| /* |
| * 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 v3 |
| |
| import ( |
| envoy_types "github.com/envoyproxy/go-control-plane/pkg/cache/types" |
| |
| "google.golang.org/protobuf/proto" |
| ) |
| |
| // SnapshotVersioner assigns versions to xDS resources in a new Snapshot. |
| type SnapshotVersioner interface { |
| Version(new, old Snapshot) Snapshot |
| } |
| |
| // SnapshotAutoVersioner assigns versions to xDS resources in a new Snapshot |
| // by reusing if possible a version from the old snapshot and |
| // generating a new version (UUID) otherwise. |
| type SnapshotAutoVersioner struct { |
| UUID func() string |
| } |
| |
| func (v SnapshotAutoVersioner) Version(new, old Snapshot) Snapshot { |
| if new == nil { |
| return nil |
| } |
| for _, typ := range new.GetSupportedTypes() { |
| version := new.GetVersion(typ) |
| if version != "" { |
| // favor a version assigned by resource generator |
| continue |
| } |
| if old != nil && v.equal(new.GetResources(typ), old.GetResources(typ)) { |
| version = old.GetVersion(typ) |
| } |
| if version == "" { |
| version = v.UUID() |
| } |
| new = new.WithVersion(typ, version) |
| } |
| return new |
| } |
| |
| func (_ SnapshotAutoVersioner) equal(new, old map[string]envoy_types.Resource) bool { |
| if len(new) != len(old) { |
| return false |
| } |
| for key, newValue := range new { |
| if oldValue, hasOldValue := old[key]; !hasOldValue || !proto.Equal(newValue, oldValue) { |
| return false |
| } |
| } |
| return true |
| } |