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
|
// Copyright 2020 The gVisor Authors.
//
// 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 cleanup provides utilities to clean "stuff" on defers.
package cleanup
// Cleanup allows defers to be aborted when cleanup needs to happen
// conditionally. Usage:
//
// cu := cleanup.Make(func() { f.Close() })
// defer cu.Clean() // failure before release is called will close the file.
// ...
// cu.Add(func() { f2.Close() }) // Adds another cleanup function
// ...
// cu.Release() // on success, aborts closing the file.
// return f
type Cleanup struct {
cleaners []func()
}
// Make creates a new Cleanup object.
func Make(f func()) Cleanup {
return Cleanup{cleaners: []func(){f}}
}
// Add adds a new function to be called on Clean().
func (c *Cleanup) Add(f func()) {
c.cleaners = append(c.cleaners, f)
}
// Clean calls all cleanup functions in reverse order.
func (c *Cleanup) Clean() {
clean(c.cleaners)
c.cleaners = nil
}
// Release releases the cleanup from its duties, i.e. cleanup functions are not
// called after this point. Returns a function that calls all registered
// functions in case the caller has use for them.
func (c *Cleanup) Release() func() {
old := c.cleaners
c.cleaners = nil
return func() { clean(old) }
}
func clean(cleaners []func()) {
for i := len(cleaners) - 1; i >= 0; i-- {
cleaners[i]()
}
}
|
