ratelimit: github.com/lrita/ratelimit Index | Files

package ratelimit

import "github.com/lrita/ratelimit"

Package ratelimit provides an efficient token bucket implementation that can be used to limit the rate of arbitrary things. See http://en.wikipedia.org/wiki/Token_bucket.

Index

Package Files

ratelimit.go reader.go

func Reader Uses

func Reader(r io.Reader, bucket *Bucket) io.Reader

Reader returns a reader that is rate limited by the given token bucket. Each token in the bucket represents one byte.

func Writer Uses

func Writer(w io.Writer, bucket *Bucket) io.Writer

Writer returns a reader that is rate limited by the given token bucket. Each token in the bucket represents one byte.

type Bucket Uses

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

Bucket represents a token bucket that fills at a predetermined rate. Methods on Bucket may be called concurrently.

func NewBucket Uses

func NewBucket(fillInterval time.Duration, capacity int64) *Bucket

NewBucket returns a new token bucket that fills at the rate of one token every fillInterval, up to the given maximum capacity. Both arguments must be positive. The bucket is initially full.

func NewBucketWithQuantum Uses

func NewBucketWithQuantum(fillInterval time.Duration, capacity, quantum int64) *Bucket

NewBucketWithQuantum is similar to NewBucket, but allows the specification of the quantum size - quantum tokens are added every fillInterval.

func NewBucketWithRate Uses

func NewBucketWithRate(rate float64, capacity int64) *Bucket

NewBucketWithRate returns a token bucket that fills the bucket at the rate of rate tokens per second up to the given maximum capacity. Because of limited clock resolution, at high rates, the actual rate may be up to 1% different from the specified rate.

func (*Bucket) Available Uses

func (tb *Bucket) Available() int64

Available returns the number of available tokens. It will be negative when there are consumers waiting for tokens. Note that if this returns greater than zero, it does not guarantee that calls that take tokens from the buffer will succeed, as the number of available tokens could have changed in the meantime. This method is intended primarily for metrics reporting and debugging.

func (*Bucket) Capacity Uses

func (tb *Bucket) Capacity() int64

Capacity returns the capacity that the bucket was created with.

func (*Bucket) Rate Uses

func (tb *Bucket) Rate() float64

Rate returns the fill rate of the bucket, in tokens per second.

func (*Bucket) Take Uses

func (tb *Bucket) Take(count int64) time.Duration

Take takes count tokens from the bucket without blocking. It returns the time that the caller should wait until the tokens are actually available.

Note that if the request is irrevocable - there is no way to return tokens to the bucket once this method commits us to taking them.

func (*Bucket) TakeAvailable Uses

func (tb *Bucket) TakeAvailable(count int64) int64

TakeAvailable takes up to count immediately available tokens from the bucket. It returns the number of tokens removed, or zero if there are no available tokens. It does not block.

func (*Bucket) TakeMaxDuration Uses

func (tb *Bucket) TakeMaxDuration(count int64, maxWait time.Duration) (time.Duration, bool)

TakeMaxDuration is like Take, except that it will only take tokens from the bucket if the wait time for the tokens is no greater than maxWait.

If it would take longer than maxWait for the tokens to become available, it does nothing and reports false, otherwise it returns the time that the caller should wait until the tokens are actually available, and reports true.

func (*Bucket) Wait Uses

func (tb *Bucket) Wait(count int64)

Wait takes count tokens from the bucket, waiting until they are available.

func (*Bucket) WaitMaxDuration Uses

func (tb *Bucket) WaitMaxDuration(count int64, maxWait time.Duration) bool

WaitMaxDuration is like Wait except that it will only take tokens from the bucket if it needs to wait for no greater than maxWait. It reports whether any tokens have been removed from the bucket If no tokens have been removed, it returns immediately.

Package ratelimit imports 6 packages (graph) and is imported by 1 packages. Updated 2019-05-17. Refresh now. Tools for package owners.