Documentation
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Overview ¶
Package limiter provides simple rate limiting primitives, and an implementation of a token bucket rate limiter.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Limiter ¶
type Limiter interface {
Allow() bool
}
Limiter is used to abstract the rate limiter implementation to only expose the needed function for rate limiting. This is for example useful for testing, allowing us to use a modified rate limiter tuned for testing through the same interface.
type TokenTicker ¶
type TokenTicker struct {
// contains filtered or unexported fields
}
TokenTicker is a thread-safe and lock-free rate limiter based on a token bucket. The idea is to have a goroutine that will update the bucket with fresh tokens at regular intervals using a time.Ticker. The advantage of using a goroutine here is that the implementation becomes easily thread-safe using a few atomic operations with little overhead overall. TokenTicker.Start() *should* be called before the first call to TokenTicker.Allow() and TokenTicker.Stop() *must* be called once done using. Note that calling TokenTicker.Allow() before TokenTicker.Start() is valid, but it means the bucket won't be refilling until the call to TokenTicker.Start() is made
func NewTokenTicker ¶
func NewTokenTicker(tokens, maxTokens int64) *TokenTicker
NewTokenTicker is a utility function that allocates a token ticker, initializes necessary fields and returns it
func (*TokenTicker) Allow ¶
func (t *TokenTicker) Allow() bool
Allow checks and returns whether a token can be retrieved from the bucket and consumed. Thread-safe.
func (*TokenTicker) Start ¶
func (t *TokenTicker) Start()
Start starts the ticker and launches the goroutine responsible for updating the token bucket. The ticker is set to tick at a fixed rate of 500us.
func (*TokenTicker) Stop ¶
func (t *TokenTicker) Stop()
Stop shuts down the rate limiter, taking care stopping the ticker and closing all channels
Source Files