mirror of
https://github.com/octoleo/restic.git
synced 2024-12-12 06:07:55 +00:00
118 lines
3.4 KiB
Markdown
118 lines
3.4 KiB
Markdown
# ratelimit
|
|
--
|
|
import "github.com/juju/ratelimit"
|
|
|
|
The ratelimit package provides an efficient token bucket implementation. See
|
|
http://en.wikipedia.org/wiki/Token_bucket.
|
|
|
|
## Usage
|
|
|
|
#### func Reader
|
|
|
|
```go
|
|
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
|
|
|
|
```go
|
|
func Writer(w io.Writer, bucket *Bucket) io.Writer
|
|
```
|
|
Writer returns a writer that is rate limited by the given token bucket. Each
|
|
token in the bucket represents one byte.
|
|
|
|
#### type Bucket
|
|
|
|
```go
|
|
type Bucket struct {
|
|
}
|
|
```
|
|
|
|
Bucket represents a token bucket that fills at a predetermined rate. Methods on
|
|
Bucket may be called concurrently.
|
|
|
|
#### func NewBucket
|
|
|
|
```go
|
|
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
|
|
|
|
```go
|
|
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
|
|
|
|
```go
|
|
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) Rate
|
|
|
|
```go
|
|
func (tb *Bucket) Rate() float64
|
|
```
|
|
Rate returns the fill rate of the bucket, in tokens per second.
|
|
|
|
#### func (*Bucket) Take
|
|
|
|
```go
|
|
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
|
|
|
|
```go
|
|
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
|
|
|
|
```go
|
|
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
|
|
|
|
```go
|
|
func (tb *Bucket) Wait(count int64)
|
|
```
|
|
Wait takes count tokens from the bucket, waiting until they are available.
|
|
|
|
#### func (*Bucket) WaitMaxDuration
|
|
|
|
```go
|
|
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.
|