generator

Documentation

Overview

The code generator for the plugin for the Google protocol buffer compiler. It generates Go code from the protocol buffer description files read by the main routine.

Index

• func CamelCase(s string) string
• func CamelCaseSlice(elem []string) string
• func RegisterPlugin(p Plugin)
• func RegisterUniquePackageName(pkg string, f *FileDescriptor) string
• type Descriptor
  • func (c *Descriptor) File() *descriptor.FileDescriptorProto
  • func (c *Descriptor) PackageName() string
  • func (d *Descriptor) TypeName() []string
• type EnumDescriptor
  • func (c *EnumDescriptor) File() *descriptor.FileDescriptorProto
  • func (c *EnumDescriptor) PackageName() string
  • func (e *EnumDescriptor) TypeName() (s []string)
• type ExtensionDescriptor
  • func (e *ExtensionDescriptor) DescName() string
  • func (c *ExtensionDescriptor) File() *descriptor.FileDescriptorProto
  • func (c *ExtensionDescriptor) PackageName() string
  • func (e *ExtensionDescriptor) TypeName() (s []string)
• type FileDescriptor
  • func (d *FileDescriptor) PackageName() string
• type Generator
  • func New() *Generator
  • func (g *Generator) BuildTypeNameMap()
  • func (g *Generator) CommandLineParameters(parameter string)
  • func (g *Generator) DefaultPackageName(obj Object) string
  • func (g *Generator) Error(err error, msgs ...string)
  • func (g *Generator) Fail(msgs ...string)
  • func (g *Generator) FileOf(fd *descriptor.FileDescriptorProto) *FileDescriptor
  • func (g *Generator) GenerateAllFiles()
  • func (g *Generator) GoType(message *Descriptor, field *descriptor.FieldDescriptorProto) (typ string, wire string)
  • func (g *Generator) In()
  • func (g *Generator) ObjectNamed(typeName string) Object
  • func (g *Generator) Out()
  • func (g *Generator) P(str ...interface{})
  • func (g *Generator) PrintComments(path string) bool
  • func (g *Generator) RecordTypeUse(t string)
  • func (g *Generator) SetPackageNames()
  • func (g *Generator) TypeName(obj Object) string
  • func (g *Generator) TypeNameWithPackage(obj Object) string
  • func (g *Generator) WrapTypes()
• type ImportedDescriptor
  • func (c *ImportedDescriptor) File() *descriptor.FileDescriptorProto
  • func (c *ImportedDescriptor) PackageName() string
  • func (id *ImportedDescriptor) TypeName() []string
• type Object
• type Plugin

Functions

func CamelCase

func CamelCase(s string) string

CamelCase returns the CamelCased name. If there is an interior underscore followed by a lower case letter, drop the underscore and convert the letter to upper case. There is a remote possibility of this rewrite causing a name collision, but it's so remote we're prepared to pretend it's nonexistent - since the C++ generator lowercases names, it's extremely unlikely to have two fields with different capitalizations. In short, _my_field_name_2 becomes XMyFieldName_2.

func CamelCaseSlice

func CamelCaseSlice(elem []string) string

CamelCaseSlice is like CamelCase, but the argument is a slice of strings to be joined with "_".

func RegisterPlugin

func RegisterPlugin(p Plugin)

RegisterPlugin installs a (second-order) plugin to be run when the Go output is generated. It is typically called during initialization.

func RegisterUniquePackageName

func RegisterUniquePackageName(pkg string, f *FileDescriptor) string

Create and remember a guaranteed unique package name for this file descriptor. Pkg is the candidate name. If f is nil, it's a builtin package like "proto" and has no file descriptor.

Types

type Descriptor

type Descriptor struct {
	*descriptor.DescriptorProto
	// contains filtered or unexported fields
}

Descriptor represents a protocol buffer message.

func (*Descriptor) File

func (c *Descriptor) File() *descriptor.FileDescriptorProto

func (*Descriptor) PackageName

func (c *Descriptor) PackageName() string

PackageName is name in the package clause in the generated file.

func (*Descriptor) TypeName

func (d *Descriptor) TypeName() []string

TypeName returns the elements of the dotted type name. The package name is not part of this name.

type EnumDescriptor

type EnumDescriptor struct {
	*descriptor.EnumDescriptorProto
	// contains filtered or unexported fields
}

EnumDescriptor describes an enum. If it's at top level, its parent will be nil. Otherwise it will be the descriptor of the message in which it is defined.

func (*EnumDescriptor) File

func (c *EnumDescriptor) File() *descriptor.FileDescriptorProto

func (*EnumDescriptor) PackageName

func (c *EnumDescriptor) PackageName() string

PackageName is name in the package clause in the generated file.

func (*EnumDescriptor) TypeName

func (e *EnumDescriptor) TypeName() (s []string)

TypeName returns the elements of the dotted type name. The package name is not part of this name.

type ExtensionDescriptor

type ExtensionDescriptor struct {
	*descriptor.FieldDescriptorProto
	// contains filtered or unexported fields
}

ExtensionDescriptor describes an extension. If it's at top level, its parent will be nil. Otherwise it will be the descriptor of the message in which it is defined.

func (*ExtensionDescriptor) DescName

func (e *ExtensionDescriptor) DescName() string

DescName returns the variable name used for the generated descriptor.

func (*ExtensionDescriptor) File

func (c *ExtensionDescriptor) File() *descriptor.FileDescriptorProto

func (*ExtensionDescriptor) PackageName

func (c *ExtensionDescriptor) PackageName() string

PackageName is name in the package clause in the generated file.

func (*ExtensionDescriptor) TypeName

func (e *ExtensionDescriptor) TypeName() (s []string)

TypeName returns the elements of the dotted type name. The package name is not part of this name.

type FileDescriptor

type FileDescriptor struct {
	*descriptor.FileDescriptorProto
	// contains filtered or unexported fields
}

FileDescriptor describes an protocol buffer descriptor file (.proto). It includes slices of all the messages and enums defined within it. Those slices are constructed by WrapTypes.

func (*FileDescriptor) PackageName

func (d *FileDescriptor) PackageName() string

PackageName is the package name we'll use in the generated code to refer to this file.

type Generator

type Generator struct {
	*bytes.Buffer

	Request  *plugin.CodeGeneratorRequest  // The input.
	Response *plugin.CodeGeneratorResponse // The output.

	Param             map[string]string // Command-line parameters.
	PackageImportPath string            // Go import path of the package we're generating code for
	ImportPrefix      string            // String to prefix to imported package file names.
	ImportMap         map[string]string // Mapping from import name to generated name

	Pkg map[string]string // The names under which we import support packages
	// contains filtered or unexported fields
}

Generator is the type whose methods generate the output, stored in the associated response structure.

func New

func New() *Generator

New creates a new generator and allocates the request and response protobufs.

func (*Generator) BuildTypeNameMap

func (g *Generator) BuildTypeNameMap()

BuildTypeNameMap builds the map from fully qualified type names to objects. The key names for the map come from the input data, which puts a period at the beginning. It should be called after SetPackageNames and before GenerateAllFiles.

func (*Generator) CommandLineParameters

func (g *Generator) CommandLineParameters(parameter string)

CommandLineParameters breaks the comma-separated list of key=value pairs in the parameter (a member of the request protobuf) into a key/value map. It then sets file name mappings defined by those entries.

func (*Generator) DefaultPackageName

func (g *Generator) DefaultPackageName(obj Object) string

DefaultPackageName returns the package name printed for the object. If its file is in a different package, it returns the package name we're using for this file, plus ".". Otherwise it returns the empty string.

func (*Generator) Error

func (g *Generator) Error(err error, msgs ...string)

Error reports a problem, including an error, and exits the program.

func (*Generator) Fail

func (g *Generator) Fail(msgs ...string)

Fail reports a problem and exits the program.

func (*Generator) FileOf

func (g *Generator) FileOf(fd *descriptor.FileDescriptorProto) *FileDescriptor

FileOf return the FileDescriptor for this FileDescriptorProto.

func (*Generator) GenerateAllFiles

func (g *Generator) GenerateAllFiles()

GenerateAllFiles generates the output for all the files we're outputting.

func (*Generator) GoType

func (g *Generator) GoType(message *Descriptor, field *descriptor.FieldDescriptorProto) (typ string, wire string)

GoType returns a string representing the type name, and the wire type

func (*Generator) In

func (g *Generator) In()

In Indents the output one tab stop.

func (*Generator) ObjectNamed

func (g *Generator) ObjectNamed(typeName string) Object

ObjectNamed, given a fully-qualified input type name as it appears in the input data, returns the descriptor for the message or enum with that name.

func (*Generator) Out

func (g *Generator) Out()

Out unindents the output one tab stop.

func (*Generator) P

func (g *Generator) P(str ...interface{})

P prints the arguments to the generated output. It handles strings and int32s, plus handling indirections because they may be *string, etc.

func (*Generator) PrintComments

func (g *Generator) PrintComments(path string) bool

PrintComments prints any comments from the source .proto file. The path is a comma-separated list of integers. It returns an indication of whether any comments were printed. See descriptor.proto for its format.

func (*Generator) RecordTypeUse

func (g *Generator) RecordTypeUse(t string)

func (*Generator) SetPackageNames

func (g *Generator) SetPackageNames()

SetPackageNames sets the package name for this run. The package name must agree across all files being generated. It also defines unique package names for all imported files.

func (*Generator) TypeName

func (g *Generator) TypeName(obj Object) string

TypeName is the printed name appropriate for an item. If the object is in the current file, TypeName drops the package name and underscores the rest. Otherwise the object is from another package; and the result is the underscored package name followed by the item name. The result always has an initial capital.

func (*Generator) TypeNameWithPackage

func (g *Generator) TypeNameWithPackage(obj Object) string

TypeNameWithPackage is like TypeName, but always includes the package name even if the object is in our own package.

func (*Generator) WrapTypes

func (g *Generator) WrapTypes()

WrapTypes walks the incoming data, wrapping DescriptorProtos, EnumDescriptorProtos and FileDescriptorProtos into file-referenced objects within the Generator. It also creates the list of files to generate and so should be called before GenerateAllFiles.

type ImportedDescriptor

type ImportedDescriptor struct {
	// contains filtered or unexported fields
}

ImportedDescriptor describes a type that has been publicly imported from another file.

func (*ImportedDescriptor) File

func (c *ImportedDescriptor) File() *descriptor.FileDescriptorProto

func (*ImportedDescriptor) PackageName

func (c *ImportedDescriptor) PackageName() string

PackageName is name in the package clause in the generated file.

func (*ImportedDescriptor) TypeName

func (id *ImportedDescriptor) TypeName() []string

type Object

type Object interface {
	PackageName() string // The name we use in our output (a_b_c), possibly renamed for uniqueness.
	TypeName() []string
	File() *descriptor.FileDescriptorProto
}

Object is an interface abstracting the abilities shared by enums, messages, extensions and imported objects.

type Plugin

type Plugin interface {
	// Name identifies the plugin.
	Name() string
	// Init is called once after data structures are built but before
	// code generation begins.
	Init(g *Generator)
	// Generate produces the code generated by the plugin for this file,
	// except for the imports, by calling the generator's methods P, In, and Out.
	Generate(file *FileDescriptor)
	// GenerateImports produces the import declarations for this file.
	// It is called after Generate.
	GenerateImports(file *FileDescriptor)
}

A Plugin provides functionality to add to the output during Go code generation, such as to produce RPC stubs.