Matteo Scandolo | a6a3aee | 2019-11-26 13:30:14 -0700 | [diff] [blame] | 1 | package descriptor |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "strings" |
| 6 | |
| 7 | "github.com/golang/glog" |
| 8 | "github.com/golang/protobuf/proto" |
| 9 | descriptor "github.com/golang/protobuf/protoc-gen-go/descriptor" |
| 10 | "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/httprule" |
| 11 | options "google.golang.org/genproto/googleapis/api/annotations" |
| 12 | ) |
| 13 | |
| 14 | // loadServices registers services and their methods from "targetFile" to "r". |
| 15 | // It must be called after loadFile is called for all files so that loadServices |
| 16 | // can resolve names of message types and their fields. |
| 17 | func (r *Registry) loadServices(file *File) error { |
| 18 | glog.V(1).Infof("Loading services from %s", file.GetName()) |
| 19 | var svcs []*Service |
| 20 | for _, sd := range file.GetService() { |
| 21 | glog.V(2).Infof("Registering %s", sd.GetName()) |
| 22 | svc := &Service{ |
| 23 | File: file, |
| 24 | ServiceDescriptorProto: sd, |
| 25 | } |
| 26 | for _, md := range sd.GetMethod() { |
| 27 | glog.V(2).Infof("Processing %s.%s", sd.GetName(), md.GetName()) |
| 28 | opts, err := extractAPIOptions(md) |
| 29 | if err != nil { |
| 30 | glog.Errorf("Failed to extract HttpRule from %s.%s: %v", svc.GetName(), md.GetName(), err) |
| 31 | return err |
| 32 | } |
| 33 | optsList := r.LookupExternalHTTPRules((&Method{Service: svc, MethodDescriptorProto: md}).FQMN()) |
| 34 | if opts != nil { |
| 35 | optsList = append(optsList, opts) |
| 36 | } |
| 37 | if len(optsList) == 0 { |
| 38 | glog.V(1).Infof("Found non-target method: %s.%s", svc.GetName(), md.GetName()) |
| 39 | } |
| 40 | meth, err := r.newMethod(svc, md, optsList) |
| 41 | if err != nil { |
| 42 | return err |
| 43 | } |
| 44 | svc.Methods = append(svc.Methods, meth) |
| 45 | } |
| 46 | if len(svc.Methods) == 0 { |
| 47 | continue |
| 48 | } |
| 49 | glog.V(2).Infof("Registered %s with %d method(s)", svc.GetName(), len(svc.Methods)) |
| 50 | svcs = append(svcs, svc) |
| 51 | } |
| 52 | file.Services = svcs |
| 53 | return nil |
| 54 | } |
| 55 | |
| 56 | func (r *Registry) newMethod(svc *Service, md *descriptor.MethodDescriptorProto, optsList []*options.HttpRule) (*Method, error) { |
| 57 | requestType, err := r.LookupMsg(svc.File.GetPackage(), md.GetInputType()) |
| 58 | if err != nil { |
| 59 | return nil, err |
| 60 | } |
| 61 | responseType, err := r.LookupMsg(svc.File.GetPackage(), md.GetOutputType()) |
| 62 | if err != nil { |
| 63 | return nil, err |
| 64 | } |
| 65 | meth := &Method{ |
| 66 | Service: svc, |
| 67 | MethodDescriptorProto: md, |
| 68 | RequestType: requestType, |
| 69 | ResponseType: responseType, |
| 70 | } |
| 71 | |
| 72 | newBinding := func(opts *options.HttpRule, idx int) (*Binding, error) { |
| 73 | var ( |
| 74 | httpMethod string |
| 75 | pathTemplate string |
| 76 | ) |
| 77 | switch { |
| 78 | case opts.GetGet() != "": |
| 79 | httpMethod = "GET" |
| 80 | pathTemplate = opts.GetGet() |
| 81 | if opts.Body != "" { |
| 82 | return nil, fmt.Errorf("must not set request body when http method is GET: %s", md.GetName()) |
| 83 | } |
| 84 | |
| 85 | case opts.GetPut() != "": |
| 86 | httpMethod = "PUT" |
| 87 | pathTemplate = opts.GetPut() |
| 88 | |
| 89 | case opts.GetPost() != "": |
| 90 | httpMethod = "POST" |
| 91 | pathTemplate = opts.GetPost() |
| 92 | |
| 93 | case opts.GetDelete() != "": |
| 94 | httpMethod = "DELETE" |
| 95 | pathTemplate = opts.GetDelete() |
| 96 | if opts.Body != "" && !r.allowDeleteBody { |
| 97 | return nil, fmt.Errorf("must not set request body when http method is DELETE except allow_delete_body option is true: %s", md.GetName()) |
| 98 | } |
| 99 | |
| 100 | case opts.GetPatch() != "": |
| 101 | httpMethod = "PATCH" |
| 102 | pathTemplate = opts.GetPatch() |
| 103 | |
| 104 | case opts.GetCustom() != nil: |
| 105 | custom := opts.GetCustom() |
| 106 | httpMethod = custom.Kind |
| 107 | pathTemplate = custom.Path |
| 108 | |
| 109 | default: |
| 110 | glog.V(1).Infof("No pattern specified in google.api.HttpRule: %s", md.GetName()) |
| 111 | return nil, nil |
| 112 | } |
| 113 | |
| 114 | parsed, err := httprule.Parse(pathTemplate) |
| 115 | if err != nil { |
| 116 | return nil, err |
| 117 | } |
| 118 | tmpl := parsed.Compile() |
| 119 | |
| 120 | if md.GetClientStreaming() && len(tmpl.Fields) > 0 { |
| 121 | return nil, fmt.Errorf("cannot use path parameter in client streaming") |
| 122 | } |
| 123 | |
| 124 | b := &Binding{ |
| 125 | Method: meth, |
| 126 | Index: idx, |
| 127 | PathTmpl: tmpl, |
| 128 | HTTPMethod: httpMethod, |
| 129 | } |
| 130 | |
| 131 | for _, f := range tmpl.Fields { |
| 132 | param, err := r.newParam(meth, f) |
| 133 | if err != nil { |
| 134 | return nil, err |
| 135 | } |
| 136 | b.PathParams = append(b.PathParams, param) |
| 137 | } |
| 138 | |
| 139 | // TODO(yugui) Handle query params |
| 140 | |
| 141 | b.Body, err = r.newBody(meth, opts.Body) |
| 142 | if err != nil { |
| 143 | return nil, err |
| 144 | } |
| 145 | |
| 146 | b.ResponseBody, err = r.newResponse(meth, opts.ResponseBody) |
| 147 | if err != nil { |
| 148 | return nil, err |
| 149 | } |
| 150 | |
| 151 | return b, nil |
| 152 | } |
| 153 | |
| 154 | applyOpts := func(opts *options.HttpRule) error { |
| 155 | b, err := newBinding(opts, len(meth.Bindings)) |
| 156 | if err != nil { |
| 157 | return err |
| 158 | } |
| 159 | |
| 160 | if b != nil { |
| 161 | meth.Bindings = append(meth.Bindings, b) |
| 162 | } |
| 163 | for _, additional := range opts.GetAdditionalBindings() { |
| 164 | if len(additional.AdditionalBindings) > 0 { |
| 165 | return fmt.Errorf("additional_binding in additional_binding not allowed: %s.%s", svc.GetName(), meth.GetName()) |
| 166 | } |
| 167 | b, err := newBinding(additional, len(meth.Bindings)) |
| 168 | if err != nil { |
| 169 | return err |
| 170 | } |
| 171 | meth.Bindings = append(meth.Bindings, b) |
| 172 | } |
| 173 | |
| 174 | return nil |
| 175 | } |
| 176 | |
| 177 | for _, opts := range optsList { |
| 178 | if err := applyOpts(opts); err != nil { |
| 179 | return nil, err |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | return meth, nil |
| 184 | } |
| 185 | |
| 186 | func extractAPIOptions(meth *descriptor.MethodDescriptorProto) (*options.HttpRule, error) { |
| 187 | if meth.Options == nil { |
| 188 | return nil, nil |
| 189 | } |
| 190 | if !proto.HasExtension(meth.Options, options.E_Http) { |
| 191 | return nil, nil |
| 192 | } |
| 193 | ext, err := proto.GetExtension(meth.Options, options.E_Http) |
| 194 | if err != nil { |
| 195 | return nil, err |
| 196 | } |
| 197 | opts, ok := ext.(*options.HttpRule) |
| 198 | if !ok { |
| 199 | return nil, fmt.Errorf("extension is %T; want an HttpRule", ext) |
| 200 | } |
| 201 | return opts, nil |
| 202 | } |
| 203 | |
| 204 | func (r *Registry) newParam(meth *Method, path string) (Parameter, error) { |
| 205 | msg := meth.RequestType |
| 206 | fields, err := r.resolveFieldPath(msg, path, true) |
| 207 | if err != nil { |
| 208 | return Parameter{}, err |
| 209 | } |
| 210 | l := len(fields) |
| 211 | if l == 0 { |
| 212 | return Parameter{}, fmt.Errorf("invalid field access list for %s", path) |
| 213 | } |
| 214 | target := fields[l-1].Target |
| 215 | switch target.GetType() { |
| 216 | case descriptor.FieldDescriptorProto_TYPE_MESSAGE, descriptor.FieldDescriptorProto_TYPE_GROUP: |
| 217 | glog.V(2).Infoln("found aggregate type:", target, target.TypeName) |
| 218 | if IsWellKnownType(*target.TypeName) { |
| 219 | glog.V(2).Infoln("found well known aggregate type:", target) |
| 220 | } else { |
| 221 | return Parameter{}, fmt.Errorf("aggregate type %s in parameter of %s.%s: %s", target.Type, meth.Service.GetName(), meth.GetName(), path) |
| 222 | } |
| 223 | } |
| 224 | return Parameter{ |
| 225 | FieldPath: FieldPath(fields), |
| 226 | Method: meth, |
| 227 | Target: fields[l-1].Target, |
| 228 | }, nil |
| 229 | } |
| 230 | |
| 231 | func (r *Registry) newBody(meth *Method, path string) (*Body, error) { |
| 232 | msg := meth.RequestType |
| 233 | switch path { |
| 234 | case "": |
| 235 | return nil, nil |
| 236 | case "*": |
| 237 | return &Body{FieldPath: nil}, nil |
| 238 | } |
| 239 | fields, err := r.resolveFieldPath(msg, path, false) |
| 240 | if err != nil { |
| 241 | return nil, err |
| 242 | } |
| 243 | return &Body{FieldPath: FieldPath(fields)}, nil |
| 244 | } |
| 245 | |
| 246 | func (r *Registry) newResponse(meth *Method, path string) (*Body, error) { |
| 247 | msg := meth.ResponseType |
| 248 | switch path { |
| 249 | case "", "*": |
| 250 | return nil, nil |
| 251 | } |
| 252 | fields, err := r.resolveFieldPath(msg, path, false) |
| 253 | if err != nil { |
| 254 | return nil, err |
| 255 | } |
| 256 | return &Body{FieldPath: FieldPath(fields)}, nil |
| 257 | } |
| 258 | |
| 259 | // lookupField looks up a field named "name" within "msg". |
| 260 | // It returns nil if no such field found. |
| 261 | func lookupField(msg *Message, name string) *Field { |
| 262 | for _, f := range msg.Fields { |
| 263 | if f.GetName() == name { |
| 264 | return f |
| 265 | } |
| 266 | } |
| 267 | return nil |
| 268 | } |
| 269 | |
| 270 | // resolveFieldPath resolves "path" into a list of fieldDescriptor, starting from "msg". |
| 271 | func (r *Registry) resolveFieldPath(msg *Message, path string, isPathParam bool) ([]FieldPathComponent, error) { |
| 272 | if path == "" { |
| 273 | return nil, nil |
| 274 | } |
| 275 | |
| 276 | root := msg |
| 277 | var result []FieldPathComponent |
| 278 | for i, c := range strings.Split(path, ".") { |
| 279 | if i > 0 { |
| 280 | f := result[i-1].Target |
| 281 | switch f.GetType() { |
| 282 | case descriptor.FieldDescriptorProto_TYPE_MESSAGE, descriptor.FieldDescriptorProto_TYPE_GROUP: |
| 283 | var err error |
| 284 | msg, err = r.LookupMsg(msg.FQMN(), f.GetTypeName()) |
| 285 | if err != nil { |
| 286 | return nil, err |
| 287 | } |
| 288 | default: |
| 289 | return nil, fmt.Errorf("not an aggregate type: %s in %s", f.GetName(), path) |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | glog.V(2).Infof("Lookup %s in %s", c, msg.FQMN()) |
| 294 | f := lookupField(msg, c) |
| 295 | if f == nil { |
| 296 | return nil, fmt.Errorf("no field %q found in %s", path, root.GetName()) |
| 297 | } |
| 298 | if !(isPathParam || r.allowRepeatedFieldsInBody) && f.GetLabel() == descriptor.FieldDescriptorProto_LABEL_REPEATED { |
| 299 | return nil, fmt.Errorf("repeated field not allowed in field path: %s in %s", f.GetName(), path) |
| 300 | } |
| 301 | result = append(result, FieldPathComponent{Name: c, Target: f}) |
| 302 | } |
| 303 | return result, nil |
| 304 | } |