Documentation
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Overview ¶
Package limiter bounds how fast, or how many at once, requests reach downstream handlers.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Concurrency ¶
func Concurrency(limit int) zinc.Middleware
Concurrency bounds the requests running downstream at once to limit and answers 429 to any beyond it, rather than queueing them.
func Doc ¶ added in v0.7.1
func Doc() zinc.MiddlewareDoc
Doc describes the middleware for the OpenAPI spec: a request over the limit is answered with 429, with Retry-After saying how many seconds until it would be allowed. Pass it to Document beside the middleware.
func New ¶
func New(configs ...Config) zinc.Middleware
New returns token-bucket rate limiting. With Key set, it keeps a bounded set of buckets; at MaxKeys it rejects new keys rather than evicting active quotas. No cleanup goroutine is required.
Types ¶
type Config ¶
type Config struct {
// Rate is the token refill rate per second. Zero uses 10.
Rate float64
// Capacity is the largest burst allowed. Zero uses 10.
Capacity float64
// Key buckets requests by the string it returns, such as c.IP(). Nil
// applies one bucket to every request.
Key func(*zinc.Context) string
// LimitReached answers a request over the limit. Nil returns a 429 error.
LimitReached zinc.HandlerFunc
// MaxKeys bounds keyed buckets; zero uses 10,000. New keys are denied at capacity.
MaxKeys int
// MaxKeyBytes bounds retained key sizes; zero uses 256.
MaxKeyBytes int
// IdleTTL is the minimum idle time before a fully refilled bucket expires.
// Zero uses five minutes. Active or depleted buckets are never evicted.
IdleTTL time.Duration
// Now supplies the clock; nil uses time.Now.
Now func() time.Time
}
Config sets the token-bucket policy. The zero value allows 10 requests per second with bursts of 10, shared by all clients.
Source Files