61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
// Copyright 2020 The gVisor 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 cleanup provides utilities to clean "stuff" on defers.
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package cleanup
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// Cleanup allows defers to be aborted when cleanup needs to happen
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// conditionally. Usage:
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// cu := cleanup.Make(func() { f.Close() })
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// defer cu.Clean() // failure before release is called will close the file.
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// ...
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// cu.Add(func() { f2.Close() }) // Adds another cleanup function
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// ...
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// cu.Release() // on success, aborts closing the file.
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// return f
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type Cleanup struct {
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cleaners []func()
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}
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// Make creates a new Cleanup object.
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func Make(f func()) Cleanup {
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return Cleanup{cleaners: []func(){f}}
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}
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// Add adds a new function to be called on Clean().
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func (c *Cleanup) Add(f func()) {
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c.cleaners = append(c.cleaners, f)
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}
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// Clean calls all cleanup functions in reverse order.
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func (c *Cleanup) Clean() {
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clean(c.cleaners)
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c.cleaners = nil
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}
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// Release releases the cleanup from its duties, i.e. cleanup functions are not
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// called after this point. Returns a function that calls all registered
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// functions in case the caller has use for them.
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func (c *Cleanup) Release() func() {
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old := c.cleaners
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c.cleaners = nil
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return func() { clean(old) }
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}
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func clean(cleaners []func()) {
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for i := len(cleaners) - 1; i >= 0; i-- {
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cleaners[i]()
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}
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}
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