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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.
47 lines
1.6 KiB
Go
47 lines
1.6 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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// Package flock provides portable file locking. It is essentially ripped out
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// from the code of github.com/syndtr/goleveldb. Strange enough that the
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// standard library does not provide this functionality. Once this package has
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// proven to work as expected, we should probably turn it into a separate
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// general purpose package for humanity.
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package flock
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import (
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"os"
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"path/filepath"
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)
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// Releaser provides the Release method to release a file lock.
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type Releaser interface {
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Release() error
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}
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// New locks the file with the provided name. If the file does not exist, it is
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// created. The returned Releaser is used to release the lock. existed is true
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// if the file to lock already existed. A non-nil error is returned if the
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// locking has failed. Neither this function nor the returned Releaser is
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// goroutine-safe.
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func New(fileName string) (r Releaser, existed bool, err error) {
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if err = os.MkdirAll(filepath.Dir(fileName), 0755); err != nil {
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return
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}
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_, err = os.Stat(fileName)
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existed = err == nil
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r, err = newLock(fileName)
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return
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}
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