| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "perfetto/ext/base/uuid.h" |
| |
| #include <random> |
| |
| #include "perfetto/ext/base/time.h" |
| |
| namespace perfetto { |
| namespace base { |
| |
| // See https://www.ietf.org/rfc/rfc4122.txt |
| std::array<uint8_t, 16> Uuidv4() { |
| static std::minstd_rand rng(static_cast<size_t>(GetBootTimeNs().count())); |
| std::array<uint8_t, 16> uuid; |
| for (size_t i = 0; i < 16; ++i) |
| uuid[i] = static_cast<uint8_t>(rng()); |
| |
| // version: |
| uuid[6] = (uuid[6] & 0x0f) | 0x40; |
| // clock_seq_hi_and_reserved: |
| uuid[8] = (uuid[8] & 0x3f) | 0x80; |
| |
| return uuid; |
| } |
| |
| } // namespace base |
| } // namespace perfetto |