52 lines
638 B
Go
52 lines
638 B
Go
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package main
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import ()
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const (
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MaxIndex = ^uint(0)
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)
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type (
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Counter struct {
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Write uint
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Read uint
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stream chan uint
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inLoop bool
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}
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)
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func NewCounter(wi, ri uint) *Counter {
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c := &Counter{Write: wi, Read: ri}
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c.stream = make(chan uint)
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go c.Loop()
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return c
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}
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func (c *Counter) Incr() {
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c.Write++
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if !c.inLoop {
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c.inLoop = true
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go c.Loop()
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}
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}
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func (c *Counter) Next() uint {
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return <-c.stream
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}
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func (c *Counter) Distance() uint {
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d := c.Write - c.Read
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if d < 0 {
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d += MaxIndex
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}
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return d
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}
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func (c *Counter) Loop() {
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for c.Write > c.Read {
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c.stream <- c.Read + 1
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c.Read++
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}
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c.inLoop = false
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}
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