go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/grpc/cmd/svcmux/template.go (about)

     1  // Copyright 2016 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package main
    16  
    17  import (
    18  	"text/template"
    19  
    20  	"go.chromium.org/luci/grpc/internal/svctool"
    21  )
    22  
    23  var (
    24  	tmpl = template.Must(template.New("").Parse(
    25  		`// Code generated by svcmux; DO NOT EDIT
    26  
    27  package {{.PackageName}}
    28  
    29  import (
    30  	"context"
    31  
    32  	svcmux "go.chromium.org/luci/server/svcmux"
    33  
    34  	{{range .ExtraImports}}
    35  	{{.Name}} "{{.Path}}"{{end}}
    36  )
    37  
    38  {{range .Services}}
    39  {{$StructName := .StructName}}
    40  type {{$StructName}} struct {
    41  	// Default is the version used if {{$.VersionMetadataKey}} metadata
    42  	// is not present.
    43  	Default string
    44  	// Impls maps versions to service implementations.
    45  	Impls map[string]{{.Service.TypeName}}
    46  }
    47  
    48  {{range .Methods}}
    49  func (s *{{$StructName}}) {{.Name}}(c context.Context, req {{.InputType}}) ({{.OutputType}}, error) {
    50  	ver := svcmux.ServiceVersion(c, s.Default)
    51  	impl := s.Impls[ver]
    52  	if impl == nil {
    53  		return nil, svcmux.NoImplementation(ver)
    54  	}
    55  	return impl.{{.Name}}(c, req)
    56  }
    57  {{end}}
    58  {{end}}
    59  `))
    60  )
    61  
    62  type (
    63  	templateArgs struct {
    64  		PackageName        string
    65  		Services           []*service
    66  		VersionMetadataKey string
    67  		ExtraImports       []svctool.Import
    68  	}
    69  
    70  	service struct {
    71  		*svctool.Service
    72  		StructName string
    73  	}
    74  )