work_queue.go

Documentation: k8s.io/kubernetes/pkg/kubelet/util/queue

     1  /*
     2  Copyright 2015 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package queue
    18  
    19  import (
    20  	"sync"
    21  	"time"
    22  
    23  	"k8s.io/apimachinery/pkg/types"
    24  	"k8s.io/utils/clock"
    25  )
    26  
    27  // WorkQueue allows queuing items with a timestamp. An item is
    28  // considered ready to process if the timestamp has expired.
    29  type WorkQueue interface {
    30  	// GetWork dequeues and returns all ready items.
    31  	GetWork() []types.UID
    32  	// Enqueue inserts a new item or overwrites an existing item.
    33  	Enqueue(item types.UID, delay time.Duration)
    34  }
    35  
    36  type basicWorkQueue struct {
    37  	clock clock.Clock
    38  	lock  sync.Mutex
    39  	queue map[types.UID]time.Time
    40  }
    41  
    42  var _ WorkQueue = &basicWorkQueue{}
    43  
    44  // NewBasicWorkQueue returns a new basic WorkQueue with the provided clock
    45  func NewBasicWorkQueue(clock clock.Clock) WorkQueue {
    46  	queue := make(map[types.UID]time.Time)
    47  	return &basicWorkQueue{queue: queue, clock: clock}
    48  }
    49  
    50  func (q *basicWorkQueue) GetWork() []types.UID {
    51  	q.lock.Lock()
    52  	defer q.lock.Unlock()
    53  	now := q.clock.Now()
    54  	var items []types.UID
    55  	for k, v := range q.queue {
    56  		if v.Before(now) {
    57  			items = append(items, k)
    58  			delete(q.queue, k)
    59  		}
    60  	}
    61  	return items
    62  }
    63  
    64  func (q *basicWorkQueue) Enqueue(item types.UID, delay time.Duration) {
    65  	q.lock.Lock()
    66  	defer q.lock.Unlock()
    67  	q.queue[item] = q.clock.Now().Add(delay)
    68  }
    69
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