forked from TrueCloudLab/frostfs-node
Evgenii Stratonikov
abd502215f
It is not a part of FSTree itself, but rather a way to solve concurrent counter update on non-linux implementations. New linux implementations is pretty simple: link fails when the file exists, unlink fails when the file doesn't exist. Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
37 lines
780 B
Go
37 lines
780 B
Go
package fstree
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import (
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"math"
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"sync/atomic"
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)
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// FileCounter used to count files in FSTree. The implementation must be thread-safe.
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type FileCounter interface {
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Set(v uint64)
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Inc()
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Dec()
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}
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type noopCounter struct{}
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func (c *noopCounter) Set(uint64) {}
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func (c *noopCounter) Inc() {}
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func (c *noopCounter) Dec() {}
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func counterEnabled(c FileCounter) bool {
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_, noop := c.(*noopCounter)
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return !noop
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}
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type SimpleCounter struct {
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v atomic.Uint64
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}
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func NewSimpleCounter() *SimpleCounter {
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return &SimpleCounter{}
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}
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func (c *SimpleCounter) Set(v uint64) { c.v.Store(v) }
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func (c *SimpleCounter) Inc() { c.v.Add(1) }
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func (c *SimpleCounter) Dec() { c.v.Add(math.MaxUint64) }
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func (c *SimpleCounter) Value() uint64 { return c.v.Load() }
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