49 строки
1,3 КиБ
Go
49 строки
1,3 КиБ
Go
package machine
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const bufferSize = 128
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//go:volatile
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type volatileByte byte
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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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//
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// It has some limitations currently due to how "volatile" variables that are
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// members of a struct are not compiled correctly by TinyGo.
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// See https://github.com/tinygo-org/tinygo/issues/151 for details.
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type RingBuffer struct {
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rxbuffer [bufferSize]volatileByte
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head volatileByte
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tail volatileByte
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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 - rb.tail)
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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++
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rb.rxbuffer[rb.head%bufferSize] = volatileByte(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++
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return byte(rb.rxbuffer[rb.tail%bufferSize]), true
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}
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return 0, false
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}
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