-
Notifications
You must be signed in to change notification settings - Fork 787
/
concurrentQueue.go
90 lines (73 loc) · 2.15 KB
/
concurrentQueue.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package collection
import "sync"
type (
concurrentQueueImpl struct {
sync.Mutex
items []interface{}
}
)
// NewConcurrentQueue creates a new concurrent queue
func NewConcurrentQueue() Queue {
return &concurrentQueueImpl{
items: make([]interface{}, 0, 1000),
}
}
func (q *concurrentQueueImpl) Peek() interface{} {
q.Lock()
defer q.Unlock()
if q.isEmptyLocked() {
return nil
}
return q.items[0]
}
func (q *concurrentQueueImpl) Add(item interface{}) {
if item == nil {
panic("cannot add nil item to queue")
}
q.Lock()
defer q.Unlock()
q.items = append(q.items, item)
}
func (q *concurrentQueueImpl) Remove() interface{} {
q.Lock()
defer q.Unlock()
if q.isEmptyLocked() {
return nil
}
item := q.items[0]
q.items[0] = nil
q.items = q.items[1:]
return item
}
func (q *concurrentQueueImpl) IsEmpty() bool {
q.Lock()
defer q.Unlock()
return q.isEmptyLocked()
}
func (q *concurrentQueueImpl) Len() int {
q.Lock()
defer q.Unlock()
return len(q.items)
}
func (q *concurrentQueueImpl) isEmptyLocked() bool {
return len(q.items) == 0
}