| // 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. |
| |
| package internal |
| |
| import ( |
| "hash" |
| "hash/crc32" |
| ) |
| |
| // crc32cTable holds the precomputed crc32 hash table |
| // used by Pulsar (crc32c) |
| var crc32cTable = crc32.MakeTable(crc32.Castagnoli) |
| |
| type CheckSum struct { |
| hash hash.Hash |
| } |
| |
| // Crc32cCheckSum handles computing the checksum. |
| func Crc32cCheckSum(data []byte) uint32 { |
| return crc32.Checksum(data, crc32cTable) |
| } |
| |
| func (cs *CheckSum) Write(p []byte) (int, error) { |
| if cs.hash == nil { |
| cs.hash = crc32.New(crc32cTable) |
| } |
| return cs.hash.Write(p) |
| } |
| |
| func (cs *CheckSum) compute() []byte { |
| if cs.hash == nil { |
| return nil |
| } |
| return cs.hash.Sum(nil) |
| } |