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38098f8c95
Prometheus is Apache 2 licensed, and most source files have the appropriate copyright license header, but some were missing it without apparent reason. Correct that by adding it.
55 lines
1.2 KiB
Go
55 lines
1.2 KiB
Go
// Copyright 2016 The Prometheus Authors
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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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// +build darwin dragonfly freebsd linux netbsd openbsd
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package flock
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import (
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"os"
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"syscall"
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)
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type unixLock struct {
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f *os.File
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}
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func (l *unixLock) Release() error {
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if err := l.set(false); err != nil {
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return err
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}
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return l.f.Close()
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}
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func (l *unixLock) set(lock bool) error {
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how := syscall.LOCK_UN
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if lock {
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how = syscall.LOCK_EX
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}
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return syscall.Flock(int(l.f.Fd()), how|syscall.LOCK_NB)
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}
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func newLock(fileName string) (Releaser, error) {
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f, err := os.OpenFile(fileName, os.O_RDWR|os.O_CREATE, 0644)
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if err != nil {
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return nil, err
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}
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l := &unixLock{f}
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err = l.set(true)
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if err != nil {
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f.Close()
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return nil, err
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}
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return l, nil
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}
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