Alexey Khit
57 lines
841 B
Go
57 lines
841 B
Go
package golomb
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import "math/bits"
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type Writer struct {
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buf []byte
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b byte // last byte
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i int // last byte index
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shift byte
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}
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func NewWriter() *Writer {
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return &Writer{i: -1}
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}
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func (g *Writer) WriteBit(b byte) {
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if g.shift == 0 {
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g.buf = append(g.buf, 0)
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g.b = 0
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g.i++
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g.shift = 7
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} else {
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g.shift--
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}
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g.b |= b << g.shift
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g.buf[g.i] = g.b
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}
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func (g *Writer) WriteBits(b, n byte) {
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for i := n - 1; i != 255; i-- {
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g.WriteBit((b >> i) & 0b1)
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}
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}
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func (g *Writer) WriteByte(b byte) {
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g.buf = append(g.buf, b)
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g.i++
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}
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func (g *Writer) WriteUEGolomb(b byte) {
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b++
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n := uint8(bits.Len8(b))*2 - 1
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g.WriteBits(b, n)
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}
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func (g *Writer) WriteSEGolomb(b int8) {
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if b > 0 {
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g.WriteUEGolomb(byte(b)*2 - 1)
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} else {
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g.WriteUEGolomb(byte(-b) * 2)
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}
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}
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func (g *Writer) Bytes() []byte {
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return g.buf
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}
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