github.com/caseydavenport/controller-tools@v0.2.6-0.20200519183242-e8a18b1a6750/pkg/crd/schema_visitor.go (about) 1 /* 2 Copyright 2019 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 crd 18 19 import ( 20 apiext "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1" 21 ) 22 23 // SchemaVisitor walks the nodes of a schema. 24 type SchemaVisitor interface { 25 // Visit is called for each schema node. If it returns a visitor, 26 // the visitor will be called on each direct child node, and then 27 // this visitor will be called again with `nil` to indicate that 28 // all children have been visited. If a nil visitor is returned, 29 // children are not visited. 30 Visit(schema *apiext.JSONSchemaProps) SchemaVisitor 31 } 32 33 // EditSchema walks the given schema using the given visitor. Actual 34 // pointers to each schema node are passed to the visitor, so any changes 35 // made by the visitor will be reflected to the passed-in schema. 36 func EditSchema(schema *apiext.JSONSchemaProps, visitor SchemaVisitor) { 37 walker := schemaWalker{visitor: visitor} 38 walker.walkSchema(schema) 39 } 40 41 // schemaWalker knows how to walk the schema, saving modifications 42 // made by the given visitor. 43 type schemaWalker struct { 44 visitor SchemaVisitor 45 } 46 47 // walkSchema walks the given schema, saving modifications made by the 48 // visitor (this is as simple as passing a pointer in most cases, 49 // but special care needs to be taken to persist with maps). 50 func (w schemaWalker) walkSchema(schema *apiext.JSONSchemaProps) { 51 subVisitor := w.visitor.Visit(schema) 52 if subVisitor == nil { 53 return 54 } 55 defer subVisitor.Visit(nil) 56 57 subWalker := schemaWalker{visitor: subVisitor} 58 if schema.Items != nil { 59 subWalker.walkPtr(schema.Items.Schema) 60 subWalker.walkSlice(schema.Items.JSONSchemas) 61 } 62 subWalker.walkSlice(schema.AllOf) 63 subWalker.walkSlice(schema.OneOf) 64 subWalker.walkSlice(schema.AnyOf) 65 subWalker.walkPtr(schema.Not) 66 subWalker.walkMap(schema.Properties) 67 if schema.AdditionalProperties != nil { 68 subWalker.walkPtr(schema.AdditionalProperties.Schema) 69 } 70 subWalker.walkMap(schema.PatternProperties) 71 for name, dep := range schema.Dependencies { 72 subWalker.walkPtr(dep.Schema) 73 schema.Dependencies[name] = dep 74 } 75 if schema.AdditionalItems != nil { 76 subWalker.walkPtr(schema.AdditionalItems.Schema) 77 } 78 subWalker.walkMap(schema.Definitions) 79 } 80 81 // walkMap walks over values of the given map, saving changes to them. 82 func (w schemaWalker) walkMap(defs map[string]apiext.JSONSchemaProps) { 83 for name, def := range defs { 84 w.walkSchema(&def) 85 // make sure the edits actually go through since we can't 86 // take a reference to the value in the map 87 defs[name] = def 88 } 89 } 90 91 // walkSlice walks over items of the given slice. 92 func (w schemaWalker) walkSlice(defs []apiext.JSONSchemaProps) { 93 for i := range defs { 94 w.walkSchema(&defs[i]) 95 } 96 } 97 98 // walkPtr walks over the contents of the given pointer, if it's not nil. 99 func (w schemaWalker) walkPtr(def *apiext.JSONSchemaProps) { 100 if def == nil { 101 return 102 } 103 w.walkSchema(def) 104 }