| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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 "kudu/util/crc.h" |
| |
| #include <crcutil/interface.h> |
| |
| #include "kudu/gutil/once.h" |
| #include "kudu/util/debug/leakcheck_disabler.h" |
| |
| namespace kudu { |
| namespace crc { |
| |
| using debug::ScopedLeakCheckDisabler; |
| |
| static GoogleOnceType crc32c_once = GOOGLE_ONCE_INIT; |
| static Crc* crc32c_instance = nullptr; |
| |
| static void InitCrc32cInstance() { |
| ScopedLeakCheckDisabler disabler; // CRC instance is never freed. |
| // TODO: Is initial = 0 and roll window = 4 appropriate for all cases? |
| crc32c_instance = crcutil_interface::CRC::CreateCrc32c(true, 0, 4, nullptr); |
| } |
| |
| Crc* GetCrc32cInstance() { |
| GoogleOnceInit(&crc32c_once, &InitCrc32cInstance); |
| return crc32c_instance; |
| } |
| |
| uint32_t Crc32c(const void* data, size_t length) { |
| uint64_t crc32 = 0; |
| GetCrc32cInstance()->Compute(data, length, &crc32); |
| return static_cast<uint32_t>(crc32); // Only uses lower 32 bits. |
| } |
| |
| uint32_t Crc32c(const void* data, size_t length, uint32_t prev_crc32) { |
| uint64_t crc_tmp = static_cast<uint64_t>(prev_crc32); |
| GetCrc32cInstance()->Compute(data, length, &crc_tmp); |
| return static_cast<uint32_t>(crc_tmp); // Only uses lower 32 bits. |
| } |
| |
| } // namespace crc |
| } // namespace kudu |