mirror of
https://github.com/prometheus/prometheus.git
synced 2024-09-21 00:07:36 -07:00
151 lines
3.1 KiB
Go
151 lines
3.1 KiB
Go
// Copyright 2013 Prometheus Team
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package metric
|
|
|
|
import (
|
|
"container/list"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/prometheus/prometheus/model"
|
|
)
|
|
|
|
// unsafe.Sizeof(Watermarks{})
|
|
const elementSize = 24
|
|
|
|
type Bytes uint64
|
|
|
|
// WatermarkCache is a thread-safe LRU cache for fingerprint watermark
|
|
// state.
|
|
type WatermarkCache struct {
|
|
mu sync.Mutex
|
|
|
|
list *list.List
|
|
table map[model.Fingerprint]*list.Element
|
|
|
|
size Bytes
|
|
|
|
allowance Bytes
|
|
}
|
|
|
|
type Watermarks struct {
|
|
High time.Time
|
|
}
|
|
|
|
type entry struct {
|
|
fingerprint *model.Fingerprint
|
|
watermarks *Watermarks
|
|
accessed time.Time
|
|
}
|
|
|
|
func NewWatermarkCache(allowance Bytes) *WatermarkCache {
|
|
return &WatermarkCache{
|
|
list: list.New(),
|
|
table: map[model.Fingerprint]*list.Element{},
|
|
allowance: allowance,
|
|
}
|
|
}
|
|
|
|
func (lru *WatermarkCache) Get(f *model.Fingerprint) (v *Watermarks, ok bool) {
|
|
lru.mu.Lock()
|
|
defer lru.mu.Unlock()
|
|
|
|
element, ok := lru.table[*f]
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
|
|
lru.moveToFront(element)
|
|
|
|
return element.Value.(*entry).watermarks, true
|
|
}
|
|
|
|
func (lru *WatermarkCache) Set(f *model.Fingerprint, w *Watermarks) {
|
|
lru.mu.Lock()
|
|
defer lru.mu.Unlock()
|
|
|
|
if element, ok := lru.table[*f]; ok {
|
|
lru.updateInplace(element, w)
|
|
} else {
|
|
lru.addNew(f, w)
|
|
}
|
|
}
|
|
|
|
func (lru *WatermarkCache) SetIfAbsent(f *model.Fingerprint, w *Watermarks) {
|
|
lru.mu.Lock()
|
|
defer lru.mu.Unlock()
|
|
|
|
if element, ok := lru.table[*f]; ok {
|
|
lru.moveToFront(element)
|
|
} else {
|
|
lru.addNew(f, w)
|
|
}
|
|
}
|
|
|
|
func (lru *WatermarkCache) Delete(f *model.Fingerprint) bool {
|
|
lru.mu.Lock()
|
|
defer lru.mu.Unlock()
|
|
|
|
element, ok := lru.table[*f]
|
|
if !ok {
|
|
return false
|
|
}
|
|
|
|
lru.list.Remove(element)
|
|
delete(lru.table, *f)
|
|
lru.size -= elementSize
|
|
|
|
return true
|
|
}
|
|
|
|
func (lru *WatermarkCache) Clear() {
|
|
lru.mu.Lock()
|
|
defer lru.mu.Unlock()
|
|
|
|
lru.list.Init()
|
|
lru.table = map[model.Fingerprint]*list.Element{}
|
|
lru.size = 0
|
|
}
|
|
|
|
func (lru *WatermarkCache) updateInplace(e *list.Element, w *Watermarks) {
|
|
e.Value.(*entry).watermarks = w
|
|
lru.moveToFront(e)
|
|
lru.checkCapacity()
|
|
}
|
|
|
|
func (lru *WatermarkCache) moveToFront(e *list.Element) {
|
|
lru.list.MoveToFront(e)
|
|
e.Value.(*entry).accessed = time.Now()
|
|
}
|
|
|
|
func (lru *WatermarkCache) addNew(f *model.Fingerprint, w *Watermarks) {
|
|
lru.table[*f] = lru.list.PushFront(&entry{
|
|
fingerprint: f,
|
|
watermarks: w,
|
|
accessed: time.Now(),
|
|
})
|
|
lru.size += elementSize
|
|
lru.checkCapacity()
|
|
}
|
|
|
|
func (lru *WatermarkCache) checkCapacity() {
|
|
for lru.size > lru.allowance {
|
|
delElem := lru.list.Back()
|
|
delWatermarks := delElem.Value.(*entry)
|
|
lru.list.Remove(delElem)
|
|
delete(lru.table, *delWatermarks.fingerprint)
|
|
lru.size -= elementSize
|
|
}
|
|
}
|