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// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package bitvector
import (
"errors"
)
var errInvalidLength = errors.New("invalid length")
type BitVector struct {
len int
b []byte
}
func New(l int) (bv *BitVector, err error) {
return NewFromBytes(make([]byte, l/8+1), l)
}
func NewFromBytes(b []byte, l int) (bv *BitVector, err error) {
if l <= 0 {
return nil, errInvalidLength
}
if len(b)*8 < l {
return nil, errInvalidLength
}
return &BitVector{
len: l,
b: b,
}, nil
}
func (bv *BitVector) Get(i int) bool {
bi := i / 8
return bv.b[bi]&(0x1<<uint(i%8)) != 0
}
func (bv *BitVector) Set(i int, v bool) {
bi := i / 8
cv := bv.Get(i)
if cv != v {
bv.b[bi] ^= 0x1 << uint8(i%8)
}
}
func (bv *BitVector) Bytes() []byte {
return bv.b
}
func (bv *BitVector) Length() int {
return bv.len
}
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