gtsocial-umbx

properties.go (9108B)

---

 // Copyright 2010 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 proto
 
 import (
 	"fmt"
 	"reflect"
 	"strconv"
 	"strings"
 	"sync"
 
 	"google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/runtime/protoimpl"
 )
 
 // StructProperties represents protocol buffer type information for a
 // generated protobuf message in the open-struct API.
 //
 // Deprecated: Do not use.
 type StructProperties struct {
 	// Prop are the properties for each field.
 	//
 	// Fields belonging to a oneof are stored in OneofTypes instead, with a
 	// single Properties representing the parent oneof held here.
 	//
 	// The order of Prop matches the order of fields in the Go struct.
 	// Struct fields that are not related to protobufs have a "XXX_" prefix
 	// in the Properties.Name and must be ignored by the user.
 	Prop []*Properties
 
 	// OneofTypes contains information about the oneof fields in this message.
 	// It is keyed by the protobuf field name.
 	OneofTypes map[string]*OneofProperties
 }
 
 // Properties represents the type information for a protobuf message field.
 //
 // Deprecated: Do not use.
 type Properties struct {
 	// Name is a placeholder name with little meaningful semantic value.
 	// If the name has an "XXX_" prefix, the entire Properties must be ignored.
 	Name string
 	// OrigName is the protobuf field name or oneof name.
 	OrigName string
 	// JSONName is the JSON name for the protobuf field.
 	JSONName string
 	// Enum is a placeholder name for enums.
 	// For historical reasons, this is neither the Go name for the enum,
 	// nor the protobuf name for the enum.
 	Enum string // Deprecated: Do not use.
 	// Weak contains the full name of the weakly referenced message.
 	Weak string
 	// Wire is a string representation of the wire type.
 	Wire string
 	// WireType is the protobuf wire type for the field.
 	WireType int
 	// Tag is the protobuf field number.
 	Tag int
 	// Required reports whether this is a required field.
 	Required bool
 	// Optional reports whether this is a optional field.
 	Optional bool
 	// Repeated reports whether this is a repeated field.
 	Repeated bool
 	// Packed reports whether this is a packed repeated field of scalars.
 	Packed bool
 	// Proto3 reports whether this field operates under the proto3 syntax.
 	Proto3 bool
 	// Oneof reports whether this field belongs within a oneof.
 	Oneof bool
 
 	// Default is the default value in string form.
 	Default string
 	// HasDefault reports whether the field has a default value.
 	HasDefault bool
 
 	// MapKeyProp is the properties for the key field for a map field.
 	MapKeyProp *Properties
 	// MapValProp is the properties for the value field for a map field.
 	MapValProp *Properties
 }
 
 // OneofProperties represents the type information for a protobuf oneof.
 //
 // Deprecated: Do not use.
 type OneofProperties struct {
 	// Type is a pointer to the generated wrapper type for the field value.
 	// This is nil for messages that are not in the open-struct API.
 	Type reflect.Type
 	// Field is the index into StructProperties.Prop for the containing oneof.
 	Field int
 	// Prop is the properties for the field.
 	Prop *Properties
 }
 
 // String formats the properties in the protobuf struct field tag style.
 func (p *Properties) String() string {
 	s := p.Wire
 	s += "," + strconv.Itoa(p.Tag)
 	if p.Required {
 		s += ",req"
 	}
 	if p.Optional {
 		s += ",opt"
 	}
 	if p.Repeated {
 		s += ",rep"
 	}
 	if p.Packed {
 		s += ",packed"
 	}
 	s += ",name=" + p.OrigName
 	if p.JSONName != "" {
 		s += ",json=" + p.JSONName
 	}
 	if len(p.Enum) > 0 {
 		s += ",enum=" + p.Enum
 	}
 	if len(p.Weak) > 0 {
 		s += ",weak=" + p.Weak
 	}
 	if p.Proto3 {
 		s += ",proto3"
 	}
 	if p.Oneof {
 		s += ",oneof"
 	}
 	if p.HasDefault {
 		s += ",def=" + p.Default
 	}
 	return s
 }
 
 // Parse populates p by parsing a string in the protobuf struct field tag style.
 func (p *Properties) Parse(tag string) {
 	// For example: "bytes,49,opt,name=foo,def=hello!"
 	for len(tag) > 0 {
 		i := strings.IndexByte(tag, ',')
 		if i < 0 {
 			i = len(tag)
 		}
 		switch s := tag[:i]; {
 		case strings.HasPrefix(s, "name="):
 			p.OrigName = s[len("name="):]
 		case strings.HasPrefix(s, "json="):
 			p.JSONName = s[len("json="):]
 		case strings.HasPrefix(s, "enum="):
 			p.Enum = s[len("enum="):]
 		case strings.HasPrefix(s, "weak="):
 			p.Weak = s[len("weak="):]
 		case strings.Trim(s, "0123456789") == "":
 			n, _ := strconv.ParseUint(s, 10, 32)
 			p.Tag = int(n)
 		case s == "opt":
 			p.Optional = true
 		case s == "req":
 			p.Required = true
 		case s == "rep":
 			p.Repeated = true
 		case s == "varint" || s == "zigzag32" || s == "zigzag64":
 			p.Wire = s
 			p.WireType = WireVarint
 		case s == "fixed32":
 			p.Wire = s
 			p.WireType = WireFixed32
 		case s == "fixed64":
 			p.Wire = s
 			p.WireType = WireFixed64
 		case s == "bytes":
 			p.Wire = s
 			p.WireType = WireBytes
 		case s == "group":
 			p.Wire = s
 			p.WireType = WireStartGroup
 		case s == "packed":
 			p.Packed = true
 		case s == "proto3":
 			p.Proto3 = true
 		case s == "oneof":
 			p.Oneof = true
 		case strings.HasPrefix(s, "def="):
 			// The default tag is special in that everything afterwards is the
 			// default regardless of the presence of commas.
 			p.HasDefault = true
 			p.Default, i = tag[len("def="):], len(tag)
 		}
 		tag = strings.TrimPrefix(tag[i:], ",")
 	}
 }
 
 // Init populates the properties from a protocol buffer struct tag.
 //
 // Deprecated: Do not use.
 func (p *Properties) Init(typ reflect.Type, name, tag string, f *reflect.StructField) {
 	p.Name = name
 	p.OrigName = name
 	if tag == "" {
 		return
 	}
 	p.Parse(tag)
 
 	if typ != nil && typ.Kind() == reflect.Map {
 		p.MapKeyProp = new(Properties)
 		p.MapKeyProp.Init(nil, "Key", f.Tag.Get("protobuf_key"), nil)
 		p.MapValProp = new(Properties)
 		p.MapValProp.Init(nil, "Value", f.Tag.Get("protobuf_val"), nil)
 	}
 }
 
 var propertiesCache sync.Map // map[reflect.Type]*StructProperties
 
 // GetProperties returns the list of properties for the type represented by t,
 // which must be a generated protocol buffer message in the open-struct API,
 // where protobuf message fields are represented by exported Go struct fields.
 //
 // Deprecated: Use protobuf reflection instead.
 func GetProperties(t reflect.Type) *StructProperties {
 	if p, ok := propertiesCache.Load(t); ok {
 		return p.(*StructProperties)
 	}
 	p, _ := propertiesCache.LoadOrStore(t, newProperties(t))
 	return p.(*StructProperties)
 }
 
 func newProperties(t reflect.Type) *StructProperties {
 	if t.Kind() != reflect.Struct {
 		panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
 	}
 
 	var hasOneof bool
 	prop := new(StructProperties)
 
 	// Construct a list of properties for each field in the struct.
 	for i := 0; i < t.NumField(); i++ {
 		p := new(Properties)
 		f := t.Field(i)
 		tagField := f.Tag.Get("protobuf")
 		p.Init(f.Type, f.Name, tagField, &f)
 
 		tagOneof := f.Tag.Get("protobuf_oneof")
 		if tagOneof != "" {
 			hasOneof = true
 			p.OrigName = tagOneof
 		}
 
 		// Rename unrelated struct fields with the "XXX_" prefix since so much
 		// user code simply checks for this to exclude special fields.
 		if tagField == "" && tagOneof == "" && !strings.HasPrefix(p.Name, "XXX_") {
 			p.Name = "XXX_" + p.Name
 			p.OrigName = "XXX_" + p.OrigName
 		} else if p.Weak != "" {
 			p.Name = p.OrigName // avoid possible "XXX_" prefix on weak field
 		}
 
 		prop.Prop = append(prop.Prop, p)
 	}
 
 	// Construct a mapping of oneof field names to properties.
 	if hasOneof {
 		var oneofWrappers []interface{}
 		if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofFuncs"); ok {
 			oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[3].Interface().([]interface{})
 		}
 		if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofWrappers"); ok {
 			oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[0].Interface().([]interface{})
 		}
 		if m, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(protoreflect.ProtoMessage); ok {
 			if m, ok := m.ProtoReflect().(interface{ ProtoMessageInfo() *protoimpl.MessageInfo }); ok {
 				oneofWrappers = m.ProtoMessageInfo().OneofWrappers
 			}
 		}
 
 		prop.OneofTypes = make(map[string]*OneofProperties)
 		for _, wrapper := range oneofWrappers {
 			p := &OneofProperties{
 				Type: reflect.ValueOf(wrapper).Type(), // *T
 				Prop: new(Properties),
 			}
 			f := p.Type.Elem().Field(0)
 			p.Prop.Name = f.Name
 			p.Prop.Parse(f.Tag.Get("protobuf"))
 
 			// Determine the struct field that contains this oneof.
 			// Each wrapper is assignable to exactly one parent field.
 			var foundOneof bool
 			for i := 0; i < t.NumField() && !foundOneof; i++ {
 				if p.Type.AssignableTo(t.Field(i).Type) {
 					p.Field = i
 					foundOneof = true
 				}
 			}
 			if !foundOneof {
 				panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
 			}
 			prop.OneofTypes[p.Prop.OrigName] = p
 		}
 	}
 
 	return prop
 }
 
 func (sp *StructProperties) Len() int           { return len(sp.Prop) }
 func (sp *StructProperties) Less(i, j int) bool { return false }
 func (sp *StructProperties) Swap(i, j int)      { return }