blob: 8f8215c71d8dbc16d4ff72618a38399f2a6d521e (
plain)
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
|
// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package queue
import (
"fmt"
)
// UniqueQueue defines a queue which guarantees only one instance of same
// data is in the queue. Instances with same identity will be
// discarded if there is already one in the line.
//
// This queue is particularly useful for preventing duplicated task
// of same purpose - please note that this does not guarantee that a particular
// task cannot be processed twice or more at the same time. Uniqueness is
// only guaranteed whilst the task is waiting in the queue.
//
// Users of this queue should be careful to push only the identifier of the
// data
type UniqueQueue interface {
Queue
PushFunc(Data, func() error) error
Has(Data) (bool, error)
}
// ErrAlreadyInQueue is returned when trying to push data to the queue that is already in the queue
var ErrAlreadyInQueue = fmt.Errorf("already in queue")
|
