|
| 1 | +package generator |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "errors" |
| 6 | + "fmt" |
| 7 | + "io/ioutil" |
| 8 | + "os" |
| 9 | + "path/filepath" |
| 10 | + "text/template" |
| 11 | + |
| 12 | + "k8s.io/gengo/types" |
| 13 | + "k8s.io/klog/v2" |
| 14 | +) |
| 15 | + |
| 16 | +const ( |
| 17 | + generatedTextWarning = "<!--- THIS FILE IS AUTOGENERATED!!! DO NOT EDIT!!! -->\n" |
| 18 | +) |
| 19 | + |
| 20 | +type Generator interface { |
| 21 | + Run() error |
| 22 | +} |
| 23 | + |
| 24 | +func NewGenerator(packageName string, requestedTypesList []string, headerTextFile string, outputFileName string, templateDirectory string) (Generator, error) { |
| 25 | + if packageName == "" { |
| 26 | + return nil, errors.New("a package name must be specified") |
| 27 | + } |
| 28 | + |
| 29 | + headerText, err := loadHeaderText(headerTextFile) |
| 30 | + if err != nil { |
| 31 | + return nil, fmt.Errorf("error loading header text: %v", err) |
| 32 | + } |
| 33 | + |
| 34 | + if err := checkTemplateDir(templateDirectory); err != nil { |
| 35 | + return nil, fmt.Errorf("invalid template directory: %v", err) |
| 36 | + } |
| 37 | + |
| 38 | + return &generator{ |
| 39 | + packageName: packageName, |
| 40 | + requestedTypes: newStringSet(requestedTypesList), |
| 41 | + headerText: headerText, |
| 42 | + outputFileName: outputFileName, |
| 43 | + templateDirectory: templateDirectory, |
| 44 | + }, nil |
| 45 | +} |
| 46 | + |
| 47 | +// checkTemplateDir checks whether the template directory given exists and can be read |
| 48 | +func checkTemplateDir(dir string) error { |
| 49 | + if dir == "" { |
| 50 | + return nil |
| 51 | + } |
| 52 | + path, err := filepath.Abs(dir) |
| 53 | + if err != nil { |
| 54 | + return err |
| 55 | + } |
| 56 | + |
| 57 | + if fi, err := os.Stat(path); err != nil { |
| 58 | + return fmt.Errorf("cannot read directory %q: %v", path, err) |
| 59 | + } else if !fi.IsDir() { |
| 60 | + return fmt.Errorf("path %q is not a directory", path) |
| 61 | + } |
| 62 | + return nil |
| 63 | +} |
| 64 | + |
| 65 | +// loadHeaderText loads the header text from the file if a filename was given |
| 66 | +func loadHeaderText(fileName string) ([]byte, error) { |
| 67 | + if fileName == "" { |
| 68 | + return []byte{}, nil |
| 69 | + } |
| 70 | + |
| 71 | + headerText, err := ioutil.ReadFile(fileName) |
| 72 | + if err != nil { |
| 73 | + return nil, fmt.Errorf("error reading file: %v", err) |
| 74 | + } |
| 75 | + return headerText, nil |
| 76 | +} |
| 77 | + |
| 78 | +type generator struct { |
| 79 | + packageName string |
| 80 | + requestedTypes stringSet |
| 81 | + headerText []byte |
| 82 | + outputFileName string |
| 83 | + templateDirectory string |
| 84 | +} |
| 85 | + |
| 86 | +// Run runs the generation logic for the generator |
| 87 | +func (g *generator) Run() error { |
| 88 | + typesToRender, err := g.loadTypesAndReferences() |
| 89 | + if err != nil { |
| 90 | + return fmt.Errorf("unable to load types: %v", err) |
| 91 | + } |
| 92 | + |
| 93 | + for typ := range typesToRender { |
| 94 | + klog.Infof("Rendering reference for type: %s", typ.Name.Name) |
| 95 | + } |
| 96 | + |
| 97 | + if err := g.renderOutput(typesToRender); err != nil { |
| 98 | + return fmt.Errorf("error rendering output: %v", err) |
| 99 | + } |
| 100 | + |
| 101 | + return nil |
| 102 | +} |
| 103 | + |
| 104 | +// loadTypes loads the package in the generator and returns a map |
| 105 | +// of types and the types that reference them. |
| 106 | +func (g *generator) loadTypesAndReferences() (map[*types.Type][]*types.Type, error) { |
| 107 | + pkg, err := loadPackage(g.packageName) |
| 108 | + if err != nil { |
| 109 | + return nil, fmt.Errorf("could not load package: %v", err) |
| 110 | + } |
| 111 | + |
| 112 | + typeReferences := findTypeReferences(pkg.Types) |
| 113 | + pkgTypeSet := newTypeSetFromStringMap(pkg.Types) |
| 114 | + |
| 115 | + if !g.requestedTypes.isEmpty() { |
| 116 | + typeReferences = filterToRequestedTypes(typeReferences, g.requestedTypes) |
| 117 | + } |
| 118 | + |
| 119 | + return filterToPackageTypes(typeReferences, pkgTypeSet), nil |
| 120 | +} |
| 121 | + |
| 122 | +func (g *generator) renderOutput(typesToRender map[*types.Type][]*types.Type) error { |
| 123 | + typeList := createTypeList(typesToRender) |
| 124 | + |
| 125 | + t, err := g.buildTemplate(typesToRender, typeList) |
| 126 | + if err != nil { |
| 127 | + return fmt.Errorf("error building template: %v", err) |
| 128 | + } |
| 129 | + |
| 130 | + // Create a buffer and render everything into that before writing out |
| 131 | + b := bytes.NewBuffer(append(g.headerText, []byte(generatedTextWarning)...)) |
| 132 | + if err := t.ExecuteTemplate(b, "package", map[string]interface{}{ |
| 133 | + "types": typeList, |
| 134 | + }); err != nil { |
| 135 | + return fmt.Errorf("error executing template: %v", err) |
| 136 | + } |
| 137 | + |
| 138 | + if err := g.writeOutput(b.Bytes()); err != nil { |
| 139 | + return fmt.Errorf("error writing output: %v", err) |
| 140 | + } |
| 141 | + return nil |
| 142 | +} |
| 143 | + |
| 144 | +func (g *generator) buildTemplate(typesToRender map[*types.Type][]*types.Type, typeList []*types.Type) (*template.Template, error) { |
| 145 | + knownTypes := newTypeSetFromList(typeList) |
| 146 | + t := template.New("").Funcs(map[string]interface{}{ |
| 147 | + "aliasDisplayName": aliasDisplayNameFunc(knownTypes), |
| 148 | + "backtick": backtick, |
| 149 | + "dereference": tryDereference, |
| 150 | + "fieldEmbedded": fieldEmbedded, |
| 151 | + "fieldName": fieldName, |
| 152 | + "isOptionalMember": isOptionalMember, |
| 153 | + "linkForType": linkForTypeFunc(knownTypes), |
| 154 | + "renderCommentsBR": renderCommentsBR, |
| 155 | + "renderCommentsLF": renderCommentsLF, |
| 156 | + "sortedTypes": sortTypes, |
| 157 | + "typeDisplayName": typeDisplayNameFunc(knownTypes), |
| 158 | + "typeReferences": typeReferencesFunc(typesToRender, knownTypes), |
| 159 | + "visibleTypes": visibleTypes, |
| 160 | + }) |
| 161 | + |
| 162 | + var err error |
| 163 | + t, err = loadTemplatesInto(t, g.templateDirectory) |
| 164 | + if err != nil { |
| 165 | + return nil, fmt.Errorf("error loading templates: %v", err) |
| 166 | + } |
| 167 | + |
| 168 | + return t, nil |
| 169 | +} |
| 170 | + |
| 171 | +func (g *generator) writeOutput(content []byte) error { |
| 172 | + if g.outputFileName == "" { |
| 173 | + _, err := os.Stdout.Write(content) |
| 174 | + if err != nil { |
| 175 | + return fmt.Errorf("error writing output to stdout: %v", err) |
| 176 | + } |
| 177 | + klog.Infof("Rendered output written to stdout") |
| 178 | + return nil |
| 179 | + } |
| 180 | + |
| 181 | + if err := ioutil.WriteFile(g.outputFileName, content, 0600); err != nil { |
| 182 | + return fmt.Errorf("could not write file %q: %v", g.outputFileName, err) |
| 183 | + } |
| 184 | + klog.Infof("Rendered output written to %q", g.outputFileName) |
| 185 | + |
| 186 | + return nil |
| 187 | +} |
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