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Diffstat (limited to 'reflect/protoreflect/type.go')
| -rw-r--r-- | reflect/protoreflect/type.go | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/reflect/protoreflect/type.go b/reflect/protoreflect/type.go new file mode 100644 index 00000000..8e53c44a --- /dev/null +++ b/reflect/protoreflect/type.go @@ -0,0 +1,665 @@ +// 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 + +// Descriptor provides a set of accessors that are common to every descriptor. +// Each descriptor type wraps the equivalent google.protobuf.XXXDescriptorProto, +// but provides efficient lookup and immutability. +// +// Each descriptor is comparable. Equality implies that the two types are +// exactly identical. However, it is possible for the same semantically +// identical proto type to be represented by multiple type descriptors. +// +// For example, suppose we have t1 and t2 which are both MessageDescriptors. +// If t1 == t2, then the types are definitely equal and all accessors return +// the same information. However, if t1 != t2, then it is still possible that +// they still represent the same proto type (e.g., t1.FullName == t2.FullName). +// This can occur if a descriptor type is created dynamically, or multiple +// versions of the same proto type are accidentally linked into the Go binary. +type Descriptor interface { + // ParentFile returns the parent file descriptor that this descriptor + // is declared within. The parent file for the file descriptor is itself. + // + // Support for this functionality is optional and may return nil. + ParentFile() FileDescriptor + + // Parent returns the parent containing this descriptor declaration. + // The following shows the mapping from child type to possible parent types: + // + // ╔═════════════════════╤═══════════════════════════════════╗ + // ║ Child type │ Possible parent types ║ + // ╠═════════════════════╪═══════════════════════════════════╣ + // ║ FileDescriptor │ nil ║ + // ║ MessageDescriptor │ FileDescriptor, MessageDescriptor ║ + // ║ FieldDescriptor │ FileDescriptor, MessageDescriptor ║ + // ║ OneofDescriptor │ MessageDescriptor ║ + // ║ EnumDescriptor │ FileDescriptor, MessageDescriptor ║ + // ║ EnumValueDescriptor │ EnumDescriptor ║ + // ║ ServiceDescriptor │ FileDescriptor ║ + // ║ MethodDescriptor │ ServiceDescriptor ║ + // ╚═════════════════════╧═══════════════════════════════════╝ + // + // Support for this functionality is optional and may return nil. + Parent() Descriptor + + // Index returns the index of this descriptor within its parent. + // It returns 0 if the descriptor does not have a parent or if the parent + // is unknown. + Index() int + + // Syntax is the protobuf syntax. + Syntax() Syntax // e.g., Proto2 or Proto3 + + // Name is the short name of the declaration (i.e., FullName.Name). + Name() Name // e.g., "Any" + + // FullName is the fully-qualified name of the declaration. + // + // The FullName is a concatenation of the full name of the type that this + // type is declared within and the declaration name. For example, + // field "foo_field" in message "proto.package.MyMessage" is + // uniquely identified as "proto.package.MyMessage.foo_field". + // Enum values are an exception to the rule (see EnumValueDescriptor). + FullName() FullName // e.g., "google.protobuf.Any" + + // IsPlaceholder reports whether type information is missing since a + // dependency is not resolved, in which case only name information is known. + // + // Placeholder types may only be returned by the following accessors + // as a result of unresolved dependencies or weak imports: + // + // ╔═══════════════════════════════════╤═════════════════════╗ + // ║ Accessor │ Descriptor ║ + // ╠═══════════════════════════════════╪═════════════════════╣ + // ║ FileImports.FileDescriptor │ FileDescriptor ║ + // ║ FieldDescriptor.Enum │ EnumDescriptor ║ + // ║ FieldDescriptor.Message │ MessageDescriptor ║ + // ║ FieldDescriptor.DefaultEnumValue │ EnumValueDescriptor ║ + // ║ FieldDescriptor.ContainingMessage │ MessageDescriptor ║ + // ║ MethodDescriptor.Input │ MessageDescriptor ║ + // ║ MethodDescriptor.Output │ MessageDescriptor ║ + // ╚═══════════════════════════════════╧═════════════════════╝ + // + // If true, only Name and FullName are valid. + // For FileDescriptor, the Path is also valid. + IsPlaceholder() bool + + // Options returns the descriptor options. The caller must not modify + // the returned value. + // + // To avoid a dependency cycle, this function returns a proto.Message value. + // The proto message type returned for each descriptor type is as follows: + // ╔═════════════════════╤══════════════════════════════════════════╗ + // ║ Go type │ Protobuf message type ║ + // ╠═════════════════════╪══════════════════════════════════════════╣ + // ║ FileDescriptor │ google.protobuf.FileOptions ║ + // ║ EnumDescriptor │ google.protobuf.EnumOptions ║ + // ║ EnumValueDescriptor │ google.protobuf.EnumValueOptions ║ + // ║ MessageDescriptor │ google.protobuf.MessageOptions ║ + // ║ FieldDescriptor │ google.protobuf.FieldOptions ║ + // ║ OneofDescriptor │ google.protobuf.OneofOptions ║ + // ║ ServiceDescriptor │ google.protobuf.ServiceOptions ║ + // ║ MethodDescriptor │ google.protobuf.MethodOptions ║ + // ╚═════════════════════╧══════════════════════════════════════════╝ + // + // This method returns a typed nil-pointer if no options are present. + // The caller must import the descriptorpb package to use this. + Options() ProtoMessage + + doNotImplement +} + +// FileDescriptor describes the types in a complete proto file and +// corresponds with the google.protobuf.FileDescriptorProto message. +// +// Top-level declarations: +// EnumDescriptor, MessageDescriptor, FieldDescriptor, and/or ServiceDescriptor. +type FileDescriptor interface { + Descriptor // Descriptor.FullName is identical to Package + + // Path returns the file name, relative to the source tree root. + Path() string // e.g., "path/to/file.proto" + // Package returns the protobuf package namespace. + Package() FullName // e.g., "google.protobuf" + + // Imports is a list of imported proto files. + Imports() FileImports + + // Enums is a list of the top-level enum declarations. + Enums() EnumDescriptors + // Messages is a list of the top-level message declarations. + Messages() MessageDescriptors + // Extensions is a list of the top-level extension declarations. + Extensions() ExtensionDescriptors + // Services is a list of the top-level service declarations. + Services() ServiceDescriptors + + // SourceLocations is a list of source locations. + SourceLocations() SourceLocations + + isFileDescriptor +} +type isFileDescriptor interface{ ProtoType(FileDescriptor) } + +// FileImports is a list of file imports. +type FileImports interface { + // Len reports the number of files imported by this proto file. + Len() int + // Get returns the ith FileImport. It panics if out of bounds. + Get(i int) FileImport + + doNotImplement +} + +// FileImport is the declaration for a proto file import. +type FileImport struct { + // FileDescriptor is the file type for the given import. + // It is a placeholder descriptor if IsWeak is set or if a dependency has + // not been regenerated to implement the new reflection APIs. + FileDescriptor + + // IsPublic reports whether this is a public import, which causes this file + // to alias declarations within the imported file. The intended use cases + // for this feature is the ability to move proto files without breaking + // existing dependencies. + // + // The current file and the imported file must be within proto package. + IsPublic bool + + // IsWeak reports whether this is a weak import, which does not impose + // a direct dependency on the target file. + // + // Weak imports are a legacy proto1 feature. Equivalent behavior is + // achieved using proto2 extension fields or proto3 Any messages. + IsWeak bool +} + +// MessageDescriptor describes a message and +// corresponds with the google.protobuf.DescriptorProto message. +// +// Nested declarations: +// FieldDescriptor, OneofDescriptor, FieldDescriptor, EnumDescriptor, +// and/or MessageDescriptor. +type MessageDescriptor interface { + Descriptor + + // IsMapEntry indicates that this is an auto-generated message type to + // represent the entry type for a map field. + // + // Map entry messages have only two fields: + // • a "key" field with a field number of 1 + // • a "value" field with a field number of 2 + // The key and value types are determined by these two fields. + // + // If IsMapEntry is true, it implies that FieldDescriptor.IsMap is true + // for some field with this message type. + IsMapEntry() bool + + // Fields is a list of nested field declarations. + Fields() FieldDescriptors + // Oneofs is a list of nested oneof declarations. + Oneofs() OneofDescriptors + + // ReservedNames is a list of reserved field names. + ReservedNames() Names + // ReservedRanges is a list of reserved ranges of field numbers. + ReservedRanges() FieldRanges + // RequiredNumbers is a list of required field numbers. + // In Proto3, it is always an empty list. + RequiredNumbers() FieldNumbers + // ExtensionRanges is the field ranges used for extension fields. + // In Proto3, it is always an empty ranges. + ExtensionRanges() FieldRanges + // ExtensionRangeOptions returns the ith extension range options. + // + // To avoid a dependency cycle, this method returns a proto.Message value, + // which always contains a google.protobuf.ExtensionRangeOptions message. + // This method returns a typed nil-pointer if no options are present. + // The caller must import the descriptorpb package to use this. + ExtensionRangeOptions(i int) ProtoMessage + + // Enums is a list of nested enum declarations. + Enums() EnumDescriptors + // Messages is a list of nested message declarations. + Messages() MessageDescriptors + // Extensions is a list of nested extension declarations. + Extensions() ExtensionDescriptors + + isMessageDescriptor +} +type isMessageDescriptor interface{ ProtoType(MessageDescriptor) } + +// MessageType encapsulates a MessageDescriptor with a concrete Go implementation. +// It is recommended that implementations of this interface also implement the +// MessageFieldTypes interface. +type MessageType interface { + // New returns a newly allocated empty message. + // It may return nil for synthetic messages representing a map entry. + New() Message + + // Zero returns an empty, read-only message. + // It may return nil for synthetic messages representing a map entry. + Zero() Message + + // Descriptor returns the message descriptor. + // + // Invariant: t.Descriptor() == t.New().Descriptor() + Descriptor() MessageDescriptor +} + +// MessageFieldTypes extends a MessageType by providing type information +// regarding enums and messages referenced by the message fields. +type MessageFieldTypes interface { + MessageType + + // Enum returns the EnumType for the ith field in Descriptor.Fields. + // It returns nil if the ith field is not an enum kind. + // It panics if out of bounds. + // + // Invariant: mt.Enum(i).Descriptor() == mt.Descriptor().Fields(i).Enum() + Enum(i int) EnumType + + // Message returns the MessageType for the ith field in Descriptor.Fields. + // It returns nil if the ith field is not a message or group kind. + // It panics if out of bounds. + // + // Invariant: mt.Message(i).Descriptor() == mt.Descriptor().Fields(i).Message() + Message(i int) MessageType +} + +// MessageDescriptors is a list of message declarations. +type MessageDescriptors interface { + // Len reports the number of messages. + Len() int + // Get returns the ith MessageDescriptor. It panics if out of bounds. + Get(i int) MessageDescriptor + // ByName returns the MessageDescriptor for a message named s. + // It returns nil if not found. + ByName(s Name) MessageDescriptor + + doNotImplement +} + +// FieldDescriptor describes a field within a message and +// corresponds with the google.protobuf.FieldDescriptorProto message. +// +// It is used for both normal fields defined within the parent message +// (e.g., MessageDescriptor.Fields) and fields that extend some remote message +// (e.g., FileDescriptor.Extensions or MessageDescriptor.Extensions). +type FieldDescriptor interface { + Descriptor + + // Number reports the unique number for this field. + Number() FieldNumber + // Cardinality reports the cardinality for this field. + Cardinality() Cardinality + // Kind reports the basic kind for this field. + Kind() Kind + + // HasJSONName reports whether this field has an explicitly set JSON name. + HasJSONName() bool + + // JSONName reports the name used for JSON serialization. + // It is usually the camel-cased form of the field name. + // Extension fields are represented by the full name surrounded by brackets. + JSONName() string + + // TextName reports the name used for text serialization. + // It is usually the name of the field, except that groups use the name + // of the inlined message, and extension fields are represented by the + // full name surrounded by brackets. + TextName() string + + // HasPresence reports whether the field distinguishes between unpopulated + // and default values. + HasPresence() bool + + // IsExtension reports whether this is an extension field. If false, + // then Parent and ContainingMessage refer to the same message. + // Otherwise, ContainingMessage and Parent likely differ. + IsExtension() bool + + // HasOptionalKeyword reports whether the "optional" keyword was explicitly + // specified in the source .proto file. + HasOptionalKeyword() bool + + // IsWeak reports whether this is a weak field, which does not impose a + // direct dependency on the target type. + // If true, then Message returns a placeholder type. + IsWeak() bool + + // IsPacked reports whether repeated primitive numeric kinds should be + // serialized using a packed encoding. + // If true, then it implies Cardinality is Repeated. + IsPacked() bool + + // IsList reports whether this field represents a list, + // where the value type for the associated field is a List. + // It is equivalent to checking whether Cardinality is Repeated and + // that IsMap reports false. + IsList() bool + + // IsMap reports whether this field represents a map, + // where the value type for the associated field is a Map. + // It is equivalent to checking whether Cardinality is Repeated, + // that the Kind is MessageKind, and that Message.IsMapEntry reports true. + IsMap() bool + + // MapKey returns the field descriptor for the key in the map entry. + // It returns nil if IsMap reports false. + MapKey() FieldDescriptor + + // MapValue returns the field descriptor for the value in the map entry. + // It returns nil if IsMap reports false. + MapValue() FieldDescriptor + + // HasDefault reports whether this field has a default value. + HasDefault() bool + + // Default returns the default value for scalar fields. + // For proto2, it is the default value as specified in the proto file, + // or the zero value if unspecified. + // For proto3, it is always the zero value of the scalar. + // The Value type is determined by the Kind. + Default() Value + + // DefaultEnumValue returns the enum value descriptor for the default value + // of an enum field, and is nil for any other kind of field. + DefaultEnumValue() EnumValueDescriptor + + // ContainingOneof is the containing oneof that this field belongs to, + // and is nil if this field is not part of a oneof. + ContainingOneof() OneofDescriptor + + // ContainingMessage is the containing message that this field belongs to. + // For extension fields, this may not necessarily be the parent message + // that the field is declared within. + ContainingMessage() MessageDescriptor + + // Enum is the enum descriptor if Kind is EnumKind. + // It returns nil for any other Kind. + Enum() EnumDescriptor + + // Message is the message descriptor if Kind is + // MessageKind or GroupKind. It returns nil for any other Kind. + Message() MessageDescriptor + + isFieldDescriptor +} +type isFieldDescriptor interface{ ProtoType(FieldDescriptor) } + +// FieldDescriptors is a list of field declarations. +type FieldDescriptors interface { + // Len reports the number of fields. + Len() int + // Get returns the ith FieldDescriptor. It panics if out of bounds. + Get(i int) FieldDescriptor + // ByName returns the FieldDescriptor for a field named s. + // It returns nil if not found. + ByName(s Name) FieldDescriptor + // ByJSONName returns the FieldDescriptor for a field with s as the JSON name. + // It returns nil if not found. + ByJSONName(s string) FieldDescriptor + // ByTextName returns the FieldDescriptor for a field with s as the text name. + // It returns nil if not found. + ByTextName(s string) FieldDescriptor + // ByNumber returns the FieldDescriptor for a field numbered n. + // It returns nil if not found. + ByNumber(n FieldNumber) FieldDescriptor + + doNotImplement +} + +// OneofDescriptor describes a oneof field set within a given message and +// corresponds with the google.protobuf.OneofDescriptorProto message. +type OneofDescriptor interface { + Descriptor + + // IsSynthetic reports whether this is a synthetic oneof created to support + // proto3 optional semantics. If true, Fields contains exactly one field + // with HasOptionalKeyword specified. + IsSynthetic() bool + + // Fields is a list of fields belonging to this oneof. + Fields() FieldDescriptors + + isOneofDescriptor +} +type isOneofDescriptor interface{ ProtoType(OneofDescriptor) } + +// OneofDescriptors is a list of oneof declarations. +type OneofDescriptors interface { + // Len reports the number of oneof fields. + Len() int + // Get returns the ith OneofDescriptor. It panics if out of bounds. + Get(i int) OneofDescriptor + // ByName returns the OneofDescriptor for a oneof named s. + // It returns nil if not found. + ByName(s Name) OneofDescriptor + + doNotImplement +} + +// ExtensionDescriptor is an alias of FieldDescriptor for documentation. +type ExtensionDescriptor = FieldDescriptor + +// ExtensionTypeDescriptor is an ExtensionDescriptor with an associated ExtensionType. +type ExtensionTypeDescriptor interface { + ExtensionDescriptor + + // Type returns the associated ExtensionType. + Type() ExtensionType + + // Descriptor returns the plain ExtensionDescriptor without the + // associated ExtensionType. + Descriptor() ExtensionDescriptor +} + +// ExtensionDescriptors is a list of field declarations. +type ExtensionDescriptors interface { + // Len reports the number of fields. + Len() int + // Get returns the ith ExtensionDescriptor. It panics if out of bounds. + Get(i int) ExtensionDescriptor + // ByName returns the ExtensionDescriptor for a field named s. + // It returns nil if not found. + ByName(s Name) ExtensionDescriptor + + doNotImplement +} + +// ExtensionType encapsulates an ExtensionDescriptor with a concrete +// Go implementation. The nested field descriptor must be for a extension field. +// +// While a normal field is a member of the parent message that it is declared +// within (see Descriptor.Parent), an extension field is a member of some other +// target message (see ExtensionDescriptor.Extendee) and may have no +// relationship with the parent. However, the full name of an extension field is +// relative to the parent that it is declared within. +// +// For example: +// syntax = "proto2"; +// package example; +// message FooMessage { +// extensions 100 to max; +// } +// message BarMessage { +// extends FooMessage { optional BarMessage bar_field = 100; } +// } +// +// Field "bar_field" is an extension of FooMessage, but its full name is +// "example.BarMessage.bar_field" instead of "example.FooMessage.bar_field". +type ExtensionType interface { + // New returns a new value for the field. + // For scalars, this returns the default value in native Go form. + New() Value + + // Zero returns a new value for the field. + // For scalars, this returns the default value in native Go form. + // For composite types, this returns an empty, read-only message, list, or map. + Zero() Value + + // TypeDescriptor returns the extension type descriptor. + TypeDescriptor() ExtensionTypeDescriptor + + // ValueOf wraps the input and returns it as a Value. + // ValueOf panics if the input value is invalid or not the appropriate type. + // + // ValueOf is more extensive than protoreflect.ValueOf for a given field's + // value as it has more type information available. + ValueOf(interface{}) Value + + // InterfaceOf completely unwraps the Value to the underlying Go type. + // InterfaceOf panics if the input is nil or does not represent the + // appropriate underlying Go type. For composite types, it panics if the + // value is not mutable. + // + // InterfaceOf is able to unwrap the Value further than Value.Interface + // as it has more type information available. + InterfaceOf(Value) interface{} + + // IsValidValue reports whether the Value is valid to assign to the field. + IsValidValue(Value) bool + + // IsValidInterface reports whether the input is valid to assign to the field. + IsValidInterface(interface{}) bool +} + +// EnumDescriptor describes an enum and +// corresponds with the google.protobuf.EnumDescriptorProto message. +// +// Nested declarations: +// EnumValueDescriptor. +type EnumDescriptor interface { + Descriptor + + // Values is a list of nested enum value declarations. + Values() EnumValueDescriptors + + // ReservedNames is a list of reserved enum names. + ReservedNames() Names + // ReservedRanges is a list of reserved ranges of enum numbers. + ReservedRanges() EnumRanges + + isEnumDescriptor +} +type isEnumDescriptor interface{ ProtoType(EnumDescriptor) } + +// EnumType encapsulates an EnumDescriptor with a concrete Go implementation. +type EnumType interface { + // New returns an instance of this enum type with its value set to n. + New(n EnumNumber) Enum + + // Descriptor returns the enum descriptor. + // + // Invariant: t.Descriptor() == t.New(0).Descriptor() + Descriptor() EnumDescriptor +} + +// EnumDescriptors is a list of enum declarations. +type EnumDescriptors interface { + // Len reports the number of enum types. + Len() int + // Get returns the ith EnumDescriptor. It panics if out of bounds. + Get(i int) EnumDescriptor + // ByName returns the EnumDescriptor for an enum named s. + // It returns nil if not found. + ByName(s Name) EnumDescriptor + + doNotImplement +} + +// EnumValueDescriptor describes an enum value and +// corresponds with the google.protobuf.EnumValueDescriptorProto message. +// +// All other proto declarations are in the namespace of the parent. +// However, enum values do not follow this rule and are within the namespace +// of the parent's parent (i.e., they are a sibling of the containing enum). +// Thus, a value named "FOO_VALUE" declared within an enum uniquely identified +// as "proto.package.MyEnum" has a full name of "proto.package.FOO_VALUE". +type EnumValueDescriptor interface { + Descriptor + + // Number returns the enum value as an integer. + Number() EnumNumber + + isEnumValueDescriptor +} +type isEnumValueDescriptor interface{ ProtoType(EnumValueDescriptor) } + +// EnumValueDescriptors is a list of enum value declarations. +type EnumValueDescriptors interface { + // Len reports the number of enum values. + Len() int + // Get returns the ith EnumValueDescriptor. It panics if out of bounds. + Get(i int) EnumValueDescriptor + // ByName returns the EnumValueDescriptor for the enum value named s. + // It returns nil if not found. + ByName(s Name) EnumValueDescriptor + // ByNumber returns the EnumValueDescriptor for the enum value numbered n. + // If multiple have the same number, the first one defined is returned + // It returns nil if not found. + ByNumber(n EnumNumber) EnumValueDescriptor + + doNotImplement +} + +// ServiceDescriptor describes a service and +// corresponds with the google.protobuf.ServiceDescriptorProto message. +// +// Nested declarations: MethodDescriptor. +type ServiceDescriptor interface { + Descriptor + + // Methods is a list of nested message declarations. + Methods() MethodDescriptors + + isServiceDescriptor +} +type isServiceDescriptor interface{ ProtoType(ServiceDescriptor) } + +// ServiceDescriptors is a list of service declarations. +type ServiceDescriptors interface { + // Len reports the number of services. + Len() int + // Get returns the ith ServiceDescriptor. It panics if out of bounds. + Get(i int) ServiceDescriptor + // ByName returns the ServiceDescriptor for a service named s. + // It returns nil if not found. + ByName(s Name) ServiceDescriptor + + doNotImplement +} + +// MethodDescriptor describes a method and +// corresponds with the google.protobuf.MethodDescriptorProto message. +type MethodDescriptor interface { + Descriptor + + // Input is the input message descriptor. + Input() MessageDescriptor + // Output is the output message descriptor. + Output() MessageDescriptor + // IsStreamingClient reports whether the client streams multiple messages. + IsStreamingClient() bool + // IsStreamingServer reports whether the server streams multiple messages. + IsStreamingServer() bool + + isMethodDescriptor +} +type isMethodDescriptor interface{ ProtoType(MethodDescriptor) } + +// MethodDescriptors is a list of method declarations. +type MethodDescriptors interface { + // Len reports the number of methods. + Len() int + // Get returns the ith MethodDescriptor. It panics if out of bounds. + Get(i int) MethodDescriptor + // ByName returns the MethodDescriptor for a service method named s. + // It returns nil if not found. + ByName(s Name) MethodDescriptor + + doNotImplement +} |