| /* |
| Copyright 2017 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 apply |
| |
| // Strategy implements a strategy for merging recorded, local and remote values contained |
| // in an element and returns the merged result. |
| // Follows the visitor pattern |
| type Strategy interface { |
| // MergeList is invoked by ListElements when Merge is called |
| MergeList(ListElement) (Result, error) |
| |
| // MergeMap is invoked by MapElements when Merge is called |
| MergeMap(MapElement) (Result, error) |
| |
| // MergeType is invoked by TypeElements when Merge is called |
| MergeType(TypeElement) (Result, error) |
| |
| // MergePrimitive is invoked by PrimitiveElements when Merge is called |
| MergePrimitive(PrimitiveElement) (Result, error) |
| |
| // MergeEmpty is invoked by EmptyElements when Merge is called |
| MergeEmpty(EmptyElement) (Result, error) |
| } |
| |
| // Operation records whether a field should be set or dropped |
| type Operation int |
| |
| const ( |
| // ERROR is an error during merge |
| ERROR Operation = iota |
| // SET sets the field on an object |
| SET |
| // DROP drops the field from an object |
| DROP |
| ) |
| |
| // Result is the result of merging fields |
| type Result struct { |
| // Operation is the operation that should be performed for the merged field |
| Operation Operation |
| // MergedResult is the new merged value |
| MergedResult interface{} |
| } |
| |
| const ( |
| // MergeStrategy is the strategy to merge the local and remote values |
| MergeStrategy = "merge" |
| |
| // RetainKeysStrategy is the strategy to merge the local and remote values, but drop any fields not defined locally |
| RetainKeysStrategy = "retainKeys" |
| |
| // ReplaceStrategy is the strategy to replace the remote value with the local value |
| ReplaceStrategy = "replace" |
| ) |