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41 lines
1.3 KiB
41 lines
1.3 KiB
// 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 fileutil |
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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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// Flock 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 Flock(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 nil, false, err |
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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 r, existed, err |
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}
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