time for a request in the queue. This is used if the token rate is 0.
	MinimumWaitTime = 10 * time.Millisecond
	// MaximumWaitTime is the maximum wait time for a request in the queue.
	MaximumWaitTime = 5 * time.Second
	// WaitExpiryMargin is the margin for expiry in addition to wait time for a request in the queue.
	WaitExpiryMargin = 100 * time.Millisecond
	// TokenRateWindowSize is the number of requests after which token rate is updated.
	TokenRateWindowSize = 10
)

Types

type ConcurrencyLimiter

type ConcurrencyLimiter interface {
	Name() string
	TakeIfAvailable(ctx context.Context, label string, count float64) (ok bool, waitTime time.Duration, remaining float64, current float64, reqID string)
	Take(ctx context.Context, label string, count float64) (ok bool, waitTime time.Duration, remaining float64, current float64, reqID string)
	Return(ctx context.Context, label string, count float64, reqID string) (ok bool, err error)
	SetPassThrough(passthrough bool)
	SetCapacity(capacity float64)
	GetPassThrough() bool
	Close() error
}

ConcurrencyLimiter is a generic limiter interface.

type GlobalTokenCounter

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

GlobalTokenCounter is a global token counter that uses a distributed map to store the state.

func NewGlobalTokenCounter

func NewGlobalTokenCounter(
	dc *distcache.DistCache,
	name string,
	maxIdleDuration time.Duration,
	maxInflightDuration time.Duration,
) (*GlobalTokenCounter, error)

NewGlobalTokenCounter creates a new GlobalTokenCounter.

func (*GlobalTokenCounter) Close

func (gtc *GlobalTokenCounter) Close() error

Close closes the global token counter.

func (*GlobalTokenCounter) GetCapacity

func (gtc *GlobalTokenCounter) GetCapacity() float64

GetCapacity returns the capacity of the global token counter.

func (*GlobalTokenCounter) GetPassThrough

func (gtc *GlobalTokenCounter) GetPassThrough() bool

GetPassThrough returns the current value of passThrough.

func (*GlobalTokenCounter) Name

func (gtc *GlobalTokenCounter) Name() string

Name returns the name of the global token counter.

func (*GlobalTokenCounter) Return

func (gtc *GlobalTokenCounter) Return(ctx context.Context, label string, count float64, reqID string) (ok bool, err error)

Return returns N tokens to the global token counter.

func (*GlobalTokenCounter) SetCapacity

func (gtc *GlobalTokenCounter) SetCapacity(capacity float64)

SetCapacity sets the capacity of the global token counter.

func (*GlobalTokenCounter) SetPassThrough

func (gtc *GlobalTokenCounter) SetPassThrough(passthrough bool)

SetPassThrough sets the value of passThrough.

func (*GlobalTokenCounter) Take

func (gtc *GlobalTokenCounter) Take(ctx context.Context, label string, count float64) (ok bool, _ time.Duration, remaining float64, current float64, reqID string)

Take takes N tokens from the global token counter.

func (*GlobalTokenCounter) TakeIfAvailable

func (gtc *GlobalTokenCounter) TakeIfAvailable(ctx context.Context, label string, n float64) (ok bool, waitTime time.Duration, remaining float64, current float64, reqID string)

TakeIfAvailable takes N tokens from the global token counter if they are available.