| // Copyright 2011 The Snappy-Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // Package zigzag implements the zigzag mapping between signed and unsigned |
| // integers: |
| // +0 <--> 0 |
| // -1 <--> 1 |
| // +1 <--> 2 |
| // -2 <--> 3 |
| // +2 <--> 4 |
| // |
| // It is the same format used by protocol buffers. The format is described at |
| // http://code.google.com/apis/protocolbuffers/docs/encoding.html |
| package zigzag |
| |
| func Itou64(i int64) uint64 { |
| return uint64(i<<1 ^ i>>63) |
| } |
| |
| func Utoi64(u uint64) int64 { |
| return int64(u>>1) ^ -int64(u&1) |
| } |
