| // Protocol Buffers for Go with Gadgets |
| // |
| // Copyright (c) 2013, The GoGo Authors. All rights reserved. |
| // http://github.com/gogo/protobuf |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| /* |
| The description (experimental) plugin generates a Description method for each message. |
| The Description method returns a populated google_protobuf.FileDescriptorSet struct. |
| This contains the description of the files used to generate this message. |
| |
| It is enabled by the following extensions: |
| |
| - description |
| - description_all |
| |
| The description plugin also generates a test given it is enabled using one of the following extensions: |
| |
| - testgen |
| - testgen_all |
| |
| Let us look at: |
| |
| github.com/gogo/protobuf/test/example/example.proto |
| |
| Btw all the output can be seen at: |
| |
| github.com/gogo/protobuf/test/example/* |
| |
| The following message: |
| |
| message B { |
| option (gogoproto.description) = true; |
| optional A A = 1 [(gogoproto.nullable) = false, (gogoproto.embed) = true]; |
| repeated bytes G = 2 [(gogoproto.customtype) = "github.com/gogo/protobuf/test/custom.Uint128", (gogoproto.nullable) = false]; |
| } |
| |
| given to the description plugin, will generate the following code: |
| |
| func (this *B) Description() (desc *google_protobuf.FileDescriptorSet) { |
| return ExampleDescription() |
| } |
| |
| and the following test code: |
| |
| func TestDescription(t *testing9.T) { |
| ExampleDescription() |
| } |
| |
| The hope is to use this struct in some way instead of reflect. |
| This package is subject to change, since a use has not been figured out yet. |
| |
| */ |
| package description |
| |
| import ( |
| "bytes" |
| "compress/gzip" |
| "fmt" |
| "github.com/gogo/protobuf/gogoproto" |
| "github.com/gogo/protobuf/proto" |
| descriptor "github.com/gogo/protobuf/protoc-gen-gogo/descriptor" |
| "github.com/gogo/protobuf/protoc-gen-gogo/generator" |
| ) |
| |
| type plugin struct { |
| *generator.Generator |
| generator.PluginImports |
| } |
| |
| func NewPlugin() *plugin { |
| return &plugin{} |
| } |
| |
| func (p *plugin) Name() string { |
| return "description" |
| } |
| |
| func (p *plugin) Init(g *generator.Generator) { |
| p.Generator = g |
| } |
| |
| func (p *plugin) Generate(file *generator.FileDescriptor) { |
| used := false |
| localName := generator.FileName(file) |
| |
| p.PluginImports = generator.NewPluginImports(p.Generator) |
| descriptorPkg := p.NewImport("github.com/gogo/protobuf/protoc-gen-gogo/descriptor") |
| protoPkg := p.NewImport("github.com/gogo/protobuf/proto") |
| gzipPkg := p.NewImport("compress/gzip") |
| bytesPkg := p.NewImport("bytes") |
| ioutilPkg := p.NewImport("io/ioutil") |
| |
| for _, message := range file.Messages() { |
| if !gogoproto.HasDescription(file.FileDescriptorProto, message.DescriptorProto) { |
| continue |
| } |
| if message.DescriptorProto.GetOptions().GetMapEntry() { |
| continue |
| } |
| used = true |
| ccTypeName := generator.CamelCaseSlice(message.TypeName()) |
| p.P(`func (this *`, ccTypeName, `) Description() (desc *`, descriptorPkg.Use(), `.FileDescriptorSet) {`) |
| p.In() |
| p.P(`return `, localName, `Description()`) |
| p.Out() |
| p.P(`}`) |
| } |
| |
| if used { |
| |
| p.P(`func `, localName, `Description() (desc *`, descriptorPkg.Use(), `.FileDescriptorSet) {`) |
| p.In() |
| //Don't generate SourceCodeInfo, since it will create too much code. |
| |
| ss := make([]*descriptor.SourceCodeInfo, 0) |
| for _, f := range p.Generator.AllFiles().GetFile() { |
| ss = append(ss, f.SourceCodeInfo) |
| f.SourceCodeInfo = nil |
| } |
| b, err := proto.Marshal(p.Generator.AllFiles()) |
| if err != nil { |
| panic(err) |
| } |
| for i, f := range p.Generator.AllFiles().GetFile() { |
| f.SourceCodeInfo = ss[i] |
| } |
| p.P(`d := &`, descriptorPkg.Use(), `.FileDescriptorSet{}`) |
| var buf bytes.Buffer |
| w, _ := gzip.NewWriterLevel(&buf, gzip.BestCompression) |
| w.Write(b) |
| w.Close() |
| b = buf.Bytes() |
| p.P("var gzipped = []byte{") |
| p.In() |
| p.P("// ", len(b), " bytes of a gzipped FileDescriptorSet") |
| for len(b) > 0 { |
| n := 16 |
| if n > len(b) { |
| n = len(b) |
| } |
| |
| s := "" |
| for _, c := range b[:n] { |
| s += fmt.Sprintf("0x%02x,", c) |
| } |
| p.P(s) |
| |
| b = b[n:] |
| } |
| p.Out() |
| p.P("}") |
| p.P(`r := `, bytesPkg.Use(), `.NewReader(gzipped)`) |
| p.P(`gzipr, err := `, gzipPkg.Use(), `.NewReader(r)`) |
| p.P(`if err != nil {`) |
| p.In() |
| p.P(`panic(err)`) |
| p.Out() |
| p.P(`}`) |
| p.P(`ungzipped, err := `, ioutilPkg.Use(), `.ReadAll(gzipr)`) |
| p.P(`if err != nil {`) |
| p.In() |
| p.P(`panic(err)`) |
| p.Out() |
| p.P(`}`) |
| p.P(`if err := `, protoPkg.Use(), `.Unmarshal(ungzipped, d); err != nil {`) |
| p.In() |
| p.P(`panic(err)`) |
| p.Out() |
| p.P(`}`) |
| p.P(`return d`) |
| p.Out() |
| p.P(`}`) |
| } |
| } |
| |
| func init() { |
| generator.RegisterPlugin(NewPlugin()) |
| } |