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authorMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
committerMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
commita031b83a09a8628435317a03f199cdc18b78262f (patch)
treebc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/juju/ratelimit
parent2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff)
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Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/juju/ratelimit')
-rw-r--r--vendor/github.com/juju/ratelimit/LICENSE191
-rw-r--r--vendor/github.com/juju/ratelimit/README.md117
-rw-r--r--vendor/github.com/juju/ratelimit/ratelimit.go284
-rw-r--r--vendor/github.com/juju/ratelimit/reader.go51
4 files changed, 643 insertions, 0 deletions
diff --git a/vendor/github.com/juju/ratelimit/LICENSE b/vendor/github.com/juju/ratelimit/LICENSE
new file mode 100644
index 000000000..ade9307b3
--- /dev/null
+++ b/vendor/github.com/juju/ratelimit/LICENSE
@@ -0,0 +1,191 @@
+All files in this repository are licensed as follows. If you contribute
+to this repository, it is assumed that you license your contribution
+under the same license unless you state otherwise.
+
+All files Copyright (C) 2015 Canonical Ltd. unless otherwise specified in the file.
+
+This software is licensed under the LGPLv3, included below.
+
+As a special exception to the GNU Lesser General Public License version 3
+("LGPL3"), the copyright holders of this Library give you permission to
+convey to a third party a Combined Work that links statically or dynamically
+to this Library without providing any Minimal Corresponding Source or
+Minimal Application Code as set out in 4d or providing the installation
+information set out in section 4e, provided that you comply with the other
+provisions of LGPL3 and provided that you meet, for the Application the
+terms and conditions of the license(s) which apply to the Application.
+
+Except as stated in this special exception, the provisions of LGPL3 will
+continue to comply in full to this Library. If you modify this Library, you
+may apply this exception to your version of this Library, but you are not
+obliged to do so. If you do not wish to do so, delete this exception
+statement from your version. This exception does not (and cannot) modify any
+license terms which apply to the Application, with which you must still
+comply.
+
+
+ GNU LESSER GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+ This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+ 0. Additional Definitions.
+
+ As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
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+other than an Application or a Combined Work as defined below.
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diff --git a/vendor/github.com/juju/ratelimit/README.md b/vendor/github.com/juju/ratelimit/README.md
new file mode 100644
index 000000000..a0fdfe2b1
--- /dev/null
+++ b/vendor/github.com/juju/ratelimit/README.md
@@ -0,0 +1,117 @@
+# 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.
diff --git a/vendor/github.com/juju/ratelimit/ratelimit.go b/vendor/github.com/juju/ratelimit/ratelimit.go
new file mode 100644
index 000000000..1c3f25b2e
--- /dev/null
+++ b/vendor/github.com/juju/ratelimit/ratelimit.go
@@ -0,0 +1,284 @@
+// Copyright 2014 Canonical Ltd.
+// Licensed under the LGPLv3 with static-linking exception.
+// See LICENCE file for details.
+
+// 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.
+package ratelimit
+
+import (
+ "math"
+ "strconv"
+ "sync"
+ "time"
+)
+
+// Bucket represents a token bucket that fills at a predetermined rate.
+// Methods on Bucket may be called concurrently.
+type Bucket struct {
+ startTime time.Time
+ capacity int64
+ quantum int64
+ fillInterval time.Duration
+ clock Clock
+
+ // The mutex guards the fields following it.
+ mu sync.Mutex
+
+ // avail holds the number of available tokens
+ // in the bucket, as of availTick ticks from startTime.
+ // It will be negative when there are consumers
+ // waiting for tokens.
+ avail int64
+ availTick int64
+}
+
+// Clock is used to inject testable fakes.
+type Clock interface {
+ Now() time.Time
+ Sleep(d time.Duration)
+}
+
+// realClock implements Clock in terms of standard time functions.
+type realClock struct{}
+
+// Now is identical to time.Now.
+func (realClock) Now() time.Time {
+ return time.Now()
+}
+
+// Sleep is identical to time.Sleep.
+func (realClock) Sleep(d time.Duration) {
+ time.Sleep(d)
+}
+
+// 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 NewBucket(fillInterval time.Duration, capacity int64) *Bucket {
+ return NewBucketWithClock(fillInterval, capacity, realClock{})
+}
+
+// NewBucketWithClock is identical to NewBucket but injects a testable clock
+// interface.
+func NewBucketWithClock(fillInterval time.Duration, capacity int64, clock Clock) *Bucket {
+ return NewBucketWithQuantumAndClock(fillInterval, capacity, 1, clock)
+}
+
+// rateMargin specifes the allowed variance of actual
+// rate from specified rate. 1% seems reasonable.
+const rateMargin = 0.01
+
+// 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 NewBucketWithRate(rate float64, capacity int64) *Bucket {
+ return NewBucketWithRateAndClock(rate, capacity, realClock{})
+}
+
+// NewBucketWithRateAndClock is identical to NewBucketWithRate but injects a
+// testable clock interface.
+func NewBucketWithRateAndClock(rate float64, capacity int64, clock Clock) *Bucket {
+ for quantum := int64(1); quantum < 1<<50; quantum = nextQuantum(quantum) {
+ fillInterval := time.Duration(1e9 * float64(quantum) / rate)
+ if fillInterval <= 0 {
+ continue
+ }
+ tb := NewBucketWithQuantumAndClock(fillInterval, capacity, quantum, clock)
+ if diff := math.Abs(tb.Rate() - rate); diff/rate <= rateMargin {
+ return tb
+ }
+ }
+ panic("cannot find suitable quantum for " + strconv.FormatFloat(rate, 'g', -1, 64))
+}
+
+// nextQuantum returns the next quantum to try after q.
+// We grow the quantum exponentially, but slowly, so we
+// get a good fit in the lower numbers.
+func nextQuantum(q int64) int64 {
+ q1 := q * 11 / 10
+ if q1 == q {
+ q1++
+ }
+ return q1
+}
+
+// NewBucketWithQuantum is similar to NewBucket, but allows
+// the specification of the quantum size - quantum tokens
+// are added every fillInterval.
+func NewBucketWithQuantum(fillInterval time.Duration, capacity, quantum int64) *Bucket {
+ return NewBucketWithQuantumAndClock(fillInterval, capacity, quantum, realClock{})
+}
+
+// NewBucketWithQuantumAndClock is identical to NewBucketWithQuantum but injects
+// a testable clock interface.
+func NewBucketWithQuantumAndClock(fillInterval time.Duration, capacity, quantum int64, clock Clock) *Bucket {
+ if fillInterval <= 0 {
+ panic("token bucket fill interval is not > 0")
+ }
+ if capacity <= 0 {
+ panic("token bucket capacity is not > 0")
+ }
+ if quantum <= 0 {
+ panic("token bucket quantum is not > 0")
+ }
+ return &Bucket{
+ clock: clock,
+ startTime: clock.Now(),
+ capacity: capacity,
+ quantum: quantum,
+ avail: capacity,
+ fillInterval: fillInterval,
+ }
+}
+
+// Wait takes count tokens from the bucket, waiting until they are
+// available.
+func (tb *Bucket) Wait(count int64) {
+ if d := tb.Take(count); d > 0 {
+ tb.clock.Sleep(d)
+ }
+}
+
+// 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.
+func (tb *Bucket) WaitMaxDuration(count int64, maxWait time.Duration) bool {
+ d, ok := tb.TakeMaxDuration(count, maxWait)
+ if d > 0 {
+ tb.clock.Sleep(d)
+ }
+ return ok
+}
+
+const infinityDuration time.Duration = 0x7fffffffffffffff
+
+// 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 (tb *Bucket) Take(count int64) time.Duration {
+ d, _ := tb.take(tb.clock.Now(), count, infinityDuration)
+ return d
+}
+
+// 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 (tb *Bucket) TakeMaxDuration(count int64, maxWait time.Duration) (time.Duration, bool) {
+ return tb.take(tb.clock.Now(), count, maxWait)
+}
+
+// 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 (tb *Bucket) TakeAvailable(count int64) int64 {
+ return tb.takeAvailable(tb.clock.Now(), count)
+}
+
+// takeAvailable is the internal version of TakeAvailable - it takes the
+// current time as an argument to enable easy testing.
+func (tb *Bucket) takeAvailable(now time.Time, count int64) int64 {
+ if count <= 0 {
+ return 0
+ }
+ tb.mu.Lock()
+ defer tb.mu.Unlock()
+
+ tb.adjust(now)
+ if tb.avail <= 0 {
+ return 0
+ }
+ if count > tb.avail {
+ count = tb.avail
+ }
+ tb.avail -= count
+ return count
+}
+
+// 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 (tb *Bucket) Available() int64 {
+ return tb.available(tb.clock.Now())
+}
+
+// available is the internal version of available - it takes the current time as
+// an argument to enable easy testing.
+func (tb *Bucket) available(now time.Time) int64 {
+ tb.mu.Lock()
+ defer tb.mu.Unlock()
+ tb.adjust(now)
+ return tb.avail
+}
+
+// Capacity returns the capacity that the bucket was created with.
+func (tb *Bucket) Capacity() int64 {
+ return tb.capacity
+}
+
+// Rate returns the fill rate of the bucket, in tokens per second.
+func (tb *Bucket) Rate() float64 {
+ return 1e9 * float64(tb.quantum) / float64(tb.fillInterval)
+}
+
+// take is the internal version of Take - it takes the current time as
+// an argument to enable easy testing.
+func (tb *Bucket) take(now time.Time, count int64, maxWait time.Duration) (time.Duration, bool) {
+ if count <= 0 {
+ return 0, true
+ }
+ tb.mu.Lock()
+ defer tb.mu.Unlock()
+
+ currentTick := tb.adjust(now)
+ avail := tb.avail - count
+ if avail >= 0 {
+ tb.avail = avail
+ return 0, true
+ }
+ // Round up the missing tokens to the nearest multiple
+ // of quantum - the tokens won't be available until
+ // that tick.
+ endTick := currentTick + (-avail+tb.quantum-1)/tb.quantum
+ endTime := tb.startTime.Add(time.Duration(endTick) * tb.fillInterval)
+ waitTime := endTime.Sub(now)
+ if waitTime > maxWait {
+ return 0, false
+ }
+ tb.avail = avail
+ return waitTime, true
+}
+
+// adjust adjusts the current bucket capacity based on the current time.
+// It returns the current tick.
+func (tb *Bucket) adjust(now time.Time) (currentTick int64) {
+ currentTick = int64(now.Sub(tb.startTime) / tb.fillInterval)
+
+ if tb.avail >= tb.capacity {
+ return
+ }
+ tb.avail += (currentTick - tb.availTick) * tb.quantum
+ if tb.avail > tb.capacity {
+ tb.avail = tb.capacity
+ }
+ tb.availTick = currentTick
+ return
+}
diff --git a/vendor/github.com/juju/ratelimit/reader.go b/vendor/github.com/juju/ratelimit/reader.go
new file mode 100644
index 000000000..6403bf78d
--- /dev/null
+++ b/vendor/github.com/juju/ratelimit/reader.go
@@ -0,0 +1,51 @@
+// Copyright 2014 Canonical Ltd.
+// Licensed under the LGPLv3 with static-linking exception.
+// See LICENCE file for details.
+
+package ratelimit
+
+import "io"
+
+type reader struct {
+ r io.Reader
+ bucket *Bucket
+}
+
+// Reader returns a reader that is rate limited by
+// the given token bucket. Each token in the bucket
+// represents one byte.
+func Reader(r io.Reader, bucket *Bucket) io.Reader {
+ return &reader{
+ r: r,
+ bucket: bucket,
+ }
+}
+
+func (r *reader) Read(buf []byte) (int, error) {
+ n, err := r.r.Read(buf)
+ if n <= 0 {
+ return n, err
+ }
+ r.bucket.Wait(int64(n))
+ return n, err
+}
+
+type writer struct {
+ w io.Writer
+ bucket *Bucket
+}
+
+// Writer returns a reader that is rate limited by
+// the given token bucket. Each token in the bucket
+// represents one byte.
+func Writer(w io.Writer, bucket *Bucket) io.Writer {
+ return &writer{
+ w: w,
+ bucket: bucket,
+ }
+}
+
+func (w *writer) Write(buf []byte) (int, error) {
+ w.bucket.Wait(int64(len(buf)))
+ return w.w.Write(buf)
+}