summaryrefslogtreecommitdiff
path: root/vendor/github.com/nxadm/tail/ratelimiter/leakybucket.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/nxadm/tail/ratelimiter/leakybucket.go')
-rw-r--r--vendor/github.com/nxadm/tail/ratelimiter/leakybucket.go97
1 files changed, 97 insertions, 0 deletions
diff --git a/vendor/github.com/nxadm/tail/ratelimiter/leakybucket.go b/vendor/github.com/nxadm/tail/ratelimiter/leakybucket.go
new file mode 100644
index 000000000..358b69e7f
--- /dev/null
+++ b/vendor/github.com/nxadm/tail/ratelimiter/leakybucket.go
@@ -0,0 +1,97 @@
+// Package ratelimiter implements the Leaky Bucket ratelimiting algorithm with memcached and in-memory backends.
+package ratelimiter
+
+import (
+ "time"
+)
+
+type LeakyBucket struct {
+ Size uint16
+ Fill float64
+ LeakInterval time.Duration // time.Duration for 1 unit of size to leak
+ Lastupdate time.Time
+ Now func() time.Time
+}
+
+func NewLeakyBucket(size uint16, leakInterval time.Duration) *LeakyBucket {
+ bucket := LeakyBucket{
+ Size: size,
+ Fill: 0,
+ LeakInterval: leakInterval,
+ Now: time.Now,
+ Lastupdate: time.Now(),
+ }
+
+ return &bucket
+}
+
+func (b *LeakyBucket) updateFill() {
+ now := b.Now()
+ if b.Fill > 0 {
+ elapsed := now.Sub(b.Lastupdate)
+
+ b.Fill -= float64(elapsed) / float64(b.LeakInterval)
+ if b.Fill < 0 {
+ b.Fill = 0
+ }
+ }
+ b.Lastupdate = now
+}
+
+func (b *LeakyBucket) Pour(amount uint16) bool {
+ b.updateFill()
+
+ var newfill float64 = b.Fill + float64(amount)
+
+ if newfill > float64(b.Size) {
+ return false
+ }
+
+ b.Fill = newfill
+
+ return true
+}
+
+// The time at which this bucket will be completely drained
+func (b *LeakyBucket) DrainedAt() time.Time {
+ return b.Lastupdate.Add(time.Duration(b.Fill * float64(b.LeakInterval)))
+}
+
+// The duration until this bucket is completely drained
+func (b *LeakyBucket) TimeToDrain() time.Duration {
+ return b.DrainedAt().Sub(b.Now())
+}
+
+func (b *LeakyBucket) TimeSinceLastUpdate() time.Duration {
+ return b.Now().Sub(b.Lastupdate)
+}
+
+type LeakyBucketSer struct {
+ Size uint16
+ Fill float64
+ LeakInterval time.Duration // time.Duration for 1 unit of size to leak
+ Lastupdate time.Time
+}
+
+func (b *LeakyBucket) Serialise() *LeakyBucketSer {
+ bucket := LeakyBucketSer{
+ Size: b.Size,
+ Fill: b.Fill,
+ LeakInterval: b.LeakInterval,
+ Lastupdate: b.Lastupdate,
+ }
+
+ return &bucket
+}
+
+func (b *LeakyBucketSer) DeSerialise() *LeakyBucket {
+ bucket := LeakyBucket{
+ Size: b.Size,
+ Fill: b.Fill,
+ LeakInterval: b.LeakInterval,
+ Lastupdate: b.Lastupdate,
+ Now: time.Now,
+ }
+
+ return &bucket
+}