forked from gitea/gitea
478 lines
16 KiB
Go
478 lines
16 KiB
Go
// Copyright 2018 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Package protoreflect provides interfaces to dynamically manipulate messages.
|
|
//
|
|
// This package includes type descriptors which describe the structure of types
|
|
// defined in proto source files and value interfaces which provide the
|
|
// ability to examine and manipulate the contents of messages.
|
|
//
|
|
//
|
|
// Protocol Buffer Descriptors
|
|
//
|
|
// Protobuf descriptors (e.g., EnumDescriptor or MessageDescriptor)
|
|
// are immutable objects that represent protobuf type information.
|
|
// They are wrappers around the messages declared in descriptor.proto.
|
|
// Protobuf descriptors alone lack any information regarding Go types.
|
|
//
|
|
// Enums and messages generated by this module implement Enum and ProtoMessage,
|
|
// where the Descriptor and ProtoReflect.Descriptor accessors respectively
|
|
// return the protobuf descriptor for the values.
|
|
//
|
|
// The protobuf descriptor interfaces are not meant to be implemented by
|
|
// user code since they might need to be extended in the future to support
|
|
// additions to the protobuf language. Protobuf descriptors can be constructed
|
|
// using the "google.golang.org/protobuf/reflect/protodesc" package.
|
|
//
|
|
//
|
|
// Go Type Descriptors
|
|
//
|
|
// A type descriptor (e.g., EnumType or MessageType) is a constructor for
|
|
// a concrete Go type that represents the associated protobuf descriptor.
|
|
// There is commonly a one-to-one relationship between protobuf descriptors and
|
|
// Go type descriptors, but it can potentially be a one-to-many relationship.
|
|
//
|
|
// Enums and messages generated by this module implement Enum and ProtoMessage,
|
|
// where the Type and ProtoReflect.Type accessors respectively
|
|
// return the protobuf descriptor for the values.
|
|
//
|
|
// The "google.golang.org/protobuf/types/dynamicpb" package can be used to
|
|
// create Go type descriptors from protobuf descriptors.
|
|
//
|
|
//
|
|
// Value Interfaces
|
|
//
|
|
// The Enum and Message interfaces provide a reflective view over an
|
|
// enum or message instance. For enums, it provides the ability to retrieve
|
|
// the enum value number for any concrete enum type. For messages, it provides
|
|
// the ability to access or manipulate fields of the message.
|
|
//
|
|
// To convert a proto.Message to a protoreflect.Message, use the
|
|
// former's ProtoReflect method. Since the ProtoReflect method is new to the
|
|
// v2 message interface, it may not be present on older message implementations.
|
|
// The "github.com/golang/protobuf/proto".MessageReflect function can be used
|
|
// to obtain a reflective view on older messages.
|
|
//
|
|
//
|
|
// Relationships
|
|
//
|
|
// The following diagrams demonstrate the relationships between
|
|
// various types declared in this package.
|
|
//
|
|
//
|
|
// ┌───────────────────────────────────┐
|
|
// V │
|
|
// ┌────────────── New(n) ─────────────┐ │
|
|
// │ │ │
|
|
// │ ┌──── Descriptor() ──┐ │ ┌── Number() ──┐ │
|
|
// │ │ V V │ V │
|
|
// ╔════════════╗ ╔════════════════╗ ╔════════╗ ╔════════════╗
|
|
// ║ EnumType ║ ║ EnumDescriptor ║ ║ Enum ║ ║ EnumNumber ║
|
|
// ╚════════════╝ ╚════════════════╝ ╚════════╝ ╚════════════╝
|
|
// Λ Λ │ │
|
|
// │ └─── Descriptor() ──┘ │
|
|
// │ │
|
|
// └────────────────── Type() ───────┘
|
|
//
|
|
// • An EnumType describes a concrete Go enum type.
|
|
// It has an EnumDescriptor and can construct an Enum instance.
|
|
//
|
|
// • An EnumDescriptor describes an abstract protobuf enum type.
|
|
//
|
|
// • An Enum is a concrete enum instance. Generated enums implement Enum.
|
|
//
|
|
//
|
|
// ┌──────────────── New() ─────────────────┐
|
|
// │ │
|
|
// │ ┌─── Descriptor() ─────┐ │ ┌── Interface() ───┐
|
|
// │ │ V V │ V
|
|
// ╔═════════════╗ ╔═══════════════════╗ ╔═════════╗ ╔══════════════╗
|
|
// ║ MessageType ║ ║ MessageDescriptor ║ ║ Message ║ ║ ProtoMessage ║
|
|
// ╚═════════════╝ ╚═══════════════════╝ ╚═════════╝ ╚══════════════╝
|
|
// Λ Λ │ │ Λ │
|
|
// │ └──── Descriptor() ────┘ │ └─ ProtoReflect() ─┘
|
|
// │ │
|
|
// └─────────────────── Type() ─────────┘
|
|
//
|
|
// • A MessageType describes a concrete Go message type.
|
|
// It has a MessageDescriptor and can construct a Message instance.
|
|
//
|
|
// • A MessageDescriptor describes an abstract protobuf message type.
|
|
//
|
|
// • A Message is a concrete message instance. Generated messages implement
|
|
// ProtoMessage, which can convert to/from a Message.
|
|
//
|
|
//
|
|
// ┌── TypeDescriptor() ──┐ ┌───── Descriptor() ─────┐
|
|
// │ V │ V
|
|
// ╔═══════════════╗ ╔═════════════════════════╗ ╔═════════════════════╗
|
|
// ║ ExtensionType ║ ║ ExtensionTypeDescriptor ║ ║ ExtensionDescriptor ║
|
|
// ╚═══════════════╝ ╚═════════════════════════╝ ╚═════════════════════╝
|
|
// Λ │ │ Λ │ Λ
|
|
// └─────── Type() ───────┘ │ └─── may implement ────┘ │
|
|
// │ │
|
|
// └────── implements ────────┘
|
|
//
|
|
// • An ExtensionType describes a concrete Go implementation of an extension.
|
|
// It has an ExtensionTypeDescriptor and can convert to/from
|
|
// abstract Values and Go values.
|
|
//
|
|
// • An ExtensionTypeDescriptor is an ExtensionDescriptor
|
|
// which also has an ExtensionType.
|
|
//
|
|
// • An ExtensionDescriptor describes an abstract protobuf extension field and
|
|
// may not always be an ExtensionTypeDescriptor.
|
|
package protoreflect
|
|
|
|
import (
|
|
"fmt"
|
|
"regexp"
|
|
"strings"
|
|
|
|
"google.golang.org/protobuf/encoding/protowire"
|
|
"google.golang.org/protobuf/internal/pragma"
|
|
)
|
|
|
|
type doNotImplement pragma.DoNotImplement
|
|
|
|
// ProtoMessage is the top-level interface that all proto messages implement.
|
|
// This is declared in the protoreflect package to avoid a cyclic dependency;
|
|
// use the proto.Message type instead, which aliases this type.
|
|
type ProtoMessage interface{ ProtoReflect() Message }
|
|
|
|
// Syntax is the language version of the proto file.
|
|
type Syntax syntax
|
|
|
|
type syntax int8 // keep exact type opaque as the int type may change
|
|
|
|
const (
|
|
Proto2 Syntax = 2
|
|
Proto3 Syntax = 3
|
|
)
|
|
|
|
// IsValid reports whether the syntax is valid.
|
|
func (s Syntax) IsValid() bool {
|
|
switch s {
|
|
case Proto2, Proto3:
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// String returns s as a proto source identifier (e.g., "proto2").
|
|
func (s Syntax) String() string {
|
|
switch s {
|
|
case Proto2:
|
|
return "proto2"
|
|
case Proto3:
|
|
return "proto3"
|
|
default:
|
|
return fmt.Sprintf("<unknown:%d>", s)
|
|
}
|
|
}
|
|
|
|
// GoString returns s as a Go source identifier (e.g., "Proto2").
|
|
func (s Syntax) GoString() string {
|
|
switch s {
|
|
case Proto2:
|
|
return "Proto2"
|
|
case Proto3:
|
|
return "Proto3"
|
|
default:
|
|
return fmt.Sprintf("Syntax(%d)", s)
|
|
}
|
|
}
|
|
|
|
// Cardinality determines whether a field is optional, required, or repeated.
|
|
type Cardinality cardinality
|
|
|
|
type cardinality int8 // keep exact type opaque as the int type may change
|
|
|
|
// Constants as defined by the google.protobuf.Cardinality enumeration.
|
|
const (
|
|
Optional Cardinality = 1 // appears zero or one times
|
|
Required Cardinality = 2 // appears exactly one time; invalid with Proto3
|
|
Repeated Cardinality = 3 // appears zero or more times
|
|
)
|
|
|
|
// IsValid reports whether the cardinality is valid.
|
|
func (c Cardinality) IsValid() bool {
|
|
switch c {
|
|
case Optional, Required, Repeated:
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// String returns c as a proto source identifier (e.g., "optional").
|
|
func (c Cardinality) String() string {
|
|
switch c {
|
|
case Optional:
|
|
return "optional"
|
|
case Required:
|
|
return "required"
|
|
case Repeated:
|
|
return "repeated"
|
|
default:
|
|
return fmt.Sprintf("<unknown:%d>", c)
|
|
}
|
|
}
|
|
|
|
// GoString returns c as a Go source identifier (e.g., "Optional").
|
|
func (c Cardinality) GoString() string {
|
|
switch c {
|
|
case Optional:
|
|
return "Optional"
|
|
case Required:
|
|
return "Required"
|
|
case Repeated:
|
|
return "Repeated"
|
|
default:
|
|
return fmt.Sprintf("Cardinality(%d)", c)
|
|
}
|
|
}
|
|
|
|
// Kind indicates the basic proto kind of a field.
|
|
type Kind kind
|
|
|
|
type kind int8 // keep exact type opaque as the int type may change
|
|
|
|
// Constants as defined by the google.protobuf.Field.Kind enumeration.
|
|
const (
|
|
BoolKind Kind = 8
|
|
EnumKind Kind = 14
|
|
Int32Kind Kind = 5
|
|
Sint32Kind Kind = 17
|
|
Uint32Kind Kind = 13
|
|
Int64Kind Kind = 3
|
|
Sint64Kind Kind = 18
|
|
Uint64Kind Kind = 4
|
|
Sfixed32Kind Kind = 15
|
|
Fixed32Kind Kind = 7
|
|
FloatKind Kind = 2
|
|
Sfixed64Kind Kind = 16
|
|
Fixed64Kind Kind = 6
|
|
DoubleKind Kind = 1
|
|
StringKind Kind = 9
|
|
BytesKind Kind = 12
|
|
MessageKind Kind = 11
|
|
GroupKind Kind = 10
|
|
)
|
|
|
|
// IsValid reports whether the kind is valid.
|
|
func (k Kind) IsValid() bool {
|
|
switch k {
|
|
case BoolKind, EnumKind,
|
|
Int32Kind, Sint32Kind, Uint32Kind,
|
|
Int64Kind, Sint64Kind, Uint64Kind,
|
|
Sfixed32Kind, Fixed32Kind, FloatKind,
|
|
Sfixed64Kind, Fixed64Kind, DoubleKind,
|
|
StringKind, BytesKind, MessageKind, GroupKind:
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// String returns k as a proto source identifier (e.g., "bool").
|
|
func (k Kind) String() string {
|
|
switch k {
|
|
case BoolKind:
|
|
return "bool"
|
|
case EnumKind:
|
|
return "enum"
|
|
case Int32Kind:
|
|
return "int32"
|
|
case Sint32Kind:
|
|
return "sint32"
|
|
case Uint32Kind:
|
|
return "uint32"
|
|
case Int64Kind:
|
|
return "int64"
|
|
case Sint64Kind:
|
|
return "sint64"
|
|
case Uint64Kind:
|
|
return "uint64"
|
|
case Sfixed32Kind:
|
|
return "sfixed32"
|
|
case Fixed32Kind:
|
|
return "fixed32"
|
|
case FloatKind:
|
|
return "float"
|
|
case Sfixed64Kind:
|
|
return "sfixed64"
|
|
case Fixed64Kind:
|
|
return "fixed64"
|
|
case DoubleKind:
|
|
return "double"
|
|
case StringKind:
|
|
return "string"
|
|
case BytesKind:
|
|
return "bytes"
|
|
case MessageKind:
|
|
return "message"
|
|
case GroupKind:
|
|
return "group"
|
|
default:
|
|
return fmt.Sprintf("<unknown:%d>", k)
|
|
}
|
|
}
|
|
|
|
// GoString returns k as a Go source identifier (e.g., "BoolKind").
|
|
func (k Kind) GoString() string {
|
|
switch k {
|
|
case BoolKind:
|
|
return "BoolKind"
|
|
case EnumKind:
|
|
return "EnumKind"
|
|
case Int32Kind:
|
|
return "Int32Kind"
|
|
case Sint32Kind:
|
|
return "Sint32Kind"
|
|
case Uint32Kind:
|
|
return "Uint32Kind"
|
|
case Int64Kind:
|
|
return "Int64Kind"
|
|
case Sint64Kind:
|
|
return "Sint64Kind"
|
|
case Uint64Kind:
|
|
return "Uint64Kind"
|
|
case Sfixed32Kind:
|
|
return "Sfixed32Kind"
|
|
case Fixed32Kind:
|
|
return "Fixed32Kind"
|
|
case FloatKind:
|
|
return "FloatKind"
|
|
case Sfixed64Kind:
|
|
return "Sfixed64Kind"
|
|
case Fixed64Kind:
|
|
return "Fixed64Kind"
|
|
case DoubleKind:
|
|
return "DoubleKind"
|
|
case StringKind:
|
|
return "StringKind"
|
|
case BytesKind:
|
|
return "BytesKind"
|
|
case MessageKind:
|
|
return "MessageKind"
|
|
case GroupKind:
|
|
return "GroupKind"
|
|
default:
|
|
return fmt.Sprintf("Kind(%d)", k)
|
|
}
|
|
}
|
|
|
|
// FieldNumber is the field number in a message.
|
|
type FieldNumber = protowire.Number
|
|
|
|
// FieldNumbers represent a list of field numbers.
|
|
type FieldNumbers interface {
|
|
// Len reports the number of fields in the list.
|
|
Len() int
|
|
// Get returns the ith field number. It panics if out of bounds.
|
|
Get(i int) FieldNumber
|
|
// Has reports whether n is within the list of fields.
|
|
Has(n FieldNumber) bool
|
|
|
|
doNotImplement
|
|
}
|
|
|
|
// FieldRanges represent a list of field number ranges.
|
|
type FieldRanges interface {
|
|
// Len reports the number of ranges in the list.
|
|
Len() int
|
|
// Get returns the ith range. It panics if out of bounds.
|
|
Get(i int) [2]FieldNumber // start inclusive; end exclusive
|
|
// Has reports whether n is within any of the ranges.
|
|
Has(n FieldNumber) bool
|
|
|
|
doNotImplement
|
|
}
|
|
|
|
// EnumNumber is the numeric value for an enum.
|
|
type EnumNumber int32
|
|
|
|
// EnumRanges represent a list of enum number ranges.
|
|
type EnumRanges interface {
|
|
// Len reports the number of ranges in the list.
|
|
Len() int
|
|
// Get returns the ith range. It panics if out of bounds.
|
|
Get(i int) [2]EnumNumber // start inclusive; end inclusive
|
|
// Has reports whether n is within any of the ranges.
|
|
Has(n EnumNumber) bool
|
|
|
|
doNotImplement
|
|
}
|
|
|
|
var (
|
|
regexName = regexp.MustCompile(`^[_a-zA-Z][_a-zA-Z0-9]*$`)
|
|
regexFullName = regexp.MustCompile(`^[_a-zA-Z][_a-zA-Z0-9]*(\.[_a-zA-Z][_a-zA-Z0-9]*)*$`)
|
|
)
|
|
|
|
// Name is the short name for a proto declaration. This is not the name
|
|
// as used in Go source code, which might not be identical to the proto name.
|
|
type Name string // e.g., "Kind"
|
|
|
|
// IsValid reports whether n is a syntactically valid name.
|
|
// An empty name is invalid.
|
|
func (n Name) IsValid() bool {
|
|
return regexName.MatchString(string(n))
|
|
}
|
|
|
|
// Names represent a list of names.
|
|
type Names interface {
|
|
// Len reports the number of names in the list.
|
|
Len() int
|
|
// Get returns the ith name. It panics if out of bounds.
|
|
Get(i int) Name
|
|
// Has reports whether s matches any names in the list.
|
|
Has(s Name) bool
|
|
|
|
doNotImplement
|
|
}
|
|
|
|
// FullName is a qualified name that uniquely identifies a proto declaration.
|
|
// A qualified name is the concatenation of the proto package along with the
|
|
// fully-declared name (i.e., name of parent preceding the name of the child),
|
|
// with a '.' delimiter placed between each Name.
|
|
//
|
|
// This should not have any leading or trailing dots.
|
|
type FullName string // e.g., "google.protobuf.Field.Kind"
|
|
|
|
// IsValid reports whether n is a syntactically valid full name.
|
|
// An empty full name is invalid.
|
|
func (n FullName) IsValid() bool {
|
|
return regexFullName.MatchString(string(n))
|
|
}
|
|
|
|
// Name returns the short name, which is the last identifier segment.
|
|
// A single segment FullName is the Name itself.
|
|
func (n FullName) Name() Name {
|
|
if i := strings.LastIndexByte(string(n), '.'); i >= 0 {
|
|
return Name(n[i+1:])
|
|
}
|
|
return Name(n)
|
|
}
|
|
|
|
// Parent returns the full name with the trailing identifier removed.
|
|
// A single segment FullName has no parent.
|
|
func (n FullName) Parent() FullName {
|
|
if i := strings.LastIndexByte(string(n), '.'); i >= 0 {
|
|
return n[:i]
|
|
}
|
|
return ""
|
|
}
|
|
|
|
// Append returns the qualified name appended with the provided short name.
|
|
//
|
|
// Invariant: n == n.Parent().Append(n.Name()) // assuming n is valid
|
|
func (n FullName) Append(s Name) FullName {
|
|
if n == "" {
|
|
return FullName(s)
|
|
}
|
|
return n + "." + FullName(s)
|
|
}
|