| /* |
| Copyright 2019 The Kubernetes Authors. |
| |
| 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. |
| */ |
| |
| package discovery |
| |
| import ( |
| "crypto/sha256" |
| "encoding/base64" |
| ) |
| |
| // StorageVersionHash calculates the storage version hash for a |
| // <group/version/kind> tuple. |
| // WARNING: this function is subject to change. Clients shouldn't depend on |
| // this function. |
| func StorageVersionHash(group, version, kind string) string { |
| gvk := group + "/" + version + "/" + kind |
| if gvk == "" { |
| return "" |
| } |
| bytes := sha256.Sum256([]byte(gvk)) |
| // Assuming there are N kinds in the cluster, and the hash is X-byte long, |
| // the chance of colliding hash P(N,X) approximates to 1-e^(-(N^2)/2^(8X+1)). |
| // P(10,000, 8) ~= 2.7*10^(-12), which is low enough. |
| // See https://en.wikipedia.org/wiki/Birthday_problem#Approximations. |
| return base64.StdEncoding.EncodeToString( |
| bytes[:8]) |
| } |
