Matthias Andreas Benkard | 832a54e | 2019-01-29 09:27:38 +0100 | [diff] [blame] | 1 | /* |
| 2 | Copyright 2015 The Kubernetes Authors. |
| 3 | |
| 4 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | you may not use this file except in compliance with the License. |
| 6 | You may obtain a copy of the License at |
| 7 | |
| 8 | http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | |
| 10 | Unless required by applicable law or agreed to in writing, software |
| 11 | distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | See the License for the specific language governing permissions and |
| 14 | limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package storage |
| 18 | |
| 19 | import ( |
| 20 | "fmt" |
| 21 | "strings" |
| 22 | "sync/atomic" |
| 23 | |
| 24 | "k8s.io/apimachinery/pkg/api/meta" |
| 25 | "k8s.io/apimachinery/pkg/api/validation/path" |
| 26 | "k8s.io/apimachinery/pkg/runtime" |
| 27 | ) |
| 28 | |
| 29 | type SimpleUpdateFunc func(runtime.Object) (runtime.Object, error) |
| 30 | |
| 31 | // SimpleUpdateFunc converts SimpleUpdateFunc into UpdateFunc |
| 32 | func SimpleUpdate(fn SimpleUpdateFunc) UpdateFunc { |
| 33 | return func(input runtime.Object, _ ResponseMeta) (runtime.Object, *uint64, error) { |
| 34 | out, err := fn(input) |
| 35 | return out, nil, err |
| 36 | } |
| 37 | } |
| 38 | |
| 39 | func EverythingFunc(runtime.Object) bool { |
| 40 | return true |
| 41 | } |
| 42 | |
| 43 | func NoTriggerFunc() []MatchValue { |
| 44 | return nil |
| 45 | } |
| 46 | |
| 47 | func NoTriggerPublisher(runtime.Object) []MatchValue { |
| 48 | return nil |
| 49 | } |
| 50 | |
| 51 | func NamespaceKeyFunc(prefix string, obj runtime.Object) (string, error) { |
| 52 | meta, err := meta.Accessor(obj) |
| 53 | if err != nil { |
| 54 | return "", err |
| 55 | } |
| 56 | name := meta.GetName() |
| 57 | if msgs := path.IsValidPathSegmentName(name); len(msgs) != 0 { |
| 58 | return "", fmt.Errorf("invalid name: %v", msgs) |
| 59 | } |
| 60 | return prefix + "/" + meta.GetNamespace() + "/" + name, nil |
| 61 | } |
| 62 | |
| 63 | func NoNamespaceKeyFunc(prefix string, obj runtime.Object) (string, error) { |
| 64 | meta, err := meta.Accessor(obj) |
| 65 | if err != nil { |
| 66 | return "", err |
| 67 | } |
| 68 | name := meta.GetName() |
| 69 | if msgs := path.IsValidPathSegmentName(name); len(msgs) != 0 { |
| 70 | return "", fmt.Errorf("invalid name: %v", msgs) |
| 71 | } |
| 72 | return prefix + "/" + name, nil |
| 73 | } |
| 74 | |
| 75 | // hasPathPrefix returns true if the string matches pathPrefix exactly, or if is prefixed with pathPrefix at a path segment boundary |
| 76 | func hasPathPrefix(s, pathPrefix string) bool { |
| 77 | // Short circuit if s doesn't contain the prefix at all |
| 78 | if !strings.HasPrefix(s, pathPrefix) { |
| 79 | return false |
| 80 | } |
| 81 | |
| 82 | pathPrefixLength := len(pathPrefix) |
| 83 | |
| 84 | if len(s) == pathPrefixLength { |
| 85 | // Exact match |
| 86 | return true |
| 87 | } |
| 88 | if strings.HasSuffix(pathPrefix, "/") { |
| 89 | // pathPrefix already ensured a path segment boundary |
| 90 | return true |
| 91 | } |
| 92 | if s[pathPrefixLength:pathPrefixLength+1] == "/" { |
| 93 | // The next character in s is a path segment boundary |
| 94 | // Check this instead of normalizing pathPrefix to avoid allocating on every call |
| 95 | return true |
| 96 | } |
| 97 | return false |
| 98 | } |
| 99 | |
| 100 | // HighWaterMark is a thread-safe object for tracking the maximum value seen |
| 101 | // for some quantity. |
| 102 | type HighWaterMark int64 |
| 103 | |
| 104 | // Update returns true if and only if 'current' is the highest value ever seen. |
| 105 | func (hwm *HighWaterMark) Update(current int64) bool { |
| 106 | for { |
| 107 | old := atomic.LoadInt64((*int64)(hwm)) |
| 108 | if current <= old { |
| 109 | return false |
| 110 | } |
| 111 | if atomic.CompareAndSwapInt64((*int64)(hwm), old, current) { |
| 112 | return true |
| 113 | } |
| 114 | } |
| 115 | } |