diff options
Diffstat (limited to 'swarm/network/bitvector/bitvector.go')
-rw-r--r-- | swarm/network/bitvector/bitvector.go | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/swarm/network/bitvector/bitvector.go b/swarm/network/bitvector/bitvector.go new file mode 100644 index 000000000..edc7c50cb --- /dev/null +++ b/swarm/network/bitvector/bitvector.go @@ -0,0 +1,66 @@ +// 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 +} |