68 lines
1.3 KiB
Go
68 lines
1.3 KiB
Go
package ringbuf
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import (
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"bytes"
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"io"
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"testing"
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)
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func TestRingBufferReader(t *testing.T) {
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buf := make([]byte, 2)
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ring := makeRing(2, 0)
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n, err := ring.Read(buf)
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if err != io.EOF {
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t.Error("Expected io.EOF, got", err)
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}
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if n != 2 {
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t.Errorf("Expected to read 2 bytes, got %d", n)
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}
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if !bytes.Equal(buf, []byte{0, 1}) {
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t.Error("Expected [0, 1], got", buf)
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}
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n, err = ring.Read(buf)
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if err != io.EOF {
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t.Error("Expected io.EOF, got", err)
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}
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if n != 0 {
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t.Error("Expected to read 0 bytes, got", n)
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}
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buf = make([]byte, 4)
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ring = makeRing(4, 4)
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n, err = io.ReadFull(ring, buf)
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if err != nil {
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t.Error("Expected nil, got", err)
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}
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if n != 4 {
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t.Errorf("Expected to read 4 bytes, got %d", n)
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}
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if !bytes.Equal(buf, []byte{0, 1, 2, 3}) {
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t.Error("Expected [0, 1, 2, 3], got", buf)
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}
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n, err = ring.Read(buf)
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if err != io.EOF {
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t.Error("Expected io.EOF, got", err)
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}
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if n != 0 {
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t.Error("Expected to read 0 bytes, got", n)
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}
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}
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func makeRing(size, offset int) *ringReader {
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if size != 0 && (size&(size-1)) != 0 {
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panic("size must be power of two")
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}
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ring := make([]byte, 2*size)
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for i := range ring {
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ring[i] = byte(i)
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}
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consumer := uint64(offset)
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producer := uint64(len(ring)/2 + offset)
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return newRingReader(&consumer, &producer, ring)
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}
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