-
Notifications
You must be signed in to change notification settings - Fork 256
/
filelock.go
95 lines (83 loc) · 3.03 KB
/
filelock.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
91
92
93
94
95
// Copyright 2020-2022 Buf Technologies, Inc.
//
// 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 filelock
import (
"context"
"time"
)
const (
// DefaultLockTimeout is the default lock timeout.
DefaultLockTimeout = 3 * time.Second
// DefaultLockRetryDelay is the default lock retry delay.
DefaultLockRetryDelay = 200 * time.Millisecond
)
// Unlocker unlocks a file lock.
type Unlocker interface {
Unlock() error
}
// Lock locks a file lock.
//
// Use in cases where you need a lock for a specific system file, such as in testing,
// otherwise use a Locker to manage your file locks.
func Lock(ctx context.Context, filePath string, options ...LockOption) (Unlocker, error) {
return lock(ctx, filePath, options...)
}
// RLock read-locks a file lock.
//
// Use in cases where you need a lock for a specific system file, such as in testing,
// otherwise use a Locker to manage your file locks.
func RLock(ctx context.Context, filePath string, options ...LockOption) (Unlocker, error) {
return rlock(ctx, filePath, options...)
}
// Locker provides file locks.
type Locker interface {
// Lock locks a file lock within the root directory of the Locker.
//
// The given path must be normalized and relative.
Lock(ctx context.Context, path string, options ...LockOption) (Unlocker, error)
// RLock read-locks a file lock within the root directory of the Locker.
//
// The given path must be normalized and relative.
RLock(ctx context.Context, path string, options ...LockOption) (Unlocker, error)
}
// NewLocker returns a new Locker for the given root directory path.
//
// The root directory path should generally be a data directory path.
// The root directory must exist.
func NewLocker(rootDirPath string) (Locker, error) {
return newLocker(rootDirPath)
}
// LockOption is an option for lock.
type LockOption func(*lockOptions)
// LockWithTimeout returns a new LockOption that sets the lock timeout.
//
// Lock returns error if the lock cannot be acquired after this amount of time.
// If this is set to 0, the lock will never timeout.
func LockWithTimeout(timeout time.Duration) LockOption {
return func(lockOptions *lockOptions) {
lockOptions.timeout = timeout
}
}
// LockWithRetryDelay returns a new LockOption that sets the lock retry delay.
//
// Lock will try to lock on this delay up until the lock timeout.
func LockWithRetryDelay(retryDelay time.Duration) LockOption {
return func(lockOptions *lockOptions) {
lockOptions.retryDelay = retryDelay
}
}
// NewNopLocker returns a new no-op Locker.
func NewNopLocker() Locker {
return newNopLocker()
}