khenaidoo | ffe076b | 2019-01-15 16:08:08 -0500 | [diff] [blame^] | 1 | // Copyright 2017 The etcd Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package namespace |
| 16 | |
| 17 | func prefixInterval(pfx string, key, end []byte) (pfxKey []byte, pfxEnd []byte) { |
| 18 | pfxKey = make([]byte, len(pfx)+len(key)) |
| 19 | copy(pfxKey[copy(pfxKey, pfx):], key) |
| 20 | |
| 21 | if len(end) == 1 && end[0] == 0 { |
| 22 | // the edge of the keyspace |
| 23 | pfxEnd = make([]byte, len(pfx)) |
| 24 | copy(pfxEnd, pfx) |
| 25 | ok := false |
| 26 | for i := len(pfxEnd) - 1; i >= 0; i-- { |
| 27 | if pfxEnd[i]++; pfxEnd[i] != 0 { |
| 28 | ok = true |
| 29 | break |
| 30 | } |
| 31 | } |
| 32 | if !ok { |
| 33 | // 0xff..ff => 0x00 |
| 34 | pfxEnd = []byte{0} |
| 35 | } |
| 36 | } else if len(end) >= 1 { |
| 37 | pfxEnd = make([]byte, len(pfx)+len(end)) |
| 38 | copy(pfxEnd[copy(pfxEnd, pfx):], end) |
| 39 | } |
| 40 | |
| 41 | return pfxKey, pfxEnd |
| 42 | } |