52 строки
1,3 КиБ
Go
52 строки
1,3 КиБ
Go
package machine
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import (
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"runtime/volatile"
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)
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const bufferSize = 128
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// RingBuffer is ring buffer implementation inspired by post at
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// https://www.embeddedrelated.com/showthread/comp.arch.embedded/77084-1.php
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type RingBuffer struct {
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rxbuffer [bufferSize]volatile.Register8
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head volatile.Register8
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tail volatile.Register8
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}
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// NewRingBuffer returns a new ring buffer.
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func NewRingBuffer() *RingBuffer {
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return &RingBuffer{}
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}
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// Used returns how many bytes in buffer have been used.
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func (rb *RingBuffer) Used() uint8 {
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return uint8(rb.head.Get() - rb.tail.Get())
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}
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// Put stores a byte in the buffer. If the buffer is already
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// full, the method will return false.
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func (rb *RingBuffer) Put(val byte) bool {
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if rb.Used() != bufferSize {
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rb.head.Set(rb.head.Get() + 1)
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rb.rxbuffer[rb.head.Get()%bufferSize].Set(val)
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return true
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}
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return false
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}
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// Get returns a byte from the buffer. If the buffer is empty,
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// the method will return a false as the second value.
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func (rb *RingBuffer) Get() (byte, bool) {
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if rb.Used() != 0 {
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rb.tail.Set(rb.tail.Get() + 1)
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return rb.rxbuffer[rb.tail.Get()%bufferSize].Get(), true
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}
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return 0, false
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}
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// Clear resets the head and tail pointer to zero.
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func (rb *RingBuffer) Clear() {
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rb.head.Set(0)
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rb.tail.Set(0)
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}
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