0becca2e96
CNI is developed by more than just CoreOS, Inc and the copyright is retained by all CNI contributors (for their respective contributed code).
51 lines
1.3 KiB
Go
51 lines
1.3 KiB
Go
// Copyright 2015 CNI authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package disk
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import (
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"os"
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"syscall"
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)
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// FileLock wraps os.File to be used as a lock using flock
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type FileLock struct {
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f *os.File
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}
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// NewFileLock opens file/dir at path and returns unlocked FileLock object
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func NewFileLock(path string) (*FileLock, error) {
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f, err := os.Open(path)
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if err != nil {
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return nil, err
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}
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return &FileLock{f}, nil
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}
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// Close closes underlying file
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func (l *FileLock) Close() error {
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return l.f.Close()
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}
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// Lock acquires an exclusive lock
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func (l *FileLock) Lock() error {
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return syscall.Flock(int(l.f.Fd()), syscall.LOCK_EX)
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}
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// Unlock releases the lock
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func (l *FileLock) Unlock() error {
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return syscall.Flock(int(l.f.Fd()), syscall.LOCK_UN)
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}
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