lotus/chain/types/bitfield.go

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package types
import (
"fmt"
"io"
"github.com/filecoin-project/go-lotus/extern/rleplus"
cbg "github.com/whyrusleeping/cbor-gen"
"golang.org/x/xerrors"
)
type BitField struct {
bits map[uint64]struct{}
}
func NewBitField() BitField {
return BitField{bits: make(map[uint64]struct{})}
}
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func BitFieldFromSet(setBits []uint64) BitField {
res := BitField{bits: make(map[uint64]struct{})}
for _, b := range setBits {
res.bits[b] = struct{}{}
}
return res
}
// Set ...s bit in the BitField
func (bf BitField) Set(bit uint64) {
bf.bits[bit] = struct{}{}
}
// Clear ...s bit in the BitField
func (bf BitField) Clear(bit uint64) {
delete(bf.bits, bit)
}
// Has checkes if bit is set in the BitField
func (bf BitField) Has(bit uint64) bool {
_, ok := bf.bits[bit]
return ok
}
// All returns all set bits, in random order
func (bf BitField) All() []uint64 {
res := make([]uint64, 0, len(bf.bits))
for i := range bf.bits {
res = append(res, i)
}
return res
}
func (bf BitField) MarshalCBOR(w io.Writer) error {
ints := make([]uint64, 0, len(bf.bits))
for i := range bf.bits {
ints = append(ints, i)
}
rle, _, err := rleplus.Encode(ints) // Encode sorts internally
if err != nil {
return err
}
if _, err := w.Write(cbg.CborEncodeMajorType(cbg.MajByteString, uint64(len(rle)))); err != nil {
return err
}
if _, err = w.Write(rle); err != nil {
return xerrors.Errorf("writing rle: %w", err)
}
return nil
}
func (bf *BitField) UnmarshalCBOR(r io.Reader) error {
br := cbg.GetPeeker(r)
maj, extra, err := cbg.CborReadHeader(br)
if err != nil {
return err
}
if extra > 8192 {
return fmt.Errorf("array too large")
}
if maj != cbg.MajByteString {
return fmt.Errorf("expected byte array")
}
rle := make([]byte, extra)
if _, err := io.ReadFull(br, rle); err != nil {
return err
}
ints, err := rleplus.Decode(rle)
if err != nil {
return xerrors.Errorf("could not decode rle+: %w", err)
}
bf.bits = make(map[uint64]struct{})
for _, i := range ints {
bf.bits[i] = struct{}{}
}
return nil
}